xref: /docs/en/application-dev/reference/apis-basic-services-kit/js-apis-zlib.md

# @ohos.zlib (Zip)
<!--Kit: Ability Kit-->
<!--Subsystem: BundleManager-->
<!--Owner: @wanghang904-->
<!--Designer: @hanfeng6-->
<!--Tester: @kongjing2-->
<!--Adviser: @Brilliantry_Rui-->

The **Zip** module provides APIs for file compression and decompression.

> **NOTE**
>
> The initial APIs of this module are supported since API version 7. Newly added APIs will be marked with a superscript to indicate their earliest API version.

## Modules to Import

```javascript
import { zlib } from '@kit.BasicServicesKit';
```

## zlib.zipFile<sup>(deprecated)</sup>
zipFile(inFile: string, outFile: string, options: Options): Promise&lt;void&gt;

Zips a file. This API uses a promise to return the result.

> **NOTE**
>
> This API is supported since API version 7 and deprecated since API version 9. You are advised to use [zlib.compressFile](#zlibcompressfile9) instead.

**System capability**: SystemCapability.BundleManager.Zlib

**Parameters**

| Name | Type               | Mandatory| Description                                                        |
| ------- | ------------------- | ---- | ------------------------------------------------------------ |
| inFile  | string              | Yes  | Path of the folder or file to zip. The path must be an application sandbox path, which can be obtained from the context. For details about the context, see [FA Model](../apis-ability-kit/js-apis-inner-app-context.md) and [Stage Model](../apis-ability-kit/js-apis-inner-application-context.md).|
| outFile | string              | Yes  | Path of the zipped file. The file name extension is .zip.                 |
| options | [Options](#options) | Yes  | Optional parameters for the zip operation.                                            |

**Returns**

| Type          | Description                                                        |
| -------------- | ------------------------------------------------------------ |
| Promise\<void> | Promise that returns no value.|

**Example**

```ts
// The path used in the code must be an application sandbox path, for example, /data/storage/el2/base/temp. You can obtain the path through the context.
import { zlib, BusinessError } from '@kit.BasicServicesKit';

let inFile = '/data/storage/el2/base/temp/filename.xxx';
let outFile = '/data/storage/el2/base/temp/xxx.zip';
let options: zlib.Options = {
  level: zlib.CompressLevel.COMPRESS_LEVEL_DEFAULT_COMPRESSION,
  memLevel: zlib.MemLevel.MEM_LEVEL_DEFAULT,
  strategy: zlib.CompressStrategy.COMPRESS_STRATEGY_DEFAULT_STRATEGY
};

zlib.zipFile(inFile, outFile, options).then((data: void) => {
  console.info('zipFile result is ' + JSON.stringify(data));
}).catch((err: BusinessError) => {
  console.error('error is ' + JSON.stringify(err));
});
```

## zlib.unzipFile<sup>(deprecated)</sup>

unzipFile(inFile:string, outFile:string, options: Options): Promise&lt;void&gt;

Unzips a file. This API uses a promise to return the result.

> **NOTE**
>
> This API is supported since API version 7 and deprecated since API version 9. You are advised to use [zlib.decompressFile](#zlibdecompressfile9) instead.
>
> The name of the zipped file or zipped folder cannot contain two consecutive periods (..). Otherwise, the error code -1 is returned.

**System capability**: SystemCapability.BundleManager.Zlib

**Parameters**

| Name | Type               | Mandatory| Description                                                        |
| ------- | ------------------- | ---- | ------------------------------------------------------------ |
| inFile  | string              | Yes  | Path of the file to unzip. The path must be an application sandbox path, which can be obtained from the context. For details about the context, see [FA Model](../apis-ability-kit/js-apis-inner-app-context.md) and [Stage Model](../apis-ability-kit/js-apis-inner-application-context.md). If the.zip file to be unzipped contains Chinese file names or folder names, use UTF-8 to encode them. Otherwise, garbled characters may be displayed after unzipping.|
| outFile | string              | Yes  | Path of the unzipped file.                                        |
| options | [Options](#options) | Yes  | Optional parameters for the unzip operation.                                            |

**Returns**

| Type          | Description                                                        |
| -------------- | ------------------------------------------------------------ |
| Promise\<void> | Promise that returns no value.|

**Example**

```ts
// The path used in the code must be an application sandbox path, for example, /data/storage/el2/base/temp. You can obtain the path through the context.
import { zlib, BusinessError } from '@kit.BasicServicesKit';

let inFile = '/data/storage/el2/base/temp/xxx.zip';
let outFile = '/data/storage/el2/base/temp/xxx';
let options: zlib.Options = {
  level: zlib.CompressLevel.COMPRESS_LEVEL_DEFAULT_COMPRESSION,
  memLevel: zlib.MemLevel.MEM_LEVEL_DEFAULT,
  strategy: zlib.CompressStrategy.COMPRESS_STRATEGY_DEFAULT_STRATEGY
};

zlib.unzipFile(inFile, outFile, options).then((data: void) => {
  console.info('unzipFile result is ' + JSON.stringify(data));
}).catch((err: BusinessError) => {
  console.error('error is ' + JSON.stringify(err));
})
```

## zlib.compressFile<sup>9+</sup>

compressFile(inFile: string, outFile: string, options: Options, callback: AsyncCallback\<void>): void

Compresses a file. This API uses an asynchronous callback to return the result. If the operation is successful, **null** is returned; otherwise, a specific error code is returned.

> **NOTE**
>
> To avoid path traversal, the input parameters of **inFile** and **outFile** cannot contain **../** since API version 13. Otherwise, error codes 900001 and 900002 are returned.

**Atomic service API**: This API can be used in atomic services since API version 11.

**System capability**: SystemCapability.BundleManager.Zlib

**Parameters**

| Name                 | Type               | Mandatory| Description                                                        |
| ----------------------- | ------------------- | ---- | ------------------------------------------------------------ |
| inFile                  | string              | Yes  | Path of the folder or file to compress. The path must be an application sandbox path, which can be obtained from the context. For details about the context, see [FA Model](../apis-ability-kit/js-apis-inner-app-context.md) and [Stage Model](../apis-ability-kit/js-apis-inner-application-context.md). The folder to compress cannot be empty. Otherwise, an error will be reported when [decompressFile](#zlibdecompressfile9) is used to decompress the folder.|
| outFile                 | string              | Yes  | Path of the compressed file. When multiple threads compress files at the same time, the values of **outFile** must be different.                                          |
| options                 | [Options](#options) | Yes  | Compression parameters.                                              |
| callback | AsyncCallback\<void>            | Yes  | Callback used to return the result.              |

**Error codes**

For details about the error codes, see [Universal Error Codes](../errorcode-universal.md) and [zlib Error Codes](./errorcode-zlib.md).

| ID| Error Message                              |
| -------- | --------------------------------------|
| 401 | Parameter error. Possible causes: 1. Mandatory parameters are left unspecified; 2. Incorrect parameter types.|
| 900001   | The input source file is invalid.      |
| 900002   | The input destination file is invalid. |

**Example**

```ts
// The path used in the code must be an application sandbox path, for example, /data/storage/el2/base/temp. You can obtain the path through the context.
import { zlib, BusinessError } from '@kit.BasicServicesKit';

let inFile = '/data/storage/el2/base/temp/filename.xxx';
let outFile = '/data/storage/el2/base/temp/xxx.zip';
let options: zlib.Options = {
  level: zlib.CompressLevel.COMPRESS_LEVEL_DEFAULT_COMPRESSION,
  memLevel: zlib.MemLevel.MEM_LEVEL_DEFAULT,
  strategy: zlib.CompressStrategy.COMPRESS_STRATEGY_DEFAULT_STRATEGY
};

try {
  zlib.compressFile(inFile, outFile, options, (errData: BusinessError) => {
    if (errData !== null) {
      console.error(`compressFile errData is errCode:${errData.code}  message:${errData.message}`);
    } else {
      console.info(`compressFile success.`);
    }
  })
} catch (errData) {
  let code = (errData as BusinessError).code;
  let message = (errData as BusinessError).message;
  console.error(`compressFile errData is errCode:${code}  message:${message}`);
}
```

## zlib.compressFile<sup>9+</sup>

compressFile(inFile: string, outFile: string, options: Options): Promise\<void>

Compresses a file. This API uses a promise to return the result. If the operation is successful, **null** is returned; otherwise, a specific error code is returned.

> **NOTE**
>
> To avoid path traversal, the input parameters of **inFile** and **outFile** cannot contain **../** since API version 13. Otherwise, error codes 900001 and 900002 are returned.

**Atomic service API**: This API can be used in atomic services since API version 11.

**System capability**: SystemCapability.BundleManager.Zlib

**Parameters**

| Name | Type               | Mandatory| Description                                                        |
| ------- | ------------------- | ---- | ------------------------------------------------------------ |
| inFile  | string              | Yes  | Path of the folder or file to compress. The path must be an application sandbox path, which can be obtained from the context. For details about the context, see [FA Model](../apis-ability-kit/js-apis-inner-app-context.md) and [Stage Model](../apis-ability-kit/js-apis-inner-application-context.md). The folder to compress cannot be empty. Otherwise, an error will be reported when [decompressFile](#zlibdecompressfile9) is used to decompress the folder.|
| outFile | string              | Yes  | Path of the compressed file. When multiple threads compress files at the same time, the values of **outFile** must be different.                                          |
| options | [Options](#options) | Yes  | Compression parameters.                                              |

**Returns**

| Type          | Description                   |
| -------------- | ----------------------- |
| Promise\<void> | Promise that returns no value.|

**Error codes**

For details about the error codes, see [Universal Error Codes](../errorcode-universal.md) and [zlib Error Codes](./errorcode-zlib.md).

| ID| Error Message                              |
| -------- | ------------------------------------- |
| 401 | Parameter error. Possible causes: 1. Mandatory parameters are left unspecified; 2. Incorrect parameter types.|
| 900001   | The input source file is invalid.      |
| 900002   | The input destination file is invalid. |

**Example**

```ts
// The path used in the code must be an application sandbox path, for example, /data/storage/el2/base/temp. You can obtain the path through the context.
import { zlib, BusinessError } from '@kit.BasicServicesKit';

let inFile = '/data/storage/el2/base/temp/filename.xxx';
let outFile = '/data/storage/el2/base/temp/xxx.zip';
let options: zlib.Options = {
  level: zlib.CompressLevel.COMPRESS_LEVEL_DEFAULT_COMPRESSION,
  memLevel: zlib.MemLevel.MEM_LEVEL_DEFAULT,
  strategy: zlib.CompressStrategy.COMPRESS_STRATEGY_DEFAULT_STRATEGY
};

try {
  zlib.compressFile(inFile, outFile, options).then((data: void) => {
    console.info('compressFile success. data: ' + JSON.stringify(data));
  }).catch((errData: BusinessError) => {
    console.error(`errData is errCode:${errData.code}  message:${errData.message}`);
  })
} catch (errData) {
  let code = (errData as BusinessError).code;
  let message = (errData as BusinessError).message;
  console.error(`errData is errCode:${code}  message:${message}`);
}
```

## zlib.decompressFile<sup>9+</sup>

decompressFile(inFile: string, outFile: string, options: Options, callback: AsyncCallback\<void>): void

Decompresses a file. This API uses an asynchronous callback to return the result. If the operation is successful, **null** is returned; otherwise, a specific error code is returned.

> **NOTE**
>
> To avoid path traversal, the input parameters of **inFile** and **outFile** cannot contain **../** since API version 13. Otherwise, error codes 900001 and 900002 are returned.
>
> The name of the zipped file or zipped folder cannot contain two consecutive periods (..). Otherwise, the error code 900003 is returned.

**Atomic service API**: This API can be used in atomic services since API version 11.

**System capability**: SystemCapability.BundleManager.Zlib

**Parameters**

| Name                 | Type               | Mandatory| Description                                                        |
| ----------------------- | ------------------- | ---- | ------------------------------------------------------------ |
| inFile                  | string              | Yes  | Path of the file to decompress. The file name extension must be .zip. The path must be an application sandbox path, which can be obtained from the context. For details about the context, see [FA Model](../apis-ability-kit/js-apis-inner-app-context.md) and [Stage Model](../apis-ability-kit/js-apis-inner-application-context.md). If the.zip file to be unzipped contains Chinese file names or folder names, use UTF-8 to encode them. Otherwise, garbled characters may be displayed after unzipping.|
| outFile                 | string              | Yes  | Path of the decompressed file. The path must exist in the system. Otherwise, the decompression fails. The path must be an application sandbox path, which can be obtained from the context. For details about the context, see [FA Model](../apis-ability-kit/js-apis-inner-app-context.md) and [Stage Model](../apis-ability-kit/js-apis-inner-application-context.md). If a file or folder with the same name already exists in the path, they will be overwritten. When multiple threads decompress files at the same time, the values of **outFile** must be different.|
| options                 | [Options](#options) | Yes  | Decompression parameters.                                            |
| callback | AsyncCallback\<void>            | Yes  | Callback used to return the result.                                              |

**Error codes**

For details about the error codes, see [Universal Error Codes](../errorcode-universal.md) and [zlib Error Codes](./errorcode-zlib.md).

| ID| Error Message                              |
| -------- | --------------------------------------|
| 401 | Parameter error. Possible causes: 1. Mandatory parameters are left unspecified; 2. Incorrect parameter types.|
| 900001   | The input source file is invalid.      |
| 900002   | The input destination file is invalid. |
| 900003 | The input source file is not in ZIP format or is damaged. |

**Example**

```ts
// The path used in the code must be an application sandbox path, for example, /data/storage/el2/base/temp. You can obtain the path through the context.
import { zlib, BusinessError } from '@kit.BasicServicesKit';

let inFile = '/data/storage/el2/base/temp/xxx.zip';
let outFileDir = '/data/storage/el2/base/temp';
let options: zlib.Options = {
  level: zlib.CompressLevel.COMPRESS_LEVEL_DEFAULT_COMPRESSION,
  parallel: zlib.ParallelStrategy.PARALLEL_STRATEGY_PARALLEL_DECOMPRESSION
};

try {
  zlib.decompressFile(inFile, outFileDir, options, (errData: BusinessError) => {
    if (errData !== null) {
      console.error(`decompressFile errData is errCode:${errData.code}  message:${errData.message}`);
    } else {
      console.info(`decompressFile success.`);
    }
  })
} catch (errData) {
  let code = (errData as BusinessError).code;
  let message = (errData as BusinessError).message;
  console.error(`decompressFile errData is errCode:${code}  message:${message}`);
}
```

## zlib.decompressFile<sup>9+</sup>

decompressFile(inFile: string, outFile: string, options?: Options): Promise\<void>

Decompresses a file. This API uses a promise to return the result.

> **NOTE**
>
> To avoid path traversal, the input parameters of **inFile** and **outFile** cannot contain **../** since API version 13. Otherwise, error codes 900001 and 900002 are returned.
>
> The name of the zipped file or zipped folder cannot contain two consecutive periods (..). Otherwise, the error code 900003 is returned.

**Atomic service API**: This API can be used in atomic services since API version 11.

**System capability**: SystemCapability.BundleManager.Zlib

**Parameters**

| Name | Type               | Mandatory| Description                                                        |
| ------- | ------------------- | ---- | ------------------------------------------------------------ |
| inFile  | string              | Yes  | Path of the file to decompress. The file name extension must be .zip. The path must be an application sandbox path, which can be obtained from the context. For details about the context, see [FA Model](../apis-ability-kit/js-apis-inner-app-context.md) and [Stage Model](../apis-ability-kit/js-apis-inner-application-context.md). If the.zip file to be unzipped contains Chinese file names or folder names, use UTF-8 to encode them. Otherwise, garbled characters may be displayed after unzipping.|
| outFile | string              | Yes  | Path of the decompressed file. The path must exist in the system. Otherwise, the decompression fails. The path must be an application sandbox path, which can be obtained from the context. For details about the context, see [FA Model](../apis-ability-kit/js-apis-inner-app-context.md) and [Stage Model](../apis-ability-kit/js-apis-inner-application-context.md). If a file or folder with the same name already exists in the path, they will be overwritten. When multiple threads decompress files at the same time, the values of **outFile** must be different.|
| options | [Options](#options) | No  | Decompression parameters.                                          |

**Returns**

| Type          | Description                   |
| -------------- | ----------------------- |
| Promise\<void> | Promise that returns no value.|

**Error codes**

For details about the error codes, see [Universal Error Codes](../errorcode-universal.md) and [zlib Error Codes](./errorcode-zlib.md).

| ID| Error Message                              |
| ------ | ------------------------------------- |
| 401 | Parameter error. Possible causes: 1. Mandatory parameters are left unspecified; 2. Incorrect parameter types.|
| 900001 | The input source file is invalid.      |
| 900002 | The input destination file is invalid. |
| 900003 | The input source file is not in ZIP format or is damaged. |

**Example**

```ts
// The path used in the code must be an application sandbox path, for example, /data/storage/el2/base/temp. You can obtain the path through the context.
import { zlib, BusinessError } from '@kit.BasicServicesKit';

let inFile = '/data/storage/el2/base/temp/xxx.zip';
let outFileDir = '/data/storage/el2/base/temp';
let options: zlib.Options = {
  level: zlib.CompressLevel.COMPRESS_LEVEL_DEFAULT_COMPRESSION
};

try {
  zlib.decompressFile(inFile, outFileDir, options).then((data: void) => {
    console.info('decompressFile success. data: ' + JSON.stringify(data));
  }).catch((errData: BusinessError) => {
    console.error(`errData is errCode:${errData.code}  message:${errData.message}`);
  })
} catch (errData) {
  let code = (errData as BusinessError).code;
  let message = (errData as BusinessError).message;
  console.error(`errData is errCode:${code}  message:${message}`);
}
```

## zlib.decompressFile<sup>10+</sup>

decompressFile(inFile: string, outFile: string, callback: AsyncCallback\<void\>): void

Decompresses a file. This API uses an asynchronous callback to return the result. If the operation is successful, **null** is returned; otherwise, a specific error code is returned.

> **NOTE**
>
> To avoid path traversal, the input parameters of **inFile** and **outFile** cannot contain **../** since API version 13. Otherwise, error codes 900001 and 900002 are returned.
>
> The name of the zipped file or zipped folder cannot contain two consecutive periods (..). Otherwise, the error code 900003 is returned.

**Atomic service API**: This API can be used in atomic services since API version 11.

**System capability**: SystemCapability.BundleManager.Zlib

**Parameters**

| Name                 | Type               | Mandatory| Description                                                        |
| ----------------------- | ------------------- | ---- | ------------------------------------------------------------ |
| inFile                  | string              | Yes  | Path of the file to decompress. The file name extension must be .zip. The path must be an application sandbox path, which can be obtained from the context. For details about the context, see [FA Model](../apis-ability-kit/js-apis-inner-app-context.md) and [Stage Model](../apis-ability-kit/js-apis-inner-application-context.md). If the.zip file to be unzipped contains Chinese file names or folder names, use UTF-8 to encode them. Otherwise, garbled characters may be displayed after unzipping.|
| outFile                 | string              | Yes  | Path of the decompressed file. The path must exist in the system. Otherwise, the decompression fails. The path must be an application sandbox path, which can be obtained from the context. For details about the context, see [FA Model](../apis-ability-kit/js-apis-inner-app-context.md) and [Stage Model](../apis-ability-kit/js-apis-inner-application-context.md). If a file or folder with the same name already exists in the path, they will be overwritten. When multiple threads decompress files at the same time, the values of **outFile** must be different.|
| callback | AsyncCallback\<void>            | Yes  | Callback used to return the result.                                              |

**Error codes**

For details about the error codes, see [Universal Error Codes](../errorcode-universal.md) and [zlib Error Codes](./errorcode-zlib.md).

| ID| Error Message                              |
| -------- | --------------------------------------|
| 401 | Parameter error. Possible causes: 1. Mandatory parameters are left unspecified; 2. Incorrect parameter types.|
| 900001   | The input source file is invalid.      |
| 900002   | The input destination file is invalid. |
| 900003 | The input source file is not in ZIP format or is damaged. |

**Example**

```ts
// The path used in the code must be an application sandbox path, for example, /data/storage/el2/base/temp. You can obtain the path through the context.
import { zlib, BusinessError } from '@kit.BasicServicesKit';

let inFile = '/data/storage/el2/base/temp/xxx.zip';
let outFileDir = '/data/storage/el2/base/temp';

try {
  zlib.decompressFile(inFile, outFileDir, (errData: BusinessError) => {
    if (errData !== null) {
      console.error(`decompressFile failed. code is ${errData.code}, message is ${errData.message}`);
    } else {
      console.info(`decompressFile success.`);
    }
  })
} catch (errData) {
  let code = (errData as BusinessError).code;
  let message = (errData as BusinessError).message;
  console.error(`decompressFile failed. code is ${code}, message is ${message}`);
}
```

## zlib.getOriginalSize<sup>12+</sup>

getOriginalSize(compressedFile: string): Promise\<number>

Obtains the original size of a compressed file and uses a promise to asynchronously return the result. The original size of the compressed file is returned upon a success. Otherwise, an error code is returned.

**Atomic service API**: This API can be used in atomic services since API version 12.

**System capability**: SystemCapability.BundleManager.Zlib

**Parameters**

| Name | Type               | Mandatory| Description                                                        |
| ------- | ------------------- | ---- | ------------------------------------------------------------ |
| compressedFile  | string              | Yes  | Specifies the path of the compressed file. Only .zip files are supported. The path must be an application sandbox path, which can be obtained from the context. For details about the context, see [FA Model](../apis-ability-kit/js-apis-inner-app-context.md) and [Stage Model](../apis-ability-kit/js-apis-inner-application-context.md).|

**Returns**

| Type          | Description                   |
| -------------- | ----------------------- |
| Promise\<number> | Promise object, which returns the original size of the compressed file, in bytes.|

**Error codes**

For details about the error codes, see [Universal Error Codes](../errorcode-universal.md) and [zlib Error Codes](./errorcode-zlib.md).

| ID| Error Message                              |
| ------ | ------------------------------------- |
| 401 | The parameter check failed. Possible causes: 1. Mandatory parameters are left unspecified; 2. Incorrect parameter types. |
| 900001 | The input source file is invalid.      |
| 900003 | The input source file is not in ZIP format or is damaged. |

**Example**

```ts
// The path used in the code must be an application sandbox path, for example, /data/storage/el2/base/temp. You can obtain the path through the context.
import { zlib, BusinessError } from '@kit.BasicServicesKit';

let compressedFile = '/data/storage/el2/base/temp/test.zip';

try {
  zlib.getOriginalSize(compressedFile).then((data: number) => {
    console.info(`getOriginalSize success. getOriginalSize: ${data}`);
  }).catch((errData: BusinessError) => {
    console.error(`errData is errCode:${errData.code}  message:${errData.message}`);
  })
} catch (errData) {
  let code = (errData as BusinessError).code;
  let message = (errData as BusinessError).message;
  console.error(`errData is errCode:${code}  message:${message}`);
}
```

## zlib.compressFiles<sup>12+</sup>

compressFiles(inFiles: Array&lt;string&gt;, outFile: string, options: Options): Promise&lt;void&gt;

Compresses multiple specified files and uses a promise to asynchronously return the result. If the operation is successful, **null** is returned; otherwise, a specific error code is returned.

**Atomic service API**: This API can be used in atomic services since API version 12.

**System capability**: SystemCapability.BundleManager.Zlib

**Parameters**

| Name | Type               | Mandatory| Description                                                        |
| ------- | ------------------- | ---- | ------------------------------------------------------------ |
| inFiles | Array&lt;string&gt; | Yes  | Path of the folder or file to compress. The path must be an application sandbox path, which can be obtained from the context. For details about the context, see [FA Model](../apis-ability-kit/js-apis-inner-app-context.md) and [Stage Model](../apis-ability-kit/js-apis-inner-application-context.md). The folder to compress cannot be empty. Otherwise, an error will be reported when [decompressFile](#zlibdecompressfile9) is used to decompress the folder.|
| outFile | string              | Yes  | Path of the compressed file. When multiple threads compress files at the same time, the values of **outFile** must be different.|
| options | [Options](#options) | Yes  | Compression parameters.                                            |

**Returns**

| Type               | Description                   |
| ------------------- | ----------------------- |
| Promise&lt;void&gt; | Promise that returns no value.|

**Error codes**

For details about the error codes, see [Universal Error Codes](../errorcode-universal.md) and [zlib Error Codes](./errorcode-zlib.md).

| ID| Error Message                                                    |
| -------- | ------------------------------------------------------------ |
| 401      | Parameter error. Possible causes: 1. Mandatory parameters are left unspecified; 2. Incorrect parameter types. |
| 900001   | The input source file is invalid.                            |
| 900002   | The input destination file is invalid.                       |

**Example**

```typescript
// The path used in the code must be an application sandbox path, for example, /data/storage/el2/base/temp. You can obtain the path through the context.
import { zlib, BusinessError } from '@kit.BasicServicesKit';

let inFile = '/data/storage/el2/base/temp/filename.xxx';
let pathDir = 'data/storage/el2/base/temp/xxx';
let outFile = '/data/storage/el2/base/temp/xxx.zip';
let options: zlib.Options = {
  level: zlib.CompressLevel.COMPRESS_LEVEL_DEFAULT_COMPRESSION,
  memLevel: zlib.MemLevel.MEM_LEVEL_DEFAULT,
  strategy: zlib.CompressStrategy.COMPRESS_STRATEGY_DEFAULT_STRATEGY
};

try {
  zlib.compressFiles([inFile, pathDir], outFile, options).then((data: void) => {
    console.info('compressFiles success. data: ' + JSON.stringify(data));
  }).catch((errData: BusinessError) => {
    console.error(`errData is errCode:${errData.code}  message:${errData.message}`);
  })
} catch (errData) {
  let code = (errData as BusinessError).code;
  let message = (errData as BusinessError).message;
  console.error(`errData is errCode:${code}  message:${message}`);
}
```

## zlib.createChecksum<sup>12+</sup>

createChecksum(): Promise&lt;Checksum&gt;

Creates a checksum object and uses a promise to asynchronously return the result. A checksum object instance is returned upon a success.

**Atomic service API**: This API can be used in atomic services since API version 12.

**System capability**: SystemCapability.BundleManager.Zlib

**Returns**

| Type                                  | Description                           |
| -------------------------------------- | ------------------------------- |
| Promise&lt;[Checksum](#checksum12)&gt; | Promise used to return the result.  |

**Example**

```ts
import { zlib } from '@kit.BasicServicesKit';

zlib.createChecksum().then((data) => {
  console.info('createChecksum success');
})
```

## zlib.createChecksumSync<sup>12+</sup>

createChecksumSync():  Checksum

Creates a checksum object. A checksum object instance is returned upon a success.

