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1/*
2 * Copyright (c) 2022 Huawei Device Co., Ltd.
3 * Licensed under the Apache License, Version 2.0 (The type of "License");
4 * you may not use this file except in compliance with the License.
5 * You may obtain a copy of the License at
6 *
7 *     http://www.apache.org/licenses/LICENSE-2.0
8 *
9 * Unless required by applicable law or agreed to in writing, software
10 * distributed under the License is distributed on an "AS IS" BASIS,
11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 * See the License for the specific language governing permissions and
13 * limitations under the License.
14 */
15
16/**
17 * @file
18 * @kit ArkTS
19 */
20
21/**
22 * The Buffer class is a global type for dealing with binary data directly. It can be constructed in a variety of ways.
23 *
24 * @namespace buffer
25 * @syscap SystemCapability.Utils.Lang
26 * @since 9
27 */
28/**
29 * The Buffer class is a global type for dealing with binary data directly. It can be constructed in a variety of ways.
30 *
31 * @namespace buffer
32 * @syscap SystemCapability.Utils.Lang
33 * @crossplatform
34 * @since 10
35 */
36/**
37 * The Buffer class is a global type for dealing with binary data directly. It can be constructed in a variety of ways.
38 *
39 * @namespace buffer
40 * @syscap SystemCapability.Utils.Lang
41 * @crossplatform
42 * @atomicservice
43 * @since arkts {'1.1':'11', '1.2':'20'}
44 * @arkts 1.1&1.2
45 */
46declare namespace buffer {
47  /**
48   * This parameter specifies the type of a common encoding format.
49   *
50   * @typedef { 'ascii' | 'utf8' | 'utf-8' | 'utf16le' | 'ucs2' | 'ucs-2' | 'base64' | 'base64url' | 'latin1' | 'binary' | 'hex' }
51   * @syscap SystemCapability.Utils.Lang
52   * @since 9
53   */
54  /**
55   * This parameter specifies the type of a common encoding format.
56   *
57   * @typedef { 'ascii' | 'utf8' | 'utf-8' | 'utf16le' | 'ucs2' | 'ucs-2' | 'base64' | 'base64url' | 'latin1' | 'binary' | 'hex' }
58   * @syscap SystemCapability.Utils.Lang
59   * @crossplatform
60   * @since 10
61   */
62  /**
63   * Enumerates the supported encoding formats.
64   *
65   * @typedef { 'ascii' | 'utf8' | 'utf-8' | 'utf16le' | 'ucs2' | 'ucs-2' | 'base64' | 'base64url' | 'latin1' | 'binary' | 'hex' }
66   * @syscap SystemCapability.Utils.Lang
67   * @crossplatform
68   * @atomicservice
69   * @since arkts {'1.1':'11', '1.2':'20'}
70   * @arkts 1.1&1.2
71   */
72  type BufferEncoding =
73    | 'ascii'
74    | 'utf8'
75    | 'utf-8'
76    | 'utf16le'
77    | 'ucs2'
78    | 'ucs-2'
79    | 'base64'
80    | 'base64url'
81    | 'latin1'
82    | 'binary'
83    | 'hex';
84  /**
85   * TypedArray inherits the features and methods of Int8Array
86   *
87   * @syscap SystemCapability.Utils.Lang
88   * @since 9
89   */
90  /**
91   * TypedArray inherits the features and methods of Int8Array
92   *
93   * @syscap SystemCapability.Utils.Lang
94   * @crossplatform
95   * @since 10
96   */
97  /**
98   * TypedArray inherits the features and methods of Int8Array
99   *
100   * @extends Int8Array
101   * @typedef TypedArray
102   * @syscap SystemCapability.Utils.Lang
103   * @crossplatform
104   * @atomicservice
105   * @since 11
106   */
107  interface TypedArray extends Int8Array {}
108  /**
109   * TypedArray  features and methods
110   *
111   * @typedef { Int8Array | Uint8Array | Uint8ClampedArray | Int16Array | Uint16Array | Int32Array | Uint32Array | Float32Array | Float64Array | BigInt64Array | BigUint64Array }
112   * @syscap SystemCapability.Utils.Lang
113   * @crossplatform
114   * @atomicservice
115   * @since 20
116   * @arkts 1.2
117   */
118  type TypedArray = Int8Array
119    | Uint8Array
120    | Uint8ClampedArray
121    | Int16Array
122    | Uint16Array
123    | Int32Array
124    | Uint32Array
125    | Float32Array
126    | Float64Array
127    | BigInt64Array
128    | BigUint64Array;
129  /**
130   * Allocates a new Buffer for a fixed size bytes. If fill is undefined, the Buffer will be zero-filled.
131   *
132   * @param { number } size - size size The desired length of the new Buffer
133   * @param { string | Buffer | number } [fill] - fill [fill=0] A value to pre-fill the new Buffer with
134   * @param { BufferEncoding } [encoding] - encoding [encoding='utf8']  If `fill` is a string, this is its encoding
135   * @returns { Buffer } Return a new allocated Buffer
136   * @throws { BusinessError } 401 - Parameter error. Possible causes:
137   * 1.Mandatory parameters are left unspecified;
138   * 2.Incorrect parameter types;
139   * 3.Parameter verification failed.
140   * @syscap SystemCapability.Utils.Lang
141   * @since 9
142   */
143  /**
144   * Creates and initializes a Buffer instance of the specified length.
145   *
146   * @param { number } size - Size of the Buffer instance to create, in bytes.
147   * @param { string | Buffer | number } [fill] - Value to be filled in the buffer. The default value is 0.
148   * @param { BufferEncoding } [encoding] - Encoding format (valid only when fill is a string). The default value is 'utf8'.
149   * @returns { Buffer } Return a new allocated Buffer
150   * @throws { BusinessError } 401 - Parameter error. Possible causes:
151   * 1.Mandatory parameters are left unspecified;
152   * 2.Incorrect parameter types;
153   * 3.Parameter verification failed.
154   * @syscap SystemCapability.Utils.Lang
155   * @crossplatform
156   * @since 10
157   */
158  /**
159   * Creates and initializes a Buffer instance of the specified length.
160   *
161   * @param { number } size - Size of the Buffer instance to create, in bytes.
162   * @param { string | Buffer | number } [fill] - Value to be filled in the buffer. The default value is 0.
163   * @param { BufferEncoding } [encoding] - Encoding format (valid only when fill is a string). The default value is 'utf8'.
164   * @returns { Buffer } Return a new allocated Buffer
165   * @throws { BusinessError } 401 - Parameter error. Possible causes:
166   * 1.Mandatory parameters are left unspecified;
167   * 2.Incorrect parameter types;
168   * 3.Parameter verification failed.
169   * @syscap SystemCapability.Utils.Lang
170   * @crossplatform
171   * @atomicservice
172   * @since arkts {'1.1':'11', '1.2':'20'}
173   * @arkts 1.1&1.2
174   */
175  function alloc(size: number, fill?: string | Buffer | number, encoding?: BufferEncoding): Buffer;
176
177  /**
178   * Allocates a new Buffer for a fixed size bytes. The Buffer will not be initially filled.
179   *
180   * @param { number } size - size size The desired length of the new Buffer
181   * @returns { Buffer } Return a new allocated Buffer
182   * @throws { BusinessError } 401 - Parameter error. Possible causes:
183   * 1.Mandatory parameters are left unspecified;
184   * 2.Incorrect parameter types;
185   * 3.Parameter verification failed.
186   * @syscap SystemCapability.Utils.Lang
187   * @since 9
188   */
189  /**
190   * Creates a Buffer instance of the specified size from the buffer pool, without initializing it.
191   * You need to use fill() to initialize the Buffer instance created.
192   *
193   * @param { number } size - Size of the Buffer instance to create, in bytes.
194   * @returns { Buffer } Return a new allocated Buffer
195   * @throws { BusinessError } 401 - Parameter error. Possible causes:
196   * 1.Mandatory parameters are left unspecified;
197   * 2.Incorrect parameter types;
198   * 3.Parameter verification failed.
199   * @syscap SystemCapability.Utils.Lang
200   * @crossplatform
201   * @since 10
202   */
203  /**
204   * Creates a Buffer instance of the specified size from the buffer pool, without initializing it.
205   * You need to use fill() to initialize the Buffer instance created.
206   *
207   * @param { number } size - Size of the Buffer instance to create, in bytes.
208   * @returns { Buffer } Return a new allocated Buffer
209   * @throws { BusinessError } 401 - Parameter error. Possible causes:
210   * 1.Mandatory parameters are left unspecified;
211   * 2.Incorrect parameter types;
212   * 3.Parameter verification failed.
213   * @syscap SystemCapability.Utils.Lang
214   * @crossplatform
215   * @atomicservice
216   * @since arkts {'1.1':'11', '1.2':'20'}
217   * @arkts 1.1&1.2
218   */
219  function allocUninitializedFromPool(size: number): Buffer;
220
221  /**
222   * Allocates a new un-pooled Buffer for a fixed size bytes. The Buffer will not be initially filled.
223   *
224   * @param { number } size - size size The desired length of the new Buffer
225   * @returns { Buffer } Return a new allocated Buffer
226   * @throws { BusinessError } 401 - Parameter error. Possible causes:
227   * 1.Mandatory parameters are left unspecified;
228   * 2.Incorrect parameter types;
229   * 3.Parameter verification failed.
230   * @syscap SystemCapability.Utils.Lang
231   * @since 9
232   */
233  /**
234   * Creates a Buffer instance of the specified size, without initializing it.
235   *
236   * @param { number } size - Size of the Buffer instance to create, in bytes.
237   * @returns { Buffer } Return a new allocated Buffer
238   * @throws { BusinessError } 401 - Parameter error. Possible causes:
239   * 1.Mandatory parameters are left unspecified;
240   * 2.Incorrect parameter types;
241   * 3.Parameter verification failed.
242   * @syscap SystemCapability.Utils.Lang
243   * @crossplatform
244   * @since 10
245   */
246  /**
247   * Creates a Buffer instance of the specified size, without initializing it.
248   *
249   * @param { number } size - Size of the Buffer instance to create, in bytes.
250   * @returns { Buffer } Return a new allocated Buffer
251   * @throws { BusinessError } 401 - Parameter error. Possible causes:
252   * 1.Mandatory parameters are left unspecified;
253   * 2.Incorrect parameter types;
254   * 3.Parameter verification failed.
255   * @syscap SystemCapability.Utils.Lang
256   * @crossplatform
257   * @atomicservice
258   * @since arkts {'1.1':'11', '1.2':'20'}
259   * @arkts 1.1&1.2
260   */
261  function allocUninitialized(size: number): Buffer;
262
263  /**
264   * Returns the byte length of a string when encoded using `encoding`.
265   * This is not the same as [`String.prototype.length`], which does not account
266   * for the encoding that is used to convert the string into bytes.
267   *
268   * @param { string | Buffer | TypedArray | DataView | ArrayBuffer | SharedArrayBuffer } string - string string A value to calculate the length of
269   * @param { BufferEncoding } [encoding] - encoding [encoding='utf8'] If `string` is a string, this is its encoding
270   * @returns { number } The number of bytes contained within `string`
271   * @throws { BusinessError } 401 - Parameter error. Possible causes:
272   * 1.Mandatory parameters are left unspecified;
273   * 2.Incorrect parameter types.
274   * @syscap SystemCapability.Utils.Lang
275   * @since 9
276   */
277  /**
278   * Returns the byte length of a string when encoded using `encoding`.
279   * This is not the same as [`String.prototype.length`], which does not account
280   * for the encoding that is used to convert the string into bytes.
281   *
282   * @param { string | Buffer | TypedArray | DataView | ArrayBuffer | SharedArrayBuffer } string - string string A value to calculate the length of
283   * @param { BufferEncoding } [encoding] - encoding [encoding='utf8'] If `string` is a string, this is its encoding
284   * @returns { number } The number of bytes contained within `string`
285   * @throws { BusinessError } 401 - Parameter error. Possible causes:
286   * 1.Mandatory parameters are left unspecified;
287   * 2.Incorrect parameter types.
288   * @syscap SystemCapability.Utils.Lang
289   * @crossplatform
290   * @since 10
291   */
292  /**
293   * Obtains the number of bytes of a string based on the encoding format.
294   *
295   * @param { string | Buffer | TypedArray | DataView | ArrayBuffer | SharedArrayBuffer } string - Target string.
296   * @param { BufferEncoding } [encoding] - Encoding format of the string. The default value is 'utf8'.
297   * @returns { number } The number of bytes contained within `string`
298   * @throws { BusinessError } 401 - Parameter error. Possible causes:
299   * 1.Mandatory parameters are left unspecified;
300   * 2.Incorrect parameter types.
301   * @syscap SystemCapability.Utils.Lang
302   * @crossplatform
303   * @atomicservice
304   * @since 11
305   */
306  function byteLength(
307    string: string | Buffer | TypedArray | DataView | ArrayBuffer | SharedArrayBuffer,
308    encoding?: BufferEncoding
309  ): number;
310
311  /**
312   * Obtains the number of bytes of a string based on the encoding format.
313   *
314   * @param { string | Buffer | TypedArray | DataView | ArrayBuffer } doc - Target string.
315   * @param { BufferEncoding } [encoding] - Encoding format of the string. The default value is 'utf8'.
316   * @returns { number } The number of bytes contained within `string`
317   * @syscap SystemCapability.Utils.Lang
318   * @crossplatform
319   * @atomicservice
320   * @since 20
321   * @arkts 1.2
322   */
323  function byteLength(
324    doc: string | Buffer | TypedArray | DataView | ArrayBuffer,
325    encoding?: BufferEncoding
326  ): number;
327
328  /**
329   * Returns a new `Buffer` which is the result of concatenating all the `Buffer`instances in the `list` together.
330   *
331   * @param { Buffer[] | Uint8Array[] } list - list list List of `Buffer` or Uint8Array instances to concatenate
332   * @param { number } [totalLength] - totalLength totalLength Total length of the `Buffer` instances in `list` when concatenated
333   * @returns { Buffer } Return a new allocated Buffer
334   * @throws { BusinessError } 401 - Parameter error. Possible causes:
335   * 1.Mandatory parameters are left unspecified;
336   * 2.Incorrect parameter types;
337   * 3.Parameter verification failed.
338   * @throws { BusinessError } 10200001 - The value of "length" is out of range. It must be >= 0 and <= uint32 max. Received value is: [length]
339   * @syscap SystemCapability.Utils.Lang
340   * @since 9
341   */
342  /**
343   * Concatenates an array of Buffer instances of the specified length into a new instance.
344   *
345   * @param { Buffer[] | Uint8Array[] } list - Array of instances to concatenate.
346   * @param { number } [totalLength] - Total length of bytes to be copied. The default value is 0.
347   * @returns { Buffer } Return a new allocated Buffer
348   * @throws { BusinessError } 401 - Parameter error. Possible causes:
349   * 1.Mandatory parameters are left unspecified;
350   * 2.Incorrect parameter types;
351   * 3.Parameter verification failed.
352   * @throws { BusinessError } 10200001 - The value of "length" is out of range. It must be >= 0 and <= uint32 max. Received value is: [length]
353   * @syscap SystemCapability.Utils.Lang
354   * @crossplatform
355   * @since 10
356   */
357  /**
358   * Concatenates an array of Buffer instances of the specified length into a new instance.
359   *
360   * @param { Buffer[] | Uint8Array[] } list - Array of instances to concatenate.
361   * @param { number } [totalLength] - Total length of bytes to be copied. The default value is 0.
362   * @returns { Buffer } Return a new allocated Buffer
363   * @throws { BusinessError } 401 - Parameter error. Possible causes:
364   * 1.Mandatory parameters are left unspecified;
365   * 2.Incorrect parameter types;
366   * 3.Parameter verification failed.
367   * @throws { BusinessError } 10200001 - The value of "length" is out of range. It must be >= 0 and <= uint32 max. Received value is: [length]
368   * @syscap SystemCapability.Utils.Lang
369   * @crossplatform
370   * @atomicservice
371   * @since arkts {'1.1':'11', '1.2':'20'}
372   * @arkts 1.1&1.2
373   */
374  function concat(list: Buffer[] | Uint8Array[], totalLength?: number): Buffer;
375
376  /**
377   * Allocates a new Buffer using an array of bytes in the range 0 – 255. Array entries outside that range will be truncated to fit into it.
378   *
379   * @param { number[] } array - array array an array of bytes in the range 0 – 255
380   * @returns { Buffer } Return a new allocated Buffer
381   * @throws { BusinessError } 401 - Parameter error. Possible causes:
382   * 1.Mandatory parameters are left unspecified;
383   * 2.Incorrect parameter types.
384   * @syscap SystemCapability.Utils.Lang
385   * @since 9
386   */
387  /**
388   * Creates a Buffer instance with the specified array.
389   *
390   * @param { number[] } array - Array to create a Buffer instance.
391   * @returns { Buffer } Return a new allocated Buffer
392   * @throws { BusinessError } 401 - Parameter error. Possible causes:
393   * 1.Mandatory parameters are left unspecified;
394   * 2.Incorrect parameter types.
395   * @syscap SystemCapability.Utils.Lang
396   * @crossplatform
397   * @since 10
398   */
399  /**
400   * Creates a Buffer instance with the specified array.
401   *
402   * @param { number[] } array - Array to create a Buffer instance.
403   * @returns { Buffer } Return a new allocated Buffer
404   * @throws { BusinessError } 401 - Parameter error. Possible causes:
405   * 1.Mandatory parameters are left unspecified;
406   * 2.Incorrect parameter types.
407   * @syscap SystemCapability.Utils.Lang
408   * @crossplatform
409   * @atomicservice
410   * @since arkts {'1.1':'11', '1.2':'20'}
411   * @arkts 1.1&1.2
412   */
413  function from(array: number[]): Buffer;
414
415  /**
416   * This creates a view of the ArrayBuffer without copying the underlying memory.