**Atomic service API**: This API can be used in atomic services since API version 12.

**System capability**: SystemCapability.BundleManager.Zlib

**Returns**

| Type                   | Description          |
| ----------------------- | -------------- |
| [Checksum](#checksum12) | Checksum object instance.|

**Example**

```ts
import { zlib } from '@kit.BasicServicesKit';

let checksum = zlib.createChecksumSync()
```

## Checksum<sup>12+</sup>

Checksum object.

### adler32<sup>12+</sup>

adler32(adler: number, buf: ArrayBuffer): Promise&lt;number&gt;

Calculates the Adler-32 checksum. This API uses a promise to return the result. The calculated Adler-32 checksum is returned upon a success. Otherwise, an error code is returned.

**Atomic service API**: This API can be used in atomic services since API version 12.

**System capability**: SystemCapability.BundleManager.Zlib

**Parameters**

| Name| Type       | Mandatory| Description                    |
| ------ | ----------- | ---- | ------------------------ |
| adler  | number      | Yes  | Initial value of the Adler-32 checksum.|
| buf    | ArrayBuffer | Yes  | Data buffer for calculating the checksum.  |

**Returns**

| Type                 | Description                                     |
| --------------------- | ----------------------------------------- |
| Promise&lt;number&gt; | Promise used to return the result.  |

**Error codes**

For details about the error codes, see [Universal Error Codes](../errorcode-universal.md).

| ID| Error Message                              |
| -------- | --------------------------------------|
| 401 | Parameter error. Possible causes: 1. Mandatory parameters are left unspecified; 2. Incorrect parameter types; 3. Parameter verification failed. |

**Example**

```ts
import { zlib } from '@kit.BasicServicesKit';

let str = 'hello world!';
let arrayBufferIn = new ArrayBuffer(12);
let data = new Uint8Array(arrayBufferIn);

for (let i = 0, j = str.length; i < j; i++) {
  data[i] = str.charCodeAt(i);
}

let checksum = zlib.createChecksumSync()

checksum.adler32(0, arrayBufferIn).then(data => {
  console.info('adler32 success', data);
})
```

### adler32Combine<sup>12+</sup>

adler32Combine(adler1: number, adler2: number, len2: number): Promise&lt;number&gt;

Combines two Adler-32 checksums. This API uses a promise to return the result. The combined Adler-32 checksum is returned upon a success. Otherwise, an error code is returned.

**Atomic service API**: This API can be used in atomic services since API version 12.

**System capability**: SystemCapability.BundleManager.Zlib

**Parameters**

| Name| Type  | Mandatory| Description                                |
| ------ | ------ | ---- | ------------------------------------ |
| adler1 | number | Yes  | The first Adler-32 checksum to be combined.      |
| adler2 | number | Yes  | The second Adler-32 checksum to be combined.      |
| len2   | number | Yes  | Length of the data block of the second Adler-32 checksum.|

**Returns**

| Type                 | Description                                     |
| --------------------- | ----------------------------------------- |
| Promise&lt;number&gt; | Promise used to return the result.  |

**Error codes**

For details about the error codes, see [Universal Error Codes](../errorcode-universal.md).

| ID| Error Message                              |
| -------- | --------------------------------------|
| 401 | Parameter error. Possible causes: 1. Mandatory parameters are left unspecified; 2. Incorrect parameter types; 3. Parameter verification failed. |

**Example**

```ts
import { zlib, BusinessError } from '@kit.BasicServicesKit';

async function demo() {
  let str = 'hello world!';
  let arrayBufferIn = new ArrayBuffer(12);
  let data = new Uint8Array(arrayBufferIn);
  for (let i = 0, j = str.length; i < j; i++) {
    data[i] = str.charCodeAt(i);
  }
  let checksum = zlib.createChecksumSync()
  let adler1 = 0;
  let adler2 = 1;
  await checksum.adler32(0, arrayBufferIn).then(data => {
    console.info('adler32 success', data);
    adler1 = data;
  })
  await checksum.adler32(1, arrayBufferIn).then(data => {
    console.info('adler32 success', data);
    adler2 = data;
  })
  await checksum.adler32Combine(adler1, adler2, 12).then((data) => {
    console.info('adler32Combine success', data);
  }).catch((errData: BusinessError) => {
    console.error(`errData is errCode:${errData.code}  message:${errData.message}`);
  })
}
```

### crc32<sup>12+</sup>

crc32(crc: number, buf: ArrayBuffer): Promise&lt;number&gt;

Updates the CRC-32 checksum. This API uses a promise to return the result. The updated CRC-32 checksum is returned upon a success. Otherwise, an error code is returned.

**Atomic service API**: This API can be used in atomic services since API version 12.

**System capability**: SystemCapability.BundleManager.Zlib

**Parameters**

| Name| Type       | Mandatory| Description                |
| ------ | ----------- | ---- | -------------------- |
| crc    | number      | Yes  | Initial value of the CRC-32 checksum.|
| buf    | ArrayBuffer | Yes  | Data buffer for calculating the checksum.|

**Returns**

| Type                 | Description                                 |
| --------------------- | ------------------------------------- |
| Promise&lt;number&gt; | Promise used to return the result.  |

**Error codes**

For details about the error codes, see [Universal Error Codes](../errorcode-universal.md).

| ID| Error Message                              |
| -------- | --------------------------------------|
| 401 | Parameter error. Possible causes: 1. Mandatory parameters are left unspecified; 2. Incorrect parameter types; 3. Parameter verification failed. |

**Example**

```ts
import { zlib, BusinessError } from '@kit.BasicServicesKit';

let str = 'hello world!';
let arrayBufferIn = new ArrayBuffer(12);
let data = new Uint8Array(arrayBufferIn);

for (let i = 0, j = str.length; i < j; i++) {
  data[i] = str.charCodeAt(i);
}

let checksum = zlib.createChecksumSync()

checksum.crc32(0, arrayBufferIn).then((data) => {
  console.info('crc32 success', data);
}).catch((errData: BusinessError) => {
  console.error(`errData is errCode:${errData.code}  message:${errData.message}`);
})
```

### crc32Combine<sup>12+</sup>

crc32Combine(crc1: number, crc2: number, len2: number): Promise&lt;number&gt;

Combines two CRC-32 checksums and uses a promise to asynchronously return the result. The combined CRC-32 checksum is returned upon a success. Otherwise, an error code is returned.

**Atomic service API**: This API can be used in atomic services since API version 12.

**System capability**: SystemCapability.BundleManager.Zlib

**Parameters**

| Name| Type  | Mandatory| Description                            |
| ------ | ------ | ---- | -------------------------------- |
| crc1 | number | Yes  | The first CRC-32 checksum to be combined.      |
| crc2 | number | Yes  | The second CRC-32 checksum to be combined.      |
| len2   | number | Yes  | Indicates the length of the second data block checked by CRC-32|

**Returns**

| Type                 | Description                                 |
| --------------------- | ------------------------------------- |
| Promise&lt;number&gt; | Promise used to return the result.  |

**Error codes**

For details about the error codes, see [Universal Error Codes](../errorcode-universal.md).

| ID| Error Message                              |
| -------- | --------------------------------------|
| 401 | Parameter error. Possible causes: 1. Mandatory parameters are left unspecified; 2. Incorrect parameter types; 3. Parameter verification failed. |

**Example**

```ts
import { zlib, BusinessError } from '@kit.BasicServicesKit';

async function demo() {
  let str = 'hello world!';
  let arrayBufferIn = new ArrayBuffer(12);
  let data = new Uint8Array(arrayBufferIn);
  for (let i = 0, j = str.length; i < j; i++) {
    data[i] = str.charCodeAt(i);
  }
  let checksum = zlib.createChecksumSync()
  let crc1 = 0;
  let crc2 = 1;
  await checksum.crc32(0, arrayBufferIn).then(data => {
    console.info('crc32 success', data);
    crc1 = data;
  })
  await checksum.crc32(1, arrayBufferIn).then(data => {
    console.info('crc32 success', data);
    crc2 = data;
  })
  await checksum.crc32Combine(crc1, crc2, 12).then((data) => {
    console.info('crc32Combine success', data);
  }).catch((errData: BusinessError) => {
    console.error(`errData is errCode:${errData.code}  message:${errData.message}`);
  })
}
```

### crc64<sup>12+</sup>

crc64(crc: number, buf: ArrayBuffer): Promise&lt;number&gt;

Updates the CRC-64 checksum. This API uses a promise to return the result. The updated CRC-64 checksum is returned upon a success. Otherwise, an error code is returned.

**Atomic service API**: This API can be used in atomic services since API version 12.

**System capability**: SystemCapability.BundleManager.Zlib

**Parameters**

| Name| Type       | Mandatory| Description                |
| ------ | ----------- | ---- | -------------------- |
| crc    | number      | Yes  | Initial value of the CRC-64 checksum.|
| buf    | ArrayBuffer | Yes  | Data buffer for calculating the checksum.|

**Returns**

| Type                 | Description                                 |
| --------------------- | ------------------------------------- |
| Promise&lt;number&gt; | Promise used to return the result.  |

**Error codes**

For details about the error codes, see [Universal Error Codes](../errorcode-universal.md).

| ID| Error Message                              |
| -------- | --------------------------------------|
| 401 | Parameter error. Possible causes: 1. Mandatory parameters are left unspecified; 2. Incorrect parameter types; 3. Parameter verification failed. |

**Example**

```ts
import { zlib, BusinessError } from '@kit.BasicServicesKit';

let str = 'hello world!';
let arrayBufferIn = new ArrayBuffer(12);
let data = new Uint8Array(arrayBufferIn);

for (let i = 0, j = str.length; i < j; i++) {
  data[i] = str.charCodeAt(i);
}

let checksum = zlib.createChecksumSync()

checksum.crc64(0, arrayBufferIn).then((data) => {
  console.info('crc64 success', data);
}).catch((errData: BusinessError) => {
  console.error(`errData is errCode:${errData.code}  message:${errData.message}`);
})
```

### getCrcTable<sup>12+</sup>

getCrcTable(): Promise&lt;Array&lt;number&gt;&gt;

Outputs the CRC-32 checksum table and uses a promise to asynchronously return the result. The CRC-32 check table is returned upon a success.

**Atomic service API**: This API can be used in atomic services since API version 12.

**System capability**: SystemCapability.BundleManager.Zlib

**Returns**

| Type                              | Description                           |
| ---------------------------------- | ------------------------------- |
| Promise&lt;Array&lt;number&gt;&gt; | Promise used to return the result.  |

**Example**

```ts
import { zlib, BusinessError } from '@kit.BasicServicesKit';

let checksum = zlib.createChecksumSync()

checksum.getCrcTable().then((data) => {
  console.info('getCrcTable success');
}).catch((errData: BusinessError) => {
  console.error(`errData is errCode:${errData.code}  message:${errData.message}`);
})
```

### getCrc64Table<sup>12+</sup>

getCrc64Table(): Promise&lt;Array&lt;number&gt;&gt;

Outputs the CRC-64 checksum table and uses a promise to asynchronously return the result. The CRC-64 check table is returned upon a success.

**Atomic service API**: This API can be used in atomic services since API version 12.

**System capability**: SystemCapability.BundleManager.Zlib

**Returns**

| Type                              | Description                           |
| ---------------------------------- | ------------------------------- |
| Promise&lt;Array&lt;number&gt;&gt; | Promise used to return the result.  |

**Example**

```ts
import { zlib, BusinessError } from '@kit.BasicServicesKit';

let checksum = zlib.createChecksumSync()

checksum.getCrc64Table().then((data) => {
  console.info('getCrc64Table success');
}).catch((errData: BusinessError) => {
  console.error(`errData is errCode:${errData.code}  message:${errData.message}`);
})
```

## zlib.createZip<sup>12+</sup>

createZip(): Promise&lt;Zip&gt;

Creates an instance of a compressed or decompressed object and uses a promise to asynchronously return the result. The instance of the compressed or decompressed object is returned upon a success.

**Atomic service API**: This API can be used in atomic services since API version 12.

**System capability**: SystemCapability.BundleManager.Zlib

**Returns**

| Type                        | Description                                 |
| ---------------------------- | ------------------------------------- |
| Promise&lt;[Zip](#zip12)&gt; | Promise used to return the result.|

**Example**

```ts
import { zlib, BusinessError } from '@kit.BasicServicesKit';

zlib.createZip().then(data => {
  console.info('createZip success');
}).catch((errData: BusinessError) => {
  console.error(`errData is errCode:${errData.code}  message:${errData.message}`);
})
```

## zlib.createZipSync<sup>12+</sup>

createZipSync(): Zip

Creates an instance of a compressed or decompressed object. The instance of the compressed or decompressed object is returned upon a success.

**Atomic service API**: This API can be used in atomic services since API version 12.

**System capability**: SystemCapability.BundleManager.Zlib

**Returns**

| Type         | Description                    |
| ------------- | ------------------------ |
| [Zip](#zip12) | Instance of the compressed or decompressed object.|

**Example**

```ts
import { zlib } from '@kit.BasicServicesKit';

let zip = zlib.createZipSync();
```

## Zip<sup>12+</sup>

Provides APIs to zip or unzip data in Zlib, Deflate, or Gzip format.

### getZStream<sup>12+</sup>

getZStream(): Promise&lt;ZStream&gt;

Outputs a stream. This API uses a promise to return the result.

**Atomic service API**: This API can be used in atomic services since API version 12.

**System capability**: SystemCapability.BundleManager.Zlib

**Returns**

| Type                                | Description                     |
| ------------------------------------ | ------------------------- |
| Promise&lt;[ZStream](#zstream12)&gt; | Promise used to return the result.  |

**Example**

```ts
import { zlib } from '@kit.BasicServicesKit';

let zip = zlib.createZipSync();

zip.getZStream().then(data => {
  console.info('getZStream success');
})
```

### zlibVersion<sup>12+</sup>

zlibVersion(): Promise&lt;string&gt;

Obtains the version information of the currently linked **zlib** library. This API uses a promise to return the result. The version information of the current **zlib** library is returned upon success.

**Atomic service API**: This API can be used in atomic services since API version 12.

**System capability**: SystemCapability.BundleManager.Zlib

**Returns**

| Type                 | Description                                   |
| --------------------- | --------------------------------------- |
| Promise&lt;string&gt; | Promise used to return the result.  |

**Example**

```ts
import { zlib } from '@kit.BasicServicesKit';

let zip = zlib.createZipSync();

zip.zlibVersion().then((data) => {
  console.info('zlibVersion success')
})
```

### zlibCompileFlags<sup>12+</sup>

zlibCompileFlags(): Promise&lt;number&gt;

Returns a flag indicating a compile-time option. This API uses a promise to return the result. The flag indicating a compile-time option is returned upon a success.

**Atomic service API**: This API can be used in atomic services since API version 12.

**System capability**: SystemCapability.BundleManager.Zlib

**Returns**

| Type                 | Description                                   |
| --------------------- | --------------------------------------- |
| Promise&lt;number&gt; | Promise used to return the result.  |

**Example**

```ts
import { zlib } from '@kit.BasicServicesKit';

let zip = zlib.createZipSync();

zip.zlibCompileFlags().then((data) => {
  console.info('zlibCompileFlags success')
})
```

### compress<sup>12+</sup>

compress(dest: ArrayBuffer, source: ArrayBuffer, sourceLen?: number): Promise&lt;ZipOutputInfo&gt;

Compresses the source buffer to the destination buffer. This API uses a promise to return the result. The result state and total size of the destination buffer are returned upon a success.

**Atomic service API**: This API can be used in atomic services since API version 12.

**System capability**: SystemCapability.BundleManager.Zlib

**Parameters**

| Name   | Type       | Mandatory| Description          |
| --------- | ----------- | ---- | -------------- |
| dest      | ArrayBuffer | Yes  | Destination buffer.  |
| source    | ArrayBuffer | Yes  | Source buffer.|
| sourceLen | number      | No  | Length of the source data. The default value is **0**.  |

**Returns**

| Type                                            | Description                                           |
| ------------------------------------------------ | ----------------------------------------------- |
| Promise&lt;[ZipOutputInfo](#zipoutputinfo12)&gt; | Promise used to return the result.  |

**Error codes**

For details about the error codes, see [Universal Error Codes](../errorcode-universal.md) and [zlib Error Codes](./errorcode-zlib.md).

| ID| Error Message                                                    |
| -------- | ------------------------------------------------------------ |
| 401      | The parameter check failed. Possible causes: <br>1. Mandatory parameters are left unspecified;<br>2. Incorrect parameter types;<br>3. Parameter verification failed. |
| 17800007 | The input buffer is incorrect, and the output buffer is too small to accommodate the compressed or decompressed data. |

**Example**

```ts
import { zlib, BusinessError } from '@kit.BasicServicesKit';

let str = 'hello world!';
let arrayBufferIn = new ArrayBuffer(str.length);
let byteArray = new Uint8Array(arrayBufferIn);

for (let i = 0, j = str.length; i < j; i++) {
  byteArray[i] = str.charCodeAt(i)
}

let arrayBufferOut = new ArrayBuffer(100);
let zip = zlib.createZipSync();

zip.compress(arrayBufferOut, arrayBufferIn, 20).then((data) => {
  console.info('compress success:');
}).catch((errData: BusinessError) => {
  console.error(`errData is errCode:${errData.code}  message:${errData.message}`);
})
```

### compress2<sup>12+</sup>

compress2(dest: ArrayBuffer, source: ArrayBuffer, level: CompressLevel, sourceLen?: number): Promise&lt;ZipOutputInfo&gt;

Compresses the source buffer to the destination buffer. This API uses a promise to return the result. The result state and total size of the destination buffer are returned upon a success.

**Atomic service API**: This API can be used in atomic services since API version 12.

**System capability**: SystemCapability.BundleManager.Zlib

**Parameters**

| Name   | Type         | Mandatory| Description                                         |
| --------- | ------------- | ---- | --------------------------------------------- |
| dest      | ArrayBuffer   | Yes  | Destination buffer.                                 |
| source    | ArrayBuffer   | Yes  | Source buffer.                               |
| level     | CompressLevel | Yes  | For details, see [CompressLevel](#compresslevel).|
| sourceLen | number        | No  | Length of the source data. The default value is **0**.                                 |

**Returns**

| Type                                            | Description                                           |
| ------------------------------------------------ | ----------------------------------------------- |
| Promise&lt;[ZipOutputInfo](#zipoutputinfo12)&gt; | Promise used to return the result.  |

**Error codes**

For details about the error codes, see [Universal Error Codes](../errorcode-universal.md) and [zlib Error Codes](./errorcode-zlib.md).

| ID| Error Message                                                    |
| -------- | ------------------------------------------------------------ |
| 401      | The parameter check failed. Possible causes: <br>1. Mandatory parameters are left unspecified;<br>2. Incorrect parameter types;<br>3. Parameter verification failed. |
| 17800004 | Compression or decompression stream error, which may be caused by an initialization error in the zlib stream structure or a modified structure. |
| 17800007 | The input buffer is incorrect, and the output buffer is too small to accommodate the compressed or decompressed data. |

**Example**

```ts
import { zlib, BusinessError } from '@kit.BasicServicesKit';

let str = 'hello world!';
let arrayBufferIn = new ArrayBuffer(str.length);
let byteArray = new Uint8Array(arrayBufferIn);

for (let i = 0, j = str.length; i < j; i++) {
  byteArray[i] = str.charCodeAt(i)
}

let arrayBufferOut = new ArrayBuffer(100);
let zip = zlib.createZipSync();

zip.compress2(arrayBufferOut, arrayBufferIn, zlib.CompressLevel.COMPRESS_LEVEL_BEST_SPEED).then((data) => {
  console.info('compress2 success');
}).catch((errData: BusinessError) => {
  console.error(`errData is errCode:${errData.code}  message:${errData.message}`);
})
```

### uncompress<sup>12+</sup>

uncompress(dest:ArrayBuffer, source: ArrayBuffer, sourceLen?: number): Promise&lt;ZipOutputInfo&gt;

Decompresses the compressed data into the original form. This API uses a promise to return the result. The result state and total size of the destination buffer are returned upon a success.

**Atomic service API**: This API can be used in atomic services since API version 12.

**System capability**: SystemCapability.BundleManager.Zlib

**Parameters**

| Name   | Type       | Mandatory| Description          |
| --------- | ----------- | ---- | -------------- |
| dest      | ArrayBuffer | Yes  | Destination buffer.  |
| source    | ArrayBuffer | Yes  | Source buffer.|
| sourceLen | number      | No  | Length of the source data. The default value is **0**.  |

**Returns**

| Type                                            | Description                                           |
| ------------------------------------------------ | ----------------------------------------------- |
| Promise&lt;[ZipOutputInfo](#zipoutputinfo12)&gt; | Promise used to return the result.  |

**Error codes**

For details about the error codes, see [Universal Error Codes](../errorcode-universal.md) and [zlib Error Codes](./errorcode-zlib.md).

| ID| Error Message                                                    |
| -------- | ------------------------------------------------------------ |
| 401      | The parameter check failed. Possible causes: <br>1. Mandatory parameters are left unspecified;<br>2. Incorrect parameter types;<br>3. Parameter verification failed. |
| 17800005 | The input data is incorrect. For example, the data does not conform to the zlib compression format, the compressed data is corrupted, or the data is not compressed. |
| 17800007 | The input buffer is incorrect, and the output buffer is too small to accommodate the compressed or decompressed data. |

**Example**

```ts
import { zlib, BusinessError } from '@kit.BasicServicesKit';

async function demo() {
  let str = 'hello world!';
  let arrayBufferIn = new ArrayBuffer(str.length);
  let byteArray = new Uint8Array(arrayBufferIn);
  for (let i = 0, j = str.length; i < j; i++) {
    byteArray[i] = str.charCodeAt(i)
  }
  let arrayBufferOut = new ArrayBuffer(100);
  let zip = zlib.createZipSync();
  await zip.compress(arrayBufferOut, arrayBufferIn, 12).then((data) => {
    console.info('compress success');
  }).catch((errData: BusinessError) => {
    console.error(`errData is errCode:${errData.code}  message:${errData.message}`);
  })
  await zip.uncompress(arrayBufferIn, arrayBufferOut, 20).then((data) => {
    console.info('uncompress success');
  }).catch((errData: BusinessError) => {
    console.error(`errData is errCode:${errData.code}  message:${errData.message}`);
  })
}
```

### uncompress2<sup>12+</sup>

uncompress2(dest: ArrayBuffer, source: ArrayBuffer, sourceLen?: number): Promise&lt;DecompressionOutputInfo&gt;

Decompresses the compressed data into the original form. This API uses a promise to return the result. The result state, total size of the destination buffer, and the length of the source data are returned upon a success.

**Atomic service API**: This API can be used in atomic services since API version 12.

**System capability**: SystemCapability.BundleManager.Zlib

**Parameters**

| Name   | Type       | Mandatory| Description          |
| --------- | ----------- | ---- | -------------- |
| dest      | ArrayBuffer | Yes  | Destination buffer.  |
| source    | ArrayBuffer | Yes  | Source buffer.|
| sourceLen | number      | No  | Length of the source data. The default value is **0**.  |

**Returns**

| Type                                                        | Description                                                       |
| ------------------------------------------------------------ | ----------------------------------------------------------- |
| Promise&lt;[DecompressionOutputInfo](#decompressionoutputinfo12)&gt; | Promise used to return the result.  |

**Error codes**

For details about the error codes, see [Universal Error Codes](../errorcode-universal.md) and [zlib Error Codes](./errorcode-zlib.md).

| ID| Error Message                                                    |
| -------- | ------------------------------------------------------------ |
| 401      | The parameter check failed. Possible causes: <br>1. Mandatory parameters are left unspecified;<br>2. Incorrect parameter types;<br>3. Parameter verification failed. |
| 17800005 | The input data is incorrect. For example, the data does not conform to the zlib compression format, the compressed data is corrupted, or the data is not compressed. |
| 17800007 | The input buffer is incorrect, and the output buffer is too small to accommodate the compressed or decompressed data. |

**Example**

```ts
import { zlib, BusinessError } from '@kit.BasicServicesKit';

async function demo() {
  let str = 'hello world!';
  let arrayBufferIn = new ArrayBuffer(str.length);
  let byteArray = new Uint8Array(arrayBufferIn);
  for (let i = 0, j = str.length; i < j; i++) {
    byteArray[i] = str.charCodeAt(i)
  }
  let arrayBufferOut = new ArrayBuffer(100);
  let zip = zlib.createZipSync();
  await zip.compress2(arrayBufferOut, arrayBufferIn, zlib.CompressLevel.COMPRESS_LEVEL_BEST_SPEED).then((data) => {
    console.info('compress2 success');
  }).catch((errData: BusinessError) => {
    console.error(`errData is errCode:${errData.code}  message:${errData.message}`);
  })
  await zip.uncompress2(arrayBufferIn, arrayBufferOut, 20).then((data) => {
    console.info('uncompress2 success');
  }).catch((errData: BusinessError) => {
    console.error(`errData is errCode:${errData.code}  message:${errData.message}`);
  })
}
```

### compressBound<sup>12+</sup>

compressBound(sourceLen: number): Promise&lt;number&gt;

Calculates the maximum size of the compressed data to be returned. This API uses a promise to return the result. The maximum size of the compressed data is returned upon a success.

**Atomic service API**: This API can be used in atomic services since API version 12.

**System capability**: SystemCapability.BundleManager.Zlib

**Parameters**

| Name   | Type  | Mandatory| Description        |
| --------- | ------ | ---- | ------------ |
| sourceLen | number | Yes  | Length of the source data.|

**Returns**

| Type                 | Description                             |
| --------------------- | --------------------------------- |
| Promise&lt;number&gt; | Promise used to return the result.  |

**Error codes**

For details about the error codes, see [Universal Error Codes](../errorcode-universal.md).

| ID| Error Message                                                    |
| -------- | ------------------------------------------------------------ |
| 401      | The parameter check failed. Possible causes: <br>1. Mandatory parameters are left unspecified;<br>2. Incorrect parameter types;<br>3. Parameter verification failed. |

**Example**

```ts
import { zlib, BusinessError } from '@kit.BasicServicesKit';

let str = 'hello world!';
let arrayBufferIn = new ArrayBuffer(str.length);
let byteArray = new Uint8Array(arrayBufferIn);

for (let i = 0, j = str.length; i < j; i++) {
  byteArray[i] = str.charCodeAt(i)
}

let zip = zlib.createZipSync();

zip.compressBound(str.length).then((data) => {
  console.info('compressBound success')
}).catch((errData: BusinessError) => {
  console.error(`errData is errCode:${errData.code}  message:${errData.message}`);
})
```

### inflateValidate<sup>12+</sup>

inflateValidate(strm: ZStream, check: number): Promise&lt;ReturnStatus&gt;

Verifies the checksum inside the compressed stream. This API uses a promise to return the result. The result state is returned upon a success.

**Atomic service API**: This API can be used in atomic services since API version 12.

**System capability**: SystemCapability.BundleManager.Zlib

**Parameters**

| Name| Type   | Mandatory| Description                           |
| ------ | ------- | ---- | ------------------------------- |
| strm   | ZStream | Yes  | For details, see [ZStream<sup>12+</sup>](#zstream12).|
| check  | number  | Yes  | Expected checksum.                 |

**Returns**

| Type                                          | Description                       |
| ---------------------------------------------- | --------------------------- |
| Promise&lt;[ReturnStatus](#returnstatus12)&gt; | Promise used to return the result.  |

**Error codes**

For details about the error codes, see [Universal Error Codes](../errorcode-universal.md) and [zlib Error Codes](./errorcode-zlib.md).

| ID| Error Message                                                    |
| -------- | ------------------------------------------------------------ |
| 401      | The parameter check failed. Possible causes: <br>1. Mandatory parameters are left unspecified;<br>2. Incorrect parameter types;<br>3. Parameter verification failed. |
| 17800004 | Compression or decompression stream error, which may be caused by an initialization error in the zlib stream structure or a modified structure. |

**Example**

```ts
import { zlib, BusinessError } from '@kit.BasicServicesKit';

async function demo() {
  let str = 'hello world!';
  let arrayBufferIn = new ArrayBuffer(str.length);
  let byteArray = new Uint8Array(arrayBufferIn);
  for (let i = 0, j = str.length; i < j; i++) {
    byteArray[i] = str.charCodeAt(i)
  }
  let arrayBufferOut = new ArrayBuffer(100);
  let zip = zlib.createZipSync();
  await zip.inflateInit({ nextIn: arrayBufferIn, availableIn: 1, nextOut: arrayBufferOut, availableOut: 1 }
  ).then(data => {
    console.info('inflateInit success')
  }).catch((errData: BusinessError) => {
    console.error(`errData is errCode:${errData.code}  message:${errData.message}`);
  })
  await zip.inflateValidate({ availableIn: 1 }, 1).then(data => {
    console.info('inflateValidate success')
  }).catch((errData: BusinessError) => {
    console.error(`errData is errCode:${errData.code}  message:${errData.message}`);
  })
}
```

### inflateSyncPoint<sup>12+</sup>

inflateSyncPoint(strm: ZStream): Promise&lt;ReturnStatus&gt;

Finds the synchronization point of the current decompressed stream. This API uses a promise to return the result. The result state is returned upon a success.

**Atomic service API**: This API can be used in atomic services since API version 12.

**System capability**: SystemCapability.BundleManager.Zlib

**Parameters**

| Name| Type   | Mandatory| Description                           |
| ------ | ------- | ---- | ------------------------------- |
| strm   | ZStream | Yes  | For details, see [ZStream<sup>12+</sup>](#zstream12).|

**Returns**

| Type                                          | Description                       |
| ---------------------------------------------- | --------------------------- |
| Promise&lt;[ReturnStatus](#returnstatus12)&gt; | Promise used to return the result.  |

**Error codes**

For details about the error codes, see [Universal Error Codes](../errorcode-universal.md) and [zlib Error Codes](./errorcode-zlib.md).

| ID| Error Message                                                    |
| -------- | ------------------------------------------------------------ |
| 401      | The parameter check failed. Possible causes: <br>1. Mandatory parameters are left unspecified;<br>2. Incorrect parameter types;<br>3. Parameter verification failed. |
| 17800004 | Compression or decompression stream error, which may be caused by an initialization error in the zlib stream structure or a modified structure. |

**Example**

```ts
import { zlib, BusinessError } from '@kit.BasicServicesKit';

async function demo() {
  let str = 'hello world!';
  let arrayBufferIn = new ArrayBuffer(str.length);
  let byteArray = new Uint8Array(arrayBufferIn);
  for (let i = 0, j = str.length; i < j; i++) {
    byteArray[i] = str.charCodeAt(i)
  }
  let arrayBufferOut = new ArrayBuffer(100);
  let zip = zlib.createZipSync();
  await zip.inflateInit({ nextIn: arrayBufferIn, availableIn: 1, nextOut: arrayBufferOut, availableOut: 1 }
  ).then(data => {
    console.info('inflateInit success');
  }).catch((errData: BusinessError) => {
    console.error(`errData is errCode:${errData.code}  message:${errData.message}`);
  })
  await zip.inflateSyncPoint({ availableIn: 1 }).then(data => {
    console.info('inflateSyncPoint success');
  }).catch((errData: BusinessError) => {
    console.error(`errData is errCode:${errData.code}  message:${errData.message}`);
  })
}
```

### inflateSync<sup>12+</sup>

inflateSync(strm: ZStream): Promise&lt;ReturnStatus&gt;

Skips invalid compressed data until a complete re-render point is found. This API uses a promise to return the result. The result state is returned upon a success.

**Atomic service API**: This API can be used in atomic services since API version 12.

**System capability**: SystemCapability.BundleManager.Zlib

**Parameters**

| Name| Type   | Mandatory| Description                           |
| ------ | ------- | ---- | ------------------------------- |
| strm   | ZStream | Yes  | For details, see [ZStream<sup>12+</sup>](#zstream12).|

**Returns**

| Type                                          | Description                       |
| ---------------------------------------------- | --------------------------- |
| Promise&lt;[ReturnStatus](#returnstatus12)&gt; | Promise used to return the result.  |

**Error codes**

For details about the error codes, see [Universal Error Codes](../errorcode-universal.md) and [zlib Error Codes](./errorcode-zlib.md).

| ID| Error Message                                                    |
| -------- | ------------------------------------------------------------ |
| 401      | The parameter check failed. Possible causes: <br>1. Mandatory parameters are left unspecified;<br>2. Incorrect parameter types;<br>3. Parameter verification failed. |
| 17800004 | Compression or decompression stream error, which may be caused by an initialization error in the zlib stream structure or a modified structure. |
| 17800005 | The input data is incorrect. For example, the data does not conform to the zlib compression format, the compressed data is corrupted, or the data is not compressed. |
| 17800007 | The input buffer is incorrect, and the output buffer is too small to accommodate the compressed or decompressed data. |

**Example**

```ts
import { zlib, BusinessError } from '@kit.BasicServicesKit';

async function demo() {
  let str = 'hello, hello!';
  let arrayBufferIn = new ArrayBuffer(str.length);
  let byteArray = new Uint8Array(arrayBufferIn);
  for (let i = 0, j = str.length; i < j; i++) {
    byteArray[i] = str.charCodeAt(i)
  }
  let arrayBufferOut = new ArrayBuffer(100);
  let zip = zlib.createZipSync();
  await zip.deflateInit({}, zlib.CompressLevel.COMPRESS_LEVEL_DEFAULT_COMPRESSION).then((data) => {
    console.info('deflateInit success')
  }).catch((errData: BusinessError) => {
    console.error(`errData is errCode:${errData.code}  message:${errData.message}`);
  })
  await zip.deflate({ nextIn: arrayBufferIn, availableIn: 3, nextOut: arrayBufferOut, availableOut: 100 }, zlib.CompressFlushMode.FULL_FLUSH).then((data) => {
    console.info('deflate success')
  }).catch((errData: BusinessError) => {
    console.error(`errData is errCode:${errData.code}  message:${errData.message}`);
  })
  await zip.deflate({ availableIn: 11 }, zlib.CompressFlushMode.FINISH).then((data) => {
    console.info('deflate success')
  }).catch((errData: BusinessError) => {
    console.error(`errData is errCode:${errData.code}  message:${errData.message}`);
  })
  await zip.deflateEnd({}).then(data => {
    console.info('deflateEnd success')
  }).catch((errData: BusinessError) => {
    console.error(`errData is errCode:${errData.code}  message:${errData.message}`);
  })
  try {
    await zip.inflateInit({ nextIn: arrayBufferOut, availableIn: 2 }).then(data => {
      console.info('inflateInit2 success')
    })
  } catch (errData) {
    console.error(`errData is errCode:${errData.code}  message:${errData.message}`);
  }
  await zip.inflate({ nextOut: arrayBufferIn, availableOut: 28 }, zlib.CompressFlushMode.NO_FLUSH).then((data) => {
    console.info('inflate success')
  }).catch((errData: BusinessError) => {
    console.error(`errData is errCode:${errData.code}  message:${errData.message}`);
  })
  await zip.inflateSync({ availableIn: 26 }).then(data => {
    console.info('inflateSync success');
  }).catch((errData: BusinessError) => {
    console.error(`errData is errCode:${errData.code}  message:${errData.message}`);
  })
  await zip.inflateEnd({ nextOut: arrayBufferOut }).then((data) => {
    console.info('inflateEnd success')
  }).catch((errData: BusinessError) => {
    console.error(`errData is errCode:${errData.code}  message:${errData.message}`);
  })
}
```

### inflateResetKeep<sup>12+</sup>

inflateResetKeep(strm: ZStream): Promise&lt;ReturnStatus&gt;

Resets the state of the decompressed stream to preserve the allocated Huffman Tree and preset dictionary. This API uses a promise to return the result. The result state is returned upon a success.

**Atomic service API**: This API can be used in atomic services since API version 12.

**System capability**: SystemCapability.BundleManager.Zlib

**Parameters**

| Name| Type   | Mandatory| Description                           |
| ------ | ------- | ---- | ------------------------------- |
| strm   | ZStream | Yes  | For details, see [ZStream<sup>12+</sup>](#zstream12).|

**Returns**

| Type                                          | Description                       |
| ---------------------------------------------- | --------------------------- |
| Promise&lt;[ReturnStatus](#returnstatus12)&gt; | Promise used to return the result.  |

**Error codes**

For details about the error codes, see [Universal Error Codes](../errorcode-universal.md) and [zlib Error Codes](./errorcode-zlib.md).

| ID| Error Message                                                    |
| -------- | ------------------------------------------------------------ |
| 401      | The parameter check failed. Possible causes: <br>1. Mandatory parameters are left unspecified;<br>2. Incorrect parameter types;<br>3. Parameter verification failed. |
| 17800004 | Compression or decompression stream error, which may be caused by an initialization error in the zlib stream structure or a modified structure. |

**Example**

```ts
import { zlib, BusinessError } from '@kit.BasicServicesKit';

async function demo() {
  let str = 'hello world!';
  let arrayBufferIn = new ArrayBuffer(str.length);
  let byteArray = new Uint8Array(arrayBufferIn);
  for (let i = 0, j = str.length; i < j; i++) {
    byteArray[i] = str.charCodeAt(i)
  }
  let arrayBufferOut = new ArrayBuffer(100);
  let zip = zlib.createZipSync();
  await zip.inflateInit({ nextIn: arrayBufferIn, availableIn: 1, nextOut: arrayBufferOut, availableOut: 1 }
  ).then(data => {
    console.info('inflateInit success');
  }).catch((errData: BusinessError) => {
    console.error(`errData is errCode:${errData.code}  message:${errData.message}`);
  })
  await zip.inflateResetKeep({ availableIn: 1 }).then(data => {
    console.info('inflateResetKeep success');
  }).catch((errData: BusinessError) => {
    console.error(`errData is errCode:${errData.code}  message:${errData.message}`);
  })
}
```

### inflateSetDictionary<sup>12+</sup>

inflateSetDictionary(strm: ZStream, dictionary: ArrayBuffer): Promise&lt;ReturnStatus&gt;

Initializes the decompression dictionary from a given uncompressed byte sequence. This API uses a promise to return the result. The result state is returned upon a success.

**Atomic service API**: This API can be used in atomic services since API version 12.

**System capability**: SystemCapability.BundleManager.Zlib

**Parameters**

| Name    | Type       | Mandatory| Description                           |
| ---------- | ----------- | ---- | ------------------------------- |
| strm       | ZStream     | Yes  | For details, see [ZStream<sup>12+</sup>](#zstream12).|
| dictionary | ArrayBuffer | Yes  | Dictionary data.                     |

**Returns**

| Type                                          | Description                       |
| ---------------------------------------------- | --------------------------- |
| Promise&lt;[ReturnStatus](#returnstatus12)&gt; | Promise used to return the result.  |

**Error codes**

For details about the error codes, see [Universal Error Codes](../errorcode-universal.md) and [zlib Error Codes](./errorcode-zlib.md).

| ID| Error Message                                                    |
| -------- | ------------------------------------------------------------ |
| 401      | The parameter check failed. Possible causes: <br>1. Mandatory parameters are left unspecified;<br>2. Incorrect parameter types;<br>3. Parameter verification failed. |
| 17800004 | Compression or decompression stream error, which may be caused by an initialization error in the zlib stream structure or a modified structure. |
| 17800005 | The input data is incorrect. For example, the data does not conform to the zlib compression format, the compressed data is corrupted, or the data is not compressed. |

**Example**

```ts
import { zlib, BusinessError } from '@kit.BasicServicesKit';

async function demo() {
  let str = 'hello, hello!';
  let arrayBufferIn = new ArrayBuffer(str.length);
  let byteArray = new Uint8Array(arrayBufferIn);
  for (let i = 0, j = str.length; i < j; i++) {
    byteArray[i] = str.charCodeAt(i)
  }
  let arrayBufferOut = new ArrayBuffer(100);
  let zip = zlib.createZipSync();
  let dictionary = 'hello'
  let dictionarybuf = new ArrayBuffer(dictionary.length);
  let dictionarybufdata = new Uint8Array(dictionarybuf);
  for (let i = 0, j = dictionary.length; i < j; i++) {
    dictionarybufdata[i] = str.charCodeAt(i);
  }
  await zip.deflateInit({}, zlib.CompressLevel.COMPRESS_LEVEL_BEST_COMPRESSION).then((data) => {
    console.info('deflateInit success')
  }).catch((errData: BusinessError) => {
    console.error(`errData is errCode:${errData.code}  message:${errData.message}`)
  })
  await zip.deflateSetDictionary({}, dictionarybuf).then((data) => {
    console.info('deflateSetDictionary success')
  }).catch((errData: BusinessError) => {
    console.error(`errData is errCode:${errData.code}  message:${errData.message}`)
  })
  await zip.deflate({ nextIn: arrayBufferIn, availableIn: 14, nextOut: arrayBufferOut, availableOut: 100 }, zlib.CompressFlushMode.FINISH).then((data) => {
    console.info('deflate success')
  }).catch((errData: BusinessError) => {
    console.error(`errData is errCode:${errData.code}  message:${errData.message}`)
  })
  await zip.deflateEnd({}).then(data => {
    console.info('deflateEnd success')
  }).catch((errData: BusinessError) => {
    console.error(`errData is errCode:${errData.code}  message:${errData.message}`)
  })
  try {
    await zip.inflateInit({ nextIn: arrayBufferOut, availableIn: 100 }).then(data => {
      console.info('inflateInit success')
    })
  } catch (errData) {
    console.error(`errData is errCode:${errData.code}  message:${errData.message}`)
  }
  await zip.inflate({ nextOut: arrayBufferIn, availableOut: 28 }, zlib.CompressFlushMode.NO_FLUSH).then((data) => {
    console.info('inflate success')
  }).catch((errData: BusinessError) => {
    console.error(`errData is errCode:${errData.code}  message:${errData.message}`)
  })
  await zip.inflateSetDictionary({}, dictionarybuf).then((data) => {
    console.info('inflateSetDictionary success')
  }).catch((errData: BusinessError) => {
    console.error(`errData is errCode:${errData.code}  message:${errData.message}`)
  })
  await zip.inflateEnd({ nextOut: arrayBufferOut }).then((data) => {
    console.info('inflateEnd success')
  }).catch((errData: BusinessError) => {
    console.error(`errData is errCode:${errData.code}  message:${errData.message}`)
  })
}
```

### inflateReset2<sup>12+</sup>

inflateReset2(strm: ZStream, windowBits: number): Promise&lt;ReturnStatus&gt;

Initializes the decompression dictionary from a given uncompressed byte sequence. This API uses a promise to return the result. The result state is returned upon a success.

**Atomic service API**: This API can be used in atomic services since API version 12.

**System capability**: SystemCapability.BundleManager.Zlib

**Parameters**

| Name    | Type   | Mandatory| Description                           |
| ---------- | ------- | ---- | ------------------------------- |
| strm       | ZStream | Yes  | For details, see [ZStream<sup>12+</sup>](#zstream12).|
| windowBits | number  | Yes  | Memory window size. The value is restricted in certain range based on the data formats. The options are as follows:<br>Zlib: [1, 15]<br>Gzip: (15, +∞)<br>Raw Deflate: [-15, -1]  |

**Returns**

| Type                                          | Description                       |
| ---------------------------------------------- | --------------------------- |
| Promise&lt;[ReturnStatus](#returnstatus12)&gt; | Promise used to return the result.  |

**Error codes**

For details about the error codes, see [Universal Error Codes](../errorcode-universal.md) and [zlib Error Codes](./errorcode-zlib.md).

| ID| Error Message                                                    |
| -------- | ------------------------------------------------------------ |
| 401      | The parameter check failed. Possible causes: <br>1. Mandatory parameters are left unspecified;<br>2. Incorrect parameter types;<br>3. Parameter verification failed. |
| 17800004 | Compression or decompression stream error, which may be caused by an initialization error in the zlib stream structure or a modified structure. |

**Example**

```ts
import { zlib, BusinessError } from '@kit.BasicServicesKit';

async function demo() {
  let str = 'hello world!';
  let arrayBufferIn = new ArrayBuffer(str.length);
  let byteArray = new Uint8Array(arrayBufferIn);
  for (let i = 0, j = str.length; i < j; i++) {
    byteArray[i] = str.charCodeAt(i)
  }
  let arrayBufferOut = new ArrayBuffer(100);
  let zip = zlib.createZipSync();
  await zip.inflateInit({ nextIn: arrayBufferIn, availableIn: 1, nextOut: arrayBufferOut, availableOut: 1 }
  ).then(data => {
    console.info('inflateInit success');
  }).catch((errData: BusinessError) => {
    console.error(`errData is errCode:${errData.code}  message:${errData.message}`);
  })
  await zip.inflateReset2({ availableOut: 8 }, 15).then(data => {
    console.info('inflateReset2 success');
  }).catch((errData: BusinessError) => {
    console.error(`errData is errCode:${errData.code}  message:${errData.message}`);
  })
}
```

### inflateReset<sup>12+</sup>

inflateReset(strm: ZStream): Promise&lt;ReturnStatus&gt;

Equivalent to call the **inflateEnd** API and then **inflateInit** API. However, this API does not release or reallocate the internal decompression state. This API uses a promise to return the result. The result state is returned upon a success.

**Atomic service API**: This API can be used in atomic services since API version 12.

**System capability**: SystemCapability.BundleManager.Zlib

**Parameters**

| Name| Type   | Mandatory| Description                           |
| ------ | ------- | ---- | ------------------------------- |
| strm   | ZStream | Yes  | For details, see [ZStream<sup>12+</sup>](#zstream12).|

**Returns**

| Type                                          | Description                       |
| ---------------------------------------------- | --------------------------- |
| Promise&lt;[ReturnStatus](#returnstatus12)&gt; | Promise used to return the result.  |

**Error codes**

For details about the error codes, see [Universal Error Codes](../errorcode-universal.md) and [zlib Error Codes](./errorcode-zlib.md).

| ID| Error Message                                                    |
| -------- | ------------------------------------------------------------ |
| 401      | The parameter check failed. Possible causes: <br>1. Mandatory parameters are left unspecified;<br>2. Incorrect parameter types;<br>3. Parameter verification failed. |
| 17800004 | Compression or decompression stream error, which may be caused by an initialization error in the zlib stream structure or a modified structure. |

**Example**

```ts
import { zlib, BusinessError } from '@kit.BasicServicesKit';

async function demo() {
  let str = 'hello world!';
  let arrayBufferIn = new ArrayBuffer(str.length);
  let byteArray = new Uint8Array(arrayBufferIn);
  for (let i = 0, j = str.length; i < j; i++) {
    byteArray[i] = str.charCodeAt(i)
  }
  let arrayBufferOut = new ArrayBuffer(100);
  let zip = zlib.createZipSync();
  await zip.inflateInit({ nextIn: arrayBufferIn, availableIn: 1, nextOut: arrayBufferOut, availableOut: 1 }
  ).then(data => {
    console.info('inflateInit success');
  }).catch((errData: BusinessError) => {
    console.error(`errData is errCode:${errData.code}  message:${errData.message}`);
  })
  await zip.inflateReset({ availableIn: 1, availableOut: 8 }).then(data => {
    console.info('inflateReset success');
  }).catch((errData: BusinessError) => {
    console.error(`errData is errCode:${errData.code}  message:${errData.message}`);
  })
}
```

### inflatePrime<sup>12+</sup>

inflatePrime(strm: ZStream, bits: number, value: number): Promise&lt;ReturnStatus&gt;

Initializes the decompression dictionary from a given uncompressed byte sequence. This API uses a promise to return the result. The result state is returned upon a success.

**Atomic service API**: This API can be used in atomic services since API version 12.

**System capability**: SystemCapability.BundleManager.Zlib

**Parameters**

| Name| Type   | Mandatory| Description                           |
| ------ | ------- | ---- | ------------------------------- |
| strm   | ZStream | Yes  | For details, see [ZStream<sup>12+</sup>](#zstream12).|
| bits   | number  | Yes  | Given bits.                     |
| value  | number  | Yes  | Given value.                     |

**Returns**

| Type                                          | Description                       |
| ---------------------------------------------- | --------------------------- |
| Promise&lt;[ReturnStatus](#returnstatus12)&gt; | Promise used to return the result.  |

**Error codes**

For details about the error codes, see [Universal Error Codes](../errorcode-universal.md) and [zlib Error Codes](./errorcode-zlib.md).

| ID| Error Message                                                    |
| -------- | ------------------------------------------------------------ |
| 401      | The parameter check failed. Possible causes: <br>1. Mandatory parameters are left unspecified;<br>2. Incorrect parameter types;<br>3. Parameter verification failed. |
| 17800004 | Compression or decompression stream error, which may be caused by an initialization error in the zlib stream structure or a modified structure. |

**Example**

```ts
import { zlib, BusinessError } from '@kit.BasicServicesKit';

async function demo() {
  let str = 'hello world!';
  let arrayBufferIn = new ArrayBuffer(str.length);
  let byteArray = new Uint8Array(arrayBufferIn);
  for (let i = 0, j = str.length; i < j; i++) {
    byteArray[i] = str.charCodeAt(i)
  }
  let arrayBufferOut = new ArrayBuffer(100);
  let zip = zlib.createZipSync();
  await zip.inflateInit({ nextIn: arrayBufferIn, availableIn: 1, nextOut: arrayBufferOut, availableOut: 1 }
  ).then(data => {
    console.info('inflateInit success');
  }).catch((errData: BusinessError) => {
    console.error(`errData is errCode:${errData.code}  message:${errData.message}`);
  })
  await zip.inflatePrime({ nextOut: arrayBufferOut }, 5, 2).then(data => {
    console.info('inflatePrime success');
  }).catch((errData: BusinessError) => {
    console.error(`errData is errCode:${errData.code}  message:${errData.message}`);
  })
}
```

### inflateMark<sup>12+</sup>

inflateMark(strm: ZStream): Promise&lt;number&gt;

Marks the location of the input data for random access. This API uses a promise to return the result. The location information is returned upon a success.

**Atomic service API**: This API can be used in atomic services since API version 12.

**System capability**: SystemCapability.BundleManager.Zlib

**Parameters**

| Name| Type   | Mandatory| Description                           |
| ------ | ------- | ---- | ------------------------------- |
| strm   | ZStream | Yes  | For details, see [ZStream<sup>12+</sup>](#zstream12).|

**Returns**

| Type                 | Description                       |
| --------------------- | --------------------------- |
| Promise&lt;number&gt; | Promise used to return the result.  |

**Error codes**

For details about the error codes, see [Universal Error Codes](../errorcode-universal.md).

| ID| Error Message                                                    |
| -------- | ------------------------------------------------------------ |
| 401      | The parameter check failed. Possible causes: <br>1. Mandatory parameters are left unspecified;<br>2. Incorrect parameter types;<br>3. Parameter verification failed. |

**Example**

```ts
import { zlib, BusinessError } from '@kit.BasicServicesKit';

async function demo() {
  let str = 'hello world!';
  let arrayBufferIn = new ArrayBuffer(str.length);
  let byteArray = new Uint8Array(arrayBufferIn);
  for (let i = 0, j = str.length; i < j; i++) {
    byteArray[i] = str.charCodeAt(i)
  }
  let arrayBufferOut = new ArrayBuffer(100);
  let zip = zlib.createZipSync();
  await zip.inflateInit({ nextIn: arrayBufferIn, availableIn: 1, nextOut: arrayBufferOut, availableOut: 1 }
  ).then(data => {
    console.info('inflateInit success');
  }).catch((errData: BusinessError) => {
    console.error(`errData is errCode:${errData.code}  message:${errData.message}`);
  })
  await zip.inflateMark({ nextIn: arrayBufferIn, availableIn: 1, nextOut: arrayBufferOut, availableOut: 1 }).then(data => {
    console.info('inflateMark success');
  }).catch((errData: BusinessError) => {
    console.error(`errData is errCode:${errData.code}  message:${errData.message}`);
  })
}
```

### inflateInit2<sup>12+</sup>

inflateInit2(strm: ZStream, windowBits: number): Promise&lt;ReturnStatus&gt;

Initializes the internal stream state for decompression. This API uses a promise to return the result. The result state is returned upon a success.

**Atomic service API**: This API can be used in atomic services since API version 12.

**System capability**: SystemCapability.BundleManager.Zlib

**Parameters**

| Name    | Type   | Mandatory| Description                           |
| ---------- | ------- | ---- | ------------------------------- |
| strm       | ZStream | Yes  | For details, see [ZStream<sup>12+</sup>](#zstream12).|
| windowBits | number  | Yes  | Memory window size. The value is restricted in certain range based on the data formats. The options are as follows:<br>Zlib: [1, 15]<br>Gzip: (15, +∞)<br>Raw Deflate: [-15, -1]  |

**Returns**

| Type                                          | Description                       |
| ---------------------------------------------- | --------------------------- |
| Promise&lt;[ReturnStatus](#returnstatus12)&gt; | Promise used to return the result.  |

**Error codes**

For details about the error codes, see [Universal Error Codes](../errorcode-universal.md) and [zlib Error Codes](./errorcode-zlib.md).

| ID| Error Message                                                    |
| -------- | ------------------------------------------------------------ |
| 401      | The parameter check failed. Possible causes: <br>1. Mandatory parameters are left unspecified;<br>2. Incorrect parameter types;<br>3. Parameter verification failed. |
| 17800004 | Compression or decompression stream error, which may be caused by an initialization error in the zlib stream structure or a modified structure. |

**Example**

```ts
import { zlib, BusinessError } from '@kit.BasicServicesKit';

let str = 'hello world!';
let arrayBufferIn = new ArrayBuffer(str.length);
let byteArray = new Uint8Array(arrayBufferIn);

for (let i = 0, j = str.length; i < j; i++) {
  byteArray[i] = str.charCodeAt(i)
}

let arrayBufferOut = new ArrayBuffer(100);
let zip = zlib.createZipSync();

zip.inflateInit2({ nextIn: arrayBufferIn, availableIn: 1, nextOut: arrayBufferOut, availableOut: 1 }, 28
).then(data => {
  console.info('inflateInit2 success');
}).catch((errData: BusinessError) => {
  console.error(`errData is errCode:${errData.code}  message:${errData.message}`);
})
```

### inflateInit<sup>12+</sup>

inflateInit(strm: ZStream): Promise&lt;ReturnStatus&gt;

Initializes the internal stream state for decompression. This API uses a promise to return the result. The result state is returned upon a success.