417   *
418   * @param { ArrayBuffer | SharedArrayBuffer } arrayBuffer - arrayBuffer arrayBuffer An ArrayBuffer,
419   * SharedArrayBuffer, for example the .buffer property of a TypedArray.
420   * @param { number } [byteOffset] - byteOffset [byteOffset = 0] Index of first byte to expose
421   * @param { number } [length] - length [length = arrayBuffer.byteLength - byteOffset] Number of bytes to expose
422   * @returns { Buffer } Return a view of the ArrayBuffer
423   * @throws { BusinessError } 401 - Parameter error. Possible causes:
424   * 1.Mandatory parameters are left unspecified;
425   * 2.Incorrect parameter types.
426   * @throws { BusinessError } 10200001 - The value of "[byteOffset/length]" is out of range.
427   * It must be >= [left range] and <= [right range]. Received value is: [byteOffset/length]
428   * @syscap SystemCapability.Utils.Lang
429   * @since 9
430   */
431  /**
432   * This creates a view of the ArrayBuffer without copying the underlying memory.
433   *
434   * @param { ArrayBuffer | SharedArrayBuffer } arrayBuffer - arrayBuffer arrayBuffer An ArrayBuffer,
435   * SharedArrayBuffer, for example the .buffer property of a TypedArray.
436   * @param { number } [byteOffset] - byteOffset [byteOffset = 0] Index of first byte to expose
437   * @param { number } [length] - length [length = arrayBuffer.byteLength - byteOffset] Number of bytes to expose
438   * @returns { Buffer } Return a view of the ArrayBuffer
439   * @throws { BusinessError } 401 - Parameter error. Possible causes:
440   * 1.Mandatory parameters are left unspecified;
441   * 2.Incorrect parameter types.
442   * @throws { BusinessError } 10200001 - The value of "[byteOffset/length]" is out of range.
443   * It must be >= [left range] and <= [right range]. Received value is: [byteOffset/length]
444   * @syscap SystemCapability.Utils.Lang
445   * @crossplatform
446   * @since 10
447   */
448  /**
449   * This creates a view of the ArrayBuffer without copying the underlying memory.
450   *
451   * @param { ArrayBuffer | SharedArrayBuffer } arrayBuffer - arrayBuffer arrayBuffer An ArrayBuffer,
452   * SharedArrayBuffer, for example the .buffer property of a TypedArray.
453   * @param { number } [byteOffset] - byteOffset [byteOffset = 0] Index of first byte to expose
454   * @param { number } [length] - length [length = arrayBuffer.byteLength - byteOffset] Number of bytes to expose
455   * @returns { Buffer } Return a view of the ArrayBuffer
456   * @throws { BusinessError } 401 - Parameter error. Possible causes:
457   * 1.Mandatory parameters are left unspecified;
458   * 2.Incorrect parameter types.
459   * @throws { BusinessError } 10200001 - The value of "[byteOffset/length]" is out of range.
460   * It must be >= [left range] and <= [right range]. Received value is: [byteOffset/length]
461   * @syscap SystemCapability.Utils.Lang
462   * @crossplatform
463   * @atomicservice
464   * @since 11
465   */
466  function from(arrayBuffer: ArrayBuffer | SharedArrayBuffer, byteOffset?: number, length?: number): Buffer;
467
468  /**
469   * This creates a view of the ArrayBuffer without copying the underlying memory.
470   *
471   * @param { ArrayBuffer } arrayBuffer - arrayBuffer arrayBuffer An ArrayBuffer,
472   * @param { number } [byteOffset] - byteOffset [byteOffset = 0] Index of first byte to expose
473   * @param { number } [length] - length [length = arrayBuffer.byteLength - byteOffset] Number of bytes to expose
474   * @returns { Buffer } Return a view of the ArrayBuffer
475   * @throws { BusinessError } 10200001 - The value of "[byteOffset/length]" is out of range.
476   * It must be >= [left range] and <= [right range]. Received value is: [byteOffset/length]
477   * @syscap SystemCapability.Utils.Lang
478   * @crossplatform
479   * @atomicservice
480   * @since 20
481   * @arkts 1.2
482   */
483  function from(arrayBuffer: ArrayBuffer, byteOffset?: number, length?: number): Buffer;
484
485  /**
486   * Copies the passed buffer data onto a new Buffer instance.
487   *
488   * @param { Buffer | Uint8Array } buffer - buffer buffer An existing Buffer or Uint8Array from which to copy data
489   * @returns { Buffer } Return a new allocated Buffer
490   * @throws { BusinessError } 401 - Parameter error. Possible causes:
491   * 1.Mandatory parameters are left unspecified;
492   * 2.Incorrect parameter types.
493   * @syscap SystemCapability.Utils.Lang
494   * @since 9
495   */
496  /**
497   * Copies the data of a passed Buffer instance to create a new Buffer instance and returns the new one.
498   *
499   * @param { Buffer | Uint8Array } buffer - Buffer or Uint8Array instance.
500   * @returns { Buffer } Return a new allocated Buffer
501   * @throws { BusinessError } 401 - Parameter error. Possible causes:
502   * 1.Mandatory parameters are left unspecified;
503   * 2.Incorrect parameter types.
504   * @syscap SystemCapability.Utils.Lang
505   * @crossplatform
506   * @since 10
507   */
508  /**
509   * Copies the data of a passed Buffer instance to create a new Buffer instance and returns the new one.
510   *
511   * @param { Buffer | Uint8Array } buffer - Buffer or Uint8Array instance.
512   * @returns { Buffer } Return a new allocated Buffer
513   * @throws { BusinessError } 401 - Parameter error. Possible causes:
514   * 1.Mandatory parameters are left unspecified;
515   * 2.Incorrect parameter types.
516   * @syscap SystemCapability.Utils.Lang
517   * @crossplatform
518   * @atomicservice
519   * @since arkts {'1.1':'11', '1.2':'20'}
520   * @arkts 1.1&1.2
521   */
522  function from(buffer: Buffer | Uint8Array): Buffer;
523
524  /**
525   * For the object whose value returned by valueof() function is strictly equal to object
526   * or supports symbol To primitive object, a new buffer instance is created.
527   *
528   * @param { Object } object - object object An object supporting Symbol.toPrimitive or valueOf()
529   * @param { number | string } offsetOrEncoding - offsetOrEncoding offsetOrEncoding A byte-offset or encoding
530   * @param { number } length - length length A length
531   * @returns { Buffer } Return a new allocated Buffer
532   * @throws { BusinessError } 401 - Parameter error. Possible causes:
533   * 1.Mandatory parameters are left unspecified;
534   * 2.Incorrect parameter types.
535   * @syscap SystemCapability.Utils.Lang
536   * @since 9
537   */
538  /**
539   * Creates a Buffer instance based on the specified object.
540   *
541   * @param { Object } object - Object that supports Symbol.toPrimitive or valueOf().
542   * @param { number | string } offsetOrEncoding - Byte offset or encoding format.
543   * @param { number } length - Length of the Buffer instance to create, in bytes.
544   * @returns { Buffer } Return a new allocated Buffer
545   * @throws { BusinessError } 401 - Parameter error. Possible causes:
546   * 1.Mandatory parameters are left unspecified;
547   * 2.Incorrect parameter types.
548   * @syscap SystemCapability.Utils.Lang
549   * @crossplatform
550   * @since 10
551   */
552  /**
553   * Creates a Buffer instance based on the specified object.
554   *
555   * @param { Object } object - Object that supports Symbol.toPrimitive or valueOf().
556   * @param { number | string } offsetOrEncoding - Byte offset or encoding format.
557   * @param { number } length - Length of the Buffer instance to create, in bytes.
558   * @returns { Buffer } Return a new allocated Buffer
559   * @throws { BusinessError } 401 - Parameter error. Possible causes:
560   * 1.Mandatory parameters are left unspecified;
561   * 2.Incorrect parameter types.
562   * @syscap SystemCapability.Utils.Lang
563   * @crossplatform
564   * @atomicservice
565   * @since arkts {'1.1':'11', '1.2':'20'}
566   * @arkts 1.1&1.2
567   */
568  function from(object: Object, offsetOrEncoding: number | string, length: number): Buffer;
569
570  /**
571   * Creates a new Buffer containing string. The encoding parameter identifies the character encoding
572   * to be used when converting string into bytes.
573   *
574   * @param { String } string - string string  A string to encode
575   * @param { BufferEncoding } [encoding] - encoding [encoding='utf8'] The encoding of string
576   * @returns { Buffer } Return a new Buffer containing string
577   * @throws { BusinessError } 401 - Parameter error. Possible causes:
578   * 1.Mandatory parameters are left unspecified;
579   * 2.Incorrect parameter types.
580   * @syscap SystemCapability.Utils.Lang
581   * @since 9
582   */
583  /**
584   * Creates a Buffer instance based on a string in the given encoding format.
585   *
586   * @param { String } string - String.
587   * @param { BufferEncoding } [encoding] - Encoding format of the string. The default value is 'utf8'.
588   * @returns { Buffer } Return a new Buffer containing string
589   * @throws { BusinessError } 401 - Parameter error. Possible causes:
590   * 1.Mandatory parameters are left unspecified;
591   * 2.Incorrect parameter types.
592   * @syscap SystemCapability.Utils.Lang
593   * @crossplatform
594   * @since 10
595   */
596  /**
597   * Creates a Buffer instance based on a string in the given encoding format.
598   *
599   * @param { String } string - String.
600   * @param { BufferEncoding } [encoding] - Encoding format of the string. The default value is 'utf8'.
601   * @returns { Buffer } Return a new Buffer containing string
602   * @throws { BusinessError } 401 - Parameter error. Possible causes:
603   * 1.Mandatory parameters are left unspecified;
604   * 2.Incorrect parameter types.
605   * @syscap SystemCapability.Utils.Lang
606   * @crossplatform
607   * @atomicservice
608   * @since arkts {'1.1':'11', '1.2':'20'}
609   * @arkts 1.1&1.2
610   */
611  function from(string: String, encoding?: BufferEncoding): Buffer;
612
613  /**
614   * Returns true if obj is a Buffer, false otherwise
615   *
616   * @param { Object } obj - obj obj Objects to be judged
617   * @returns { boolean } true or false
618   * @syscap SystemCapability.Utils.Lang
619   * @since 9
620   */
621  /**
622   * Checks whether the specified object is a Buffer instance.
623   *
624   * @param { Object } obj - Object to check.
625   * @returns { boolean } true or false
626   * @syscap SystemCapability.Utils.Lang
627   * @crossplatform
628   * @since 10
629   */
630  /**
631   * Checks whether the specified object is a Buffer instance.
632   *
633   * @param { Object } obj - Object to check.
634   * @returns { boolean } true or false
635   * @syscap SystemCapability.Utils.Lang
636   * @crossplatform
637   * @atomicservice
638   * @since arkts {'1.1':'11', '1.2':'20'}
639   * @arkts 1.1&1.2
640   */
641  function isBuffer(obj: Object): boolean;
642
643  /**
644   * Returns true if encoding is the name of a supported character encoding, or false otherwise.
645   *
646   * @param { string } encoding - encoding encoding A character encoding name to check
647   * @returns { boolean } true or false
648   * @syscap SystemCapability.Utils.Lang
649   * @since 9
650   */
651  /**
652   * Checks whether the encoding format is supported.
653   *
654   * @param { string } encoding - Encoding format.
655   * @returns { boolean } true or false
656   * @syscap SystemCapability.Utils.Lang
657   * @crossplatform
658   * @since 10
659   */
660  /**
661   * Checks whether the encoding format is supported.
662   *
663   * @param { string } encoding - Encoding format.
664   * @returns { boolean } true or false
665   * @syscap SystemCapability.Utils.Lang
666   * @crossplatform
667   * @atomicservice
668   * @since arkts {'1.1':'11', '1.2':'20'}
669   * @arkts 1.1&1.2
670   */
671  function isEncoding(encoding: string): boolean;
672
673  /**
674   * Compares buf1 to buf2
675   *
676   * @param { Buffer | Uint8Array } buf1 - buf1 buf1 A Buffer or Uint8Array instance.
677   * @param { Buffer | Uint8Array } buf2 - buf2 buf2 A Buffer or Uint8Array instance.
678   * @returns { -1 | 0 | 1 } 0 is returned if target is the same as buf
679   *         1 is returned if target should come before buf when sorted.
680   *        -1 is returned if target should come after buf when sorted.
681   * @throws { BusinessError } 401 - Parameter error. Possible causes:
682   * 1.Mandatory parameters are left unspecified;
683   * 2.Incorrect parameter types.
684   * @syscap SystemCapability.Utils.Lang
685   * @since 9
686   */
687  /**
688   * Compares buf1 to buf2
689   *
690   * @param { Buffer | Uint8Array } buf1 - buf1 buf1 A Buffer or Uint8Array instance.
691   * @param { Buffer | Uint8Array } buf2 - buf2 buf2 A Buffer or Uint8Array instance.
692   * @returns { -1 | 0 | 1 } 0 is returned if target is the same as buf
693   *         1 is returned if target should come before buf when sorted.
694   *        -1 is returned if target should come after buf when sorted.
695   * @throws { BusinessError } 401 - Parameter error. Possible causes:
696   * 1.Mandatory parameters are left unspecified;
697   * 2.Incorrect parameter types.
698   * @syscap SystemCapability.Utils.Lang
699   * @crossplatform
700   * @since 10
701   */
702  /**
703   * Compares buf1 to buf2
704   *
705   * @param { Buffer | Uint8Array } buf1 - buf1 buf1 A Buffer or Uint8Array instance.
706   * @param { Buffer | Uint8Array } buf2 - buf2 buf2 A Buffer or Uint8Array instance.
707   * @returns { -1 | 0 | 1 } 0 is returned if target is the same as buf
708   *         1 is returned if target should come before buf when sorted.
709   *        -1 is returned if target should come after buf when sorted.
710   * @throws { BusinessError } 401 - Parameter error. Possible causes:
711   * 1.Mandatory parameters are left unspecified;
712   * 2.Incorrect parameter types.
713   * @syscap SystemCapability.Utils.Lang
714   * @crossplatform
715   * @atomicservice
716   * @since 11
717   */
718  function compare(buf1: Buffer | Uint8Array, buf2: Buffer | Uint8Array): -1 | 0 | 1;
719
720  /**
721   * Compares buf1 to buf2
722   *
723   * @param { Buffer | Uint8Array } buf1 - buf1 buf1 A Buffer or Uint8Array instance.
724   * @param { Buffer | Uint8Array } buf2 - buf2 buf2 A Buffer or Uint8Array instance.
725   * @returns { number } 0 is returned if target is the same as buf
726   *         1 is returned if target should come before buf when sorted.
727   *        -1 is returned if target should come after buf when sorted.
728   * @syscap SystemCapability.Utils.Lang
729   * @crossplatform
730   * @atomicservice
731   * @since 20
732   * @arkts 1.2
733   */
734  function compare(buf1: Buffer | Uint8Array, buf2: Buffer | Uint8Array): number;
735
736  /**
737   * Re-encodes the given Buffer or Uint8Array instance from one character encoding to another.
738   *
739   * @param { Buffer | Uint8Array } source - source source A Buffer or Uint8Array instance.
740   * @param { string } fromEnc - fromEnc fromEnc The current encoding
741   * @param { string } toEnc - toEnc toEnc To target encoding
742   * @returns { Buffer } Returns a new Buffer instance
743   * @throws { BusinessError } 401 - Parameter error. Possible causes:
744   * 1.Mandatory parameters are left unspecified;
745   * 2.Incorrect parameter types.
746   * @syscap SystemCapability.Utils.Lang
747   * @since 9
748   */
749  /**
750   * Transcodes the given Buffer or Uint8Array object from one encoding format to another.
751   *
752   * @param { Buffer | Uint8Array } source - Instance to encode.
753   * @param { string } fromEnc - Current encoding format
754   * @param { string } toEnc - Target encoding format.
755   * @returns { Buffer } Returns a new Buffer instance
756   * @throws { BusinessError } 401 - Parameter error. Possible causes:
757   * 1.Mandatory parameters are left unspecified;
758   * 2.Incorrect parameter types.
759   * @syscap SystemCapability.Utils.Lang
760   * @crossplatform
761   * @since 10
762   */
763  /**
764   * Transcodes the given Buffer or Uint8Array object from one encoding format to another.
765   *
766   * @param { Buffer | Uint8Array } source - Instance to encode.
767   * @param { string } fromEnc - Current encoding format
768   * @param { string } toEnc - Target encoding format.
769   * @returns { Buffer } Returns a new Buffer instance
770   * @throws { BusinessError } 401 - Parameter error. Possible causes:
771   * 1.Mandatory parameters are left unspecified;
772   * 2.Incorrect parameter types.
773   * @syscap SystemCapability.Utils.Lang
774   * @crossplatform
775   * @atomicservice
776   * @since arkts {'1.1':'11', '1.2':'20'}
777   * @arkts 1.1&1.2
778   */
779  function transcode(source: Buffer | Uint8Array, fromEnc: string, toEnc: string): Buffer;
780
781
782  /**
783   * The Buffer object is a method of handling buffers dedicated to binary data.
784   *
785   * @syscap SystemCapability.Utils.Lang
786   * @since 9
787   */
788  /**
789   * The Buffer object is a method of handling buffers dedicated to binary data.
790   *
791   * @syscap SystemCapability.Utils.Lang
792   * @crossplatform
793   * @since 10
794   */
795  /**
796   * The Buffer object is a method of handling buffers dedicated to binary data.
797   *
798   * @syscap SystemCapability.Utils.Lang
799   * @crossplatform
800   * @atomicservice
801   * @since arkts {'1.1':'11', '1.2':'20'}
802   * @arkts 1.1&1.2
803   */
804  class Buffer {
805    /**
806     * Returns the number of bytes in buf
807     *
808     * @type { number }
809     * @throws { BusinessError } 10200013 - Length  cannot be set for the buffer that has only a getter.
810     * @syscap SystemCapability.Utils.Lang
811     * @since 9
812     */
813    /**
814     * Returns the number of bytes in buf
815     *
816     * @type { number }
817     * @throws { BusinessError } 10200013 - Length  cannot be set for the buffer that has only a getter.
818     * @syscap SystemCapability.Utils.Lang
819     * @crossplatform
820     * @since 10
821     */
822    /**
823     * Returns the number of bytes in buf
824     *
825     * @type { number }
826     * @throws { BusinessError } 10200013 - Length  cannot be set for the buffer that has only a getter.
827     * @syscap SystemCapability.Utils.Lang
828     * @crossplatform
829     * @atomicservice
830     * @since 11
831     */
832    length: number;
833
834    /**
835     * Gets the element number of the buffer.
836     *
837     * @type { number }
838     * @syscap SystemCapability.Utils.Lang
839     * @crossplatform
840     * @atomicservice
841     * @since 20
842     * @arkts 1.2
843     */
844    get length(): number;
845
846    /**
847     * The underlying ArrayBuffer object based on which this Buffer object is created.
848     *
849     * @type { ArrayBuffer }
850     * @throws { BusinessError } 10200013 - Buffer cannot be set for the buffer that has only a getter.
851     * @syscap SystemCapability.Utils.Lang
852     * @since 9
853     */
854    /**
855     * The underlying ArrayBuffer object based on which this Buffer object is created.
856     *
857     * @type { ArrayBuffer }
858     * @throws { BusinessError } 10200013 - Buffer cannot be set for the buffer that has only a getter.
859     * @syscap SystemCapability.Utils.Lang
860     * @crossplatform
861     * @since 10
862     */
863    /**
864     * The underlying ArrayBuffer object based on which this Buffer object is created.
865     *
866     * @type { ArrayBuffer }
867     * @throws { BusinessError } 10200013 - Buffer cannot be set for the buffer that has only a getter.
868     * @syscap SystemCapability.Utils.Lang
869     * @crossplatform
870     * @atomicservice
871     * @since 11
872     */
873    buffer: ArrayBuffer;
874
875    /**
876     * The underlying ArrayBuffer object based on which this Buffer object is created.
877     *
878     * @type { ArrayBuffer }
879     * @throws { BusinessError } 10200013 - Buffer cannot be set for the buffer that has only a getter.
880     * @syscap SystemCapability.Utils.Lang
881     * @crossplatform
882     * @atomicservice
883     * @since 20
884     * @arkts 1.2
885     */
886    get buffer(): ArrayBuffer;
887
888    /**
889     * The byteOffset of the Buffers underlying ArrayBuffer object
890     *
891     * @type { number }
892     * @throws { BusinessError } 10200013 - ByteOffset  cannot be set for the buffer that has only a getter.
893     * @syscap SystemCapability.Utils.Lang
894     * @since 9
895     */
896    /**
897     * The byteOffset of the Buffers underlying ArrayBuffer object
898     *
899     * @type { number }
900     * @throws { BusinessError } 10200013 - ByteOffset  cannot be set for the buffer that has only a getter.
901     * @syscap SystemCapability.Utils.Lang
902     * @crossplatform
903     * @since 10
904     */
905    /**
906     * The byteOffset of the Buffers underlying ArrayBuffer object
907     *
908     * @type { number }
909     * @throws { BusinessError } 10200013 - ByteOffset  cannot be set for the buffer that has only a getter.
910     * @syscap SystemCapability.Utils.Lang
911     * @crossplatform
912     * @atomicservice
913     * @since 11
914     */
915    byteOffset: number;
916
917    /**
918     * The byteOffset of the Buffers underlying ArrayBuffer object
919     *
920     * @type { number }
921     * @throws { BusinessError } 10200013 - ByteOffset  cannot be set for the buffer that has only a getter.
922     * @syscap SystemCapability.Utils.Lang
923     * @crossplatform
924     * @atomicservice
925     * @since 20
926     * @arkts 1.2
927     */
928    get byteOffset(): number;
929
930    /**
931     * Fills buf with the specified value. If the offset and end are not given, the entire buf will be filled.
932     *
933     * @param { string | Buffer | Uint8Array | number } value - value value The value with which to fill buf
934     * @param { number } [offset] - offset [offset = 0] Number of bytes to skip before starting to fill buf
935     * @param { number } [end] - end [end = buf.length] Where to stop filling buf (not inclusive)
936     * @param { BufferEncoding } [encoding] - encoding [encoding='utf8'] The encoding for value if value is a string
937     * @returns { Buffer } A reference to buf
938     * @throws { BusinessError } 10200001 - The value of "[offset/end]" is out of range. It must be >= 0 and <= [right range]. Received value is: [offset/end]
939     * @throws { BusinessError } 401 - Parameter error. Possible causes:
940     * 1.Incorrect parameter types;
941     * 2.Parameter verification failed.
942     * @syscap SystemCapability.Utils.Lang
943     * @since 9
944     */
945    /**
946     * Fills this Buffer instance at the specified position. By default, data is filled cyclically.
947     *
948     * @param { string | Buffer | Uint8Array | number } value - Value to fill.
949     * @param { number } [offset] - Offset to the start position in this Buffer instance where data is filled. The default value is 0.
950     * @param { number } [end] - Offset to the end position in this Buffer instance (not inclusive). The default value is the length of this Buffer instance.
951     * @param { BufferEncoding } [encoding] - Encoding format (valid only when value is a string). The default value is 'utf8'.
952     * @returns { Buffer } A reference to buf
953     * @throws { BusinessError } 10200001 - The value of "[offset/end]" is out of range. It must be >= 0 and <= [right range]. Received value is: [offset/end]
954     * @throws { BusinessError } 401 - Parameter error. Possible causes:
955     * 1.Incorrect parameter types;
956     * 2.Parameter verification failed.
957     * @syscap SystemCapability.Utils.Lang
958     * @crossplatform
959     * @since 10
960     */
961    /**
962     * Fills this Buffer instance at the specified position. By default, data is filled cyclically.
963     *
964     * @param { string | Buffer | Uint8Array | number } value - Value to fill.
965     * @param { number } [offset] - Offset to the start position in this Buffer instance where data is filled. The default value is 0.
966     * @param { number } [end] - Offset to the end position in this Buffer instance (not inclusive). The default value is the length of this Buffer instance.
967     * @param { BufferEncoding } [encoding] - Encoding format (valid only when value is a string). The default value is 'utf8'.
968     * @returns { Buffer } A reference to buf
969     * @throws { BusinessError } 10200001 - The value of "[offset/end]" is out of range. It must be >= 0 and <= [right range]. Received value is: [offset/end]
970     * @throws { BusinessError } 401 - Parameter error. Possible causes:
971     * 1.Incorrect parameter types;
972     * 2.Parameter verification failed.
973     * @syscap SystemCapability.Utils.Lang
974     * @crossplatform
975     * @atomicservice
976     * @since arkts {'1.1':'11', '1.2':'20'}
977     * @arkts 1.1&1.2
978     */
979    fill(
980      value: string | Buffer | Uint8Array | number,
981      offset?: number,
982      end?: number,
983      encoding?: BufferEncoding
984    ): Buffer;
985
986    /**
987     * Compares buf with target and returns a number indicating whether buf comes before, after,
988     * or is the same as target in sort order. Comparison is based on the actual sequence of bytes in each Buffer.
989     *
990     * @param { Buffer | Uint8Array } target - target target A Buffer or Uint8Array with which to compare buf
991     * @param { number } [targetStart] - targetStart [targetStart = 0] The offset within target at which to begin comparison
992     * @param { number } [targetEnd] - targetEnd [targetEnd = target.length] The offset within target at which to end comparison (not inclusive)
993     * @param { number } [sourceStart] - sourceStart [sourceStart = 0] The offset within buf at which to begin comparison
994     * @param { number } [sourceEnd] - sourceEnd [sourceEnd = buf.length] The offset within buf at which to end comparison (not inclusive)
995     * @returns { -1 | 0 | 1 } 0 is returned if target is the same as buf
996     *         1 is returned if target should come before buf when sorted.
997     *        -1 is returned if target should come after buf when sorted.
998     * @throws { BusinessError } 401 - Parameter error. Possible causes:
999     * 1.Mandatory parameters are left unspecified;
1000     * 2.Incorrect parameter types.
1001     * @throws { BusinessError } 10200001 - The value of "[targetStart/targetEnd/sourceStart/sourceEnd]" is out of range.
1002     *         It must be >= 0 and <= [right range]. Received value is: [targetStart/targetEnd/sourceStart/sourceEnd]
1003     * @syscap SystemCapability.Utils.Lang
1004     * @since 9
1005     */
1006    /**
1007     * Compares buf with target and returns a number indicating whether buf comes before, after,
1008     * or is the same as target in sort order. Comparison is based on the actual sequence of bytes in each Buffer.
1009     *
1010     * @param { Buffer | Uint8Array } target - target target A Buffer or Uint8Array with which to compare buf
1011     * @param { number } [targetStart] - targetStart [targetStart = 0] The offset within target at which to begin comparison
1012     * @param { number } [targetEnd] - targetEnd [targetEnd = target.length] The offset within target at which to end comparison (not inclusive)
1013     * @param { number } [sourceStart] - sourceStart [sourceStart = 0] The offset within buf at which to begin comparison
1014     * @param { number } [sourceEnd] - sourceEnd [sourceEnd = buf.length] The offset within buf at which to end comparison (not inclusive)
1015     * @returns { -1 | 0 | 1 } 0 is returned if target is the same as buf
1016     *         1 is returned if target should come before buf when sorted.
1017     *        -1 is returned if target should come after buf when sorted.
1018     * @throws { BusinessError } 401 - Parameter error. Possible causes:
1019     * 1.Mandatory parameters are left unspecified;
1020     * 2.Incorrect parameter types.
1021     * @throws { BusinessError } 10200001 - The value of "[targetStart/targetEnd/sourceStart/sourceEnd]" is out of range.
1022     *         It must be >= 0 and <= [right range]. Received value is: [targetStart/targetEnd/sourceStart/sourceEnd]
1023     * @syscap SystemCapability.Utils.Lang
1024     * @crossplatform
1025     * @since 10
1026     */
1027    /**
1028     * Compares buf with target and returns a number indicating whether buf comes before, after,
1029     * or is the same as target in sort order. Comparison is based on the actual sequence of bytes in each Buffer.
1030     *
1031     * @param { Buffer | Uint8Array } target - target target A Buffer or Uint8Array with which to compare buf
1032     * @param { number } [targetStart] - targetStart [targetStart = 0] The offset within target at which to begin comparison
1033     * @param { number } [targetEnd] - targetEnd [targetEnd = target.length] The offset within target at which to end comparison (not inclusive)
1034     * @param { number } [sourceStart] - sourceStart [sourceStart = 0] The offset within buf at which to begin comparison
1035     * @param { number } [sourceEnd] - sourceEnd [sourceEnd = buf.length] The offset within buf at which to end comparison (not inclusive)
1036     * @returns { -1 | 0 | 1 } 0 is returned if target is the same as buf
1037     *         1 is returned if target should come before buf when sorted.
1038     *        -1 is returned if target should come after buf when sorted.
1039     * @throws { BusinessError } 401 - Parameter error. Possible causes:
1040     * 1.Mandatory parameters are left unspecified;
1041     * 2.Incorrect parameter types.
1042     * @throws { BusinessError } 10200001 - The value of "[targetStart/targetEnd/sourceStart/sourceEnd]" is out of range.
1043     *         It must be >= 0 and <= [right range]. Received value is: [targetStart/targetEnd/sourceStart/sourceEnd]
1044     * @syscap SystemCapability.Utils.Lang
1045     * @crossplatform
1046     * @atomicservice
1047     * @since 11
1048     */
1049    compare(
1050      target: Buffer | Uint8Array,
1051      targetStart?: number,
1052      targetEnd?: number,
1053      sourceStart?: number,
1054      sourceEnd?: number
1055    ): -1 | 0 | 1;
1056
1057    /**
1058     * Compares buf with target and returns a number indicating whether buf comes before, after,
1059     * or is the same as target in sort order. Comparison is based on the actual sequence of bytes in each Buffer.
1060     *
1061     * @param { Buffer | Uint8Array } target - target target A Buffer or Uint8Array with which to compare buf
1062     * @param { number } [targetStart] - targetStart [targetStart = 0] The offset within target at which to begin comparison
1063     * @param { number } [targetEnd] - targetEnd [targetEnd = target.length] The offset within target at which to end comparison (not inclusive)
1064     * @param { number } [sourceStart] - sourceStart [sourceStart = 0] The offset within buf at which to begin comparison
1065     * @param { number } [sourceEnd] - sourceEnd [sourceEnd = buf.length] The offset within buf at which to end comparison (not inclusive)
1066     * @returns { number } number is returned if target is the same as buf
1067     * @throws { BusinessError } 401 - Parameter error. Possible causes:
1068     * 1.Mandatory parameters are left unspecified;
1069     * 2.Incorrect parameter types.
1070     * @throws { BusinessError } 10200001 - The value of "[targetStart/targetEnd/sourceStart/sourceEnd]" is out of range.
1071     *         It must be >= 0 and <= [right range]. Received value is: [targetStart/targetEnd/sourceStart/sourceEnd]
1072     * @syscap SystemCapability.Utils.Lang
1073     * @crossplatform
1074     * @atomicservice
1075     * @since 20
1076     * @arkts 1.2
1077     */
1078    compare(
1079      target: Buffer | Uint8Array,
1080      targetStart?: number,
1081      targetEnd?: number,
1082      sourceStart?: number,
1083      sourceEnd?: number
1084    ): number;
1085
1086    /**
1087     * Copies data from a region of buf to a region in target, even if the target memory region overlaps with buf.
1088     * If sourceEnd is greater than the length of the target, the length of the target shall prevail, and the extra part will not be overwritten.
1089     *
1090     * @param { Buffer | Uint8Array } target - target target A Buffer or Uint8Array to copy into
1091     * @param { number } [targetStart] - targetStart [targetStart = 0] The offset within target at which to begin writing
1092     * @param { number } [sourceStart] - sourceStart [sourceStart = 0] The offset within buf from which to begin copying
1093     * @param { number } [sourceEnd] - sourceEnd [sourceEnd = buf.length] The offset within buf at which to stop copying (not inclusive)
1094     * @returns { number } The number of bytes copied
1095     * @throws { BusinessError } 401 - Parameter error. Possible causes:
1096     * 1.Mandatory parameters are left unspecified;
1097     * 2.Incorrect parameter types.
1098     * @throws { BusinessError } 10200001 - The value of "[targetStart/sourceStart/sourceEnd]" is out of range. It must be >= 0.
1099     *                                    Received value is: [targetStart/sourceStart/sourceEnd]
1100     * @syscap SystemCapability.Utils.Lang
1101     * @since 9
1102     */
1103    /**
1104     * Copies data at the specified position in this Buffer instance to the specified position in another Buffer instance.
1105     *
1106     * @param { Buffer | Uint8Array } target - Instance to which data is copied.
1107     * @param { number } [targetStart] - Offset to the start position in the target instance where data is copied. The default value is 0.
1108     * @param { number } [sourceStart] - Offset to the start position in this Buffer instance where data is copied. The default value is 0.
1109     * @param { number } [sourceEnd] - Offset to the end position in this Buffer instance (not inclusive).
1110     * The default value is the length of this Buffer instance.
1111     * @returns { number } The number of bytes copied
1112     * @throws { BusinessError } 401 - Parameter error. Possible causes:
1113     * 1.Mandatory parameters are left unspecified;
1114     * 2.Incorrect parameter types.
1115     * @throws { BusinessError } 10200001 - The value of "[targetStart/sourceStart/sourceEnd]" is out of range. It must be >= 0.
1116     *                                    Received value is: [targetStart/sourceStart/sourceEnd]
1117     * @syscap SystemCapability.Utils.Lang
1118     * @crossplatform
1119     * @since 10
1120     */
1121    /**
1122     * Copies data at the specified position in this Buffer instance to the specified position in another Buffer instance.
1123     *
1124     * @param { Buffer | Uint8Array } target - Instance to which data is copied.
1125     * @param { number } [targetStart] - Offset to the start position in the target instance where data is copied. The default value is 0.
1126     * @param { number } [sourceStart] - Offset to the start position in this Buffer instance where data is copied. The default value is 0.
1127     * @param { number } [sourceEnd] - Offset to the end position in this Buffer instance (not inclusive).
1128     * The default value is the length of this Buffer instance.
1129     * @returns { number } The number of bytes copied
1130     * @throws { BusinessError } 401 - Parameter error. Possible causes:
1131     * 1.Mandatory parameters are left unspecified;
1132     * 2.Incorrect parameter types.
1133     * @throws { BusinessError } 10200001 - The value of "[targetStart/sourceStart/sourceEnd]" is out of range. It must be >= 0.
1134     *                                    Received value is: [targetStart/sourceStart/sourceEnd]
1135     * @syscap SystemCapability.Utils.Lang
1136     * @crossplatform
1137     * @atomicservice
1138     * @since arkts {'1.1':'11', '1.2':'20'}
1139     * @arkts 1.1&1.2
1140     */
1141    copy(target: Buffer | Uint8Array, targetStart?: number, sourceStart?: number, sourceEnd?: number): number;
1142
1143    /**
1144     * Returns true if both buf and otherBuffer have exactly the same bytes, false otherwise
1145     *
1146     * @param { Uint8Array | Buffer } otherBuffer - otherBuffer otherBuffer A Buffer or Uint8Array with which to compare buf
1147     * @returns { boolean } true or false
1148     * @throws { BusinessError } 401 - Parameter error. Possible causes: 1.Mandatory parameters are left unspecified; 2.Incorrect parameter types.
1149     * @syscap SystemCapability.Utils.Lang
1150     * @since 9
1151     */
1152    /**
1153     * Checks whether this Buffer instance is the same as another Buffer instance.
1154     *
1155     * @param { Uint8Array | Buffer } otherBuffer - Buffer instance to compare.