**Atomic service API**: This API can be used in atomic services since API version 12.

**System capability**: SystemCapability.BundleManager.Zlib

**Parameters**

| Name| Type   | Mandatory| Description                           |
| ------ | ------- | ---- | ------------------------------- |
| strm   | ZStream | Yes  | For details, see [ZStream<sup>12+</sup>](#zstream12).|

**Returns**

| Type                                          | Description                       |
| ---------------------------------------------- | --------------------------- |
| Promise&lt;[ReturnStatus](#returnstatus12)&gt; | Promise used to return the result.  |

**Error codes**

For details about the error codes, see [Universal Error Codes](../errorcode-universal.md).

| ID| Error Message                                                    |
| -------- | ------------------------------------------------------------ |
| 401      | The parameter check failed. Possible causes: <br>1. Mandatory parameters are left unspecified;<br>2. Incorrect parameter types;<br>3. Parameter verification failed. |

**Example**

```ts
import { zlib, BusinessError } from '@kit.BasicServicesKit';

let str = 'hello world!';
let arrayBufferIn = new ArrayBuffer(str.length);
let byteArray = new Uint8Array(arrayBufferIn);

for (let i = 0, j = str.length; i < j; i++) {
  byteArray[i] = str.charCodeAt(i)
}

let arrayBufferOut = new ArrayBuffer(100);
let zip = zlib.createZipSync();

zip.inflateInit({ nextIn: arrayBufferIn, availableIn: 1, nextOut: arrayBufferOut, availableOut: 1 }
).then(data => {
  console.info('inflateInit success');
}).catch((errData: BusinessError) => {
  console.error(`errData is errCode:${errData.code}  message:${errData.message}`);
})
```

### inflateGetHeader<sup>12+</sup>

inflateGetHeader(strm: ZStream, header: GzHeader): Promise&lt;ReturnStatus&gt;

Sets the header information of a gzip file before decompressing data. This API uses a promise to return the result. The result state is returned upon a success.

**Atomic service API**: This API can be used in atomic services since API version 12.

**System capability**: SystemCapability.BundleManager.Zlib

**Parameters**

| Name| Type                   | Mandatory| Description                            |
| ------ | ----------------------- | ---- | -------------------------------- |
| strm   | ZStream                 | Yes  | For details, see [ZStream<sup>12+</sup>](#zstream12). |
| header | [GzHeader](#gzheader12) | Yes  | Header information of a gzip file extracted from the compressed data stream.|

**Returns**

| Type                                          | Description                       |
| ---------------------------------------------- | --------------------------- |
| Promise&lt;[ReturnStatus](#returnstatus12)&gt; | Promise used to return the result.  |

**Error codes**

For details about the error codes, see [Universal Error Codes](../errorcode-universal.md) and [zlib Error Codes](./errorcode-zlib.md).

| ID| Error Message                                                    |
| -------- | ------------------------------------------------------------ |
| 401      | The parameter check failed. Possible causes: <br>1. Mandatory parameters are left unspecified;<br>2. Incorrect parameter types;<br>3. Parameter verification failed. |
| 17800004 | Compression or decompression stream error, which may be caused by an initialization error in the zlib stream structure or a modified structure. |

**Example**

```ts
import { zlib, BusinessError } from '@kit.BasicServicesKit';

async function demo() {
  let str = 'hello world!';
  let arrayBufferIn = new ArrayBuffer(str.length);
  let byteArray = new Uint8Array(arrayBufferIn);
  for (let i = 0, j = str.length; i < j; i++) {
    byteArray[i] = str.charCodeAt(i)
  }
  let arrayBufferOut = new ArrayBuffer(100);
  let zip = zlib.createZipSync();
  await zip.inflateInit2({ nextIn: arrayBufferIn, availableIn: 1, nextOut: arrayBufferOut, availableOut: 1 }, 28
  ).then(data => {
    console.info('inflateInit2 success');
  }).catch((errData: BusinessError) => {
    console.error(`errData is errCode:${errData.code}  message:${errData.message}`);
  })
  await zip.inflateGetHeader({ availableIn: 1, availableOut: 1 }, { isText: true, os: 1, time: 1, xflags: 1, extra: arrayBufferIn, extraLen: 12, name: arrayBufferIn, comment: arrayBufferOut, hcrc: true, done: true }).then(data => {
    console.info('inflateGetHeader success');
  }).catch((errData: BusinessError) => {
    console.error(`errData is errCode:${errData.code}  message:${errData.message}`);
  })
}
```

### inflateGetDictionary<sup>12+</sup>

inflateGetDictionary(strm: ZStream, dictionary: ArrayBuffer): Promise&lt;DictionaryOutputInfo&gt;

Obtains the content and length of the decompression dictionary used in the current decompression stream. This API uses a promise to return the result. The result state and length of the dictionary are returned upon a success.

**Atomic service API**: This API can be used in atomic services since API version 12.

**System capability**: SystemCapability.BundleManager.Zlib

**Parameters**

| Name    | Type       | Mandatory| Description                           |
| ---------- | ----------- | ---- | ------------------------------- |
| strm       | ZStream     | Yes  | For details, see [ZStream<sup>12+</sup>](#zstream12).|
| dictionary | ArrayBuffer | Yes  | Receives the actual contents of the decompression dictionary.     |

**Returns**

| Type                                                        | Description                                   |
| ------------------------------------------------------------ | --------------------------------------- |
| Promise&lt;[DictionaryOutputInfo](#dictionaryoutputinfo12)&gt; | Promise used to return the result.  |

**Error codes**

For details about the error codes, see [Universal Error Codes](../errorcode-universal.md) and [zlib Error Codes](./errorcode-zlib.md).

| ID| Error Message                                                    |
| -------- | ------------------------------------------------------------ |
| 401      | The parameter check failed. Possible causes: <br>1. Mandatory parameters are left unspecified;<br>2. Incorrect parameter types;<br>3. Parameter verification failed. |
| 17800004 | Compression or decompression stream error, which may be caused by an initialization error in the zlib stream structure or a modified structure. |

**Example**

```ts
import { zlib, BusinessError } from '@kit.BasicServicesKit';

async function demo() {
  let str = 'hello world!';
  let arrayBufferIn = new ArrayBuffer(str.length);
  let byteArray = new Uint8Array(arrayBufferIn);
  for (let i = 0, j = str.length; i < j; i++) {
    byteArray[i] = str.charCodeAt(i)
  }
  let arrayBufferOut = new ArrayBuffer(100);
  let zip = zlib.createZipSync();
  await zip.inflateInit2({ nextIn: arrayBufferIn, availableIn: 1, nextOut: arrayBufferOut, availableOut: 1 }, 28
  ).then(data => {
    console.info('inflateInit2 success');
  }).catch((errData: BusinessError) => {
    console.error(`errData is errCode:${errData.code}  message:${errData.message}`);
  })
  await zip.inflateGetDictionary({ nextOut: arrayBufferOut }, arrayBufferOut).then((data) => {
    console.info('inflateGetDictionary success:')
  }).catch((errData: BusinessError) => {
    console.error(`errData is errCode:${errData.code}  message:${errData.message}`);
  })
}
```

### inflateEnd<sup>12+</sup>

inflateEnd(strm: ZStream): Promise&lt;ReturnStatus&gt;

Frees up all dynamically allocated data structures of the decompression stream. This API uses a promise to return the result. The result state is returned upon a success.

**Atomic service API**: This API can be used in atomic services since API version 12.

**System capability**: SystemCapability.BundleManager.Zlib

**Parameters**

| Name| Type   | Mandatory| Description                           |
| ------ | ------- | ---- | ------------------------------- |
| strm   | ZStream | Yes  | For details, see [ZStream<sup>12+</sup>](#zstream12).|

**Returns**

| Type                                          | Description                       |
| ---------------------------------------------- | --------------------------- |
| Promise&lt;[ReturnStatus](#returnstatus12)&gt; | Promise used to return the result.  |

**Error codes**

For details about the error codes, see [Universal Error Codes](../errorcode-universal.md) and [zlib Error Codes](./errorcode-zlib.md).

| ID| Error Message                                                    |
| -------- | ------------------------------------------------------------ |
| 401      | The parameter check failed. Possible causes: <br>1. Mandatory parameters are left unspecified;<br>2. Incorrect parameter types;<br>3. Parameter verification failed. |
| 17800004 | Compression or decompression stream error, which may be caused by an initialization error in the zlib stream structure or a modified structure. |

**Example**

```ts
import { zlib, BusinessError } from '@kit.BasicServicesKit';

async function demo() {
  let str = 'hello world!';
  let arrayBufferIn = new ArrayBuffer(str.length);
  let byteArray = new Uint8Array(arrayBufferIn);
  for (let i = 0, j = str.length; i < j; i++) {
    byteArray[i] = str.charCodeAt(i)
  }
  let arrayBufferOut = new ArrayBuffer(100);
  let zip = zlib.createZipSync();
  await zip.inflateInit({ nextIn: arrayBufferIn, availableIn: 1, nextOut: arrayBufferOut, availableOut: 1 }
  ).then(data => {
    console.info('inflateInit success');
  }).catch((errData: BusinessError) => {
    console.error(`errData is errCode:${errData.code}  message:${errData.message}`);
  })
  await zip.inflate({ availableIn: 8, availableOut: 8 }, 0).then((data) => {
    console.info('inflate success')
  }).catch((errData: BusinessError) => {
    console.error(`errData is errCode:${errData.code}  message:${errData.message}`);
  })
  await zip.inflateEnd({ nextOut: arrayBufferOut }).then((data) => {
    console.info('inflateEnd success')
  }).catch((errData: BusinessError) => {
    console.error(`errData is errCode:${errData.code}  message:${errData.message}`);
  })
}
```

### inflateCopy<sup>12+</sup>

inflateCopy(source: Zip): Promise&lt;ReturnStatus&gt;

Copies the decompression stream. This API uses a promise to return the result. The result state is returned upon a success.

**Atomic service API**: This API can be used in atomic services since API version 12.

**System capability**: SystemCapability.BundleManager.Zlib

**Parameters**

| Name| Type| Mandatory| Description                   |
| ------ | ---- | ---- | ----------------------- |
| source | Zip  | Yes  | For details, see [Zip<sup>12+</sup>](#zip12).|

**Returns**

| Type                                          | Description                       |
| ---------------------------------------------- | --------------------------- |
| Promise&lt;[ReturnStatus](#returnstatus12)&gt; | Promise used to return the result.  |

**Error codes**

For details about the error codes, see [Universal Error Codes](../errorcode-universal.md) and [zlib Error Codes](./errorcode-zlib.md).

| ID| Error Message                                                    |
| -------- | ------------------------------------------------------------ |
| 401      | The parameter check failed. Possible causes: <br>1. Mandatory parameters are left unspecified;<br>2. Incorrect parameter types;<br>3. Parameter verification failed. |
| 17800004 | Compression or decompression stream error, which may be caused by an initialization error in the zlib stream structure or a modified structure. |

**Example**

```ts
import { zlib, BusinessError } from '@kit.BasicServicesKit';

async function demo() {
  let str = 'hello world!';
  let arrayBufferIn = new ArrayBuffer(str.length);
  let byteArray = new Uint8Array(arrayBufferIn);
  for (let i = 0, j = str.length; i < j; i++) {
    byteArray[i] = str.charCodeAt(i)
  }
  let arrayBufferOut = new ArrayBuffer(100);
  let zip = zlib.createZipSync();
  await zip.inflateInit({ nextIn: arrayBufferIn, availableIn: 1, nextOut: arrayBufferOut, availableOut: 1 }
  ).then(data => {
    console.info('inflateInit success');
  }).catch((errData: BusinessError) => {
    console.error(`errData is errCode:${errData.code}  message:${errData.message}`);
  })
  let destZip = zlib.createZipSync();
  await destZip.inflateCopy(zip).then((data) => {
    console.info('inflateCopy success')
  }).catch((errData: BusinessError) => {
    console.error(`errData is errCode:${errData.code}  message:${errData.message}`);
  })
}
```

### inflateCodesUsed<sup>12+</sup>

inflateCodesUsed(strm: ZStream): Promise&lt;number&gt;

Describes the number of Huffman Trees used in the current decompression stream. This API uses a promise to return the result. The number of used Huffman Trees is returned upon a success.

**Atomic service API**: This API can be used in atomic services since API version 12.

**System capability**: SystemCapability.BundleManager.Zlib

**Parameters**

| Name| Type   | Mandatory| Description                           |
| ------ | ------- | ---- | ------------------------------- |
| strm   | ZStream | Yes  | For details, see [ZStream<sup>12+</sup>](#zstream12).|

**Returns**

| Type                 | Description                                         |
| --------------------- | --------------------------------------------- |
| Promise&lt;number&gt; | Promise used to return the result.  |

**Error codes**

For details about the error codes, see [Universal Error Codes](../errorcode-universal.md).

| ID| Error Message                                                    |
| -------- | ------------------------------------------------------------ |
| 401      | The parameter check failed. Possible causes: <br>1. Mandatory parameters are left unspecified;<br>2. Incorrect parameter types;<br>3. Parameter verification failed. |

**Example**

```ts
import { zlib, BusinessError } from '@kit.BasicServicesKit';

async function demo() {
  let str = 'hello world!';
  let arrayBufferIn = new ArrayBuffer(str.length);
  let byteArray = new Uint8Array(arrayBufferIn);
  for (let i = 0, j = str.length; i < j; i++) {
    byteArray[i] = str.charCodeAt(i)
  }
  let arrayBufferOut = new ArrayBuffer(100);
  let zip = zlib.createZipSync();
  await zip.inflateInit({ nextIn: arrayBufferIn, availableIn: 1, nextOut: arrayBufferOut, availableOut: 1 }
  ).then(data => {
    console.info('inflateInit success');
  }).catch((errData: BusinessError) => {
    console.error(`errData is errCode:${errData.code}  message:${errData.message}`);
  })
  await zip.inflateCodesUsed({ nextIn: arrayBufferIn, availableIn: 1, nextOut: arrayBufferOut, availableOut: 8 }).then(data => {
    console.info('inflateCodesUsed success');
  }).catch((errData: BusinessError) => {
    console.error(`errData is errCode:${errData.code}  message:${errData.message}`);
  })
}
```

### inflateBackInit<sup>12+</sup>

inflateBackInit(strm: ZStream, windowBits: number, window: ArrayBuffer): Promise&lt;ReturnStatus&gt;

Initializes the internal stream state for decompression before using the **inflateBack()** function. This API uses a promise to return the result. The result state is returned upon a success.

**Atomic service API**: This API can be used in atomic services since API version 12.

**System capability**: SystemCapability.BundleManager.Zlib

**Parameters**

| Name    | Type       | Mandatory| Description                                         |
| ---------- | ----------- | ---- | --------------------------------------------- |
| strm       | ZStream     | Yes  | For details, see [ZStream<sup>12+</sup>](#zstream12).              |
| windowBits | number      | Yes  | Memory window size. The value is restricted in certain range based on the data formats. The options are as follows:<br>Zlib: [1, 15]<br>Gzip: (15, +∞)<br>Raw Deflate: [-15, -1]|
| window     | ArrayBuffer | Yes  | Preset window buffer.                           |

**Returns**

| Type                                          | Description                       |
| ---------------------------------------------- | --------------------------- |
| Promise&lt;[ReturnStatus](#returnstatus12)&gt; | Promise used to return the result.  |

**Error codes**

For details about the error codes, see [Universal Error Codes](../errorcode-universal.md) and [zlib Error Codes](./errorcode-zlib.md).

| ID| Error Message                                                    |
| -------- | ------------------------------------------------------------ |
| 401      | The parameter check failed. Possible causes: <br>1. Mandatory parameters are left unspecified;<br>2. Incorrect parameter types;<br>3. Parameter verification failed. |
| 17800004 | Compression or decompression stream error, which may be caused by an initialization error in the zlib stream structure or a modified structure. |

**Example**

For details about the sample code, see [inflateBack](#inflateback12).

### inflateBackEnd<sup>12+</sup>

inflateBackEnd(strm: ZStream): Promise&lt;ReturnStatus&gt;

Releases all memory allocated by the **inflateBackInit()** function. This API uses a promise to return the result. The result state is returned upon a success.

**Atomic service API**: This API can be used in atomic services since API version 12.

**System capability**: SystemCapability.BundleManager.Zlib

**Parameters**

| Name| Type   | Mandatory| Description                           |
| ------ | ------- | ---- | ------------------------------- |
| strm   | ZStream | Yes  | For details, see [ZStream<sup>12+</sup>](#zstream12).|

**Returns**

| Type                                          | Description                       |
| ---------------------------------------------- | --------------------------- |
| Promise&lt;[ReturnStatus](#returnstatus12)&gt; | Promise used to return the result.  |

**Error codes**

For details about the error codes, see [Universal Error Codes](../errorcode-universal.md) and [zlib Error Codes](./errorcode-zlib.md).

| ID| Error Message                                                    |
| -------- | ------------------------------------------------------------ |
| 401      | The parameter check failed. Possible causes: <br>1. Mandatory parameters are left unspecified;<br>2. Incorrect parameter types;<br>3. Parameter verification failed. |
| 17800004 | Compression or decompression stream error, which may be caused by an initialization error in the zlib stream structure or a modified structure. |

**Example**

For details about the sample code, see [inflateBack](#inflateback12).

### inflateBack<sup>12+</sup>

inflateBack(strm: ZStream, backIn: InflateBackInputCallback, inDesc: object, backOut: InflateBackOutputCallback, outDesc: object): Promise&lt;ReturnStatus&gt;

Uses callback APIs to input and output data for raw decompression. This API uses a promise to return the result. The result state is returned upon a success.

**Atomic service API**: This API can be used in atomic services since API version 12.

**System capability**: SystemCapability.BundleManager.Zlib

**Parameters**

| Name | Type                     | Mandatory| Description                                                        |
| ------- | ------------------------- | ---- | ------------------------------------------------------------ |
| strm    | ZStream                   | Yes  | For details, see [ZStream<sup>12+</sup>](#zstream12).                             |
| backIn  | InflateBackInputCallback  | Yes  | A function used to decompress data from the end of the array to read the original compressed data from the input source.|
| inDesc  | object                    | Yes  | Common object.                                                  |
| backOut | InflateBackOutputCallback | Yes  | Writes the decompressed data to the destination buffer.                                |
| outDesc | object                    | Yes  | Common object.                                                  |

**Returns**

| Type                                          | Description                       |
| ---------------------------------------------- | --------------------------- |
| Promise&lt;[ReturnStatus](#returnstatus12)&gt; | Promise used to return the result.  |

**Error codes**

For details about the error codes, see [Universal Error Codes](../errorcode-universal.md) and [zlib Error Codes](./errorcode-zlib.md).

| ID| Error Message                                                    |
| -------- | ------------------------------------------------------------ |
| 401      | The parameter check failed. Possible causes: <br>1. Mandatory parameters are left unspecified. <br>2. Incorrect parameter types. <br>3. Parameter verification failed. |
| 17800004 | Compression or decompression stream error, which may be caused by an initialization error in the zlib stream structure or a modified structure. |

**Example**

```ts
import { zlib, BusinessError } from '@kit.BasicServicesKit';

async function demo() {
  let readIn: (inDesc: object) => ArrayBuffer = (inDesc: object): ArrayBuffer => {
    console.info("inDesc = ", JSON.stringify(inDesc));
    let buffer = new ArrayBuffer(26)
    let array = new Uint8Array(buffer);
    array.set([31, 139, 8, 0, 0, 0, 0, 0, 0, 10, 243, 72, 205, 201, 201, 231, 2, 0, 22, 53, 150, 49, 6, 0, 0, 0]);
    return buffer;
  }

  let writeOut: (outDesc: object, buffer: ArrayBuffer, length: number) => number = (outDesc: object, buffer: ArrayBuffer, length: number): number => {
    console.info("outDesc = ", outDesc);
    console.info("buffer = ", buffer);
    console.info("length = ", length);
    let array = new Uint8Array(buffer);
    let dataString = "";
    for (let i = 0; i < length; i++) {
      dataString += String.fromCharCode(array[i]);
    }
    console.info('writeOut ', dataString);
    return 0;
  }

  let have = 0;
  let first = 1;
  let arrayBuffer = new ArrayBuffer(26);
  let next = new Uint8Array(arrayBuffer);
  let last = 0;
  let index = 0;
  let flags = 0;
  let NEXT2: () => number = (): number => {
    let o6: object = new Object()
    if (!have) {
      arrayBuffer = readIn(o6)
      next = new Uint8Array(arrayBuffer);
      console.info('readIn next = ', next.length)
      have = next.length;
    }
    if (have) {
      have--;
      last = next[index];
      index++;
    }
    else {
      last = -1;
    }
    return last;
  }

  let inflateBackTest: () => void = (async () => {
    try {
      have = 0;
      first = 1;
      arrayBuffer = new ArrayBuffer(26);
      next = new Uint8Array(arrayBuffer);
      last = 0;
      index = 0;
      flags = 0;
      let sr = zlib.createZipSync();
      let buffer = new ArrayBuffer(1024)
      await sr.inflateBackInit({}, 15, buffer).then((result) => {
        console.info('inflateBackInit Call result res', result)
      })
      let ret = 0;
      for (; ;) {
        if (NEXT2() == -1) {
          ret = 0;
          console.info('inflateBackTest Call result NEXT2() == -1')
          break;
        }
        console.info('have =  last = ', have, last)
        if (last != 31 || NEXT2() != 139 ) {
          ret = first ? -3 : -1;
          console.info('inflateBackTest Call result last != 31 || (NEXT2() != 139 && last != 157)')
          break;
        }
        first = 0;
        ret = -5;
        if (NEXT2() != 8) {
          if (last < 0) {
            console.info('inflateBackTest Call result 1 last == -1')
            break;
          }
        }
        flags = NEXT2();
        NEXT2();
        NEXT2();
        NEXT2();
        NEXT2();
        NEXT2();
        NEXT2();
        if (last < 0) {
          console.info('inflateBackTest Call result 2 last == -1')
          break;
        }
        console.info('index =  have = ', next[index], have)
        let newArrayBuffer = new ArrayBuffer(have);
        let newNext = new Uint8Array(newArrayBuffer);
        for (let i = 0; i < have; i++) {
          newNext[i] = next[26 - have + i];
        }
        console.info('newArrayBuffer.length = ', newArrayBuffer.byteLength)
        console.info('newNext.length = ', newNext.length)
        let zStream: zlib.ZStream = {
          nextIn: newArrayBuffer,
          availableIn: have,
        };
        await sr.inflateBack(
          zStream,
          readIn,
          { fileName: 'test.gz' },
          writeOut,
          { fileName: 'test.gz' }).then((result) => {
            ret = result;
            console.info('inflateBack Call result res', result)
          })
        if (ret == 1) {
          console.info('inflateBackTest Call result success')
          break;
        }
      }
      await sr.inflateBackEnd({}).then((result) => {
        console.info('inflateBackEnd Call result res', result)
      })
    }
    catch (errData) {
      console.error(`errData is message:${errData}`);
    }
  })
  inflateBackTest();
}
```

### InflateBackInputCallback<sup>12+</sup>

type InflateBackInputCallback = (inDesc: object) => ArrayBuffer

Inputs data.

**Atomic service API**: This API can be used in atomic services since API version 12.

**System capability**: SystemCapability.BundleManager.Zlib

**Parameters**

| Name| Type  | Mandatory| Description              |
| ------ | ------ | ---- | ------------------ |
| inDesc | object | Yes  | User-defined data object.|

**Returns**

| Type                                          | Description                       |
| ---------------------------------------------- | --------------------------- |
| ArrayBuffer | Content buffer that is successfully read from the input data source.|

### InflateBackOutputCallback<sup>12+</sup>

type InflateBackOutputCallback = (outDesc: object, buf: ArrayBuffer, length: number) => number

Outputs data.

**Atomic service API**: This API can be used in atomic services since API version 12.

**System capability**: SystemCapability.BundleManager.Zlib

**Parameters**

| Name | Type       | Mandatory| Description                  |
| ------- | ----------- | ---- | ---------------------- |
| outDesc | object      | Yes  | User-defined data object.    |
| buf     | ArrayBuffer | Yes  | Stores the data to be written.|
| length  | number      | Yes  | Length of the data written to the output buffer.|

**Returns**

| Type                                          | Description                       |
| ---------------------------------------------- | --------------------------- |
| number | Number of bytes in the output buffer.|

### inflate<sup>12+</sup>

inflate(strm: ZStream, flush: CompressFlushMode): Promise&lt;ReturnStatus&gt;

Decompresses the data. This API uses a promise to return the result. The result state is returned upon a success.

**Atomic service API**: This API can be used in atomic services since API version 12.

**System capability**: SystemCapability.BundleManager.Zlib

**Parameters**

| Name| Type             | Mandatory| Description                                               |
| ------ | ----------------- | ---- | --------------------------------------------------- |
| strm   | ZStream           | Yes  | For details, see [ZStream<sup>12+</sup>](#zstream12).                    |
| flush  | CompressFlushMode | Yes  | For details, see [CompressFlushMode](#compressflushmode12).|

**Returns**

| Type                                          | Description                       |
| ---------------------------------------------- | --------------------------- |
| Promise&lt;[ReturnStatus](#returnstatus12)&gt; | Promise used to return the result.  |

**Error codes**

For details about the error codes, see [Universal Error Codes](../errorcode-universal.md) and [zlib Error Codes](./errorcode-zlib.md).

| ID| Error Message                                                    |
| -------- | ------------------------------------------------------------ |
| 401      | The parameter check failed. Possible causes: <br>1. Mandatory parameters are left unspecified;<br>2. Incorrect parameter types;<br>3. Parameter verification failed. |
| 17800004 | Compression or decompression stream error, which may be caused by an initialization error in the zlib stream structure or a modified structure. |
| 17800005 | The input data is incorrect. For example, the data does not conform to the zlib compression format, the compressed data is corrupted, or the data is not compressed. |

**Example**

```ts
import { zlib, BusinessError } from '@kit.BasicServicesKit';

async function demo() {
  let str = 'hello world!';
  let arrayBufferIn = new ArrayBuffer(str.length);
  let byteArray = new Uint8Array(arrayBufferIn);
  for (let i = 0, j = str.length; i < j; i++) {
    byteArray[i] = str.charCodeAt(i)
  }
  let arrayBufferOut = new ArrayBuffer(100);
  let zStream: zlib.ZStream = {
    nextIn: arrayBufferIn,
    availableIn: 1,
    nextOut: arrayBufferOut,
    availableOut: 1
  };
  let zip = zlib.createZipSync();
  await zip.deflateInit(zStream, zlib.CompressLevel.COMPRESS_LEVEL_BEST_SPEED).then((data) => {
    console.info('deflateInit success')
  }).catch((errData: BusinessError) => {
    console.error(`errData is errCode:${errData.code}  message:${errData.message}`)
  })
  await zip.deflate({ availableOut: 8 }, zlib.CompressFlushMode.FINISH).then((data) => {
    console.info('deflate success')
  }).catch((errData: BusinessError) => {
    console.error(`errData is errCode:${errData.code}  message:${errData.message}`)
  })
  await zip.deflateEnd({ nextOut: arrayBufferOut }).then(data => {
    console.info('deflateEnd success')
  }).catch((errData: BusinessError) => {
    console.error(`errData is errCode:${errData.code}  message:${errData.message}`);
  })
  await zip.inflateInit({ nextIn: arrayBufferIn, availableIn: 1, nextOut: arrayBufferOut, availableOut: 1 }
  ).then(data => {
    console.info('inflateInit success');
  }).catch((errData: BusinessError) => {
    console.error(`errData is errCode:${errData.code}  message:${errData.message}`);
  })
  await zip.inflate({ availableIn: 8, availableOut: 8 }, 0).then((data) => {
    console.info('inflate success')
  }).catch((errData: BusinessError) => {
    console.error(`errData is errCode:${errData.code}  message:${errData.message}`);
  })
  await zip.inflateEnd({ nextOut: arrayBufferOut }).then((data) => {
    console.info('inflateEnd success')
  }).catch((errData: BusinessError) => {
    console.error(`errData is errCode:${errData.code}  message:${errData.message}`);
  })
}
```

### deflateInit<sup>12+</sup>

deflateInit(strm: ZStream, level: CompressLevel): Promise&lt;ReturnStatus&gt;

Initializes the internal stream state for compression. This API uses a promise to return the result. The result state is returned upon a success.

**Atomic service API**: This API can be used in atomic services since API version 12.

**System capability**: SystemCapability.BundleManager.Zlib

**Parameters**

| Name| Type         | Mandatory| Description                                         |
| ------ | ------------- | ---- | --------------------------------------------- |
| strm   | ZStream       | Yes  | For details, see [ZStream<sup>12+</sup>](#zstream12).              |
| level  | CompressLevel | Yes  | For details, see [CompressLevel](#compresslevel).|

**Returns**

| Type                                          | Description                       |
| ---------------------------------------------- | --------------------------- |
| Promise&lt;[ReturnStatus](#returnstatus12)&gt; | Promise used to return the result.  |

**Error codes**

For details about the error codes, see [Universal Error Codes](../errorcode-universal.md) and [zlib Error Codes](./errorcode-zlib.md).

| ID| Error Message                                                    |
| -------- | ------------------------------------------------------------ |
| 401      | The parameter check failed. Possible causes: <br>1. Mandatory parameters are left unspecified;<br>2. Incorrect parameter types;<br>3. Parameter verification failed. |
| 17800004 | Compression or decompression stream error, which may be caused by an initialization error in the zlib stream structure or a modified structure. |

**Example**

```ts
import { zlib, BusinessError } from '@kit.BasicServicesKit';

async function demo() {
  let str = 'hello world!';
  let arrayBufferIn = new ArrayBuffer(str.length);
  let byteArray = new Uint8Array(arrayBufferIn);
  for (let i = 0, j = str.length; i < j; i++) {
    byteArray[i] = str.charCodeAt(i)
  }
  let arrayBufferOut = new ArrayBuffer(100);
  let zStream: zlib.ZStream = {
    nextIn: arrayBufferIn,
    availableIn: 1,
    nextOut: arrayBufferOut,
    availableOut: 1
  };
  let zip = zlib.createZipSync();
  await zip.deflateInit(zStream, zlib.CompressLevel.COMPRESS_LEVEL_BEST_SPEED).then((data) => {
    console.info('deflateInit success')
  }).catch((errData: BusinessError) => {
    console.error(`errData is errCode:${errData.code}  message:${errData.message}`)
  })
}
```

### deflateInit2<sup>12+</sup>

deflateInit2(strm: ZStream, level: CompressLevel, method: CompressMethod, windowBits: number, memLevel: MemLevel, strategy: CompressStrategy): Promise&lt;ReturnStatus&gt;

Initializes the internal stream state for compression. This API uses a promise to return the result. The result state is returned upon a success.

**Atomic service API**: This API can be used in atomic services since API version 12.

**System capability**: SystemCapability.BundleManager.Zlib

**Parameters**

| Name    | Type            | Mandatory| Description                                               |
| ---------- | ---------------- | ---- | --------------------------------------------------- |
| strm       | ZStream          | Yes  | For details, see [ZStream<sup>12+</sup>](#zstream12).                    |
| level      | CompressLevel    | Yes  | For details, see [CompressLevel](#compresslevel).      |
| method     | CompressMethod   | Yes  | For details, see [CompressMethod](#compressmethod12).  |
| windowBits | number           | Yes  | Memory window size. The value is restricted in certain range based on the data formats. The options are as follows:<br>Zlib: [1, 15]<br>Gzip: (15, +∞)<br>Raw Deflate: [-15, -1]                      |
| memLevel   | MemLevel         | Yes  | For details, see [MemLevel](#memlevel).                |
| strategy   | CompressStrategy | Yes  | For details, see [CompressStrategy](#compressstrategy).|

**Returns**

| Type                                          | Description                       |
| ---------------------------------------------- | --------------------------- |
| Promise&lt;[ReturnStatus](#returnstatus12)&gt; | Promise used to return the result.  |

**Error codes**

For details about the error codes, see [Universal Error Codes](../errorcode-universal.md) and [zlib Error Codes](./errorcode-zlib.md).

| ID| Error Message                                                    |
| -------- | ------------------------------------------------------------ |
| 401      | The parameter check failed. Possible causes: <br>1. Mandatory parameters are left unspecified;<br>2. Incorrect parameter types;<br>3. Parameter verification failed. |
| 17800004 | Compression or decompression stream error, which may be caused by an initialization error in the zlib stream structure or a modified structure. |

**Example**

```ts
import { zlib, BusinessError } from '@kit.BasicServicesKit';

async function demo() {
  let str = 'hello world!';
  let arrayBufferIn = new ArrayBuffer(str.length);
  let byteArray = new Uint8Array(arrayBufferIn);
  for (let i = 0, j = str.length; i < j; i++) {
    byteArray[i] = str.charCodeAt(i)
  }
  let arrayBufferOut = new ArrayBuffer(100);
  let zStream: zlib.ZStream = {
    nextIn: arrayBufferIn,
    availableIn: 1,
    nextOut: arrayBufferOut,
    availableOut: 1
  };
  let zip = zlib.createZipSync()
  await zip.deflateInit2(zStream, zlib.CompressLevel.COMPRESS_LEVEL_BEST_SPEED, zlib.CompressMethod.DEFLATED, 28,
    zlib.MemLevel.MEM_LEVEL_DEFAULT, zlib.CompressStrategy.COMPRESS_STRATEGY_DEFAULT_STRATEGY).then((data) => {
      console.info('deflateInit2 success');
    }).catch((errData: BusinessError) => {
      console.error(`errData is errCode:${errData.code}  message:${errData.message}`)
    })
}
```

### deflate<sup>12+</sup>

deflate(strm: ZStream, flush: CompressFlushMode): Promise&lt;ReturnStatus&gt;

Compresses data. This API uses a promise to return the result. The result state is returned upon a success.

**Atomic service API**: This API can be used in atomic services since API version 12.

**System capability**: SystemCapability.BundleManager.Zlib

**Parameters**

| Name| Type             | Mandatory| Description                                               |
| ------ | ----------------- | ---- | --------------------------------------------------- |
| strm   | ZStream           | Yes  | For details, see [ZStream<sup>12+</sup>](#zstream12).                    |
| flush  | CompressFlushMode | Yes  | For details, see [CompressFlushMode](#compressflushmode12).|

**Returns**

| Type                                          | Description                       |
| ---------------------------------------------- | --------------------------- |
| Promise&lt;[ReturnStatus](#returnstatus12)&gt; | Promise used to return the result.  |

**Error codes**

For details about the error codes, see [Universal Error Codes](../errorcode-universal.md) and [zlib Error Codes](./errorcode-zlib.md).

| ID| Error Message                                                    |
| -------- | ------------------------------------------------------------ |
| 401      | The parameter check failed. Possible causes: <br>1. Mandatory parameters are left unspecified;<br>2. Incorrect parameter types;<br>3. Parameter verification failed. |
| 17800004 | Compression or decompression stream error, which may be caused by an initialization error in the zlib stream structure or a modified structure. |
| 17800007 | The input buffer is incorrect, and the output buffer is too small to accommodate the compressed or decompressed data. |

**Example**

```ts
import { zlib, BusinessError } from '@kit.BasicServicesKit';

async function demo() {
  let str = 'hello world!';
  let arrayBufferIn = new ArrayBuffer(str.length);
  let byteArray = new Uint8Array(arrayBufferIn);
  for (let i = 0, j = str.length; i < j; i++) {
    byteArray[i] = str.charCodeAt(i)
  }
  let arrayBufferOut = new ArrayBuffer(100);
  let zStream: zlib.ZStream = {
    nextIn: arrayBufferIn,
    availableIn: 1,
    nextOut: arrayBufferOut,
    availableOut: 1
  };
  let zip = zlib.createZipSync();
  await zip.deflateInit(zStream, zlib.CompressLevel.COMPRESS_LEVEL_BEST_SPEED).then((data) => {
    console.info('deflateInit success')
  }).catch((errData: BusinessError) => {
    console.error(`errData is errCode:${errData.code}  message:${errData.message}`)
  })
  await zip.deflate({ availableOut: 8 }, zlib.CompressFlushMode.FINISH).then((data) => {
    console.info('deflate success')
  }).catch((errData: BusinessError) => {
    console.error(`errData is errCode:${errData.code}  message:${errData.message}`)
  })
}
```

### deflateEnd<sup>12+</sup>

deflateEnd(strm: ZStream): Promise&lt;ReturnStatus&gt;

Frees up all dynamically allocated data structures of the compression stream. This API uses a promise to return the result. The result state is returned upon a success.

**Atomic service API**: This API can be used in atomic services since API version 12.

**System capability**: SystemCapability.BundleManager.Zlib

**Parameters**

| Name| Type   | Mandatory| Description                           |
| ------ | ------- | ---- | ------------------------------- |
| strm   | ZStream | Yes  | For details, see [ZStream<sup>12+</sup>](#zstream12).|

**Returns**

| Type                                          | Description                       |
| ---------------------------------------------- | --------------------------- |
| Promise&lt;[ReturnStatus](#returnstatus12)&gt; | Promise used to return the result.  |

**Error codes**

For details about the error codes, see [Universal Error Codes](../errorcode-universal.md) and [zlib Error Codes](./errorcode-zlib.md).

| ID| Error Message                                                    |
| -------- | ------------------------------------------------------------ |
| 401      | The parameter check failed. Possible causes: <br>1. Mandatory parameters are left unspecified;<br>2. Incorrect parameter types;<br>3. Parameter verification failed. |
| 17800004 | Compression or decompression stream error, which may be caused by an initialization error in the zlib stream structure or a modified structure. |

**Example**

```ts
import { zlib, BusinessError } from '@kit.BasicServicesKit';

async function demo() {
  let str = 'hello world!';
  let arrayBufferIn = new ArrayBuffer(str.length);
  let byteArray = new Uint8Array(arrayBufferIn);
  for (let i = 0, j = str.length; i < j; i++) {
    byteArray[i] = str.charCodeAt(i)
  }
  let arrayBufferOut = new ArrayBuffer(100);
  let zStream: zlib.ZStream = {
    nextIn: arrayBufferIn,
    availableIn: 1,
    nextOut: arrayBufferOut,
    availableOut: 1
  };
  let zip = zlib.createZipSync();
  await zip.deflateInit(zStream, zlib.CompressLevel.COMPRESS_LEVEL_BEST_SPEED).then((data) => {
    console.info('deflateInit success')
  }).catch((errData: BusinessError) => {
    console.error(`errData is errCode:${errData.code}  message:${errData.message}`)
  })
  await zip.deflate({ availableOut: 8 }, zlib.CompressFlushMode.FINISH).then((data) => {
    console.info('deflate success')
  }).catch((errData: BusinessError) => {
    console.error(`errData is errCode:${errData.code}  message:${errData.message}`)
  })
  await zip.deflateEnd({ nextOut: arrayBufferOut }).then(data => {
    console.info('deflateEnd success')
  }).catch((errData: BusinessError) => {
    console.error(`errData is errCode:${errData.code}  message:${errData.message}`);
  })
}
```

### deflateBound<sup>12+</sup>

deflateBound(strm: ZStream, sourceLength: number): Promise&lt;number&gt;

Calculates the maximum size of the compressed data. This API uses a promise to return the result. The maximum size of the compressed data is returned upon a success.

**Atomic service API**: This API can be used in atomic services since API version 12.

**System capability**: SystemCapability.BundleManager.Zlib

**Parameters**

| Name   | Type   | Mandatory| Description                           |
| --------- | ------- | ---- | ------------------------------- |
| strm      | ZStream | Yes  | For details, see [ZStream<sup>12+</sup>](#zstream12).|
| sourceLength | number  | Yes  | Length of the source data.                   |

**Returns**

| Type                 | Description                             |
| --------------------- | --------------------------------- |
| Promise&lt;number&gt; | Promise used to return the result.  |

**Error codes**

For details about the error codes, see [Universal Error Codes](../errorcode-universal.md).

| ID| Error Message                                                    |
| -------- | ------------------------------------------------------------ |
| 401      | The parameter check failed. Possible causes: <br>1. Mandatory parameters are left unspecified;<br>2. Incorrect parameter types;<br>3. Parameter verification failed. |

**Example**

```ts
import { zlib, BusinessError } from '@kit.BasicServicesKit';

async function demo() {
  let str = 'hello world!';
  let arrayBufferIn = new ArrayBuffer(str.length);
  let byteArray = new Uint8Array(arrayBufferIn);
  for (let i = 0, j = str.length; i < j; i++) {
    byteArray[i] = str.charCodeAt(i)
  }
  let arrayBufferOut = new ArrayBuffer(100);
  let zStream: zlib.ZStream = {
    nextIn: arrayBufferIn,
    availableIn: 1,
    nextOut: arrayBufferOut,
    availableOut: 1
  };
  let zip = zlib.createZipSync();
  await zip.deflateInit(zStream, zlib.CompressLevel.COMPRESS_LEVEL_BEST_SPEED).then((data) => {
    console.info('deflateInit success')
  }).catch((errData: BusinessError) => {
    console.error(`errData is errCode:${errData.code}  message:${errData.message}`);
  })
  await zip.deflateBound({ nextOut: arrayBufferOut }, 12).then((data) => {
    console.info('deflateBound success')
  }).catch((errData: BusinessError) => {
    console.error(`errData is errCode:${errData.code}  message:${errData.message}`);
  })
}
```

### deflateSetHeader<sup>12+</sup>

deflateSetHeader(strm: ZStream, head: GzHeader): Promise&lt;ReturnStatus&gt;

Provides the header information of the gzip file when **deflateInit2()** requests a gzip stream. This API uses a promise to return the result. The result state is returned upon a success.

**Atomic service API**: This API can be used in atomic services since API version 12.

**System capability**: SystemCapability.BundleManager.Zlib

**Parameters**

| Name| Type                   | Mandatory| Description                            |
| ------ | ----------------------- | ---- | -------------------------------- |
| strm   | ZStream                 | Yes  | For details, see [ZStream<sup>12+</sup>](#zstream12). |
| head   | [GzHeader](#gzheader12) | Yes  | Header information of a gzip file extracted from the compressed data stream.|

**Returns**

| Type                                          | Description                       |
| ---------------------------------------------- | --------------------------- |
| Promise&lt;[ReturnStatus](#returnstatus12)&gt; | Promise used to return the result.  |

**Error codes**

For details about the error codes, see [Universal Error Codes](../errorcode-universal.md) and [zlib Error Codes](./errorcode-zlib.md).

| ID| Error Message                                                    |
| -------- | ------------------------------------------------------------ |
| 401      | The parameter check failed. Possible causes: <br>1. Mandatory parameters are left unspecified;<br>2. Incorrect parameter types;<br>3. Parameter verification failed. |
| 17800004 | Compression or decompression stream error, which may be caused by an initialization error in the zlib stream structure or a modified structure. |

**Example**

```ts
import { zlib, BusinessError } from '@kit.BasicServicesKit';

async function demo() {
  let str = 'hello world!';
  let arrayBufferIn = new ArrayBuffer(str.length);
  let byteArray = new Uint8Array(arrayBufferIn);
  for (let i = 0, j = str.length; i < j; i++) {
    byteArray[i] = str.charCodeAt(i)
  }
  let arrayBufferOut = new ArrayBuffer(100);
  let zStream: zlib.ZStream = {
    nextIn: arrayBufferIn,
    availableIn: 1,
    nextOut: arrayBufferOut,
    availableOut: 1
  };
  let zip = zlib.createZipSync()
  await zip.deflateInit2(zStream, zlib.CompressLevel.COMPRESS_LEVEL_BEST_SPEED, zlib.CompressMethod.DEFLATED, 28,
    zlib.MemLevel.MEM_LEVEL_DEFAULT, zlib.CompressStrategy.COMPRESS_STRATEGY_DEFAULT_STRATEGY).then((data) => {
      console.info('deflateInit2 success');
    }).catch((errData: BusinessError) => {
      console.error(`errData is errCode:${errData.code}  message:${errData.message}`)
    })
  await zip.deflateSetHeader({ nextIn: arrayBufferIn, availableIn: 1, nextOut: arrayBufferOut, availableOut: 1 }, { isText: true, os: 1, time: 1, xflags: 1, extra: arrayBufferIn, extraLen: 12, name: arrayBufferIn, comment: arrayBufferOut, hcrc: true, done: true }).then((data) => {
    console.info('deflateSetHeader success');
  }).catch((errData: BusinessError) => {
    console.error(`errData is errCode:${errData.code}  message:${errData.message}`)
  })
}
```

### deflateCopy<sup>12+</sup>

deflateCopy(source: Zip): Promise&lt;ReturnStatus&gt;

Copies the compression stream. This API uses a promise to return the result. The result state is returned upon a success.

**Atomic service API**: This API can be used in atomic services since API version 12.

**System capability**: SystemCapability.BundleManager.Zlib

**Parameters**

| Name| Type| Mandatory| Description                   |
| ------ | ---- | ---- | ----------------------- |
| source | Zip  | Yes  | For details, see [Zip<sup>12+</sup>](#zip12).|

**Returns**

| Type                                          | Description                       |
| ---------------------------------------------- | --------------------------- |
| Promise&lt;[ReturnStatus](#returnstatus12)&gt; | Promise used to return the result.  |

**Error codes**

For details about the error codes, see [Universal Error Codes](../errorcode-universal.md) and [zlib Error Codes](./errorcode-zlib.md).

| ID| Error Message                                                    |
| -------- | ------------------------------------------------------------ |
| 401      | The parameter check failed. Possible causes: <br>1. Mandatory parameters are left unspecified;<br>2. Incorrect parameter types;<br>3. Parameter verification failed. |
| 17800004 | Compression or decompression stream error, which may be caused by an initialization error in the zlib stream structure or a modified structure. |

**Example**

```ts
import { zlib, BusinessError } from '@kit.BasicServicesKit';

async function demo() {
  let str = 'hello world!';
  let arrayBufferIn = new ArrayBuffer(str.length);
  let byteArray = new Uint8Array(arrayBufferIn);
  for (let i = 0, j = str.length; i < j; i++) {
    byteArray[i] = str.charCodeAt(i)
  }
  let arrayBufferOut = new ArrayBuffer(100);
  let zStream: zlib.ZStream = {
    nextIn: arrayBufferIn,
    availableIn: 1,
    nextOut: arrayBufferOut,
    availableOut: 1
  };
  let zip = zlib.createZipSync();
  await zip.deflateInit(zStream, zlib.CompressLevel.COMPRESS_LEVEL_BEST_SPEED).then((data) => {
    console.info('deflateInit success')
  }).catch((errData: BusinessError) => {
    console.error(`errData is errCode:${errData.code}  message:${errData.message}`);
  })
  await zip.deflateCopy(zip).then((data) => {
    console.info('deflateCopy success')
  }).catch((errData: BusinessError) => {
    console.error(`errData is errCode:${errData.code}  message:${errData.message}`);
  })
}
```

### deflateSetDictionary<sup>12+</sup>

deflateSetDictionary(strm: ZStream, dictionary: ArrayBuffer): Promise&lt;ReturnStatus&gt;

Initializes the compression dictionary from a given sequence of bytes. This API uses a promise to return the result. The result state is returned upon a success.

**Atomic service API**: This API can be used in atomic services since API version 12.

**System capability**: SystemCapability.BundleManager.Zlib

**Parameters**

| Name    | Type       | Mandatory| Description                           |
| ---------- | ----------- | ---- | ------------------------------- |
| strm       | ZStream     | Yes  | For details, see [ZStream<sup>12+</sup>](#zstream12).|
| dictionary | ArrayBuffer | Yes  | Dictionary data.                     |

**Returns**

| Type                                          | Description                       |
| ---------------------------------------------- | --------------------------- |
| Promise&lt;[ReturnStatus](#returnstatus12)&gt; | Promise used to return the result.  |

**Error codes**

For details about the error codes, see [Universal Error Codes](../errorcode-universal.md) and [zlib Error Codes](./errorcode-zlib.md).

| ID| Error Message                                                    |
| -------- | ------------------------------------------------------------ |
| 401      | The parameter check failed. Possible causes: <br>1. Mandatory parameters are left unspecified;<br>2. Incorrect parameter types;<br>3. Parameter verification failed. |
| 17800004 | Compression or decompression stream error, which may be caused by an initialization error in the zlib stream structure or a modified structure. |

**Example**

```ts
import { zlib, BusinessError } from '@kit.BasicServicesKit';

async function demo() {
  let str = 'hello world!';
  let arrayBufferIn = new ArrayBuffer(str.length);
  let byteArray = new Uint8Array(arrayBufferIn);
  for (let i = 0, j = str.length; i < j; i++) {
    byteArray[i] = str.charCodeAt(i)
  }
  let arrayBufferOut = new ArrayBuffer(100);
  let zStream: zlib.ZStream = {
    nextIn: arrayBufferIn,
    availableIn: 1,
    nextOut: arrayBufferOut,
    availableOut: 1
  };
  let zip = zlib.createZipSync();
  await zip.deflateInit(zStream, zlib.CompressLevel.COMPRESS_LEVEL_BEST_SPEED).then((data) => {
    console.info('deflateInit success')
  }).catch((errData: BusinessError) => {
    console.error(`errData is errCode:${errData.code}  message:${errData.message}`);
  })
  await zip.deflateSetDictionary({ nextOut: arrayBufferOut }, arrayBufferOut).then((data) => {
    console.info('deflateSetDictionary success')
  }).catch((errData: BusinessError) => {
    console.error(`errData is errCode:${errData.code}  message:${errData.message}`);
  })
}
```

### deflateGetDictionary<sup>12+</sup>

deflateGetDictionary(strm: ZStream, dictionary: ArrayBuffer): Promise&lt;DictionaryOutputInfo&gt;

Obtains the content and length of the decompression dictionary used in the current decompression stream. This API uses a promise to return the result. The result state and length of the dictionary are returned upon a success.

**Atomic service API**: This API can be used in atomic services since API version 12.

**System capability**: SystemCapability.BundleManager.Zlib

**Parameters**

| Name    | Type       | Mandatory| Description                           |
| ---------- | ----------- | ---- | ------------------------------- |
| strm       | ZStream     | Yes  | For details, see [ZStream<sup>12+</sup>](#zstream12).|
| dictionary | ArrayBuffer | Yes  | Receives the actual contents of the decompression dictionary.     |

**Returns**

| Type                                                        | Description                                   |
| ------------------------------------------------------------ | --------------------------------------- |
| Promise&lt;[DictionaryOutputInfo](#dictionaryoutputinfo12)&gt; | Promise used to return the result.  |

**Error codes**

For details about the error codes, see [Universal Error Codes](../errorcode-universal.md) and [zlib Error Codes](./errorcode-zlib.md).

| ID| Error Message                                                    |
| -------- | ------------------------------------------------------------ |
| 401      | The parameter check failed. Possible causes: <br>1. Mandatory parameters are left unspecified;<br>2. Incorrect parameter types;<br>3. Parameter verification failed. |
| 17800004 | Compression or decompression stream error, which may be caused by an initialization error in the zlib stream structure or a modified structure. |

**Example**

```ts
import { zlib, BusinessError } from '@kit.BasicServicesKit';

async function demo() {
  let str = 'hello world!';
  let arrayBufferIn = new ArrayBuffer(str.length);
  let byteArray = new Uint8Array(arrayBufferIn);
  for (let i = 0, j = str.length; i < j; i++) {
    byteArray[i] = str.charCodeAt(i)
  }
  let arrayBufferOut = new ArrayBuffer(100);
  let zStream: zlib.ZStream = {
    nextIn: arrayBufferIn,
    availableIn: 1,
    nextOut: arrayBufferOut,
    availableOut: 1
  };
  let zip = zlib.createZipSync();
  await zip.deflateInit(zStream, zlib.CompressLevel.COMPRESS_LEVEL_BEST_SPEED).then((data) => {
    console.info('deflateInit success')
  }).catch((errData: BusinessError) => {
    console.error(`errData is errCode:${errData.code}  message:${errData.message}`);
  })
  await zip.deflateSetDictionary({ nextOut: arrayBufferOut }, arrayBufferOut).then((data) => {
    console.info('deflateSetDictionary success')
  }).catch((errData: BusinessError) => {
    console.error(`errData is errCode:${errData.code}  message:${errData.message}`);
  })
  await zip.deflateGetDictionary({ nextOut: arrayBufferOut }, arrayBufferOut).then((data) => {
    console.info('deflateGetDictionary success')
  }).catch((errData: BusinessError) => {
    console.error(`errData is errCode:${errData.code}  message:${errData.message}`);
  })
}
```

### deflateTune<sup>12+</sup>

deflateTune(strm: ZStream, goodLength: number, maxLazy: number, niceLength: number, maxChain: number): Promise&lt;ReturnStatus&gt;

Fine-tunes the internal compressed parameters of **deflate**. This API uses a promise to return the result. The result state is returned upon a success.