1156     * @returns { boolean } true or false
1157     * @throws { BusinessError } 401 - Parameter error. Possible causes: 1.Mandatory parameters are left unspecified; 2.Incorrect parameter types.
1158     * @syscap SystemCapability.Utils.Lang
1159     * @crossplatform
1160     * @since 10
1161     */
1162    /**
1163     * Checks whether this Buffer instance is the same as another Buffer instance.
1164     *
1165     * @param { Uint8Array | Buffer } otherBuffer - Buffer instance to compare.
1166     * @returns { boolean } true or false
1167     * @throws { BusinessError } 401 - Parameter error. Possible causes: 1.Mandatory parameters are left unspecified; 2.Incorrect parameter types.
1168     * @syscap SystemCapability.Utils.Lang
1169     * @crossplatform
1170     * @atomicservice
1171     * @since arkts {'1.1':'11', '1.2':'20'}
1172     * @arkts 1.1&1.2
1173     */
1174    equals(otherBuffer: Uint8Array | Buffer): boolean;
1175
1176    /**
1177     * Returns true if value was found in buf, false otherwise
1178     *
1179     * @param { string | number | Buffer | Uint8Array } value - value value What to search for
1180     * @param { number } [byteOffset] - byteOffset [byteOffset = 0] Where to begin searching in buf. If negative, then offset is calculated from the end of buf
1181     * @param { BufferEncoding } [encoding] - encoding [encoding='utf8'] If value is a string, this is its encoding
1182     * @returns { boolean } true or false
1183     * @throws { BusinessError } 401 - Parameter error. Possible causes:
1184     * 1.Mandatory parameters are left unspecified;
1185     * 2.Incorrect parameter types.
1186     * @syscap SystemCapability.Utils.Lang
1187     * @since 9
1188     */
1189    /**
1190     * Checks whether this Buffer instance contains the specified value.
1191     *
1192     * @param { string | number | Buffer | Uint8Array } value - Value to match.
1193     * @param { number } [byteOffset] - Number of bytes to skip before starting to check data.
1194     * Number of bytes to skip before starting to check data. If the offset is a negative number,
1195     * data is checked from the end of the Buffer instance. The default value is 0.
1196     * @param { BufferEncoding } [encoding] - Encoding format (valid only when value is a string). The default value is 'utf8'.
1197     * @returns { boolean } true or false
1198     * @throws { BusinessError } 401 - Parameter error. Possible causes:
1199     * 1.Mandatory parameters are left unspecified;
1200     * 2.Incorrect parameter types.
1201     * @syscap SystemCapability.Utils.Lang
1202     * @crossplatform
1203     * @since 10
1204     */
1205    /**
1206     * Checks whether this Buffer instance contains the specified value.
1207     *
1208     * @param { string | number | Buffer | Uint8Array } value - Value to match.
1209     * @param { number } [byteOffset] - Number of bytes to skip before starting to check data.
1210     * Number of bytes to skip before starting to check data. If the offset is a negative number,
1211     * data is checked from the end of the Buffer instance. The default value is 0.
1212     * @param { BufferEncoding } [encoding] - Encoding format (valid only when value is a string). The default value is 'utf8'.
1213     * @returns { boolean } true or false
1214     * @throws { BusinessError } 401 - Parameter error. Possible causes:
1215     * 1.Mandatory parameters are left unspecified;
1216     * 2.Incorrect parameter types.
1217     * @syscap SystemCapability.Utils.Lang
1218     * @crossplatform
1219     * @atomicservice
1220     * @since arkts {'1.1':'11', '1.2':'20'}
1221     * @arkts 1.1&1.2
1222     */
1223    includes(value: string | number | Buffer | Uint8Array, byteOffset?: number, encoding?: BufferEncoding): boolean;
1224
1225    /**
1226     * The index of the first occurrence of value in buf
1227     *
1228     * @param { string | number | Buffer | Uint8Array } value - value value What to search for
1229     * @param { number } [byteOffset] - byteOffset [byteOffset = 0] Where to begin searching in buf
1230     * @param { BufferEncoding } [encoding] - encoding [encoding='utf8'] If value is a string,
1231     * this is the encoding used to determine the binary representation of the string that will be searched for in buf
1232     * @returns { number } The index of the first occurrence of value in buf, or -1 if buf does not contain value
1233     * @throws { BusinessError } 401 - Parameter error. Possible causes:
1234     * 1.Mandatory parameters are left unspecified;
1235     * 2.Incorrect parameter types.
1236     * @syscap SystemCapability.Utils.Lang
1237     * @since 9
1238     */
1239    /**
1240     * Obtains the index of the first occurrence of the specified value in this Buffer instance.
1241     *
1242     * @param { string | number | Buffer | Uint8Array } value - Value to match.
1243     * @param { number } [byteOffset] - Number of bytes to skip before starting to check data.
1244     * If the offset is a negative number, data is checked from the end of the Buffer instance. The default value is 0.
1245     * @param { BufferEncoding } [encoding] - Encoding format (valid only when value is a string). The default value is 'utf8'.
1246     * @returns { number } The index of the first occurrence of value in buf, or -1 if buf does not contain value
1247     * @throws { BusinessError } 401 - Parameter error. Possible causes:
1248     * 1.Mandatory parameters are left unspecified;
1249     * 2.Incorrect parameter types.
1250     * @syscap SystemCapability.Utils.Lang
1251     * @crossplatform
1252     * @since 10
1253     */
1254    /**
1255     * Obtains the index of the first occurrence of the specified value in this Buffer instance.
1256     *
1257     * @param { string | number | Buffer | Uint8Array } value - Value to match.
1258     * @param { number } [byteOffset] - Number of bytes to skip before starting to check data.
1259     * If the offset is a negative number, data is checked from the end of the Buffer instance. The default value is 0.
1260     * @param { BufferEncoding } [encoding] - Encoding format (valid only when value is a string). The default value is 'utf8'.
1261     * @returns { number } The index of the first occurrence of value in buf, or -1 if buf does not contain value
1262     * @throws { BusinessError } 401 - Parameter error. Possible causes:
1263     * 1.Mandatory parameters are left unspecified;
1264     * 2.Incorrect parameter types.
1265     * @syscap SystemCapability.Utils.Lang
1266     * @crossplatform
1267     * @atomicservice
1268     * @since arkts {'1.1':'11', '1.2':'20'}
1269     * @arkts 1.1&1.2
1270     */
1271    indexOf(value: string | number | Buffer | Uint8Array, byteOffset?: number, encoding?: BufferEncoding): number;
1272
1273    /**
1274     * Creates and returns an iterator of buf keys (indices).
1275     *
1276     * @returns { IterableIterator<number> }
1277     * @syscap SystemCapability.Utils.Lang
1278     * @since 9
1279     */
1280    /**
1281     * Creates and returns an iterator that contains the keys of this Buffer instance.
1282     *
1283     * @returns { IterableIterator<number> }
1284     * @syscap SystemCapability.Utils.Lang
1285     * @crossplatform
1286     * @since 10
1287     */
1288    /**
1289     * Creates and returns an iterator that contains the keys of this Buffer instance.
1290     *
1291     * @returns { IterableIterator<number> }
1292     * @syscap SystemCapability.Utils.Lang
1293     * @crossplatform
1294     * @atomicservice
1295     * @since arkts {'1.1':'11', '1.2':'20'}
1296     * @arkts 1.1&1.2
1297     */
1298    keys(): IterableIterator<number>;
1299
1300    /**
1301     * Creates and returns an iterator for buf values (bytes).
1302     *
1303     * @returns { IterableIterator<number> }
1304     * @syscap SystemCapability.Utils.Lang
1305     * @since 9
1306     */
1307    /**
1308     * Creates and returns an iterator that contains the values of this Buffer instance.
1309     *
1310     * @returns { IterableIterator<number> }
1311     * @syscap SystemCapability.Utils.Lang
1312     * @crossplatform
1313     * @since 10
1314     */
1315    /**
1316     * Creates and returns an iterator that contains the values of this Buffer instance.
1317     *
1318     * @returns { IterableIterator<number> }
1319     * @syscap SystemCapability.Utils.Lang
1320     * @crossplatform
1321     * @atomicservice
1322     * @since arkts {'1.1':'11', '1.2':'20'}
1323     * @arkts 1.1&1.2
1324     */
1325    values(): IterableIterator<number>;
1326
1327    /**
1328     * Creates and returns an iterator of [index, byte] pairs from the contents of buf.
1329     *
1330     * @returns { IterableIterator<[number, number]> }
1331     * @syscap SystemCapability.Utils.Lang
1332     * @since 9
1333     */
1334    /**
1335     * Creates and returns an iterator that contains key-value pairs of this Buffer instance.
1336     *
1337     * @returns { IterableIterator<[number, number]> }
1338     * @syscap SystemCapability.Utils.Lang
1339     * @crossplatform
1340     * @since 10
1341     */
1342    /**
1343     * Creates and returns an iterator that contains key-value pairs of this Buffer instance.
1344     *
1345     * @returns { IterableIterator<[number, number]> }
1346     * @syscap SystemCapability.Utils.Lang
1347     * @crossplatform
1348     * @atomicservice
1349     * @since arkts {'1.1':'11', '1.2':'20'}
1350     * @arkts 1.1&1.2
1351     */
1352    entries(): IterableIterator<[number, number]>;
1353
1354    /**
1355     * The index of the last occurrence of value in buf
1356     *
1357     * @param { string | number | Buffer | Uint8Array } value - value value What to search for
1358     * @param { number } [byteOffset] - byteOffset [byteOffset = 0] Where to begin searching in buf
1359     * @param { BufferEncoding } [encoding] - encoding [encoding='utf8'] If value is a string,
1360     * this is the encoding used to determine the binary representation of the string that will be searched for in buf
1361     * @returns { number } The index of the last occurrence of value in buf, or -1 if buf does not contain value
1362     * @throws { BusinessError } 401 - Parameter error. Possible causes:
1363     * 1.Mandatory parameters are left unspecified;
1364     * 2.Incorrect parameter types.
1365     * @syscap SystemCapability.Utils.Lang
1366     * @since 9
1367     */
1368    /**
1369     * Obtains the index of the last occurrence of the specified value in this Buffer instance.
1370     *
1371     * @param { string | number | Buffer | Uint8Array } value - Value to match.
1372     * @param { number } [byteOffset] - Number of bytes to skip before starting to check data.
1373     * If the offset is a negative number, data is checked from the end of the Buffer instance.
1374     * The default value is the length of this Buffer instance.
1375     * @param { BufferEncoding } [encoding] - Encoding format (valid only when value is a string). The default value is 'utf8'.
1376     * this is the encoding used to determine the binary representation of the string that will be searched for in buf
1377     * @returns { number } The index of the last occurrence of value in buf, or -1 if buf does not contain value
1378     * @throws { BusinessError } 401 - Parameter error. Possible causes:
1379     * 1.Mandatory parameters are left unspecified;
1380     * 2.Incorrect parameter types.
1381     * @syscap SystemCapability.Utils.Lang
1382     * @crossplatform
1383     * @since 10
1384     */
1385    /**
1386     * Obtains the index of the last occurrence of the specified value in this Buffer instance.
1387     *
1388     * @param { string | number | Buffer | Uint8Array } value - Value to match.
1389     * @param { number } [byteOffset] - Number of bytes to skip before starting to check data.
1390     * If the offset is a negative number, data is checked from the end of the Buffer instance.
1391     * The default value is the length of this Buffer instance.
1392     * @param { BufferEncoding } [encoding] - Encoding format (valid only when value is a string). The default value is 'utf8'.
1393     * @returns { number } The index of the last occurrence of value in buf, or -1 if buf does not contain value
1394     * @throws { BusinessError } 401 - Parameter error. Possible causes:
1395     * 1.Mandatory parameters are left unspecified;
1396     * 2.Incorrect parameter types.
1397     * @syscap SystemCapability.Utils.Lang
1398     * @crossplatform
1399     * @atomicservice
1400     * @since arkts {'1.1':'11', '1.2':'20'}
1401     * @arkts 1.1&1.2
1402     */
1403    lastIndexOf(value: string | number | Buffer | Uint8Array, byteOffset?: number, encoding?: BufferEncoding): number;
1404
1405    /**
1406     * Reads a signed, big-endian 64-bit integer from buf at the specified offset
1407     *
1408     * @param { number } [offset] - offset [offset = 0] Number of bytes to skip before starting to read. Must satisfy: 0 <= offset <= buf.length - 8
1409     * @returns { bigint } Return a signed, big-endian 64-bit integer
1410     * @throws { BusinessError } 401 - Parameter error. Possible causes: 1.Incorrect parameter types.
1411     * @throws { BusinessError } 10200001 - The value of "offset" is out of range. It must be >= 0 and <= buf.length - 8. Received value is: [offset]
1412     * @syscap SystemCapability.Utils.Lang
1413     * @since 9
1414     */
1415    /**
1416     * Reads a 64-bit, big-endian, signed big integer from this Buffer instance at the specified offset.
1417     *
1418     * @param { number } [offset] - Number of bytes to skip before starting to read data. The default value is 0. The value range is [0, Buffer.length - 8].
1419     * @returns { bigint } Return a signed, big-endian 64-bit integer
1420     * @throws { BusinessError } 401 - Parameter error. Possible causes: 1.Incorrect parameter types.
1421     * @throws { BusinessError } 10200001 - The value of "offset" is out of range. It must be >= 0 and <= buf.length - 8. Received value is: [offset]
1422     * @syscap SystemCapability.Utils.Lang
1423     * @crossplatform
1424     * @since 10
1425     */
1426    /**
1427     * Reads a 64-bit, big-endian, signed big integer from this Buffer instance at the specified offset.
1428     *
1429     * @param { number } [offset] - Number of bytes to skip before starting to read data. The default value is 0. The value range is [0, Buffer.length - 8].
1430     * @returns { bigint } Return a signed, big-endian 64-bit integer
1431     * @throws { BusinessError } 401 - Parameter error. Possible causes: 1.Incorrect parameter types.
1432     * @throws { BusinessError } 10200001 - The value of "offset" is out of range. It must be >= 0 and <= buf.length - 8. Received value is: [offset]
1433     * @syscap SystemCapability.Utils.Lang
1434     * @crossplatform
1435     * @atomicservice
1436     * @since arkts {'1.1':'11', '1.2':'20'}
1437     * @arkts 1.1&1.2
1438     */
1439    readBigInt64BE(offset?: number): bigint;
1440
1441    /**
1442     * Reads a signed, little-endian 64-bit integer from buf at the specified offset
1443     *
1444     * @param { number } [offset] - offset [offset = 0] Number of bytes to skip before starting to read. Must satisfy: 0 <= offset <= buf.length - 8
1445     * @returns { bigint } Return a signed, little-endian 64-bit integer
1446     * @throws { BusinessError } 401 - Parameter error. Possible causes: 1.Incorrect parameter types.
1447     * @throws { BusinessError } 10200001 - The value of "offset" is out of range. It must be >= 0 and <= buf.length - 8. Received value is: [offset]
1448     * @syscap SystemCapability.Utils.Lang
1449     * @since 9
1450     */
1451    /**
1452     * Reads a 64-bit, little-endian, signed big integer from this Buffer instance at the specified offset.
1453     *
1454     * @param { number } [offset] - Number of bytes to skip before starting to read data. The default value is 0. The value range is [0, Buffer.length - 8].
1455     * @returns { bigint } Return a signed, little-endian 64-bit integer
1456     * @throws { BusinessError } 401 - Parameter error. Possible causes: 1.Incorrect parameter types.
1457     * @throws { BusinessError } 10200001 - The value of "offset" is out of range. It must be >= 0 and <= buf.length - 8. Received value is: [offset]
1458     * @syscap SystemCapability.Utils.Lang
1459     * @crossplatform
1460     * @since 10
1461     */
1462    /**
1463     * Reads a 64-bit, little-endian, signed big integer from this Buffer instance at the specified offset.
1464     *
1465     * @param { number } [offset] - Number of bytes to skip before starting to read data. The default value is 0. The value range is [0, Buffer.length - 8].
1466     * @returns { bigint } Return a signed, little-endian 64-bit integer
1467     * @throws { BusinessError } 401 - Parameter error. Possible causes: 1.Incorrect parameter types.
1468     * @throws { BusinessError } 10200001 - The value of "offset" is out of range. It must be >= 0 and <= buf.length - 8. Received value is: [offset]
1469     * @syscap SystemCapability.Utils.Lang
1470     * @crossplatform
1471     * @atomicservice
1472     * @since arkts {'1.1':'11', '1.2':'20'}
1473     * @arkts 1.1&1.2
1474     */
1475    readBigInt64LE(offset?: number): bigint;
1476
1477    /**
1478     * Reads a unsigned, big-endian 64-bit integer from buf at the specified offset
1479     *
1480     * @param { number } [offset] - offset [offset = 0] Number of bytes to skip before starting to read. Must satisfy: 0 <= offset <= buf.length - 8
1481     * @returns { bigint } Return a unsigned, big-endian 64-bit integer
1482     * @throws { BusinessError } 401 - Parameter error. Possible causes: 1.Incorrect parameter types.
1483     * @throws { BusinessError } 10200001 - The value of "offset" is out of range. It must be >= 0 and <= buf.length - 8. Received value is: [offset]
1484     * @syscap SystemCapability.Utils.Lang
1485     * @since 9
1486     */
1487    /**
1488     * Reads a 64-bit, big-endian, unsigned big integer from this Buffer instance at the specified offset.
1489     *
1490     * @param { number } [offset] - Number of bytes to skip before starting to read data. The default value is 0. The value range is [0, Buffer.length - 8].
1491     * @returns { bigint } Return a unsigned, big-endian 64-bit integer
1492     * @throws { BusinessError } 401 - Parameter error. Possible causes: 1.Incorrect parameter types.