**Atomic service API**: This API can be used in atomic services since API version 12.

**System capability**: SystemCapability.BundleManager.Zlib

**Parameters**

| Name    | Type   | Mandatory| Description                           |
| ---------- | ------- | ---- | ------------------------------- |
| strm       | ZStream | Yes  | For details, see [ZStream<sup>12+</sup>](#zstream12).|
| goodLength | number  | Yes  | Matched length threshold.               |
| maxLazy    | number  | Yes  | Delay matching policy used when the compression algorithm builds a Huffman tree. The value is an integer ranging from 0 to 4. **1**–**4**: A larger value indicates a lazier algorithm, which performs a slower matching process but generates a better compression result. **0**: Lazy matching is disabled. The algorithm builds a Huffman tree as soon as possible. The compression speed is fast, but the compression ratio is low. |
| niceLength | number  | Yes  | Appropriate delay length threshold.             |
| maxChain   | number  | Yes  | Maximum chain length.                   |

**Returns**

| Type                                          | Description                       |
| ---------------------------------------------- | --------------------------- |
| Promise&lt;[ReturnStatus](#returnstatus12)&gt; | Promise used to return the result.  |

**Error codes**

For details about the error codes, see [Universal Error Codes](../errorcode-universal.md) and [zlib Error Codes](./errorcode-zlib.md).

| ID| Error Message                                                    |
| -------- | ------------------------------------------------------------ |
| 401      | The parameter check failed. Possible causes: <br>1. Mandatory parameters are left unspecified;<br>2. Incorrect parameter types;<br>3. Parameter verification failed. |
| 17800004 | Compression or decompression stream error, which may be caused by an initialization error in the zlib stream structure or a modified structure. |

**Example**

```ts
import { zlib, BusinessError } from '@kit.BasicServicesKit';

async function demo() {
  let str = 'hello world!';
  let arrayBufferIn = new ArrayBuffer(str.length);
  let byteArray = new Uint8Array(arrayBufferIn);
  for (let i = 0, j = str.length; i < j; i++) {
    byteArray[i] = str.charCodeAt(i)
  }
  let arrayBufferOut = new ArrayBuffer(100);
  let zStream: zlib.ZStream = {
    nextIn: arrayBufferIn,
    availableIn: 1,
    nextOut: arrayBufferOut,
    availableOut: 1
  };
  let zip = zlib.createZipSync();
  await zip.deflateInit(zStream, zlib.CompressLevel.COMPRESS_LEVEL_BEST_SPEED).then((data) => {
    console.info('deflateInit success')
  }).catch((errData: BusinessError) => {
    console.error(`errData is errCode:${errData.code}  message:${errData.message}`);
  })
  await zip.deflateTune({ nextOut: arrayBufferOut }, 2, 2, 2, 2).then((data) => {
    console.info('deflateTune success:')
  }).catch((errData: BusinessError) => {
    console.error(`errData is errCode:${errData.code}  message:${errData.message}`);
  })
}
```

### deflateReset<sup>12+</sup>

deflateReset(strm: ZStream): Promise&lt;ReturnStatus&gt;

Equivalent to call the **deflateEnd** API and then **deflateInit** API. However, this API does not release or reallocate the internal decompression state. This API uses a promise to return the result. The result state is returned upon a success.

**Atomic service API**: This API can be used in atomic services since API version 12.

**System capability**: SystemCapability.BundleManager.Zlib

**Parameters**

| Name| Type   | Mandatory| Description                           |
| ------ | ------- | ---- | ------------------------------- |
| strm   | ZStream | Yes  | For details, see [ZStream<sup>12+</sup>](#zstream12).|

**Returns**

| Type                                          | Description                       |
| ---------------------------------------------- | --------------------------- |
| Promise&lt;[ReturnStatus](#returnstatus12)&gt; | Promise used to return the result.  |

**Error codes**

For details about the error codes, see [Universal Error Codes](../errorcode-universal.md) and [zlib Error Codes](./errorcode-zlib.md).

| ID| Error Message                                                    |
| -------- | ------------------------------------------------------------ |
| 401      | The parameter check failed. Possible causes: <br>1. Mandatory parameters are left unspecified;<br>2. Incorrect parameter types;<br>3. Parameter verification failed. |
| 17800004 | Compression or decompression stream error, which may be caused by an initialization error in the zlib stream structure or a modified structure. |

**Example**

```ts
import { zlib, BusinessError } from '@kit.BasicServicesKit';

async function demo() {
  let str = 'hello world!';
  let arrayBufferIn = new ArrayBuffer(str.length);
  let byteArray = new Uint8Array(arrayBufferIn);
  for (let i = 0, j = str.length; i < j; i++) {
    byteArray[i] = str.charCodeAt(i)
  }
  let arrayBufferOut = new ArrayBuffer(100);
  let zStream: zlib.ZStream = {
    nextIn: arrayBufferIn,
    availableIn: 1,
    nextOut: arrayBufferOut,
    availableOut: 1
  };
  let zip = zlib.createZipSync();
  await zip.deflateInit(zStream, zlib.CompressLevel.COMPRESS_LEVEL_BEST_SPEED).then((data) => {
    console.info('deflateInit success')
  }).catch((errData: BusinessError) => {
    console.error(`errData is errCode:${errData.code}  message:${errData.message}`);
  })
  await zip.deflateReset({ nextOut: arrayBufferOut }).then((data) => {
    console.info('deflateReset success')
  }).catch((errData: BusinessError) => {
    console.error(`errData is errCode:${errData.code}  message:${errData.message}`);
  })
}
```

### deflateResetKeep<sup>12+</sup>

deflateResetKeep(strm: ZStream): Promise&lt;ReturnStatus&gt;

Resets the initialized deflate compression stream, but retains the compression parameters and dictionaries set by it. This API uses a promise to return the result. The result state is returned upon a success.

**Atomic service API**: This API can be used in atomic services since API version 12.

**System capability**: SystemCapability.BundleManager.Zlib

**Parameters**

| Name| Type   | Mandatory| Description                           |
| ------ | ------- | ---- | ------------------------------- |
| strm   | ZStream | Yes  | For details, see [ZStream<sup>12+</sup>](#zstream12).|

**Returns**

| Type                                          | Description                       |
| ---------------------------------------------- | --------------------------- |
| Promise&lt;[ReturnStatus](#returnstatus12)&gt; | Promise used to return the result.  |

**Error codes**

For details about the error codes, see [Universal Error Codes](../errorcode-universal.md) and [zlib Error Codes](./errorcode-zlib.md).

| ID| Error Message                                                    |
| -------- | ------------------------------------------------------------ |
| 401      | The parameter check failed. Possible causes: <br>1. Mandatory parameters are left unspecified;<br>2. Incorrect parameter types;<br>3. Parameter verification failed. |
| 17800004 | Compression or decompression stream error, which may be caused by an initialization error in the zlib stream structure or a modified structure. |

**Example**

```ts
import { zlib, BusinessError } from '@kit.BasicServicesKit';

async function demo() {
  let str = 'hello world!';
  let arrayBufferIn = new ArrayBuffer(str.length);
  let byteArray = new Uint8Array(arrayBufferIn);
  for (let i = 0, j = str.length; i < j; i++) {
    byteArray[i] = str.charCodeAt(i)
  }
  let arrayBufferOut = new ArrayBuffer(100);
  let zStream: zlib.ZStream = {
    nextIn: arrayBufferIn,
    availableIn: 1,
    nextOut: arrayBufferOut,
    availableOut: 1
  };
  let zip = zlib.createZipSync();
  await zip.deflateInit(zStream, zlib.CompressLevel.COMPRESS_LEVEL_BEST_SPEED).then((data) => {
    console.info('deflateInit success')
  }).catch((errData: BusinessError) => {
    console.error(`errData is errCode:${errData.code}  message:${errData.message}`);
  })
  await zip.deflateResetKeep({ nextOut: arrayBufferOut }).then((data) => {
    console.info('deflateResetKeep success')
  }).catch((errData: BusinessError) => {
    console.error(`errData is errCode:${errData.code}  message:${errData.message}`);
  })
}
```

### deflatePending<sup>12+</sup>

deflatePending(strm: ZStream): Promise&lt;DeflatePendingOutputInfo&gt;

Returns the number of bytes and bits that has been generated but has not yet been output. This API uses a promise to return the result. The result state and the umber of output bytes and bits are returned upon a success.

**Atomic service API**: This API can be used in atomic services since API version 12.

**System capability**: SystemCapability.BundleManager.Zlib

**Parameters**

| Name| Type   | Mandatory| Description                           |
| ------ | ------- | ---- | ------------------------------- |
| strm   | ZStream | Yes  | For details, see [ZStream<sup>12+</sup>](#zstream12).|

**Returns**

| Type                                                        | Description                                             |
| ------------------------------------------------------------ | ------------------------------------------------- |
| Promise&lt;[DeflatePendingOutputInfo](#deflatependingoutputinfo12)&gt; | Promise used to return the result.  |

**Error codes**

For details about the error codes, see [Universal Error Codes](../errorcode-universal.md) and [zlib Error Codes](./errorcode-zlib.md).

| ID| Error Message                                                    |
| -------- | ------------------------------------------------------------ |
| 401      | The parameter check failed. Possible causes: <br>1. Mandatory parameters are left unspecified;<br>2. Incorrect parameter types;<br>3. Parameter verification failed. |
| 17800004 | Compression or decompression stream error, which may be caused by an initialization error in the zlib stream structure or a modified structure. |

**Example**

```ts
import { zlib, BusinessError } from '@kit.BasicServicesKit';

async function demo() {
  let str = 'hello world!';
  let arrayBufferIn = new ArrayBuffer(str.length);
  let byteArray = new Uint8Array(arrayBufferIn);
  for (let i = 0, j = str.length; i < j; i++) {
    byteArray[i] = str.charCodeAt(i)
  }
  let arrayBufferOut = new ArrayBuffer(100);
  let zStream: zlib.ZStream = {
    nextIn: arrayBufferIn,
    availableIn: 1,
    nextOut: arrayBufferOut,
    availableOut: 1
  };
  let zip = zlib.createZipSync();
  await zip.deflateInit(zStream, zlib.CompressLevel.COMPRESS_LEVEL_BEST_SPEED).then((data) => {
    console.info('deflateInit success')
  }).catch((errData: BusinessError) => {
    console.error(`errData is errCode:${errData.code}  message:${errData.message}`);
  })
  await zip.deflatePending({ nextOut: arrayBufferOut }).then((data) => {
    console.info('deflatePending success')
  }).catch((errData: BusinessError) => {
    console.error(`errData is errCode:${errData.code}  message:${errData.message}`);
  })
}
```

### deflateParams<sup>12+</sup>

deflateParams(strm: ZStream, level: CompressLevel, strategy: CompressStrategy): Promise&lt;ReturnStatus&gt;

Dynamically updates the compression level and compression strategy. This API uses a promise to return the result. The result state is returned upon a success.

**Atomic service API**: This API can be used in atomic services since API version 12.

**System capability**: SystemCapability.BundleManager.Zlib

**Parameters**

| Name  | Type            | Mandatory| Description                                               |
| -------- | ---------------- | ---- | --------------------------------------------------- |
| strm     | ZStream          | Yes  | For details, see [ZStream<sup>12+</sup>](#zstream12).                    |
| level    | CompressLevel    | Yes  | For details, see [CompressLevel](#compresslevel).      |
| strategy | CompressStrategy | Yes  | For details, see [CompressStrategy](#compressstrategy).|

**Returns**

| Type                                          | Description                       |
| ---------------------------------------------- | --------------------------- |
| Promise&lt;[ReturnStatus](#returnstatus12)&gt; | Promise used to return the result.  |

**Error codes**

For details about the error codes, see [Universal Error Codes](../errorcode-universal.md) and [zlib Error Codes](./errorcode-zlib.md).

| ID| Error Message                                                    |
| -------- | ------------------------------------------------------------ |
| 401      | The parameter check failed. Possible causes: <br>1. Mandatory parameters are left unspecified;<br>2. Incorrect parameter types;<br>3. Parameter verification failed. |
| 17800004 | Compression or decompression stream error, which may be caused by an initialization error in the zlib stream structure or a modified structure. |

**Example**

```ts
import { zlib, BusinessError } from '@kit.BasicServicesKit';

async function demo() {
  let str = 'hello world!';
  let arrayBufferIn = new ArrayBuffer(str.length);
  let byteArray = new Uint8Array(arrayBufferIn);
  for (let i = 0, j = str.length; i < j; i++) {
    byteArray[i] = str.charCodeAt(i)
  }
  let arrayBufferOut = new ArrayBuffer(100);
  let zStream: zlib.ZStream = {
    nextIn: arrayBufferIn,
    availableIn: 1,
    nextOut: arrayBufferOut,
    availableOut: 1
  };
  let zip = zlib.createZipSync()
  await zip.deflateInit(zStream, zlib.CompressLevel.COMPRESS_LEVEL_BEST_SPEED).then((data) => {
    console.info('deflateInit success')
  }).catch((errData: BusinessError) => {
    console.error(`errData is errCode:${errData.code}  message:${errData.message}`);
  })
  await zip.deflateParams(zStream, zlib.CompressLevel.COMPRESS_LEVEL_DEFAULT_COMPRESSION, zlib.CompressStrategy.COMPRESS_STRATEGY_DEFAULT_STRATEGY).then((data) => {
    console.info('deflateParams success')
  }).catch((errData: BusinessError) => {
    console.error(`errData is errCode:${errData.code}  message:${errData.message}`);
  })
}
```

### deflatePrime<sup>12+</sup>

deflatePrime(strm: ZStream, bits: number, value: number): Promise&lt;ReturnStatus&gt;

Inserts bits and values into the compression stream. This API uses a promise to return the result. The result state is returned upon a success.

**Atomic service API**: This API can be used in atomic services since API version 12.

**System capability**: SystemCapability.BundleManager.Zlib

**Parameters**

| Name| Type   | Mandatory| Description                           |
| ------ | ------- | ---- | ------------------------------- |
| strm   | ZStream | Yes  | For details, see [ZStream<sup>12+</sup>](#zstream12).|
| bits   | number  | Yes  | Number of bits to be inserted. The value ranges from 0 to 16. |
| value  | number  | Yes  | Bit value corresponding to the number of bits.           |

**Returns**

| Type                                          | Description                       |
| ---------------------------------------------- | --------------------------- |
| Promise&lt;[ReturnStatus](#returnstatus12)&gt; | Promise used to return the result.  |

**Error codes**

For details about the error codes, see [Universal Error Codes](../errorcode-universal.md) and [zlib Error Codes](./errorcode-zlib.md).

| ID| Error Message                                                    |
| -------- | ------------------------------------------------------------ |
| 401      | The parameter check failed. Possible causes: <br>1. Mandatory parameters are left unspecified;<br>2. Incorrect parameter types;<br>3. Parameter verification failed. |
| 17800004 | Compression or decompression stream error, which may be caused by an initialization error in the zlib stream structure or a modified structure. |

**Example**

```ts
import { zlib, BusinessError } from '@kit.BasicServicesKit';

async function demo() {
  let str = 'hello world!';
  let arrayBufferIn = new ArrayBuffer(str.length);
  let byteArray = new Uint8Array(arrayBufferIn);
  for (let i = 0, j = str.length; i < j; i++) {
    byteArray[i] = str.charCodeAt(i)
  }
  let arrayBufferOut = new ArrayBuffer(100);
  let zStream: zlib.ZStream = {
    nextIn: arrayBufferIn,
    availableIn: 1,
    nextOut: arrayBufferOut,
    availableOut: 1
  };
  let zip = zlib.createZipSync();
  await zip.deflateInit(zStream, zlib.CompressLevel.COMPRESS_LEVEL_BEST_SPEED).then((data) => {
    console.info('deflateInit success')
  }).catch((errData: BusinessError) => {
    console.error(`errData is errCode:${errData.code}  message:${errData.message}`);
  })
  await zip.deflatePrime({ nextOut: arrayBufferOut }, 5, 2).then((data) => {
    console.info('deflatePrime success')
  }).catch((errData: BusinessError) => {
    console.error(`errData is errCode:${errData.code}  message:${errData.message}`);
  })
}
```

## Options

**System capability**: SystemCapability.BundleManager.Zlib

| Name    | Type            | Read-Only| Optional| Description                                                      |
| -------- | ---------------- | ---- | ---------------------------------------------------------- | ---- |
| level    | [CompressLevel](#compresslevel)     | No  | Yes | For details, see [CompressLevel](#compresslevel).<br>**Atomic service API**: This API can be used in atomic services since API version 11.      |
| memLevel | [MemLevel](#memlevel)         | No  | Yes | For details, see [MemLevel](#memlevel).<br>**Atomic service API**: This API can be used in atomic services since API version 11.                       |
| strategy | [CompressStrategy](#compressstrategy) | No  | Yes | For details, see [CompressStrategy](#compressstrategy).<br>**Atomic service API**: This API can be used in atomic services since API version 11.       |
| parallel<sup>18+</sup> | [ParallelStrategy](#parallelstrategy18) | No  | Yes | For details, see [ParallelStrategy](#parallelstrategy18).<br>**Atomic service API**: This API can be used in atomic services since API version 18.       |

## CompressLevel

**Atomic service API**: This API can be used in atomic services since API version 11.

**System capability**: SystemCapability.BundleManager.Zlib

| Name                              | Value  | Description             |
| ---------------------------------- | ---- | ----------------- |
| COMPRESS_LEVEL_NO_COMPRESSION      | 0    | Compress level 0 that indicates uncompressed.|
| COMPRESS_LEVEL_BEST_SPEED          | 1    | Compression level 1 that gives the best speed. |
| COMPRESS_LEVEL_BEST_COMPRESSION    | 9    | Compression level 9 that gives the best compression.     |
| COMPRESS_LEVEL_DEFAULT_COMPRESSION | -1   | Default compression level.     |

## MemLevel

**Atomic service API**: This API can be used in atomic services since API version 11.

**System capability**: SystemCapability.BundleManager.Zlib

| Name             | Value  | Description                            |
| ----------------- | ---- | -------------------------------- |
| MEM_LEVEL_MIN     | 1    | Minimum memory used by the **zlib** API during compression.|
| MEM_LEVEL_MAX     | 9    | Maximum memory used by the **zlib** API during compression.|
| MEM_LEVEL_DEFAULT | 8    | Default memory used by the **zlib** API during compression.|

## CompressStrategy

**Atomic service API**: This API can be used in atomic services since API version 11.

**System capability**: SystemCapability.BundleManager.Zlib

| Name                              | Value  | Description                    |
| ---------------------------------- | ---- | ------------------------ |
| COMPRESS_STRATEGY_DEFAULT_STRATEGY | 0    | Default compression strategy.            |
| COMPRESS_STRATEGY_FILTERED         | 1    | Filtered compression strategy.|
| COMPRESS_STRATEGY_HUFFMAN_ONLY     | 2    | Huffman coding compression strategy.  |
| COMPRESS_STRATEGY_RLE              | 3    | RLE compression strategy.        |
| COMPRESS_STRATEGY_FIXED            | 4    | Fixed compression strategy.          |

## ParallelStrategy<sup>18+</sup>

**Atomic service API**: This API can be used in atomic services since API version 18.

**System capability**: SystemCapability.BundleManager.Zlib

| Name                                    | Value  | Description                     |
| ---------------------------------------- | ---- | ------------------------ |
| PARALLEL_STRATEGY_SEQUENTIAL             | 0    | Serial compression/decompression policy (default).|
| PARALLEL_STRATEGY_PARALLEL_DECOMPRESSION | 1    | Parallel decompression policy.           |

## ErrorCode<sup>(deprecated)<sup>

> **NOTE**
>
> The initial APIs of this module are supported since API version 7.
>
> This module is deprecated since API version 9.

**System capability**: SystemCapability.BundleManager.Zlib

| Name            | Value  | Description        |
| ---------------- | ---- | ------------ |
| ERROR_CODE_OK    | 0    | The API is successfully called.|
| ERROR_CODE_ERRNO | -1   | Failed to call the API.|

## CompressFlushMode<sup>12+</sup>

**Atomic service API**: This API can be used in atomic services since API version 12.

**System capability**: SystemCapability.BundleManager.Zlib

| Name         | Value  | Description                                        |
| ------------- | ---- | -------------------------------------------- |
| NO_FLUSH      | 0    | Default value, indicating a normal operation.                      |
| PARTIAL_FLUSH | 1    | Generates some refresh points in the stream.                      |
| SYNC_FLUSH    | 2    | Forcibly outputs all compressed data while maintaining the compression stream state.|
| FULL_FLUSH    | 3    | Resets the compression state.                              |
| FINISH        | 4    | Ends the compression or decompression process.                      |
| BLOCK         | 5    | Allows more precise control.                          |
| TREES         | 6    | Implements special purposes.                      |

## CompressMethod<sup>12+</sup>

**Atomic service API**: This API can be used in atomic services since API version 12.

**System capability**: SystemCapability.BundleManager.Zlib

| Name    | Value  | Description      |
| -------- | ---- | ---------- |
| DEFLATED | 8    | Compression method.|

## ReturnStatus<sup>12+</sup>

**Atomic service API**: This API can be used in atomic services since API version 12.

**System capability**: SystemCapability.BundleManager.Zlib

| Name      | Value  | Description                                          |
| ---------- | ---- | ---------------------------------------------- |
| OK         | 0    | The API is successfully called.                                |
| STREAM_END | 1    | The API is successfully called, indicating that the entire data has been processed.          |
| NEED_DICT  | 2    | The API is successfully called, indicating that a preset dictionary is required to continue decompression.|

## ZStream<sup>12+</sup>

**Atomic service API**: This API can be used in atomic services since API version 12.

**System capability**: SystemCapability.BundleManager.Zlib

| Name        | Type       | Read-Only| Optional| Description                                                        |
| ------------ | ----------- | ---- | ---- | ------------------------------------------------------------ |
| nextIn       | ArrayBuffer | No  | Yes  | Input bytes to be compressed.                                          |
| availableIn  | number      | No  | Yes  | Number of bytes available for **nextIn**.                                          |
| totalIn      | number      | No  | Yes  | Total number of input bytes read so far.                                |
| nextOut      | ArrayBuffer | No  | Yes  | Output bytes after compression.                                            |
| availableOut | number      | No  | Yes  | Number of remaining bytes available for **nextOut**.                                     |
| totalOut     | number      | No  | Yes  | Total number of output bytes.                                      |
| dataType     | number      | No  | Yes  | Binary or text of **deflate**, or decoding state of **inflate**.|
| adler        | number      | No  | Yes  | Adler-32 or CRC-32 value of uncompressed data.                              |

## ZipOutputInfo<sup>12+</sup>

**Atomic service API**: This API can be used in atomic services since API version 12.

**System capability**: SystemCapability.BundleManager.Zlib

| Name   | Type        | Read-Only| Optional| Description                                         |
| ------- | ------------ | ---- | ---- | --------------------------------------------- |
| status  | ReturnStatus | No  | No  | For details, see [ReturnStatus](#returnstatus12).|
| destLen | number       | No  | No  | Total length of the destination buffer.                         |

## DictionaryOutputInfo<sup>12+</sup>

**Atomic service API**: This API can be used in atomic services since API version 12.

**System capability**: SystemCapability.BundleManager.Zlib

| Name            | Type        | Read-Only| Optional| Description                                         |
| ---------------- | ------------ | ---- | ---- | --------------------------------------------- |
| status           | ReturnStatus | No  | No  | For details, see [ReturnStatus](#returnstatus12).|
| dictionaryLength | number       | No  | No  | Length of a dictionary.                                 |

## DecompressionOutputInfo<sup>12+</sup>

**Atomic service API**: This API can be used in atomic services since API version 12.

**System capability**: SystemCapability.BundleManager.Zlib

| Name        | Type        | Read-Only| Optional| Description                                         |
| ------------ | ------------ | ---- | ---- | --------------------------------------------- |
| status       | ReturnStatus | No  | No  | For details, see [ReturnStatus](#returnstatus12).|
| destLength   | number       | No  | No  | Length of the destination buffer.                           |
| sourceLength | number       | No  | No  | Length of the source buffer.                             |

## DeflatePendingOutputInfo<sup>12+</sup>

**Atomic service API**: This API can be used in atomic services since API version 12.

**System capability**: SystemCapability.BundleManager.Zlib

| Name   | Type        | Read-Only| Optional| Description                                         |
| ------- | ------------ | ---- | ---- | --------------------------------------------- |
| status  | ReturnStatus | No  | No  | For details, see [ReturnStatus](#returnstatus12).|
| pending | number       | No  | No  | Number of output bytes that have been generated.                         |
| bits    | number       | No  | No  | Number of output bits that have been generated.                           |

## GzHeader<sup>12+</sup>

**Atomic service API**: This API can be used in atomic services since API version 12.

**System capability**: SystemCapability.BundleManager.Zlib

| Name    | Type       | Read-Only| Optional| Description                                |
| -------- | ----------- | ---- | ---- | ------------------------------------ |
| isText   | boolean     | No  | Yes  | Returns **True** if the compressed data is considered text.|
| os       | number      | No  | Yes  | Operating system.                          |
| time     | number      | No  | Yes  | Modification time.                          |
| xflags   | number      | No  | Yes  | Extra flag.                          |
| extra    | ArrayBuffer | No  | Yes  | Extra field.                          |
| extraLen | number      | No  | Yes  | Length of the extra field.                    |
| name     | ArrayBuffer | No  | Yes  | File name.                            |
| comment  | ArrayBuffer | No  | Yes  | Comment.                              |
| hcrc     | boolean     | No  | Yes  | Returns **True** if the **crc** header exists.         |
| done     | boolean     | No  | Yes  | Returns **True** after reading the gzip file header.              |

## zlib.createGZip<sup>12+</sup>

createGZip(): Promise&lt;GZip&gt;

Creates a gzip object. This API uses a promise to return the result. The gzip object instance is returned upon a success.

**Atomic service API**: This API can be used in atomic services since API version 12.

**System capability**: SystemCapability.BundleManager.Zlib

**Returns**

| Type                          | Description                           |
| ------------------------------ | ------------------------------- |
| Promise&lt;[GZip](#gzip12)&gt; | Promise used to return the result.  |

**Example**

```ts
import { zlib } from '@kit.BasicServicesKit';

zlib.createGZip().then((data) => {
  console.info('createGZip success');
})
```

## zlib.createGZipSync<sup>12+</sup>

createGZipSync():  GZip

Creates a gzip object. The gzip object instance is returned upon a success.

**Atomic service API**: This API can be used in atomic services since API version 12.

**System capability**: SystemCapability.BundleManager.Zlib

**Returns**

| Type           | Description          |
| --------------- | -------------- |
| [GZip](#gzip12) | gzip object instance.|

**Example**

```ts
import { zlib } from '@kit.BasicServicesKit';

let gzip = zlib.createGZipSync();
```

## GZip<sup>12+</sup>

Describes gzip-related APIs.

### gzdopen<sup>12+</sup>

gzdopen(fd: number, mode: string): Promise&lt;void&gt;

Associates gzip file with the file descriptor (fd) and opens the file for reading and decompressing, or compressing and writing. This API uses a promise to return the result.

**Atomic service API**: This API can be used in atomic services since API version 12.

**System capability**: SystemCapability.BundleManager.Zlib

**Parameters**

| Name| Type  | Mandatory| Description                                                        |
| ------ | ------ | ---- | ------------------------------------------------------------ |
| fd     | number | Yes  | File descriptor. Generally, the value is obtained by calling the **open** method or other methods.|
| mode   | string | Yes  | Specifies the access mode.                                          |

**Returns**

| Type               | Description                   |
| ------------------- | ----------------------- |
| Promise&lt;void&gt; | Promise that returns no value.|

**Error codes**

For details about the error codes, see [Universal Error Codes](../errorcode-universal.md) and [zlib Error Codes](./errorcode-zlib.md).

| ID| Error Message                                                    |
| -------- | ------------------------------------------------------------ |
| 401      | The parameter check failed. Possible causes: <br>1. Mandatory parameters are left unspecified;<br>2. Incorrect parameter types;<br>3. Parameter verification failed. |
| 17800002 | No such file or access mode error.                           |

**Example**

```ts
import { zlib } from '@kit.BasicServicesKit';
import { fileIo as fs } from '@kit.CoreFileKit';

async function gzdopenDemo(pathDir: string) {
  fs.mkdirSync(pathDir + "/gzdopen");
  let path = pathDir + "/gzdopen/test.gz";
  let file = fs.openSync(path, fs.OpenMode.READ_WRITE | fs.OpenMode.CREATE);
  let gzip = zlib.createGZipSync();
  await gzip.gzdopen(file.fd, "wb");
  await gzip.gzclose();
}

@Entry
@Component
struct Index {
  build() {
    Row() {
      Column() {
        Button('test gzip interface')
          .type(ButtonType.Capsule)
          .height(60)
          .width(200)
          .onClick(() => {
            let pathDir = this.getUIContext()?.getHostContext()?.cacheDir;
            if (typeof pathDir === 'string') {
              gzdopenDemo(pathDir);
            }
          })
      }
      .width('100%')
    }
    .height('100%')
  }
}
```

### gzbuffer<sup>12+</sup>

gzbuffer(size: number):Promise&lt;number&gt;

Sets the internal buffer size for the current library function. This API uses a promise to return the result.

**Atomic service API**: This API can be used in atomic services since API version 12.

**System capability**: SystemCapability.BundleManager.Zlib

**Parameters**

| Name| Type  | Mandatory| Description                      |
| ------ | ------ | ---- | -------------------------- |
| size   | number | Yes  | Size of the internal buffer to be set.|

**Returns**

| Type                 | Description                        |
| --------------------- | ---------------------------- |
| Promise&lt;number&gt; | Promise used to return the result. If the operation is successful, **0** is returned.|

**Error codes**

For details about the error codes, see [Universal Error Codes](../errorcode-universal.md).

| ID| Error Message                                                    |
| -------- | ------------------------------------------------------------ |
| 401      | The parameter check failed. Possible causes: <br>1. Mandatory parameters are left unspecified;<br>2. Incorrect parameter types;<br>3. Parameter verification failed. |
| 17800009   | Internal structure error. |

**Example**

```ts
import { fileIo as fs } from '@kit.CoreFileKit';
import { zlib } from '@kit.BasicServicesKit';

async function gzbufferDemo(pathDir: string) {
  fs.mkdirSync(pathDir + "/gzbuffer");
  let path = pathDir + "/gzbuffer/test.gz";
  let gzip = zlib.createGZipSync();
  await gzip.gzopen(path, "wb");
  await gzip.gzclose();
  await gzip.gzopen(path, "rb");
  let result = await gzip.gzbuffer(648);
  await gzip.gzclose();
}

@Entry
@Component
struct Index {
  build() {
    Row() {
      Column() {
        Button('test gzip interface')
          .type(ButtonType.Capsule)
          .height(60)
          .width(200)
          .onClick(() => {
            let pathDir = this.getUIContext()?.getHostContext()?.cacheDir;
            if (typeof pathDir === 'string') {
              gzbufferDemo(pathDir);
            }
          })
      }
      .width('100%')
    }
    .height('100%')
  }
}
```

### gzopen<sup>12+</sup>

gzopen(path: string, mode: string): Promise&lt;void&gt;

Opens the .gz file in the specified path for reading and decompressing, or compressing and writing. This API uses a promise to return the result.

**Atomic service API**: This API can be used in atomic services since API version 12.

**System capability**: SystemCapability.BundleManager.Zlib

**Parameters**

| Name| Type  | Mandatory| Description                |
| ------ | ------ | ---- | -------------------- |
| path   | string | Yes  | Path of the file to be opened.|
| mode   | string | Yes  | Specifies a method for opening a file.  |

**Returns**

| Type               | Description                   |
| ------------------- | ----------------------- |
| Promise&lt;void&gt; | Promise that returns no value.|

**Error codes**

For details about the error codes, see [Universal Error Codes](../errorcode-universal.md) and [zlib Error Codes](./errorcode-zlib.md).

| ID| Error Message                                                    |
| -------- | ------------------------------------------------------------ |
| 401      | The parameter check failed. Possible causes: <br>1. Mandatory parameters are left unspecified;<br>2. Incorrect parameter types;<br>3. Parameter verification failed. |
| 17800002 | No such file or access mode error.                           |

**Example**

```ts
import { zlib } from '@kit.BasicServicesKit';
import { fileIo as fs } from '@kit.CoreFileKit';

async function gzopenDemo(pathDir: string) {
  fs.mkdirSync(pathDir + "/gzopen");
  let path = pathDir + "/gzopen/test.gz";
  let gzip = zlib.createGZipSync();
  await gzip.gzopen(path, "wb");
  await gzip.gzclose();
}

@Entry
@Component
struct Index {
  build() {
    Row() {
      Column() {
        Button('test gzip interface')
          .type(ButtonType.Capsule)
          .height(60)
          .width(200)
          .onClick(() => {
            let pathDir = this.getUIContext()?.getHostContext()?.cacheDir;
            if (typeof pathDir === 'string') {
              gzopenDemo(pathDir);
            }
          })
      }
      .width('100%')
    }
    .height('100%')
  }
}
```

### gzeof<sup>12+</sup>

gzeof(): Promise&lt;number&gt;

Checks whether the read position (position from which data is read) of the gzip file has reached the end of the file. This API uses a promise to return the result.

**Atomic service API**: This API can be used in atomic services since API version 12.

**System capability**: SystemCapability.BundleManager.Zlib

**Returns**

| Type                 | Description                                                        |
| --------------------- | ------------------------------------------------------------ |
| Promise&lt;number&gt; | Promise used to return the result. If the end-of-file indicator is set while reading, **1** is returned.|

**Example**

```ts
import { zlib } from '@kit.BasicServicesKit';
import { fileIo as fs } from '@kit.CoreFileKit';

async function gzeofDemo(pathDir: string) {
  fs.mkdirSync(pathDir + "/gzeof");
  let path = pathDir + "/gzeof/test.gz";
  let gzip = zlib.createGZipSync();
  await gzip.gzopen(path, "wb");
  let writeBufferWithData = new ArrayBuffer(16);
  let uint8View = new Uint8Array(writeBufferWithData);
  for (let i = 0; i < uint8View.length; i++) {
    uint8View[i] = i;
  }
  let writeNum = await gzip.gzwrite(writeBufferWithData, 16)
  await gzip.gzclose();
  await gzip.gzopen(path, "rb");
  let readBufferWithData = new ArrayBuffer(20);
  let readNum = await gzip.gzread(readBufferWithData);
  let eofNum = await gzip.gzeof();
  await gzip.gzclose();
}

@Entry
@Component
struct Index {
  build() {
    Row() {
      Column() {
        Button('test gzip interface')
          .type(ButtonType.Capsule)
          .height(60)
          .width(200)
          .onClick(() => {
            let pathDir = this.getUIContext()?.getHostContext()?.cacheDir;
            if (typeof pathDir === 'string') {
              gzeofDemo(pathDir);
            }
          })
      }
      .width('100%')
    }
    .height('100%')
  }
}
```

### gzdirect<sup>12+</sup>

gzdirect(): Promise&lt;number&gt;

Checks whether the specified gzip file handle directly accesses the original uncompressed data and reallocates the buffer. This API uses a promise to return the result.

**Atomic service API**: This API can be used in atomic services since API version 12.

**System capability**: SystemCapability.BundleManager.Zlib

**Returns**

| Type                 | Description                                              |
| --------------------- | -------------------------------------------------- |
| Promise&lt;number&gt; | Promise used to return the result. If the original uncompressed data is directly accessed, **1** is returned.|

**Example**

```ts
import { zlib } from '@kit.BasicServicesKit';
import { fileIo as fs } from '@kit.CoreFileKit';

async function gzdirectDemo(pathDir: string) {
  fs.mkdirSync(pathDir + "/gzdirect");
  let path = pathDir + "/gzdirect/test.gz";
  let gzip = zlib.createGZipSync();
  await gzip.gzopen(path, "wb");
  let directNum = await gzip.gzdirect();
  await gzip.gzclose();
}

@Entry
@Component
struct Index {
  build() {
    Row() {
      Column() {
        Button('test gzip interface')
          .type(ButtonType.Capsule)
          .height(60)
          .width(200)
          .onClick(() => {
            let pathDir = this.getUIContext()?.getHostContext()?.cacheDir;
            if (typeof pathDir === 'string') {
              gzdirectDemo(pathDir);
            }
          })
      }
      .width('100%')
    }
    .height('100%')
  }
}
```

### gzclose<sup>12+</sup>

gzclose(): Promise&lt;ReturnStatus&gt;

Clears all pending output of the file. Closes the file and releases the decompression or compression state if necessary. This API uses a promise to return the result. The result state is returned.

**Atomic service API**: This API can be used in atomic services since API version 12.

**System capability**: SystemCapability.BundleManager.Zlib

**Returns**

| Type                                          | Description                       |
| ---------------------------------------------- | --------------------------- |
| Promise&lt;[ReturnStatus](#returnstatus12)&gt; | Promise used to return the result.|

**Error codes**

For details about the error codes, see [zlib Error Codes](errorcode-zlib.md).

| ID| Error Message                 |
| -------- | ------------------------- |
| 17800004 | Compression or decompression stream error, which may be caused by an initialization error in the zlib stream structure or a modified structure. |
| 17800006 | Memory allocation failed. |

**Example**

```ts
import { zlib } from '@kit.BasicServicesKit';
import { fileIo as fs } from '@kit.CoreFileKit';

async function gzcloseDemo(pathDir: string) {
  fs.mkdirSync(pathDir + "/gzclose");
  let path = pathDir + "/gzclose/test.gz";
  let gzip = zlib.createGZipSync();
  await gzip.gzopen(path, "wb");
  await gzip.gzclose();
}

@Entry
@Component
struct Index {
  build() {
    Row() {
      Column() {
        Button('test gzip interface')
          .type(ButtonType.Capsule)
          .height(60)
          .width(200)
          .onClick(() => {
            let pathDir = this.getUIContext()?.getHostContext()?.cacheDir;
            if (typeof pathDir === 'string') {
              gzcloseDemo(pathDir);
            }
          })
      }
      .width('100%')
    }
    .height('100%')
  }
}
```

### gzclearerr<sup>12+</sup>

gzclearerr(): Promise&lt;void&gt;

Clears the errors and end-of-file flags of a file. This API uses a promise to return the result.

**Atomic service API**: This API can be used in atomic services since API version 12.

**System capability**: SystemCapability.BundleManager.Zlib

**Returns**

| Type               | Description                   |
| ------------------- | ----------------------- |
| Promise&lt;void&gt; | Promise that returns no value.|

**Example**

```ts
import { zlib } from '@kit.BasicServicesKit';
import { fileIo as fs } from '@kit.CoreFileKit';

async function gzclearerrDemo(pathDir: string) {
  fs.mkdirSync(pathDir + "/gzclearerr");
  let path = pathDir + "/gzclearerr/test.gz";
  let gzip = zlib.createGZipSync();
  await gzip.gzopen(path, "wb");
  let writeBufferWithData = new ArrayBuffer(16);
  let uint8View = new Uint8Array(writeBufferWithData);
  for (let i = 0; i < uint8View.length; i++) {
    uint8View[i] = i;
  }
  let writeNum = await gzip.gzwrite(writeBufferWithData, 16)
  await gzip.gzclose();
  await gzip.gzopen(path, "rb");
  let readBufferWithData = new ArrayBuffer(20);
  let readNum = await gzip.gzread(readBufferWithData);
  let eofNum = await gzip.gzeof();
  await gzip.gzclearerr();
  let eofNumClear = await gzip.gzeof();
  await gzip.gzclose();
}

@Entry
@Component
struct Index {
  build() {
    Row() {
      Column() {
        Button('test gzip interface')
          .type(ButtonType.Capsule)
          .height(60)
          .width(200)
          .onClick(() => {
            let pathDir = this.getUIContext()?.getHostContext()?.cacheDir;
            if (typeof pathDir === 'string') {
              gzclearerrDemo(pathDir);
            }
          })
      }
      .width('100%')
    }
    .height('100%')
  }
}
```

### gzerror<sup>12+</sup>

gzerror(): Promise&lt;GzErrorOutputInfo&gt;

Describes the last error message that reported for the file. This API uses a promise to return the result. The result state and the last state message are returned.

**Atomic service API**: This API can be used in atomic services since API version 12.

**System capability**: SystemCapability.BundleManager.Zlib

**Returns**

| Type                                                    | Description                                                     |
| -------------------------------------------------------- | --------------------------------------------------------- |
| Promise&lt;[GzErrorOutputInfo](#gzerroroutputinfo12)&gt; | Promise used to return the result.|

**Error codes**

For details about the error codes, see [zlib Error Codes](errorcode-zlib.md).

| ID| Error Message      |
| -------- | -------------- |
| 17800004 | Compression or decompression stream error, which may be caused by an initialization error in the zlib stream structure or a modified structure. |

**Example**

```ts
import { zlib } from '@kit.BasicServicesKit';
import { fileIo as fs } from '@kit.CoreFileKit';

async function gzerrorDemo(pathDir: string) {
  fs.mkdirSync(pathDir + "/gzerror");
  let path = pathDir + "/gzerror/test.gz";
  let gzip = zlib.createGZipSync();
  await gzip.gzopen(path, "wb");
  let writeBufferWithData = new ArrayBuffer(16);
  let uint8View = new Uint8Array(writeBufferWithData);
  for (let i = 0; i < uint8View.length; i++) {
    uint8View[i] = i;
  }
  try {
    await gzip.gzwrite(writeBufferWithData, -1);
  } catch (errData) {
    await gzip.gzerror().then((GzErrorOutputInfo) => {
      console.info('errCode', GzErrorOutputInfo.status);
      console.info('errMsg', GzErrorOutputInfo.statusMsg);
    })
  }
  await gzip.gzclose();
}

@Entry
@Component
struct Index {
  build() {
    Row() {
      Column() {
        Button('test gzip interface')
          .type(ButtonType.Capsule)
          .height(60)
          .width(200)
          .onClick(() => {
            let pathDir = this.getUIContext()?.getHostContext()?.cacheDir;
            if (typeof pathDir === 'string') {
              gzerrorDemo(pathDir);
            }
          })
      }
      .width('100%')
    }
    .height('100%')
  }
}
```

### gzgetc<sup>12+</sup>

gzgetc(): Promise&lt;number&gt;

Reads and decompresses a byte from a file. This API uses a promise to return the result. The ASCII value of the read character is returned.

**Atomic service API**: This API can be used in atomic services since API version 12.

**System capability**: SystemCapability.BundleManager.Zlib

**Returns**

| Type                 | Description                                |
| --------------------- | ------------------------------------ |
| Promise&lt;number&gt; | Promise used to return the result.|

**Error codes**

For details about the error codes, see [zlib Error Codes](errorcode-zlib.md).

| ID| Error Message                 |
| -------- | ------------------------- |
| 17800009 | Internal structure error. |

**Example**

```ts
import { zlib } from '@kit.BasicServicesKit';
import { fileIo as fs } from '@kit.CoreFileKit';

async function gzgetcDemo(pathDir: string) {
  fs.mkdirSync(pathDir + "/gzgetc");
  let path = pathDir + "/gzgetc/test.gz";
  let gzip = zlib.createGZipSync();
  await gzip.gzopen(path, "wb");
  await gzip.gzputc(1);
  await gzip.gzclose();
  await gzip.gzopen(path, "rb");
  let resulit = await gzip.gzgetc();
  await gzip.gzclose();
}

@Entry
@Component
struct Index {
  build() {
    Row() {
      Column() {
        Button('test gzip interface')
          .type(ButtonType.Capsule)
          .height(60)
          .width(200)
          .onClick(() => {
            let pathDir = this.getUIContext()?.getHostContext()?.cacheDir;
            if (typeof pathDir === 'string') {
              gzgetcDemo(pathDir);
            }
          })
      }
      .width('100%')
    }
    .height('100%')
  }
}
```

### gzflush<sup>12+</sup>

gzflush(flush: CompressFlushMode): Promise&lt;ReturnStatus&gt;

Flushes all pending output into a compressed file. This API uses a promise to return the result. The result state is returned.

**Atomic service API**: This API can be used in atomic services since API version 12.

**System capability**: SystemCapability.BundleManager.Zlib

**Parameters**

| Name| Type             | Mandatory| Description                                                        |
| ------ | ----------------- | ---- | ------------------------------------------------------------ |
| flush  | CompressFlushMode | Yes  | Controls the flushing mode. For details, see [CompressFlushMode](#compressflushmode12).|

**Returns**

| Type                                          | Description                       |
| ---------------------------------------------- | --------------------------- |
| Promise&lt;[ReturnStatus](#returnstatus12)&gt; | Promise used to return the result.|

**Error codes**

For details about the error codes, see [Universal Error Codes](../errorcode-universal.md) and [zlib Error Codes](./errorcode-zlib.md).

| ID| Error Message                                                    |
| -------- | ------------------------------------------------------------ |
| 401      | The parameter check failed. Possible causes: <br>1. Mandatory parameters are left unspecified;<br>2. Incorrect parameter types;<br>3. Parameter verification failed. |
| 17800004 | Compression or decompression stream error, which may be caused by an initialization error in the zlib stream structure or a modified structure. |

**Example**

```ts
import { zlib } from '@kit.BasicServicesKit';
import { fileIo as fs } from '@kit.CoreFileKit';

async function gzflushDemo(pathDir: string) {
  fs.mkdirSync(pathDir + "/gzflush");
  let path = pathDir + "/gzflush/test.gz";
  let gzip = zlib.createGZipSync();
  await gzip.gzopen(path, "wb");
  let flushNum = await gzip.gzflush(zlib.CompressFlushMode.NO_FLUSH);
  await gzip.gzclose();
}

@Entry
@Component
struct Index {
  build() {
    Row() {
      Column() {
        Button('test gzip interface')
          .type(ButtonType.Capsule)
          .height(60)
          .width(200)
          .onClick(() => {
            let pathDir = this.getUIContext()?.getHostContext()?.cacheDir;
            if (typeof pathDir === 'string') {
              gzflushDemo(pathDir);
            }
          })
      }
      .width('100%')
    }
    .height('100%')
  }
}
```

### gzfwrite<sup>12+</sup>

gzfwrite(buf: ArrayBuffer, size: number, nitems: number): Promise&lt;number&gt;

Compresses data blocks that are declared with size and nitems from the buffer and writes the data blocks to a file. This API uses a promise to return the result. The number of complete data blocks that are declared with size are returned.

**Atomic service API**: This API can be used in atomic services since API version 12.

**System capability**: SystemCapability.BundleManager.Zlib

**Parameters**

| Name| Type       | Mandatory| Description                  |
| ------ | ----------- | ---- | ---------------------- |
| buf    | ArrayBuffer | Yes  | Buffer to which data is to be written.|
| size   | number      | Yes  | Number of bytes in a single data block.|
| nitems | number      | Yes  | Number of data blocks to be written.    |

**Returns**

| Type                 | Description                                               |
| --------------------- | --------------------------------------------------- |
| Promise&lt;number&gt; | Promise used to return the result.|

**Error codes**

For details about the error codes, see [Universal Error Codes](../errorcode-universal.md) and [zlib Error Codes](./errorcode-zlib.md).

| ID| Error Message                                                    |
| -------- | ------------------------------------------------------------ |
| 401      | The parameter check failed. Possible causes: <br>1. Mandatory parameters are left unspecified;<br>2. Incorrect parameter types;<br>3. Parameter verification failed. |
| 17800009 | Internal structure error.                                    |

**Example**

```ts
import { zlib } from '@kit.BasicServicesKit';
import { fileIo as fs } from '@kit.CoreFileKit';

async function gzfwriteDemo(pathDir: string) {
  fs.mkdirSync(pathDir + "/gzfwrite");
  let path = pathDir + "/gzfwrite/test.gz";
  let gzip = zlib.createGZipSync();
  await gzip.gzopen(path, "wb");
  let bufferWithData = new ArrayBuffer(16);
  let uint8View = new Uint8Array(bufferWithData);
  for (let i = 0; i < uint8View.length; i++) {
    uint8View[i] = i;
  }
  let resulit = await gzip.gzfwrite(bufferWithData, 8, 2)
  await gzip.gzclose();
}

@Entry
@Component
struct Index {
  build() {
    Row() {
      Column() {
        Button('test gzip interface')
          .type(ButtonType.Capsule)
          .height(60)
          .width(200)
          .onClick(() => {
            let pathDir = this.getUIContext()?.getHostContext()?.cacheDir;
            if (typeof pathDir === 'string') {
              gzfwriteDemo(pathDir);
            }
          })
      }
      .width('100%')
    }
    .height('100%')
  }
}
```

### gzfread<sup>12+</sup>

gzfread(buf: ArrayBuffer, size: number, nitems: number): Promise&lt;number&gt;

Decompresses and reads data from a gzip file. This API uses a promise to return the result. The number of complete data blocks that are declared with size are returned.

**Atomic service API**: This API can be used in atomic services since API version 12.

**System capability**: SystemCapability.BundleManager.Zlib

**Parameters**

| Name| Type       | Mandatory| Description                          |
| ------ | ----------- | ---- | ------------------------------ |
| buf    | ArrayBuffer | Yes  | Destination buffer for storing read results.|
| size   | number      | Yes  | Number of bytes in a single data block.        |
| nitems | number      | Yes  | Number of data blocks to be written.            |

**Returns**

| Type                 | Description                                               |
| --------------------- | --------------------------------------------------- |
| Promise&lt;number&gt; | Promise used to return the result.|

**Error codes**

For details about the error codes, see [Universal Error Codes](../errorcode-universal.md) and [zlib Error Codes](./errorcode-zlib.md).

| ID| Error Message                                                    |
| -------- | ------------------------------------------------------------ |
| 401      | The parameter check failed. Possible causes: <br>1. Mandatory parameters are left unspecified;<br>2. Incorrect parameter types;<br>3. Parameter verification failed. |
| 17800009 | Internal structure error.                                    |

**Example**

```ts
import { zlib } from '@kit.BasicServicesKit';
import { fileIo as fs } from '@kit.CoreFileKit';

async function gzfreadDemo(pathDir: string) {
  fs.mkdirSync(pathDir + "/gzfread");
  let path = pathDir + "/gzfread/test.gz";
  let gzip = zlib.createGZipSync();
  await gzip.gzopen(path, "wb");
  let writeBuffer = new ArrayBuffer(16);
  let uint8View = new Uint8Array(writeBuffer);
  for (let i = 0; i < uint8View.length; i++) {
    uint8View[i] = i;
  }
  await gzip.gzfwrite(writeBuffer, 8, 2);
  await gzip.gzclose();
  await gzip.gzopen(path, "rb");
  let readBuffer = new ArrayBuffer(16);
  let result = await gzip.gzfread(readBuffer, 8, 2);
  await gzip.gzclose();
}

@Entry
@Component
struct Index {
  build() {
    Row() {
      Column() {
        Button('test gzip interface')
          .type(ButtonType.Capsule)
          .height(60)
          .width(200)
          .onClick(() => {
            let pathDir = this.getUIContext()?.getHostContext()?.cacheDir;
            if (typeof pathDir === 'string') {
              gzfreadDemo(pathDir);
            }
          })
      }
      .width('100%')
    }
    .height('100%')
  }
}
```

### gzclosew<sup>12+</sup>

gzclosew(): Promise&lt;ReturnStatus&gt;

Implements the same functions as that of **gzclose()** for writing or appending. This API uses a promise to return the result. The result state is returned.

**Atomic service API**: This API can be used in atomic services since API version 12.

**System capability**: SystemCapability.BundleManager.Zlib

**Returns**

| Type                                          | Description                       |
| ---------------------------------------------- | --------------------------- |
| Promise&lt;[ReturnStatus](#returnstatus12)&gt; | Promise used to return the result.|

**Error codes**

For details about the error codes, see [zlib Error Codes](errorcode-zlib.md).

| ID| Error Message                 |
| -------- | ------------------------- |
| 17800004 | Compression or decompression stream error, which may be caused by an initialization error in the zlib stream structure or a modified structure. |
| 17800006 | Memory allocation failed. |

**Example**

```ts
import { zlib } from '@kit.BasicServicesKit';
import { fileIo as fs } from '@kit.CoreFileKit';

async function gzclosewDemo(pathDir: string) {
  fs.mkdirSync(pathDir + "/gzclosew");
  let path = pathDir + "/gzclosew/test.gz";
  let gzip = zlib.createGZipSync();
  await gzip.gzopen(path, "wb");
  await gzip.gzclosew();
}

@Entry
@Component
struct Index {
  build() {
    Row() {
      Column() {
        Button('test gzip interface')
          .type(ButtonType.Capsule)
          .height(60)
          .width(200)
          .onClick(() => {
            let pathDir = this.getUIContext()?.getHostContext()?.cacheDir;
            if (typeof pathDir === 'string') {
              gzclosewDemo(pathDir);
            }
          })
      }
      .width('100%')
    }
    .height('100%')
  }
}
```

### gzcloser<sup>12+</sup>

gzcloser(): Promise&lt;ReturnStatus&gt;

Implements the same functions as that of **gzclose()** for reading only. This API uses a promise to return the result. The result state is returned.