1493     * @throws { BusinessError } 10200001 - The value of "offset" is out of range. It must be >= 0 and <= buf.length - 8. Received value is: [offset]
1494     * @syscap SystemCapability.Utils.Lang
1495     * @crossplatform
1496     * @since 10
1497     */
1498    /**
1499     * Reads a 64-bit, big-endian, unsigned big integer from this Buffer instance at the specified offset.
1500     *
1501     * @param { number } [offset] - Number of bytes to skip before starting to read data. The default value is 0. The value range is [0, Buffer.length - 8].
1502     * @returns { bigint } Return a unsigned, big-endian 64-bit integer
1503     * @throws { BusinessError } 401 - Parameter error. Possible causes: 1.Incorrect parameter types.
1504     * @throws { BusinessError } 10200001 - The value of "offset" is out of range. It must be >= 0 and <= buf.length - 8. Received value is: [offset]
1505     * @syscap SystemCapability.Utils.Lang
1506     * @crossplatform
1507     * @atomicservice
1508     * @since arkts {'1.1':'11', '1.2':'20'}
1509     * @arkts 1.1&1.2
1510     */
1511    readBigUInt64BE(offset?: number): bigint;
1512
1513    /**
1514     * Reads a unsigned, little-endian 64-bit integer from buf at the specified offset
1515     *
1516     * @param { number } [offset] - offset [offset = 0] Number of bytes to skip before starting to read. Must satisfy: 0 <= offset <= buf.length - 8
1517     * @returns { bigint } Return a unsigned, little-endian 64-bit integer
1518     * @throws { BusinessError } 401 - Parameter error. Possible causes: 1.Incorrect parameter types.
1519     * @throws { BusinessError } 10200001 - The value of "offset" is out of range. It must be >= 0 and <= buf.length - 8. Received value is: [offset]
1520     * @syscap SystemCapability.Utils.Lang
1521     * @since 9
1522     */
1523    /**
1524     * Reads a 64-bit, little-endian, unsigned big integer from this Buffer instance at the specified offset.
1525     *
1526     * @param { number } [offset] - Number of bytes to skip before starting to read data. The default value is 0. The value range is [0, Buffer.length - 8].
1527     * @returns { bigint } Return a unsigned, little-endian 64-bit integer
1528     * @throws { BusinessError } 401 - Parameter error. Possible causes: 1.Incorrect parameter types.
1529     * @throws { BusinessError } 10200001 - The value of "offset" is out of range. It must be >= 0 and <= buf.length - 8. Received value is: [offset]
1530     * @syscap SystemCapability.Utils.Lang
1531     * @crossplatform
1532     * @since 10
1533     */
1534    /**
1535     * Reads a 64-bit, little-endian, unsigned big integer from this Buffer instance at the specified offset.
1536     *
1537     * @param { number } [offset] - Number of bytes to skip before starting to read data. The default value is 0. The value range is [0, Buffer.length - 8].
1538     * @returns { bigint } Return a unsigned, little-endian 64-bit integer
1539     * @throws { BusinessError } 401 - Parameter error. Possible causes: 1.Incorrect parameter types.
1540     * @throws { BusinessError } 10200001 - The value of "offset" is out of range. It must be >= 0 and <= buf.length - 8. Received value is: [offset]
1541     * @syscap SystemCapability.Utils.Lang
1542     * @crossplatform
1543     * @atomicservice
1544     * @since arkts {'1.1':'11', '1.2':'20'}
1545     * @arkts 1.1&1.2
1546     */
1547    readBigUInt64LE(offset?: number): bigint;
1548
1549    /**
1550     * Reads a 64-bit, big-endian double from buf at the specified offset
1551     *
1552     * @param { number } [offset] - offset [offset = 0] Number of bytes to skip before starting to read. Must satisfy: 0 <= offset <= buf.length - 8
1553     * @returns { number } Return a 64-bit, big-endian double
1554     * @throws { BusinessError } 401 - Parameter error. Possible causes: 1.Incorrect parameter types.
1555     * @throws { BusinessError } 10200001 - The value of "offset" is out of range. It must be >= 0 and <= buf.length - 8. Received value is: [offset]
1556     * @syscap SystemCapability.Utils.Lang
1557     * @since 9
1558     */
1559    /**
1560     * Reads a 64-bit, big-endian, double-precision floating-point number from this Buffer instance at the specified offset.
1561     *
1562     * @param { number } [offset] - Number of bytes to skip before starting to read data. The default value is 0. The value range is [0, Buffer.length - 8].
1563     * @returns { number } Return a 64-bit, big-endian double
1564     * @throws { BusinessError } 401 - Parameter error. Possible causes: 1.Incorrect parameter types.
1565     * @throws { BusinessError } 10200001 - The value of "offset" is out of range. It must be >= 0 and <= buf.length - 8. Received value is: [offset]
1566     * @syscap SystemCapability.Utils.Lang
1567     * @crossplatform
1568     * @since 10
1569     */
1570    /**
1571     * Reads a 64-bit, big-endian, double-precision floating-point number from this Buffer instance at the specified offset.
1572     *
1573     * @param { number } [offset] - Number of bytes to skip before starting to read data. The default value is 0. The value range is [0, Buffer.length - 8].
1574     * @returns { number } Return a 64-bit, big-endian double
1575     * @throws { BusinessError } 401 - Parameter error. Possible causes: 1.Incorrect parameter types.
1576     * @throws { BusinessError } 10200001 - The value of "offset" is out of range. It must be >= 0 and <= buf.length - 8. Received value is: [offset]
1577     * @syscap SystemCapability.Utils.Lang
1578     * @crossplatform
1579     * @atomicservice
1580     * @since arkts {'1.1':'11', '1.2':'20'}
1581     * @arkts 1.1&1.2
1582     */
1583    readDoubleBE(offset?: number): number;
1584
1585    /**
1586     * Reads a 64-bit, little-endian double from buf at the specified offset
1587     *
1588     * @param { number } [offset] - offset [offset = 0] Number of bytes to skip before starting to read. Must satisfy: 0 <= offset <= buf.length - 8
1589     * @returns { number } Return a 64-bit, little-endian double
1590     * @throws { BusinessError } 401 - Parameter error. Possible causes: 1.Incorrect parameter types.
1591     * @throws { BusinessError } 10200001 - The value of "offset" is out of range. It must be >= 0 and <= buf.length - 8. Received value is: [offset]
1592     * @syscap SystemCapability.Utils.Lang
1593     * @since 9
1594     */
1595    /**
1596     * Reads a 64-bit, little-endian, double-precision floating-point number from this Buffer instance at the specified offset.
1597     *
1598     * @param { number } [offset] - Number of bytes to skip before starting to read data. The default value is 0. The value range is [0, Buffer.length - 8].
1599     * @returns { number } Return a 64-bit, little-endian double
1600     * @throws { BusinessError } 401 - Parameter error. Possible causes: 1.Incorrect parameter types.
1601     * @throws { BusinessError } 10200001 - The value of "offset" is out of range. It must be >= 0 and <= buf.length - 8. Received value is: [offset]
1602     * @syscap SystemCapability.Utils.Lang
1603     * @crossplatform
1604     * @since 10
1605     */
1606    /**
1607     * Reads a 64-bit, little-endian, double-precision floating-point number from this Buffer instance at the specified offset.
1608     *
1609     * @param { number } [offset] - Number of bytes to skip before starting to read data. The default value is 0. The value range is [0, Buffer.length - 8].
1610     * @returns { number } Return a 64-bit, little-endian double
1611     * @throws { BusinessError } 401 - Parameter error. Possible causes: 1.Incorrect parameter types.
1612     * @throws { BusinessError } 10200001 - The value of "offset" is out of range. It must be >= 0 and <= buf.length - 8. Received value is: [offset]
1613     * @syscap SystemCapability.Utils.Lang
1614     * @crossplatform
1615     * @atomicservice
1616     * @since arkts {'1.1':'11', '1.2':'20'}
1617     * @arkts 1.1&1.2
1618     */
1619    readDoubleLE(offset?: number): number;
1620
1621    /**
1622     * Reads a 32-bit, big-endian float from buf at the specified offset
1623     *
1624     * @param { number } [offset] - offset [offset = 0] Number of bytes to skip before starting to read. Must satisfy: 0 <= offset <= buf.length - 4
1625     * @returns { number } Return a 32-bit, big-endian float
1626     * @throws { BusinessError } 401 - Parameter error. Possible causes: 1.Incorrect parameter types.
1627     * @throws { BusinessError } 10200001 - The value of "offset" is out of range. It must be >= 0 and <= buf.length - 4. Received value is: [offset]
1628     * @syscap SystemCapability.Utils.Lang
1629     * @since 9
1630     */
1631    /**
1632     * Reads a 32-bit, big-endian, single-precision floating-point number from this Buffer instance at the specified offset.
1633     *
1634     * @param { number } [offset] - Number of bytes to skip before starting to read data. The default value is 0. The value range is [0, Buffer.length - 4].
1635     * @returns { number } Return a 32-bit, big-endian float
1636     * @throws { BusinessError } 401 - Parameter error. Possible causes: 1.Incorrect parameter types.
1637     * @throws { BusinessError } 10200001 - The value of "offset" is out of range. It must be >= 0 and <= buf.length - 4. Received value is: [offset]
1638     * @syscap SystemCapability.Utils.Lang
1639     * @crossplatform
1640     * @since 10
1641     */
1642    /**
1643     * Reads a 32-bit, big-endian, single-precision floating-point number from this Buffer instance at the specified offset.
1644     *
1645     * @param { number } [offset] - Number of bytes to skip before starting to read data. The default value is 0. The value range is [0, Buffer.length - 4].
1646     * @returns { number } Return a 32-bit, big-endian float
1647     * @throws { BusinessError } 401 - Parameter error. Possible causes: 1.Incorrect parameter types.
1648     * @throws { BusinessError } 10200001 - The value of "offset" is out of range. It must be >= 0 and <= buf.length - 4. Received value is: [offset]
1649     * @syscap SystemCapability.Utils.Lang
1650     * @crossplatform
1651     * @atomicservice
1652     * @since arkts {'1.1':'11', '1.2':'20'}
1653     * @arkts 1.1&1.2
1654     */
1655    readFloatBE(offset?: number): number;
1656
1657    /**
1658     * Reads a 32-bit, little-endian float from buf at the specified offset
1659     *
1660     * @param { number } [offset] - offset [offset = 0] Number of bytes to skip before starting to read. Must satisfy: 0 <= offset <= buf.length - 4
1661     * @returns { number } Return a 32-bit, little-endian float
1662     * @throws { BusinessError } 401 - Parameter error. Possible causes: 1.Incorrect parameter types.
1663     * @throws { BusinessError } 10200001 - The value of "offset" is out of range. It must be >= 0 and <= buf.length - 4. Received value is: [offset]
1664     * @syscap SystemCapability.Utils.Lang
1665     * @since 9
1666     */
1667    /**
1668     * Reads a 32-bit, little-endian, single-precision floating-point number from this Buffer instance at the specified offset.
1669     *
1670     * @param { number } [offset] - Number of bytes to skip before starting to read data. The default value is 0. The value range is [0, Buffer.length - 4].
1671     * @returns { number } Return a 32-bit, little-endian float
1672     * @throws { BusinessError } 401 - Parameter error. Possible causes: 1.Incorrect parameter types.
1673     * @throws { BusinessError } 10200001 - The value of "offset" is out of range. It must be >= 0 and <= buf.length - 4. Received value is: [offset]
1674     * @syscap SystemCapability.Utils.Lang
1675     * @crossplatform
1676     * @since 10
1677     */
1678    /**
1679     * Reads a 32-bit, little-endian, single-precision floating-point number from this Buffer instance at the specified offset.
1680     *
1681     * @param { number } [offset] - Number of bytes to skip before starting to read data. The default value is 0. The value range is [0, Buffer.length - 4].
1682     * @returns { number } Return a 32-bit, little-endian float
1683     * @throws { BusinessError } 401 - Parameter error. Possible causes: 1.Incorrect parameter types.
1684     * @throws { BusinessError } 10200001 - The value of "offset" is out of range. It must be >= 0 and <= buf.length - 4. Received value is: [offset]
1685     * @syscap SystemCapability.Utils.Lang
1686     * @crossplatform
1687     * @atomicservice
1688     * @since arkts {'1.1':'11', '1.2':'20'}
1689     * @arkts 1.1&1.2
1690     */
1691    readFloatLE(offset?: number): number;
1692
1693    /**
1694     * Reads a signed 8-bit integer from buf at the specified offset
1695     *
1696     * @param { number } [offset] - offset [offset = 0] Number of bytes to skip before starting to read. Must satisfy: 0 <= offset <= buf.length - 1
1697     * @returns { number } Return a signed 8-bit integer
1698     * @throws { BusinessError } 401 - Parameter error. Possible causes: 1.Incorrect parameter types.
1699     * @throws { BusinessError } 10200001 - The value of "offset" is out of range. It must be >= 0 and <= buf.length - 1. Received value is: [offset]
1700     * @syscap SystemCapability.Utils.Lang
1701     * @since 9
1702     */
1703    /**
1704     * Reads an 8-bit signed integer from this Buffer instance at the specified offset.
1705     *
1706     * @param { number } [offset] - Number of bytes to skip before starting to read data. The default value is 0. The value range is [0, Buffer.length - 1].
1707     * @returns { number } Return a signed 8-bit integer
1708     * @throws { BusinessError } 401 - Parameter error. Possible causes: 1.Incorrect parameter types.
1709     * @throws { BusinessError } 10200001 - The value of "offset" is out of range. It must be >= 0 and <= buf.length - 1. Received value is: [offset]
1710     * @syscap SystemCapability.Utils.Lang
1711     * @crossplatform
1712     * @since 10
1713     */
1714    /**
1715     * Reads an 8-bit signed integer from this Buffer instance at the specified offset.
1716     *
1717     * @param { number } [offset] - Number of bytes to skip before starting to read data. The default value is 0. The value range is [0, Buffer.length - 1].
1718     * @returns { number } Return a signed 8-bit integer
1719     * @throws { BusinessError } 401 - Parameter error. Possible causes: 1.Incorrect parameter types.
1720     * @throws { BusinessError } 10200001 - The value of "offset" is out of range. It must be >= 0 and <= buf.length - 1. Received value is: [offset]
1721     * @syscap SystemCapability.Utils.Lang
1722     * @crossplatform
1723     * @atomicservice
1724     * @since arkts {'1.1':'11', '1.2':'20'}
1725     * @arkts 1.1&1.2
1726     */
1727    readInt8(offset?: number): number;
1728
1729    /**
1730     * Reads a signed, big-endian 16-bit integer from buf at the specified offset
1731     *
1732     * @param { number } [offset] - offset [offset = 0] Number of bytes to skip before starting to read. Must satisfy: 0 <= offset <= buf.length - 2
1733     * @returns { number } Return a signed, big-endian 16-bit integer
1734     * @throws { BusinessError } 401 - Parameter error. Possible causes: 1.Incorrect parameter types.
1735     * @throws { BusinessError } 10200001 - The value of "offset" is out of range. It must be >= 0 and <= buf.length - 2. Received value is: [offset]
1736     * @syscap SystemCapability.Utils.Lang
1737     * @since 9
1738     */
1739    /**
1740     * Reads a 16-bit, big-endian, signed integer from this Buffer instance at the specified offset.
1741     *
1742     * @param { number } [offset] - Number of bytes to skip before starting to read data. The default value is 0. The value range is [0, Buffer.length - 2].
1743     * @returns { number } Return a signed, big-endian 16-bit integer
1744     * @throws { BusinessError } 401 - Parameter error. Possible causes: 1.Incorrect parameter types.
1745     * @throws { BusinessError } 10200001 - The value of "offset" is out of range. It must be >= 0 and <= buf.length - 2. Received value is: [offset]
1746     * @syscap SystemCapability.Utils.Lang
1747     * @crossplatform
1748     * @since 10
1749     */
1750    /**
1751     * Reads a 16-bit, big-endian, signed integer from this Buffer instance at the specified offset.
1752     *
1753     * @param { number } [offset] - Number of bytes to skip before starting to read data. The default value is 0. The value range is [0, Buffer.length - 2].
1754     * @returns { number } Return a signed, big-endian 16-bit integer
1755     * @throws { BusinessError } 401 - Parameter error. Possible causes: 1.Incorrect parameter types.
1756     * @throws { BusinessError } 10200001 - The value of "offset" is out of range. It must be >= 0 and <= buf.length - 2. Received value is: [offset]
1757     * @syscap SystemCapability.Utils.Lang
1758     * @crossplatform
1759     * @atomicservice
1760     * @since arkts {'1.1':'11', '1.2':'20'}
1761     * @arkts 1.1&1.2
1762     */
1763    readInt16BE(offset?: number): number;
1764
1765    /**
1766     * Reads a signed, little-endian 16-bit integer from buf at the specified offset
1767     *
1768     * @param { number } [offset] - offset [offset = 0] Number of bytes to skip before starting to read. Must satisfy: 0 <= offset <= buf.length - 2
1769     * @returns { number } Return a signed, little-endian 16-bit integer
1770     * @throws { BusinessError } 401 - Parameter error. Possible causes: 1.Incorrect parameter types.
1771     * @throws { BusinessError } 10200001 - The value of "offset" is out of range. It must be >= 0 and <= buf.length - 2. Received value is: [offset]
1772     * @syscap SystemCapability.Utils.Lang
1773     * @since 9
1774     */
1775    /**
1776     * Reads a 16-bit, little-endian, signed integer from this Buffer instance at the specified offset.
1777     *
1778     * @param { number } [offset] - Number of bytes to skip before starting to read data. The default value is 0. The value range is [0, Buffer.length - 2].
1779     * @returns { number } Return a signed, little-endian 16-bit integer
1780     * @throws { BusinessError } 401 - Parameter error. Possible causes: 1.Incorrect parameter types.
1781     * @throws { BusinessError } 10200001 - The value of "offset" is out of range. It must be >= 0 and <= buf.length - 2. Received value is: [offset]
1782     * @syscap SystemCapability.Utils.Lang
1783     * @crossplatform
1784     * @since 10
1785     */
1786    /**
1787     * Reads a 16-bit, little-endian, signed integer from this Buffer instance at the specified offset.