**Atomic service API**: This API can be used in atomic services since API version 12.

**System capability**: SystemCapability.BundleManager.Zlib

**Returns**

| Type                                          | Description                       |
| ---------------------------------------------- | --------------------------- |
| Promise&lt;[ReturnStatus](#returnstatus12)&gt; | Promise used to return the result.|

**Error codes**

For details about the error codes, see [zlib Error Codes](errorcode-zlib.md).

| ID| Error Message      |
| -------- | -------------- |
| 17800004 | Compression or decompression stream error, which may be caused by an initialization error in the zlib stream structure or a modified structure. |

**Example**

```ts
import { zlib } from '@kit.BasicServicesKit';
import { fileIo as fs } from '@kit.CoreFileKit';

async function gzcloserDemo(pathDir: string) {
  fs.mkdirSync(pathDir + "/gzcloser");
  let path = pathDir + "/gzcloser/test.gz";
  let gzip = zlib.createGZipSync();
  await gzip.gzopen(path, "wb");
  await gzip.gzclose();
  await gzip.gzopen(path, "rb");
  await gzip.gzcloser();
}

@Entry
@Component
struct Index {
  build() {
    Row() {
      Column() {
        Button('test gzip interface')
          .type(ButtonType.Capsule)
          .height(60)
          .width(200)
          .onClick(() => {
            let pathDir = this.getUIContext()?.getHostContext()?.cacheDir;
            if (typeof pathDir === 'string') {
              gzcloserDemo(pathDir);
            }
          })
      }
      .width('100%')
    }
    .height('100%')
  }
}
```

### gzwrite<sup>12+</sup>

gzwrite(buf: ArrayBuffer, len: number): Promise&lt;number&gt;

Compresses the uncompressed bytes of the declared length in the buffer and writes them to the file. This API uses a promise to return the result. The number of uncompressed bytes written is returned.

**Atomic service API**: This API can be used in atomic services since API version 12.

**System capability**: SystemCapability.BundleManager.Zlib

**Parameters**

| Name| Type       | Mandatory| Description                        |
| ------ | ----------- | ---- | ---------------------------- |
| buf    | ArrayBuffer | Yes  | Data buffer pointed by an object to be written.|
| len    | number      | Yes  | Length of uncompressed bytes.            |

**Returns**

| Type                 | Description                                 |
| --------------------- | ------------------------------------- |
| Promise&lt;number&gt; | Promise used to return the result.|

**Error codes**

For details about the error codes, see [Universal Error Codes](../errorcode-universal.md) and [zlib Error Codes](./errorcode-zlib.md).

| ID| Error Message                                                    |
| -------- | ------------------------------------------------------------ |
| 401      | The parameter check failed. Possible causes: <br>1. Mandatory parameters are left unspecified;<br>2. Incorrect parameter types;<br>3. Parameter verification failed. |
| 17800009 | Internal structure error.                                    |

**Example**

```ts
import { zlib } from '@kit.BasicServicesKit';
import { fileIo as fs } from '@kit.CoreFileKit';

async function gzwriteDemo(pathDir: string) {
  fs.mkdirSync(pathDir + "/gzwrite");
  let path = pathDir + "/gzwrite/test.gz";
  let gzip = zlib.createGZipSync();
  await gzip.gzopen(path, "wb");
  let bufferWithData = new ArrayBuffer(16);
  let uint8View = new Uint8Array(bufferWithData);
  for (let i = 0; i < uint8View.length; i++) {
    uint8View[i] = i;
  }
  let result = await gzip.gzwrite(bufferWithData, 16);
  await gzip.gzclose();
}

@Entry
@Component
struct Index {
  build() {
    Row() {
      Column() {
        Button('test gzip interface')
          .type(ButtonType.Capsule)
          .height(60)
          .width(200)
          .onClick(() => {
            let pathDir = this.getUIContext()?.getHostContext()?.cacheDir;
            if (typeof pathDir === 'string') {
              gzwriteDemo(pathDir);
            }
          })
      }
      .width('100%')
    }
    .height('100%')
  }
}
```

### gzungetc<sup>12+</sup>

gzungetc(c: number): Promise&lt;number&gt;

Pushes **c** back into the input stream so that it will be read as the first character the next time the file is read. This API uses a promise to return the result. The pushed characters are returned.

**Atomic service API**: This API can be used in atomic services since API version 12.

**System capability**: SystemCapability.BundleManager.Zlib

**Parameters**

| Name| Type  | Mandatory| Description                    |
| ------ | ------ | ---- | ------------------------ |
| c      | number | Yes  | Characters before being pushed into the input stream.|

**Returns**

| Type                 | Description                         |
| --------------------- | ----------------------------- |
| Promise&lt;number&gt; | Promise used to return the result.|

**Error codes**

For details about the error codes, see [Universal Error Codes](../errorcode-universal.md) and [zlib Error Codes](./errorcode-zlib.md).

| ID| Error Message                                                    |
| -------- | ------------------------------------------------------------ |
| 401      | The parameter check failed. Possible causes: <br>1. Mandatory parameters are left unspecified;<br>2. Incorrect parameter types;<br>3. Parameter verification failed. |
| 17800009 | Internal structure error.                                    |

**Example**

```ts
import { zlib } from '@kit.BasicServicesKit';
import { fileIo as fs } from '@kit.CoreFileKit';

async function gzungetcDemo(pathDir: string) {
  fs.mkdirSync(pathDir + "/gzungetc");
  let path = pathDir + "/gzungetc/test.gz";
  let gzip = zlib.createGZipSync();
  await gzip.gzopen(path, "wb");
  await gzip.gzclose();
  await gzip.gzopen(path, "rb");
  await gzip.gzread(new ArrayBuffer(1));
  let result = await gzip.gzungetc(1);
  await gzip.gzclose();
}

@Entry
@Component
struct Index {
  build() {
    Row() {
      Column() {
        Button('test gzip interface')
          .type(ButtonType.Capsule)
          .height(60)
          .width(200)
          .onClick(() => {
            let pathDir = this.getUIContext()?.getHostContext()?.cacheDir;
            if (typeof pathDir === 'string') {
              gzungetcDemo(pathDir);
            }
          })
      }
      .width('100%')
    }
    .height('100%')
  }
}
```

### gztell<sup>12+</sup>

gztell(): Promise&lt;number&gt;

Returns the start position of the next **gzread** or **gzwrite** in the file. This API uses a promise to return the result.

**Atomic service API**: This API can be used in atomic services since API version 12.

**System capability**: SystemCapability.BundleManager.Zlib

**Returns**

| Type                 | Description                                                    |
| --------------------- | -------------------------------------------------------- |
| Promise&lt;number&gt; | Promise used to return the result.|

**Error codes**

For details about the error codes, see [zlib Error Codes](errorcode-zlib.md).

| ID| Error Message                 |
| -------- | ------------------------- |
| 17800009 | Internal structure error. |

**Example**

```ts
import { zlib } from '@kit.BasicServicesKit';
import { fileIo as fs } from '@kit.CoreFileKit';

async function gztellDemo(pathDir: string) {
  fs.mkdirSync(pathDir + "/gztell");
  let path = pathDir + "/gztell/test.gz";
  let gzip = zlib.createGZipSync();
  await gzip.gzopen(path, "wb");
  let result = await gzip.gztell();
  await gzip.gzclose();
}

@Entry
@Component
struct Index {
  build() {
    Row() {
      Column() {
        Button('test gzip interface')
          .type(ButtonType.Capsule)
          .height(60)
          .width(200)
          .onClick(() => {
            let pathDir = this.getUIContext()?.getHostContext()?.cacheDir;
            if (typeof pathDir === 'string') {
              gztellDemo(pathDir);
            }
          })
      }
      .width('100%')
    }
    .height('100%')
  }
}
```

### gzsetparams<sup>12+</sup>

gzsetparams(level: CompressLevel, strategy: CompressStrategy): Promise&lt;ReturnStatus&gt;

Dynamically updates the compression level and compression policy of a file. This API uses a promise to return the result. The result state is returned.

**Atomic service API**: This API can be used in atomic services since API version 12.

**System capability**: SystemCapability.BundleManager.Zlib

**Parameters**

| Name  | Type            | Mandatory| Description                                                        |
| -------- | ---------------- | ---- | ------------------------------------------------------------ |
| level    | CompressLevel    | Yes  | Compression level. For details, see [CompressLevel](#compresslevel).     |
| strategy | CompressStrategy | Yes  | Compression policy. For details, see [CompressStrategy](#compressstrategy).|

**Returns**

| Type                                          | Description                       |
| ---------------------------------------------- | --------------------------- |
| Promise&lt;[ReturnStatus](#returnstatus12)&gt; | Promise used to return the result.|

**Error codes**

For details about the error codes, see [Universal Error Codes](../errorcode-universal.md) and [zlib Error Codes](./errorcode-zlib.md).

| ID| Error Message                                                    |
| -------- | ------------------------------------------------------------ |
| 401      | The parameter check failed. Possible causes: <br>1. Mandatory parameters are left unspecified;<br>2. Incorrect parameter types;<br>3. Parameter verification failed. |
| 17800004 | Compression or decompression stream error, which may be caused by an initialization error in the zlib stream structure or a modified structure. |

**Example**

```ts
import { zlib } from '@kit.BasicServicesKit';
import { fileIo as fs } from '@kit.CoreFileKit';

async function gzsetparamsDemo(pathDir: string) {
  fs.mkdirSync(pathDir + "/gzsetparams");
  let path = pathDir + "/gzsetparams/test.gz";
  let gzip = zlib.createGZipSync();
  await gzip.gzopen(path, "wb");
  let result = await gzip.gzsetparams(zlib.CompressLevel.COMPRESS_LEVEL_DEFAULT_COMPRESSION,
    zlib.CompressStrategy.COMPRESS_STRATEGY_DEFAULT_STRATEGY);
  await gzip.gzclose();
}

@Entry
@Component
struct Index {
  build() {
    Row() {
      Column() {
        Button('test gzip interface')
          .type(ButtonType.Capsule)
          .height(60)
          .width(200)
          .onClick(() => {
            let pathDir = this.getUIContext()?.getHostContext()?.cacheDir;
            if (typeof pathDir === 'string') {
              gzsetparamsDemo(pathDir);
            }
          })
      }
      .width('100%')
    }
    .height('100%')
  }
}
```

### gzseek<sup>12+</sup>

gzseek(offset: number, whence: OffsetReferencePoint): Promise&lt;number&gt;

Sets the start position to the offset position relative to the next **gzread** or **gzwrite** in the file. This API uses a promise to return the result. The result offset position measured in bytes from the beginning of an uncompressed stream is returned.

**Atomic service API**: This API can be used in atomic services since API version 12.

**System capability**: SystemCapability.BundleManager.Zlib

**Parameters**

| Name| Type                | Mandatory| Description                                                        |
| ------ | -------------------- | ---- | ------------------------------------------------------------ |
| offset | number               | Yes  | Target offset position.                                              |
| whence | OffsetReferencePoint | Yes  | Defines the reference point for the offset. For details, see [OffsetReferencePoint](#offsetreferencepoint12).|

**Returns**

| Type                 | Description                                                        |
| --------------------- | ------------------------------------------------------------ |
| Promise&lt;number&gt; | Promise used to return the result.|

**Error codes**

For details about the error codes, see [Universal Error Codes](../errorcode-universal.md) and [zlib Error Codes](./errorcode-zlib.md).

| ID| Error Message                                                    |
| -------- | ------------------------------------------------------------ |
| 401      | The parameter check failed. Possible causes: <br>1. Mandatory parameters are left unspecified;<br>2. Incorrect parameter types;<br>3. Parameter verification failed. |
| 17800009 | Internal structure error.                                    |

**Example**

```ts
import { zlib } from '@kit.BasicServicesKit';
import { fileIo as fs } from '@kit.CoreFileKit';

async function gzseekDemo(pathDir: string) {
  fs.mkdirSync(pathDir + "/gzseek");
  let path = pathDir + "/gzseek/test.gz";
  let gzip = zlib.createGZipSync();
  await gzip.gzopen(path, "wb");
  let result = await gzip.gzseek(2, zlib.OffsetReferencePoint.SEEK_CUR);
  await gzip.gzclose();
}

@Entry
@Component
struct Index {
  build() {
    Row() {
      Column() {
        Button('test gzip interface')
          .type(ButtonType.Capsule)
          .height(60)
          .width(200)
          .onClick(() => {
            let pathDir = this.getUIContext()?.getHostContext()?.cacheDir;
            if (typeof pathDir === 'string') {
              gzseekDemo(pathDir);
            }
          })
      }
      .width('100%')
    }
    .height('100%')
  }
}
```

### gzrewind<sup>12+</sup>

gzrewind(): Promise&lt;ReturnStatus&gt;

Repositions the file pointer to the beginning of the file. This feature is applied only for reading. This API uses a promise to return the result. The result state is returned.

**Atomic service API**: This API can be used in atomic services since API version 12.

**System capability**: SystemCapability.BundleManager.Zlib

**Returns**

| Type                                          | Description                       |
| ---------------------------------------------- | --------------------------- |
| Promise&lt;[ReturnStatus](#returnstatus12)&gt; | Promise used to return the result.|

**Error codes**

For details about the error codes, see [zlib Error Codes](errorcode-zlib.md).

| ID| Error Message                 |
| -------- | ------------------------- |
| 17800009 | Internal structure error. |

**Example**

```ts
import { zlib } from '@kit.BasicServicesKit';
import { fileIo as fs } from '@kit.CoreFileKit';

async function gzrewindDemo(pathDir: string) {
  fs.mkdirSync(pathDir + "/gzrewind");
  let path = pathDir + "/gzrewind/test.gz";
  let gzip = zlib.createGZipSync();
  await gzip.gzopen(path, "wb");
  await gzip.gzclose();
  await gzip.gzopen(path, "rb");
  let result = await gzip.gzrewind();
  await gzip.gzclose();
}

@Entry
@Component
struct Index {
  build() {
    Row() {
      Column() {
        Button('test gzip interface')
          .type(ButtonType.Capsule)
          .height(60)
          .width(200)
          .onClick(() => {
            let pathDir = this.getUIContext()?.getHostContext()?.cacheDir;
            if (typeof pathDir === 'string') {
              gzrewindDemo(pathDir);
            }
          })
      }
      .width('100%')
    }
    .height('100%')
  }
}
```

### gzread<sup>12+</sup>

gzread(buf: ArrayBuffer): Promise&lt;number&gt;

Reads a maximum of **len** uncompressed bytes from a file and decompresses them into the buffer. This API uses a promise to return the result. The number of uncompressed bytes that are actually read is returned.

**Atomic service API**: This API can be used in atomic services since API version 12.

**System capability**: SystemCapability.BundleManager.Zlib

**Parameters**

| Name| Type       | Mandatory| Description          |
| ------ | ----------- | ---- | -------------- |
| buf    | ArrayBuffer | Yes  | Target offset position.|

**Returns**

| Type                 | Description                                     |
| --------------------- | ----------------------------------------- |
| Promise&lt;number&gt; | Promise used to return the result.|

**Error codes**

For details about the error codes, see [Universal Error Codes](../errorcode-universal.md) and [zlib Error Codes](./errorcode-zlib.md).

| ID| Error Message                                                    |
| -------- | ------------------------------------------------------------ |
| 401      | The parameter check failed. Possible causes: <br>1. Mandatory parameters are left unspecified;<br>2. Incorrect parameter types;<br>3. Parameter verification failed. |
| 17800009 | Internal structure error.                                    |

**Example**

```ts
import { zlib } from '@kit.BasicServicesKit';
import { fileIo as fs } from '@kit.CoreFileKit';

async function gzreadDemo(pathDir: string) {
  fs.mkdirSync(pathDir + "/gzread");
  let path = pathDir + "/gzread/test.gz";
  let gzip = zlib.createGZipSync();
  await gzip.gzopen(path, "wb");
  let writeBuffer = new ArrayBuffer(16);
  let uint8View = new Uint8Array(writeBuffer);
  for (let i = 0; i < uint8View.length; i++) {
    uint8View[i] = i;
  }
  await gzip.gzwrite(writeBuffer, 16);
  await gzip.gzclose();
  await gzip.gzopen(path, "rb");
  let readBuffer = new ArrayBuffer(16);
  let result = await gzip.gzread(readBuffer);
  await gzip.gzclose();
}

@Entry
@Component
struct Index {
  build() {
    Row() {
      Column() {
        Button('test gzip interface')
          .type(ButtonType.Capsule)
          .height(60)
          .width(200)
          .onClick(() => {
            let pathDir = this.getUIContext()?.getHostContext()?.cacheDir;
            if (typeof pathDir === 'string') {
              gzreadDemo(pathDir);
            }
          })
      }
      .width('100%')
    }
    .height('100%')
  }
}
```

### gzputs<sup>12+</sup>

gzputs(str: string): Promise&lt;number&gt;

Compresses the given null-terminated strings and writes them to the file, excluding the terminating null characters. This API uses a promise to return the result. The number of written characters is returned.

**Atomic service API**: This API can be used in atomic services since API version 12.

**System capability**: SystemCapability.BundleManager.Zlib

**Parameters**

| Name| Type  | Mandatory| Description                  |
| ------ | ------ | ---- | ---------------------- |
| str    | string | Yes  | Format descriptors and plain text.|

**Returns**

| Type                 | Description                           |
| --------------------- | ------------------------------- |
| Promise&lt;number&gt; | Promise used to return the result.|

**Error codes**

For details about the error codes, see [Universal Error Codes](../errorcode-universal.md) and [zlib Error Codes](./errorcode-zlib.md).

| ID| Error Message                                                    |
| -------- | ------------------------------------------------------------ |
| 401      | The parameter check failed. Possible causes: <br>1. Mandatory parameters are left unspecified;<br>2. Incorrect parameter types;<br>3. Parameter verification failed. |
| 17800009 | Internal structure error.                                    |

**Example**

```ts
import { zlib } from '@kit.BasicServicesKit';
import { fileIo as fs } from '@kit.CoreFileKit';

async function gzputsDemo(pathDir: string) {
  fs.mkdirSync(pathDir + "/gzputs");
  let path = pathDir + "/gzputs/test.gz";
  let gzip = zlib.createGZipSync();
  await gzip.gzopen(path, "wb");
  let result = await gzip.gzputs("hello");
  await gzip.gzclose();
}

@Entry
@Component
struct Index {
  build() {
    Row() {
      Column() {
        Button('test gzip interface')
          .type(ButtonType.Capsule)
          .height(60)
          .width(200)
          .onClick(() => {
            let pathDir = this.getUIContext()?.getHostContext()?.cacheDir;
            if (typeof pathDir === 'string') {
              gzputsDemo(pathDir);
            }
          })
      }
      .width('100%')
    }
    .height('100%')
  }
}
```

### gzputc<sup>12+</sup>

gzputc(char: number): Promise&lt;number&gt;

Compresses **char** converted to an unsigned character and writes it to a file. This API uses a promise to return the result. The written value is returned.

**Atomic service API**: This API can be used in atomic services since API version 12.

**System capability**: SystemCapability.BundleManager.Zlib

**Parameters**

| Name| Type  | Mandatory| Description           |
| ------ | ------ | ---- | --------------- |
| char   | number | Yes  | Write character ASCII.|

**Returns**

| Type                 | Description                         |
| --------------------- | ----------------------------- |
| Promise&lt;number&gt; | Promise used to return the result.|

**Error codes**

For details about the error codes, see [Universal Error Codes](../errorcode-universal.md) and [zlib Error Codes](./errorcode-zlib.md).

| ID| Error Message                                                    |
| -------- | ------------------------------------------------------------ |
| 401      | The parameter check failed. Possible causes: <br>1. Mandatory parameters are left unspecified;<br>2. Incorrect parameter types;<br>3. Parameter verification failed. |
| 17800009 | Internal structure error.                                    |

**Example**

```ts
import { zlib } from '@kit.BasicServicesKit';
import { fileIo as fs } from '@kit.CoreFileKit';

async function gzputcDemo(pathDir: string) {
  fs.mkdirSync(pathDir + "/gzputc");
  let path = pathDir + "/gzputc/test.gz";
  let gzip = zlib.createGZipSync();
  await gzip.gzopen(path, "wb");
  let result = await gzip.gzputc(0);
  await gzip.gzclose();
}

@Entry
@Component
struct Index {
  build() {
    Row() {
      Column() {
        Button('test gzip interface')
          .type(ButtonType.Capsule)
          .height(60)
          .width(200)
          .onClick(() => {
            let pathDir = this.getUIContext()?.getHostContext()?.cacheDir;
            if (typeof pathDir === 'string') {
              gzputcDemo(pathDir);
            }
          })
      }
      .width('100%')
    }
    .height('100%')
  }
}
```

### gzprintf<sup>12+</sup>

gzprintf(format: string, ...args: Array&lt;string | number&gt;): Promise&lt;number&gt;

Converts and formats the parameters under the control of the string format and then compresses and writes them into a file, as shown in the **fprintf()**. This API uses a promise to return the result. The number of uncompressed bytes that are actually written is returned.

**Atomic service API**: This API can be used in atomic services since API version 12.

**System capability**: SystemCapability.BundleManager.Zlib

**Parameters**

| Name| Type                         | Mandatory| Description                  |
| ------ | ----------------------------- | ---- | ---------------------- |
| format | string                        | Yes  | Format descriptors and plain text.|
| ...args   | Array&lt;string \| number&gt; | No  | List of variable parameters.        |

**Returns**

| Type                 | Description                                     |
| --------------------- | ----------------------------------------- |
| Promise&lt;number&gt; | Promise used to return the result.|

**Error codes**

For details about the error codes, see [Universal Error Codes](../errorcode-universal.md) and [zlib Error Codes](./errorcode-zlib.md).

| ID| Error Message                                                    |
| -------- | ------------------------------------------------------------ |
| 401      | The parameter check failed. Possible causes: <br>1. Mandatory parameters are left unspecified;<br>2. Incorrect parameter types;<br>3. Parameter verification failed. |
| 17800004 | Compression or decompression stream error, which may be caused by an initialization error in the zlib stream structure or a modified structure. |
| 17800009 | Internal structure error.                                    |

**Example**

```ts
import { zlib } from '@kit.BasicServicesKit';
import { fileIo as fs } from '@kit.CoreFileKit';

async function gzprintfDemo(pathDir: string) {
  fs.mkdirSync(pathDir + "/gzprintf");
  let path = pathDir + "/gzprintf/test.gz";
  let gzip = zlib.createGZipSync();
  await gzip.gzopen(path, "wb");
  let result = await gzip.gzprintf("name is %s, age is %d", "Tom", 23);
  await gzip.gzclose();
}

@Entry
@Component
struct Index {
  build() {
    Row() {
      Column() {
        Button('test gzip interface')
          .type(ButtonType.Capsule)
          .height(60)
          .width(200)
          .onClick(() => {
            let pathDir = this.getUIContext()?.getHostContext()?.cacheDir;
            if (typeof pathDir === 'string') {
              gzprintfDemo(pathDir);
            }
          })
      }
      .width('100%')
    }
    .height('100%')
  }
}
```

### gzoffset<sup>12+</sup>

gzoffset(): Promise&lt;number&gt;

Returns the current compressed read or write offset of the file. This API uses a promise to return the result.

**Atomic service API**: This API can be used in atomic services since API version 12.

**System capability**: SystemCapability.BundleManager.Zlib

**Returns**

| Type                 | Description                                                 |
| --------------------- | ----------------------------------------------------- |
| Promise&lt;number&gt; | Promise used to return the result.|

**Error codes**

For details about the error codes, see [zlib Error Codes](errorcode-zlib.md).

| ID| Error Message                 |
| -------- | ------------------------- |
| 17800009 | Internal structure error. |

**Example**

```ts
import { zlib } from '@kit.BasicServicesKit';
import { fileIo as fs } from '@kit.CoreFileKit';

async function gzoffsetDemo(pathDir: string) {
  fs.mkdirSync(pathDir + "/gzoffset");
  let path = pathDir + "/gzoffset/test.gz";
  let gzip = zlib.createGZipSync();
  await gzip.gzopen(path, "wb");
  let result = await gzip.gzoffset();
  await gzip.gzclose();
}

@Entry
@Component
struct Index {
  build() {
    Row() {
      Column() {
        Button('test gzip interface')
          .type(ButtonType.Capsule)
          .height(60)
          .width(200)
          .onClick(() => {
            let pathDir = this.getUIContext()?.getHostContext()?.cacheDir;
            if (typeof pathDir === 'string') {
              gzoffsetDemo(pathDir);
            }
          })
      }
      .width('100%')
    }
    .height('100%')
  }
}
```

### gzgets<sup>12+</sup>

gzgets(buf: ArrayBuffer): Promise&lt;string&gt;

Reads bytes from a compressed file until len-1 characters are read, a newline character is read and transferred to a buffer, or an end-of-file condition is encountered. This API uses a promise to return the result. The null-terminated strings are returned.

**Atomic service API**: This API can be used in atomic services since API version 12.

**System capability**: SystemCapability.BundleManager.Zlib

**Parameters**

| Name| Type       | Mandatory| Description              |
| ------ | ----------- | ---- | ------------------ |
| buf    | ArrayBuffer | Yes  | Stores the read row data.|

**Returns**

| Type                 | Description                                 |
| --------------------- | ------------------------------------- |
| Promise&lt;string&gt; | Promise used to return a string ended with **null**.|

**Error codes**

For details about the error codes, see [Universal Error Codes](../errorcode-universal.md) and [zlib Error Codes](./errorcode-zlib.md).

| ID| Error Message                                                    |
| -------- | ------------------------------------------------------------ |
| 401      | The parameter check failed. Possible causes: <br>1. Mandatory parameters are left unspecified;<br>2. Incorrect parameter types;<br>3. Parameter verification failed. |
| 17800009 | Internal structure error.                                    |

**Example**

```ts
import { zlib } from '@kit.BasicServicesKit';
import { fileIo as fs } from '@kit.CoreFileKit';

async function gzgetsDemo(pathDir: string) {
  fs.mkdirSync(pathDir + "/gzgets");
  let path = pathDir + "/gzgets/test.gz";
  let gzip = zlib.createGZipSync();
  await gzip.gzopen(path, "wb");
  await gzip.gzputs("hello");
  await gzip.gzclose();
  await gzip.gzopen(path, "rb");
  let bufferWithData = new ArrayBuffer(16);
  let result = await gzip.gzgets(bufferWithData);
  await gzip.gzclose();
}

@Entry
@Component
struct Index {
  build() {
    Row() {
      Column() {
        Button('test gzip interface')
          .type(ButtonType.Capsule)
          .height(60)
          .width(200)
          .onClick(() => {
            let pathDir = this.getUIContext()?.getHostContext()?.cacheDir;
            if (typeof pathDir === 'string') {
              gzgetsDemo(pathDir);
            }
          })
      }
      .width('100%')
    }
    .height('100%')
  }
}
```

## GzErrorOutputInfo<sup>12+</sup>

**Atomic service API**: This API can be used in atomic services since API version 12.

**System capability**: SystemCapability.BundleManager.Zlib

| Name     | Type        | Read-Only| Optional| Description                                        |
| --------- | ------------ | ---- | ---- | -------------------------------------------- |
| status    | ReturnStatus | No  | No  | Returns the zlib file status code. For details, see ReturnStatus definition.|
| statusMsg | string       | No  | No  | The last status message reported on the zlib file.    |

## OffsetReferencePoint<sup>12+</sup>

**Atomic service API**: This API can be used in atomic services since API version 12.

**System capability**: SystemCapability.BundleManager.Zlib

| Name    | Value  | Description            |
| -------- | ---- | ---------------- |
| SEEK_SET | 0    | Searches from the beginning of a file.|
| SEEK_CUR | 1    | Search from the current location.|