1788     *
1789     * @param { number } [offset] - Number of bytes to skip before starting to read data. The default value is 0. The value range is [0, Buffer.length - 2].
1790     * @returns { number } Return a signed, little-endian 16-bit integer
1791     * @throws { BusinessError } 401 - Parameter error. Possible causes: 1.Incorrect parameter types.
1792     * @throws { BusinessError } 10200001 - The value of "offset" is out of range. It must be >= 0 and <= buf.length - 2. Received value is: [offset]
1793     * @syscap SystemCapability.Utils.Lang
1794     * @crossplatform
1795     * @atomicservice
1796     * @since arkts {'1.1':'11', '1.2':'20'}
1797     * @arkts 1.1&1.2
1798     */
1799    readInt16LE(offset?: number): number;
1800
1801    /**
1802     * Reads a signed, big-endian 32-bit integer from buf at the specified offset
1803     *
1804     * @param { number } [offset] - offset [offset = 0] Number of bytes to skip before starting to read. Must satisfy: 0 <= offset <= buf.length - 4
1805     * @returns { number } Return a signed, big-endian 32-bit integer
1806     * @throws { BusinessError } 401 - Parameter error. Possible causes: 1.Incorrect parameter types.
1807     * @throws { BusinessError } 10200001 - The value of "offset" is out of range. It must be >= 0 and <= buf.length - 4. Received value is: [offset]
1808     * @syscap SystemCapability.Utils.Lang
1809     * @since 9
1810     */
1811    /**
1812     * Reads a 32-bit, big-endian, signed integer from this Buffer instance at the specified offset.
1813     *
1814     * @param { number } [offset] - Number of bytes to skip before starting to read data. The default value is 0. The value range is [0, Buffer.length - 4].
1815     * @returns { number } Return a signed, big-endian 32-bit integer
1816     * @throws { BusinessError } 401 - Parameter error. Possible causes: 1.Incorrect parameter types.
1817     * @throws { BusinessError } 10200001 - The value of "offset" is out of range. It must be >= 0 and <= buf.length - 4. Received value is: [offset]
1818     * @syscap SystemCapability.Utils.Lang
1819     * @crossplatform
1820     * @since 10
1821     */
1822    /**
1823     * Reads a 32-bit, big-endian, signed integer from this Buffer instance at the specified offset.
1824     *
1825     * @param { number } [offset] - Number of bytes to skip before starting to read data. The default value is 0. The value range is [0, Buffer.length - 4].
1826     * @returns { number } Return a signed, big-endian 32-bit integer
1827     * @throws { BusinessError } 401 - Parameter error. Possible causes: 1.Incorrect parameter types.
1828     * @throws { BusinessError } 10200001 - The value of "offset" is out of range. It must be >= 0 and <= buf.length - 4. Received value is: [offset]
1829     * @syscap SystemCapability.Utils.Lang
1830     * @crossplatform
1831     * @atomicservice
1832     * @since arkts {'1.1':'11', '1.2':'20'}
1833     * @arkts 1.1&1.2
1834     */
1835    readInt32BE(offset?: number): number;
1836
1837    /**
1838     * Reads a signed, little-endian 32-bit integer from buf at the specified offset
1839     *
1840     * @param { number } [offset] - offset [offset = 0] Number of bytes to skip before starting to read. Must satisfy: 0 <= offset <= buf.length - 4
1841     * @returns { number } Return a signed, little-endian 32-bit integer
1842     * @throws { BusinessError } 401 - Parameter error. Possible causes: 1.Incorrect parameter types.
1843     * @throws { BusinessError } 10200001 - The value of "offset" is out of range. It must be >= 0 and <= buf.length - 4. Received value is: [offset]
1844     * @syscap SystemCapability.Utils.Lang
1845     * @since 9
1846     */
1847    /**
1848     * Reads a 32-bit, little-endian, signed integer from this Buffer instance at the specified offset.
1849     *
1850     * @param { number } [offset] - Number of bytes to skip before starting to read data. The default value is 0. The value range is [0, Buffer.length - 4].
1851     * @returns { number } Return a signed, little-endian 32-bit integer
1852     * @throws { BusinessError } 401 - Parameter error. Possible causes: 1.Incorrect parameter types.
1853     * @throws { BusinessError } 10200001 - The value of "offset" is out of range. It must be >= 0 and <= buf.length - 4. Received value is: [offset]
1854     * @syscap SystemCapability.Utils.Lang
1855     * @crossplatform
1856     * @since 10
1857     */
1858    /**
1859     * Reads a 32-bit, little-endian, signed integer from this Buffer instance at the specified offset.
1860     *
1861     * @param { number } [offset] - Number of bytes to skip before starting to read data. The default value is 0. The value range is [0, Buffer.length - 4].
1862     * @returns { number } Return a signed, little-endian 32-bit integer
1863     * @throws { BusinessError } 401 - Parameter error. Possible causes: 1.Incorrect parameter types.
1864     * @throws { BusinessError } 10200001 - The value of "offset" is out of range. It must be >= 0 and <= buf.length - 4. Received value is: [offset]
1865     * @syscap SystemCapability.Utils.Lang
1866     * @crossplatform
1867     * @atomicservice
1868     * @since arkts {'1.1':'11', '1.2':'20'}
1869     * @arkts 1.1&1.2
1870     */
1871    readInt32LE(offset?: number): number;
1872
1873    /**
1874     * Reads byteLength number of bytes from buf at the specified offset and interprets the result as a big-endian,
1875     * two's complement signed value supporting up to 48 bits of accuracy
1876     *
1877     * @param { number } offset - offset offset Number of bytes to skip before starting to read. Must satisfy: 0 <= offset <= buf.length - byteLength
1878     * @param { number } byteLength - byteLength byteLength Number of bytes to read. Must satisfy 0 < byteLength <= 6
1879     * @returns { number }
1880     * @throws { BusinessError } 401 - Parameter error. Possible causes:
1881     * 1.Mandatory parameters are left unspecified;
1882     * 2.Incorrect parameter types.
1883     * @throws { BusinessError } 10200001 - The value of "[param]" is out of range. It must be >= [left range] and <= [right range]. Received value is: [param]
1884     * @syscap SystemCapability.Utils.Lang
1885     * @since 9
1886     */
1887    /**
1888     * Reads the specified number of bytes from this Buffer instance at the specified offset, and interprets the result as a big-endian,
1889     * two's complement signed value that supports up to 48 bits of precision.
1890     *
1891     * @param { number } offset - Number of bytes to skip before starting to read data.
1892     *     The default value is 0. The value range is [0, Buffer.length - byteLength].
1893     * @param { number } byteLength - Number of bytes to read. The value range is [1, 6].
1894     * @returns { number }
1895     * @throws { BusinessError } 401 - Parameter error. Possible causes:
1896     * 1.Mandatory parameters are left unspecified;
1897     * 2.Incorrect parameter types.
1898     * @throws { BusinessError } 10200001 - The value of "[param]" is out of range. It must be >= [left range] and <= [right range]. Received value is: [param]
1899     * @syscap SystemCapability.Utils.Lang
1900     * @crossplatform
1901     * @since 10
1902     */
1903    /**
1904     * Reads the specified number of bytes from this Buffer instance at the specified offset, and interprets the result as a big-endian,
1905     * two's complement signed value that supports up to 48 bits of precision.
1906     *
1907     * @param { number } offset - Number of bytes to skip before starting to read data.
1908     *     The default value is 0. The value range is [0, Buffer.length - byteLength].
1909     * @param { number } byteLength - Number of bytes to read. The value range is [1, 6].
1910     * @returns { number }
1911     * @throws { BusinessError } 401 - Parameter error. Possible causes:
1912     * 1.Mandatory parameters are left unspecified;
1913     * 2.Incorrect parameter types.
1914     * @throws { BusinessError } 10200001 - The value of "[param]" is out of range. It must be >= [left range] and <= [right range]. Received value is: [param]
1915     * @syscap SystemCapability.Utils.Lang
1916     * @crossplatform
1917     * @atomicservice
1918     * @since arkts {'1.1':'11', '1.2':'20'}
1919     * @arkts 1.1&1.2
1920     */
1921    readIntBE(offset: number, byteLength: number): number;
1922
1923    /**
1924     * Reads byteLength number of bytes from buf at the specified offset and interprets the result as a little-endian,
1925     * two's complement signed value supporting up to 48 bits of accuracy.
1926     *
1927     * @param { number } offset - offset offset Number of bytes to skip before starting to read. Must satisfy: 0 <= offset <= buf.length - byteLength
1928     * @param { number } byteLength - byteLength byteLength Number of bytes to read. Must satisfy 0 < byteLength <= 6
1929     * @returns { number }
1930     * @throws { BusinessError } 401 - Parameter error. Possible causes:
1931     * 1.Mandatory parameters are left unspecified;
1932     * 2.Incorrect parameter types.
1933     * @throws { BusinessError } 10200001 - The value of "[param]" is out of range. It must be >= [left range] and <= [right range]. Received value is: [param]
1934     * @syscap SystemCapability.Utils.Lang
1935     * @since 9
1936     */
1937    /**
1938     * Reads the specified number of bytes from this Buffer instance at the specified offset and interprets the result as a little-endian,
1939     * two's complement signed value that supports up to 48 bits of precision.
1940     *
1941     * @param { number } offset - Number of bytes to skip before starting to read data.
1942     *     The default value is 0. The value range is [0, Buffer.length - byteLength].
1943     * @param { number } byteLength - Number of bytes to read. The value range is [1, 6].
1944     * @returns { number }
1945     * @throws { BusinessError } 401 - Parameter error. Possible causes:
1946     * 1.Mandatory parameters are left unspecified;
1947     * 2.Incorrect parameter types.
1948     * @throws { BusinessError } 10200001 - The value of "[param]" is out of range. It must be >= [left range] and <= [right range]. Received value is: [param]
1949     * @syscap SystemCapability.Utils.Lang
1950     * @crossplatform
1951     * @since 10
1952     */
1953    /**
1954     * Reads the specified number of bytes from this Buffer instance at the specified offset and interprets the result as a little-endian,
1955     * two's complement signed value that supports up to 48 bits of precision.
1956     *
1957     * @param { number } offset - Number of bytes to skip before starting to read data.
1958     *     The default value is 0. The value range is [0, Buffer.length - byteLength].
1959     * @param { number } byteLength - Number of bytes to read. The value range is [1, 6].
1960     * @returns { number }
1961     * @throws { BusinessError } 401 - Parameter error. Possible causes:
1962     * 1.Mandatory parameters are left unspecified;
1963     * 2.Incorrect parameter types.
1964     * @throws { BusinessError } 10200001 - The value of "[param]" is out of range. It must be >= [left range] and <= [right range]. Received value is: [param]
1965     * @syscap SystemCapability.Utils.Lang
1966     * @crossplatform
1967     * @atomicservice
1968     * @since arkts {'1.1':'11', '1.2':'20'}
1969     * @arkts 1.1&1.2
1970     */
1971    readIntLE(offset: number, byteLength: number): number;
1972
1973    /**
1974     * Reads an unsigned 8-bit integer from buf at the specified offset
1975     *
1976     * @param { number } [offset] - offset [offset = 0] Number of bytes to skip before starting to read. Must satisfy 0 <= offset <= buf.length - 1
1977     * @returns { number } Reads an unsigned 8-bit integer
1978     * @throws { BusinessError } 401 - Parameter error. Possible causes: 1.Incorrect parameter types.
1979     * @throws { BusinessError } 10200001 - The value of "offset" is out of range. It must be >= 0 and <= buf.length - 1. Received value is: [offset]
1980     * @syscap SystemCapability.Utils.Lang
1981     * @since 9
1982     */
1983    /**
1984     * Reads an 8-bit unsigned integer from this Buffer instance at the specified offset.
1985     *
1986     * @param { number } [offset] - Number of bytes to skip before starting to read data. The default value is 0. The value range is [0, Buffer.length - 1].
1987     * @returns { number } Reads an unsigned 8-bit integer
1988     * @throws { BusinessError } 401 - Parameter error. Possible causes: 1.Incorrect parameter types.
1989     * @throws { BusinessError } 10200001 - The value of "offset" is out of range. It must be >= 0 and <= buf.length - 1. Received value is: [offset]
1990     * @syscap SystemCapability.Utils.Lang
1991     * @crossplatform
1992     * @since 10
1993     */
1994    /**
1995     * Reads an 8-bit unsigned integer from this Buffer instance at the specified offset.
1996     *
1997     * @param { number } [offset] - Number of bytes to skip before starting to read data. The default value is 0. The value range is [0, Buffer.length - 1].
1998     * @returns { number } Reads an unsigned 8-bit integer
1999     * @throws { BusinessError } 401 - Parameter error. Possible causes: 1.Incorrect parameter types.
2000     * @throws { BusinessError } 10200001 - The value of "offset" is out of range. It must be >= 0 and <= buf.length - 1. Received value is: [offset]
2001     * @syscap SystemCapability.Utils.Lang
2002     * @crossplatform
2003     * @atomicservice
2004     * @since arkts {'1.1':'11', '1.2':'20'}
2005     * @arkts 1.1&1.2
2006     */
2007    readUInt8(offset?: number): number;
2008
2009    /**
2010     * Reads an unsigned, big-endian 16-bit integer from buf at the specified offset
2011     *
2012     * @param { number } [offset] - offset [offset = 0] Number of bytes to skip before starting to read. Must satisfy 0 <= offset <= buf.length - 2
2013     * @returns { number } Reads an unsigned, big-endian 16-bit integer
2014     * @throws { BusinessError } 401 - Parameter error. Possible causes: 1.Incorrect parameter types.
2015     * @throws { BusinessError } 10200001 - The value of "offset" is out of range. It must be >= 0 and <= buf.length - 2. Received value is: [offset]
2016     * @syscap SystemCapability.Utils.Lang
2017     * @since 9
2018     */
2019    /**
2020     * Reads a 16-bit, big-endian, unsigned integer from this Buffer instance at the specified offset.
2021     *
2022     * @param { number } [offset] - Number of bytes to skip before starting to read data. The default value is 0. The value range is [0, Buffer.length - 2].
2023     * @returns { number } Reads an unsigned, big-endian 16-bit integer
2024     * @throws { BusinessError } 401 - Parameter error. Possible causes: 1.Incorrect parameter types.
2025     * @throws { BusinessError } 10200001 - The value of "offset" is out of range. It must be >= 0 and <= buf.length - 2. Received value is: [offset]
2026     * @syscap SystemCapability.Utils.Lang
2027     * @crossplatform
2028     * @since 10
2029     */
2030    /**
2031     * Reads a 16-bit, big-endian, unsigned integer from this Buffer instance at the specified offset.
2032     *
2033     * @param { number } [offset] - Number of bytes to skip before starting to read data. The default value is 0. The value range is [0, Buffer.length - 2].
2034     * @returns { number } Reads an unsigned, big-endian 16-bit integer
2035     * @throws { BusinessError } 401 - Parameter error. Possible causes: 1.Incorrect parameter types.
2036     * @throws { BusinessError } 10200001 - The value of "offset" is out of range. It must be >= 0 and <= buf.length - 2. Received value is: [offset]
2037     * @syscap SystemCapability.Utils.Lang
2038     * @crossplatform
2039     * @atomicservice
2040     * @since arkts {'1.1':'11', '1.2':'20'}
2041     * @arkts 1.1&1.2
2042     */
2043    readUInt16BE(offset?: number): number;
2044
2045    /**
2046     * Reads an unsigned, little-endian 16-bit integer from buf at the specified offset
2047     *
2048     * @param { number } [offset] - offset [offset = 0] Number of bytes to skip before starting to read. Must satisfy 0 <= offset <= buf.length - 2
2049     * @returns { number } Reads an unsigned, little-endian 16-bit integer
2050     * @throws { BusinessError } 401 - Parameter error. Possible causes: 1.Incorrect parameter types.
2051     * @throws { BusinessError } 10200001 - The value of "offset" is out of range. It must be >= 0 and <= buf.length - 2. Received value is: [offset]
2052     * @syscap SystemCapability.Utils.Lang
2053     * @since 9
2054     */
2055    /**
2056     * Reads a 16-bit, little-endian, unsigned integer from this Buffer instance at the specified offset.
2057     *
2058     * @param { number } [offset] - Number of bytes to skip before starting to read data. The default value is 0. The value range is [0, Buffer.length - 2].
2059     * @returns { number } Reads an unsigned, little-endian 16-bit integer
2060     * @throws { BusinessError } 401 - Parameter error. Possible causes: 1.Incorrect parameter types.
2061     * @throws { BusinessError } 10200001 - The value of "offset" is out of range. It must be >= 0 and <= buf.length - 2. Received value is: [offset]
2062     * @syscap SystemCapability.Utils.Lang
2063     * @crossplatform
2064     * @since 10
2065     */
2066    /**
2067     * Reads a 16-bit, little-endian, unsigned integer from this Buffer instance at the specified offset.
2068     *
2069     * @param { number } [offset] - Number of bytes to skip before starting to read data. The default value is 0. The value range is [0, Buffer.length - 2].
2070     * @returns { number } Reads an unsigned, little-endian 16-bit integer
2071     * @throws { BusinessError } 401 - Parameter error. Possible causes: 1.Incorrect parameter types.
2072     * @throws { BusinessError } 10200001 - The value of "offset" is out of range. It must be >= 0 and <= buf.length - 2. Received value is: [offset]
2073     * @syscap SystemCapability.Utils.Lang
2074     * @crossplatform
2075     * @atomicservice
2076     * @since arkts {'1.1':'11', '1.2':'20'}
2077     * @arkts 1.1&1.2
2078     */
2079    readUInt16LE(offset?: number): number;
2080
2081    /**
2082     * Reads an unsigned, big-endian 32-bit integer from buf at the specified offset
2083     *
2084     * @param { number } [offset] - offset [offset = 0] Number of bytes to skip before starting to read. Must satisfy 0 <= offset <= buf.length - 4
2085     * @returns { number } Reads an unsigned, big-endian 32-bit integer
2086     * @throws { BusinessError } 401 - Parameter error. Possible causes: 1.Incorrect parameter types.
2087     * @throws { BusinessError } 10200001 - The value of "offset" is out of range. It must be >= 0 and <= buf.length - 4. Received value is: [offset]
2088     * @syscap SystemCapability.Utils.Lang
2089     * @since 9
2090     */
2091    /**
2092     * Reads a 32-bit, big-endian, unsigned integer from this Buffer instance at the specified offset.
2093     *
2094     * @param { number } [offset] - Number of bytes to skip before starting to read data. The default value is 0. The value range is [0, Buffer.length - 4].
2095     * @returns { number } Reads an unsigned, big-endian 32-bit integer
2096     * @throws { BusinessError } 401 - Parameter error. Possible causes: 1.Incorrect parameter types.
2097     * @throws { BusinessError } 10200001 - The value of "offset" is out of range. It must be >= 0 and <= buf.length - 4. Received value is: [offset]
2098     * @syscap SystemCapability.Utils.Lang
2099     * @crossplatform
2100     * @since 10
2101     */
2102    /**
2103     * Reads a 32-bit, big-endian, unsigned integer from this Buffer instance at the specified offset.
2104     *
2105     * @param { number } [offset] - Number of bytes to skip before starting to read data. The default value is 0. The value range is [0, Buffer.length - 4].
2106     * @returns { number } Reads an unsigned, big-endian 32-bit integer
2107     * @throws { BusinessError } 401 - Parameter error. Possible causes: 1.Incorrect parameter types.
2108     * @throws { BusinessError } 10200001 - The value of "offset" is out of range. It must be >= 0 and <= buf.length - 4. Received value is: [offset]
2109     * @syscap SystemCapability.Utils.Lang
2110     * @crossplatform
2111     * @atomicservice
2112     * @since arkts {'1.1':'11', '1.2':'20'}
2113     * @arkts 1.1&1.2
2114     */
2115    readUInt32BE(offset?: number): number;
2116
2117    /**
2118     * Reads an unsigned, little-endian 32-bit integer from buf at the specified offset
2119     *
2120     * @param { number } [offset] - offset [offset = 0] Number of bytes to skip before starting to read. Must satisfy 0 <= offset <= buf.length - 4
2121     * @returns { number } Reads an unsigned, little-endian 32-bit integer
2122     * @throws { BusinessError } 401 - Parameter error. Possible causes: 1.Incorrect parameter types.
2123     * @throws { BusinessError } 10200001 - The value of "offset" is out of range. It must be >= 0 and <= buf.length - 4. Received value is: [offset]
2124     * @syscap SystemCapability.Utils.Lang
2125     * @since 9
2126     */
2127    /**
2128     * Reads a 32-bit, little-endian, unsigned integer from this Buffer instance at the specified offset.
2129     *
2130     * @param { number } [offset] - Number of bytes to skip before starting to read data. The default value is 0. The value range is [0, Buffer.length - 4].
2131     * @returns { number } Reads an unsigned, little-endian 32-bit integer
2132     * @throws { BusinessError } 401 - Parameter error. Possible causes: 1.Incorrect parameter types.
2133     * @throws { BusinessError } 10200001 - The value of "offset" is out of range. It must be >= 0 and <= buf.length - 4. Received value is: [offset]
2134     * @syscap SystemCapability.Utils.Lang
2135     * @crossplatform
2136     * @since 10
2137     */
2138    /**
2139     * Reads a 32-bit, little-endian, unsigned integer from this Buffer instance at the specified offset.
2140     *
2141     * @param { number } [offset] - Number of bytes to skip before starting to read data. The default value is 0. The value range is [0, Buffer.length - 4].
2142     * @returns { number } Reads an unsigned, little-endian 32-bit integer
2143     * @throws { BusinessError } 401 - Parameter error. Possible causes: 1.Incorrect parameter types.
2144     * @throws { BusinessError } 10200001 - The value of "offset" is out of range. It must be >= 0 and <= buf.length - 4. Received value is: [offset]
2145     * @syscap SystemCapability.Utils.Lang
2146     * @crossplatform
2147     * @atomicservice
2148     * @since arkts {'1.1':'11', '1.2':'20'}
2149     * @arkts 1.1&1.2
2150     */
2151    readUInt32LE(offset?: number): number;
2152
2153    /**
2154     * Reads byteLength number of bytes from buf at the specified offset and interprets the result as
2155     * an unsigned big-endian integer supporting up to 48 bits of accuracy.
2156     *
2157     * @param { number } offset - offset offset Number of bytes to skip before starting to read. Must satisfy: 0 <= offset <= buf.length - byteLength
2158     * @param { number } byteLength - byteLength byteLength Number of bytes to read. Must satisfy 0 < byteLength <= 6
2159     * @returns { number }
2160     * @throws { BusinessError } 401 - Parameter error. Possible causes:
2161     * 1.Mandatory parameters are left unspecified;
2162     * 2.Incorrect parameter types.
2163     * @throws { BusinessError } 10200001 - The value of "[param]" is out of range. It must be >= [left range] and <= [right range]. Received value is: [param]
2164     * @syscap SystemCapability.Utils.Lang
2165     * @since 9
2166     */
2167    /**
2168     * Reads the specified number of bytes from this Buffer instance at the specified offset, and interprets the result as an unsigned,
2169     * big-endian integer that supports up to 48 bits of precision.
2170     *
2171     * @param { number } offset - Number of bytes to skip before starting to read data.
2172     *     The default value is 0. The value range is [0, Buffer.length - byteLength].
2173     * @param { number } byteLength - Number of bytes to read. The value range is [1, 6].
2174     * @returns { number }
2175     * @throws { BusinessError } 401 - Parameter error. Possible causes:
2176     * 1.Mandatory parameters are left unspecified;
2177     * 2.Incorrect parameter types.
2178     * @throws { BusinessError } 10200001 - The value of "[param]" is out of range. It must be >= [left range] and <= [right range]. Received value is: [param]
2179     * @syscap SystemCapability.Utils.Lang
2180     * @crossplatform
2181     * @since 10
2182     */
2183    /**
2184     * Reads the specified number of bytes from this Buffer instance at the specified offset, and interprets the result as an unsigned,
2185     * big-endian integer that supports up to 48 bits of precision.
2186     *
2187     * @param { number } offset - Number of bytes to skip before starting to read data.
2188     *     The default value is 0. The value range is [0, Buffer.length - byteLength].
2189     * @param { number } byteLength - Number of bytes to read. The value range is [1, 6].
2190     * @returns { number }
2191     * @throws { BusinessError } 401 - Parameter error. Possible causes:
2192     * 1.Mandatory parameters are left unspecified;
2193     * 2.Incorrect parameter types.
2194     * @throws { BusinessError } 10200001 - The value of "[param]" is out of range. It must be >= [left range] and <= [right range]. Received value is: [param]
2195     * @syscap SystemCapability.Utils.Lang
2196     * @crossplatform
2197     * @atomicservice
2198     * @since arkts {'1.1':'11', '1.2':'20'}
2199     * @arkts 1.1&1.2
2200     */
2201    readUIntBE(offset: number, byteLength: number): number;
2202
2203    /**
2204     * Reads byteLength number of bytes from buf at the specified offset and interprets the result as an unsigned,
2205     * little-endian integer supporting up to 48 bits of accuracy.
2206     *
2207     * @param { number } offset - offset offset Number of bytes to skip before starting to read. Must satisfy: 0 <= offset <= buf.length - byteLength
2208     * @param { number } byteLength - byteLength byteLength Number of bytes to read. Must satisfy 0 < byteLength <= 6
2209     * @returns { number }
2210     * @throws { BusinessError } 401 - Parameter error. Possible causes:
2211     * 1.Mandatory parameters are left unspecified;
2212     * 2.Incorrect parameter types.
2213     * @throws { BusinessError } 10200001 - The value of "[param]" is out of range. It must be >= [left range] and <= [right range]. Received value is: [param]
2214     * @syscap SystemCapability.Utils.Lang
2215     * @since 9
2216     */
2217    /**
2218     * Reads the specified number of bytes from this Buffer instance at the specified offset, and interprets the result as an unsigned,
2219     * little-endian integer that supports up to 48 bits of precision.
2220     *
2221     * @param { number } offset - Number of bytes to skip before starting to read data.
2222     *     The default value is 0. The value range is [0, Buffer.length - byteLength].
2223     * @param { number } byteLength - Number of bytes to read. The value range is [1, 6].
2224     * @returns { number }
2225     * @throws { BusinessError } 401 - Parameter error. Possible causes:
2226     * 1.Mandatory parameters are left unspecified;
2227     * 2.Incorrect parameter types.
2228     * @throws { BusinessError } 10200001 - The value of "[param]" is out of range. It must be >= [left range] and <= [right range]. Received value is: [param]
2229     * @syscap SystemCapability.Utils.Lang
2230     * @crossplatform
2231     * @since 10
2232     */
2233    /**
2234     * Reads the specified number of bytes from this Buffer instance at the specified offset, and interprets the result as an unsigned,
2235     * little-endian integer that supports up to 48 bits of precision.
2236     *
2237     * @param { number } offset - Number of bytes to skip before starting to read data.
2238     *     The default value is 0. The value range is [0, Buffer.length - byteLength].
2239     * @param { number } byteLength - Number of bytes to read. The value range is [1, 6].
2240     * @returns { number }
2241     * @throws { BusinessError } 401 - Parameter error. Possible causes:
2242     * 1.Mandatory parameters are left unspecified;
2243     * 2.Incorrect parameter types.
2244     * @throws { BusinessError } 10200001 - The value of "[param]" is out of range. It must be >= [left range] and <= [right range]. Received value is: [param]
2245     * @syscap SystemCapability.Utils.Lang
2246     * @crossplatform
2247     * @atomicservice
2248     * @since arkts {'1.1':'11', '1.2':'20'}
2249     * @arkts 1.1&1.2
2250     */
2251    readUIntLE(offset: number, byteLength: number): number;
2252
2253    /**
2254     * Returns a new Buffer that references the same memory as the original, but offset and cropped by the start and end indices.
2255     *
2256     * @param { number } [start] - start [start = 0] Where the new Buffer will start
2257     * @param { number } [end] - end [end = buf.length] Where the new Buffer will end (not inclusive)
2258     * @returns { Buffer } Returns a new Buffer that references the same memory as the original
2259     * @syscap SystemCapability.Utils.Lang
2260     * @since 9
2261     */
2262    /**
2263     * Truncates this Buffer instance from the specified position to create a new Buffer instance.
2264     *
2265     * @param { number } [start] - Offset to the start position in this Buffer instance where data is truncated. The default value is 0.
2266     * @param { number } [end] - Offset to the end position in this Buffer instance (not inclusive). The default value is the length of this Buffer instance.
2267     * @returns { Buffer } Returns a new Buffer that references the same memory as the original
2268     * @syscap SystemCapability.Utils.Lang
2269     * @crossplatform
2270     * @since 10
2271     */
2272    /**
2273     * Truncates this Buffer instance from the specified position to create a new Buffer instance.
2274     *
2275     * @param { number } [start] - Offset to the start position in this Buffer instance where data is truncated. The default value is 0.
2276     * @param { number } [end] - Offset to the end position in this Buffer instance (not inclusive). The default value is the length of this Buffer instance.
2277     * @returns { Buffer } Returns a new Buffer that references the same memory as the original
2278     * @syscap SystemCapability.Utils.Lang
2279     * @crossplatform
2280     * @atomicservice
2281     * @since arkts {'1.1':'11', '1.2':'20'}
2282     * @arkts 1.1&1.2
2283     */
2284    subarray(start?: number, end?: number): Buffer;
2285
2286    /**
2287     * Interprets buf as an array of unsigned 16-bit integers and swaps the byte order in-place.
2288     *
2289     * @returns { Buffer } A reference to buf
2290     * @throws { BusinessError } 10200009 - The buffer size must be a multiple of 16-bits
2291     * @syscap SystemCapability.Utils.Lang
2292     * @since 9
2293     */
2294    /**
2295     * Interprets this Buffer instance as an array of unsigned 16-bit integers and swaps the byte order in place.
2296     *
2297     * @returns { Buffer } A reference to buf
2298     * @throws { BusinessError } 10200009 - The buffer size must be a multiple of 16-bits
2299     * @syscap SystemCapability.Utils.Lang
2300     * @crossplatform
2301     * @since 10
2302     */
2303    /**
2304     * Interprets this Buffer instance as an array of unsigned 16-bit integers and swaps the byte order in place.
2305     *
2306     * @returns { Buffer } A reference to buf
2307     * @throws { BusinessError } 10200009 - The buffer size must be a multiple of 16-bits
2308     * @syscap SystemCapability.Utils.Lang
2309     * @crossplatform
2310     * @atomicservice
2311     * @since arkts {'1.1':'11', '1.2':'20'}
2312     * @arkts 1.1&1.2
2313     */
2314    swap16(): Buffer;
2315
2316    /**
2317     * Interprets buf as an array of unsigned 32-bit integers and swaps the byte order in-place.
2318     *
2319     * @returns { Buffer } A reference to buf
2320     * @throws { BusinessError } 10200009 - The buffer size must be a multiple of 32-bits
2321     * @syscap SystemCapability.Utils.Lang
2322     * @since 9
2323     */
2324    /**
2325     * Interprets this Buffer instance as an array of unsigned 32-bit integers and swaps the byte order in place.
2326     *
2327     * @returns { Buffer } A reference to buf
2328     * @throws { BusinessError } 10200009 - The buffer size must be a multiple of 32-bits
2329     * @syscap SystemCapability.Utils.Lang
2330     * @crossplatform
2331     * @since 10
2332     */
2333    /**
2334     * Interprets this Buffer instance as an array of unsigned 32-bit integers and swaps the byte order in place.
2335     *
2336     * @returns { Buffer } A reference to buf
2337     * @throws { BusinessError } 10200009 - The buffer size must be a multiple of 32-bits
2338     * @syscap SystemCapability.Utils.Lang
2339     * @crossplatform
2340     * @atomicservice
2341     * @since arkts {'1.1':'11', '1.2':'20'}
2342     * @arkts 1.1&1.2
2343     */
2344    swap32(): Buffer;
2345
2346    /**
2347     * Interprets buf as an array of unsigned 64-bit integers and swaps the byte order in-place.
2348     *
2349     * @returns { Buffer } A reference to buf
2350     * @throws { BusinessError } 10200009 - The buffer size must be a multiple of 64-bits
2351     * @syscap SystemCapability.Utils.Lang
2352     * @since 9
2353     */
2354    /**
2355     * Interprets this Buffer instance as an array of unsigned 64-bit integers and swaps the byte order in place.
2356     *
2357     * @returns { Buffer } A reference to buf
2358     * @throws { BusinessError } 10200009 - The buffer size must be a multiple of 64-bits
2359     * @syscap SystemCapability.Utils.Lang
2360     * @crossplatform
2361     * @since 10
2362     */
2363    /**
2364     * Interprets this Buffer instance as an array of unsigned 64-bit integers and swaps the byte order in place.
2365     *
2366     * @returns { Buffer } A reference to buf
2367     * @throws { BusinessError } 10200009 - The buffer size must be a multiple of 64-bits
2368     * @syscap SystemCapability.Utils.Lang
2369     * @crossplatform
2370     * @atomicservice
2371     * @since arkts {'1.1':'11', '1.2':'20'}
2372     * @arkts 1.1&1.2
2373     */
2374    swap64(): Buffer;
2375
2376    /**
2377     * Returns a JSON representation of buf
2378     *
2379     * @returns { Object } Returns a JSON
2380     * @syscap SystemCapability.Utils.Lang
2381     * @since 9
2382     */
2383    /**
2384     * Returns a JSON representation of buf
2385     *
2386     * @returns { Object } Returns a JSON
2387     * @syscap SystemCapability.Utils.Lang
2388     * @crossplatform
2389     * @since 10
2390     */
2391    /**
2392     * Converts this Buffer instance into a JSON object.
2393     *
2394     * @returns { Object } Returns a JSON
2395     * @syscap SystemCapability.Utils.Lang
2396     * @crossplatform
2397     * @atomicservice
2398     * @since 11
2399     */
2400    toJSON(): Object;
2401
2402    /**
2403     * Decodes buf to a string according to the specified character encoding in encoding
2404     *
2405     * @param { string } [encoding] - encoding [encoding='utf8'] The character encoding to use
2406     * @param { number } [start] - start [start = 0] The byte offset to start decoding at
2407     * @param { number } [end] - end [end = buf.length] The byte offset to stop decoding at (not inclusive)
2408     * @returns { string }
2409     * @throws { BusinessError } 401 - Parameter error. Possible causes: 1.Incorrect parameter types.
2410     * @syscap SystemCapability.Utils.Lang
2411     * @since 9
2412     */
2413    /**
2414     * Decodes buf to a string according to the specified character encoding in encoding
2415     *
2416     * @param { string } [encoding] - encoding [encoding='utf8'] The character encoding to use
2417     * @param { number } [start] - start [start = 0] The byte offset to start decoding at
2418     * @param { number } [end] - end [end = buf.length] The byte offset to stop decoding at (not inclusive)
2419     * @returns { string }
2420     * @throws { BusinessError } 401 - Parameter error. Possible causes: 1.Incorrect parameter types.
2421     * @syscap SystemCapability.Utils.Lang
2422     * @crossplatform
2423     * @since 10
2424     */
2425    /**
2426     * Converts the data at the specified position in this Buffer instance into a string in the specified encoding format.
2427     *
2428     * @param { string } [encoding] - Encoding format (valid only when value is a string). The default value is 'utf8'.
2429     * @param { number } [start] - Offset to the start position of the data to convert. The default value is 0.
2430     * @param { number } [end] - Offset to the end position of the data to convert. The default value is the length of this Buffer instance.
2431     * @returns { string }
2432     * @throws { BusinessError } 401 - Parameter error. Possible causes: 1.Incorrect parameter types.
2433     * @syscap SystemCapability.Utils.Lang
2434     * @crossplatform
2435     * @atomicservice
2436     * @since 11
2437     */
2438    toString(encoding?: string, start?: number, end?: number): string;
2439
2440    /**
2441     * Decodes buf to a string according to the specified character encoding in encoding
2442     *
2443     * @param { BufferEncoding } [encoding] - encoding [encoding='utf8'] The character encoding to use
2444     * @param { number } [start] - start [start = 0] The byte offset to start decoding at
2445     * @param { number } [end] - end [end = buf.length] The byte offset to stop decoding at (not inclusive)
2446     * @returns { string }
2447     * @syscap SystemCapability.Utils.Lang
2448     * @crossplatform
2449     * @atomicservice
2450     * @since 20
2451     * @arkts 1.2
2452     */
2453    toString(encoding?: BufferEncoding, start?: number, end?: number): string;
2454
2455    /**
2456     * Writes string to buf at offset according to the character encoding in encoding
2457     *
2458     * @param { string } str - str str Writes string to buf at offset according to the character encoding in encoding
2459     * @param { number } [offset] - offset [offset = 0] Number of bytes to skip before starting to write string
2460     * @param { number } [length] - length [length = buf.length - offset] Maximum number of bytes to write (written bytes will not exceed buf.length - offset)
2461     * @param { string } [encoding] - encoding [encoding='utf8'] The character encoding of string.
2462     * @returns { number } Number of bytes written.
2463     * @throws { BusinessError } 401 - Parameter error. Possible causes:
2464     * 1.Mandatory parameters are left unspecified;
2465     * 2.Incorrect parameter types.
2466     * @throws { BusinessError } 10200001 - The value of "[offset/length]" is out of range. It must be >= 0 and <= buf.length. Received value is: [offset/length]
2467     * @syscap SystemCapability.Utils.Lang
2468     * @since 9
2469     */
2470    /**
2471     * Writes a string of the specified length to this Buffer instance at the specified position in the given encoding format.
2472     *
2473     * @param { string } str - String to write.
2474     * @param { number } [offset] - Number of bytes to skip before starting to write data. The default value is 0.
2475     * @param { number } [length] - Maximum number of bytes to write. The default value is Buffer.length minus offset.
2476     * @param { string } [encoding] - Encoding format of the string. The default value is 'utf8'.
2477     * @returns { number } Number of bytes written.
2478     * @throws { BusinessError } 401 - Parameter error. Possible causes:
2479     * 1.Mandatory parameters are left unspecified;
2480     * 2.Incorrect parameter types.
2481     * @throws { BusinessError } 10200001 - The value of "[offset/length]" is out of range. It must be >= 0 and <= buf.length. Received value is: [offset/length]
2482     * @syscap SystemCapability.Utils.Lang
2483     * @crossplatform
2484     * @since 10
2485     */
2486    /**
2487     * Writes a string of the specified length to this Buffer instance at the specified position in the given encoding format.
2488     *
2489     * @param { string } str - String to write.
2490     * @param { number } [offset] - Number of bytes to skip before starting to write data. The default value is 0.
2491     * @param { number } [length] - Maximum number of bytes to write. The default value is Buffer.length minus offset.
2492     * @param { string } [encoding] - Encoding format of the string. The default value is 'utf8'.
2493     * @returns { number } Number of bytes written.
2494     * @throws { BusinessError } 401 - Parameter error. Possible causes:
2495     * 1.Mandatory parameters are left unspecified;
2496     * 2.Incorrect parameter types.
2497     * @throws { BusinessError } 10200001 - The value of "[offset/length]" is out of range. It must be >= 0 and <= buf.length. Received value is: [offset/length]
2498     * @syscap SystemCapability.Utils.Lang
2499     * @crossplatform
2500     * @atomicservice
2501     * @since arkts {'1.1':'11', '1.2':'20'}
2502     * @arkts 1.1&1.2
2503     */
2504    write(str: string, offset?: number, length?: number, encoding?: string): number;
2505
2506    /**
2507     * Writes value to buf at the specified offset as big-endian.
2508     *
2509     * @param { bigint } value - value value Number to be written to buf
2510     * @param { number } [offset] - offset [offset = 0]  Number of bytes to skip before starting to write. Must satisfy: 0 <= offset <= buf.length - 8
2511     * @returns { number } offset plus the number of bytes written
2512     * @throws { BusinessError } 401 - Parameter error. Possible causes:
2513     * 1.Mandatory parameters are left unspecified;
2514     * 2.Incorrect parameter types; 3.Parameter verification failed.
2515     * @throws { BusinessError } 10200001 - The value of "[param]" is out of range. It must be >= [left range] and <= [right range]. Received value is: [param]
2516     * @syscap SystemCapability.Utils.Lang
2517     * @since 9
2518     */
2519    /**
2520     * Writes a 64-bit, big-endian, signed big integer to this Buffer instance at the specified offset.
2521     *
2522     * @param { bigint } value - Data to write.
2523     * @param { number } [offset] - Number of bytes to skip before starting to write data. The default value is 0. The value range is [0, Buffer.length - 8].
2524     * @returns { number } offset plus the number of bytes written
2525     * @throws { BusinessError } 401 - Parameter error. Possible causes:
2526     * 1.Mandatory parameters are left unspecified;
2527     * 2.Incorrect parameter types;
2528     * 3.Parameter verification failed.
2529     * @throws { BusinessError } 10200001 - The value of "[param]" is out of range. It must be >= [left range] and <= [right range]. Received value is: [param]
2530     * @syscap SystemCapability.Utils.Lang
2531     * @crossplatform
2532     * @since 10
2533     */
2534    /**
2535     * Writes a 64-bit, big-endian, signed big integer to this Buffer instance at the specified offset.
2536     *
2537     * @param { bigint } value - Data to write.
2538     * @param { number } [offset] - Number of bytes to skip before starting to write data. The default value is 0. The value range is [0, Buffer.length - 8].
2539     * @returns { number } offset plus the number of bytes written
2540     * @throws { BusinessError } 401 - Parameter error. Possible causes:
2541     * 1.Mandatory parameters are left unspecified;
2542     * 2.Incorrect parameter types;
2543     * 3.Parameter verification failed.
2544     * @throws { BusinessError } 10200001 - The value of "[param]" is out of range. It must be >= [left range] and <= [right range]. Received value is: [param]
2545     * @syscap SystemCapability.Utils.Lang
2546     * @crossplatform
2547     * @atomicservice
2548     * @since arkts {'1.1':'11', '1.2':'20'}
2549     * @arkts 1.1&1.2
2550     */
2551    writeBigInt64BE(value: bigint, offset?: number): number;
2552
2553    /**
2554     * Writes value to buf at the specified offset as little-endian.
2555     *
2556     * @param { bigint } value - value value Number to be written to buf
2557     * @param { number } [offset] - offset [offset = 0]  Number of bytes to skip before starting to write. Must satisfy: 0 <= offset <= buf.length - 8
2558     * @returns { number } offset plus the number of bytes written
2559     * @throws { BusinessError } 401 - Parameter error. Possible causes:
2560     * 1.Mandatory parameters are left unspecified;
2561     * 2.Incorrect parameter types;
2562     * 3.Parameter verification failed.
2563     * @throws { BusinessError } 10200001 - The value of "[param]" is out of range. It must be >= [left range] and <= [right range]. Received value is: [param]
2564     * @syscap SystemCapability.Utils.Lang
2565     * @since 9
2566     */
2567    /**
2568     * Writes a 64-bit, little-endian, signed big integer to this Buffer instance at the specified offset.
2569     *
2570     * @param { bigint } value - Data to write.
2571     * @param { number } [offset] - Number of bytes to skip before starting to write data. The default value is 0. The value range is [0, Buffer.length - 8].
2572     * @returns { number } offset plus the number of bytes written
2573     * @throws { BusinessError } 401 - Parameter error. Possible causes:
2574     * 1.Mandatory parameters are left unspecified;
2575     * 2.Incorrect parameter types;
2576     * 3.Parameter verification failed.
2577     * @throws { BusinessError } 10200001 - The value of "[param]" is out of range. It must be >= [left range] and <= [right range]. Received value is: [param]
2578     * @syscap SystemCapability.Utils.Lang
2579     * @crossplatform
2580     * @since 10
2581     */
2582    /**
2583     * Writes a 64-bit, little-endian, signed big integer to this Buffer instance at the specified offset.
2584     *
2585     * @param { bigint } value - Data to write.
2586     * @param { number } [offset] - Number of bytes to skip before starting to write data. The default value is 0. The value range is [0, Buffer.length - 8].
2587     * @returns { number } offset plus the number of bytes written
2588     * @throws { BusinessError } 401 - Parameter error. Possible causes:
2589     * 1.Mandatory parameters are left unspecified;
2590     * 2.Incorrect parameter types;
2591     * 3.Parameter verification failed.
2592     * @throws { BusinessError } 10200001 - The value of "[param]" is out of range. It must be >= [left range] and <= [right range]. Received value is: [param]
2593     * @syscap SystemCapability.Utils.Lang
2594     * @crossplatform
2595     * @atomicservice
2596     * @since arkts {'1.1':'11', '1.2':'20'}
2597     * @arkts 1.1&1.2
2598     */
2599    writeBigInt64LE(value: bigint, offset?: number): number;
2600
2601    /**
2602     * Writes value to buf at the specified offset as big-endian.
2603     *
2604     * @param { bigint } value - value value Number to be written to buf
2605     * @param { number } [offset] - offset [offset = 0]  Number of bytes to skip before starting to write. Must satisfy: 0 <= offset <= buf.length - 8
2606     * @returns { number } offset plus the number of bytes written
2607     * @throws { BusinessError } 401 - Parameter error. Possible causes:
2608     * 1.Mandatory parameters are left unspecified;
2609     * 2.Incorrect parameter types;
2610     * 3.Parameter verification failed.
2611     * @throws { BusinessError } 10200001 - The value of "[param]" is out of range. It must be >= [left range] and <= [right range]. Received value is: [param]
2612     * @syscap SystemCapability.Utils.Lang
2613     * @since 9
2614     */
2615    /**
2616     * Writes a 64-bit, big-endian, unsigned big integer to this Buffer instance at the specified offset.
2617     *
2618     * @param { bigint } value - Data to write.
2619     * @param { number } [offset] - Number of bytes to skip before starting to write data. The default value is 0. The value range is [0, Buffer.length - 8].
2620     * @returns { number } offset plus the number of bytes written
2621     * @throws { BusinessError } 401 - Parameter error. Possible causes:
2622     * 1.Mandatory parameters are left unspecified;
2623     * 2.Incorrect parameter types;
2624     * 3.Parameter verification failed.
2625     * @throws { BusinessError } 10200001 - The value of "[param]" is out of range. It must be >= [left range] and <= [right range]. Received value is: [param]
2626     * @syscap SystemCapability.Utils.Lang
2627     * @crossplatform
2628     * @since 10
2629     */
2630    /**
2631     * Writes a 64-bit, big-endian, unsigned big integer to this Buffer instance at the specified offset.
2632     *
2633     * @param { bigint } value - Data to write.
2634     * @param { number } [offset] - Number of bytes to skip before starting to write data. The default value is 0. The value range is [0, Buffer.length - 8].
2635     * @returns { number } offset plus the number of bytes written
2636     * @throws { BusinessError } 401 - Parameter error. Possible causes:
2637     * 1.Mandatory parameters are left unspecified;
2638     * 2.Incorrect parameter types;
2639     * 3.Parameter verification failed.
2640     * @throws { BusinessError } 10200001 - The value of "[param]" is out of range. It must be >= [left range] and <= [right range]. Received value is: [param]
2641     * @syscap SystemCapability.Utils.Lang
2642     * @crossplatform
2643     * @atomicservice
2644     * @since arkts {'1.1':'11', '1.2':'20'}
2645     * @arkts 1.1&1.2
2646     */
2647    writeBigUInt64BE(value: bigint, offset?: number): number;
2648
2649    /**
2650     * Writes value to buf at the specified offset as little-endian.
2651     *
2652     * @param { bigint } value - value value Number to be written to buf
2653     * @param { number } [offset] - offset [offset = 0]  Number of bytes to skip before starting to write. Must satisfy: 0 <= offset <= buf.length - 8
2654     * @returns { number } offset plus the number of bytes written
2655     * @throws { BusinessError } 401 - Parameter error. Possible causes:
2656     * 1.Mandatory parameters are left unspecified;
2657     * 2.Incorrect parameter types;
2658     * 3.Parameter verification failed.
2659     * @throws { BusinessError } 10200001 - The value of "[param]" is out of range. It must be >= [left range] and <= [right range]. Received value is: [param]
2660     * @syscap SystemCapability.Utils.Lang
2661     * @since 9
2662     */
2663    /**
2664     * Writes a 64-bit, little-endian, unsigned big integer to this Buffer instance at the specified offset.
2665     *
2666     * @param { bigint } value - Data to write.
2667     * @param { number } [offset] - Number of bytes to skip before starting to write data. The default value is 0. The value range is [0, Buffer.length - 8].
2668     * @returns { number } offset plus the number of bytes written
2669     * @throws { BusinessError } 401 - Parameter error. Possible causes:
2670     * 1.Mandatory parameters are left unspecified;
2671     * 2.Incorrect parameter types;
2672     * 3.Parameter verification failed.
2673     * @throws { BusinessError } 10200001 - The value of "[param]" is out of range. It must be >= [left range] and <= [right range]. Received value is: [param]
2674     * @syscap SystemCapability.Utils.Lang
2675     * @crossplatform
2676     * @since 10
2677     */
2678    /**
2679     * Writes a 64-bit, little-endian, unsigned big integer to this Buffer instance at the specified offset.
2680     *
2681     * @param { bigint } value - Data to write.
2682     * @param { number } [offset] - Number of bytes to skip before starting to write data. The default value is 0. The value range is [0, Buffer.length - 8].
2683     * @returns { number } offset plus the number of bytes written
2684     * @throws { BusinessError } 401 - Parameter error. Possible causes:
2685     * 1.Mandatory parameters are left unspecified;
2686     * 2.Incorrect parameter types;
2687     * 3.Parameter verification failed.
2688     * @throws { BusinessError } 10200001 - The value of "[param]" is out of range. It must be >= [left range] and <= [right range]. Received value is: [param]
2689     * @syscap SystemCapability.Utils.Lang
2690     * @crossplatform
2691     * @atomicservice
2692     * @since arkts {'1.1':'11', '1.2':'20'}
2693     * @arkts 1.1&1.2
2694     */
2695    writeBigUInt64LE(value: bigint, offset?: number): number;
2696
2697    /**
2698     * Writes value to buf at the specified offset as big-endian.
2699     *
2700     * @param { number } value - value value Number to be written to buf
2701     * @param { number } [offset] - offset [offset = 0]  Number of bytes to skip before starting to write. Must satisfy: 0 <= offset <= buf.length - 8
2702     * @returns { number } offset plus the number of bytes written
2703     * @throws { BusinessError } 401 - Parameter error. Possible causes:
2704     * 1.Mandatory parameters are left unspecified;
2705     * 2.Incorrect parameter types.
2706     * @throws { BusinessError } 10200001 - The value of "offset" is out of range. It must be >= 0 and <= buf.length - 8. Received value is: [offset]
2707     * @syscap SystemCapability.Utils.Lang
2708     * @since 9
2709     */
2710    /**
2711     * Writes a 64-bit, big-endian, double-precision floating-point number to this Buffer instance at the specified offset.
2712     *
2713     * @param { number } value - Data to write.
2714     * @param { number } [offset] - Number of bytes to skip before starting to write data. The default value is 0. The value range is [0, Buffer.length - 8].
2715     * @returns { number } offset plus the number of bytes written
2716     * @throws { BusinessError } 401 - Parameter error. Possible causes:
2717     * 1.Mandatory parameters are left unspecified;
2718     * 2.Incorrect parameter types.
2719     * @throws { BusinessError } 10200001 - The value of "offset" is out of range. It must be >= 0 and <= buf.length - 8. Received value is: [offset]
2720     * @syscap SystemCapability.Utils.Lang
2721     * @crossplatform
2722     * @since 10
2723     */
2724    /**
2725     * Writes a 64-bit, big-endian, double-precision floating-point number to this Buffer instance at the specified offset.
2726     *
2727     * @param { number } value - Data to write.
2728     * @param { number } [offset] - Number of bytes to skip before starting to write data. The default value is 0. The value range is [0, Buffer.length - 8].
2729     * @returns { number } offset plus the number of bytes written
2730     * @throws { BusinessError } 401 - Parameter error. Possible causes:
2731     * 1.Mandatory parameters are left unspecified;
2732     * 2.Incorrect parameter types.
2733     * @throws { BusinessError } 10200001 - The value of "offset" is out of range. It must be >= 0 and <= buf.length - 8. Received value is: [offset]
2734     * @syscap SystemCapability.Utils.Lang
2735     * @crossplatform
2736     * @atomicservice
2737     * @since arkts {'1.1':'11', '1.2':'20'}
2738     * @arkts 1.1&1.2
2739     */
2740    writeDoubleBE(value: number, offset?: number): number;
2741
2742    /**
2743     * Writes value to buf at the specified offset as little-endian.
2744     *
2745     * @param { number } value - value value Number to be written to buf
2746     * @param { number } [offset] - offset [offset = 0]  Number of bytes to skip before starting to write. Must satisfy: 0 <= offset <= buf.length - 8
2747     * @returns { number } offset plus the number of bytes written
2748     * @throws { BusinessError } 401 - Parameter error. Possible causes:
2749     * 1.Mandatory parameters are left unspecified;
2750     * 2.Incorrect parameter types.
2751     * @throws { BusinessError } 10200001 - The value of "offset" is out of range. It must be >= 0 and <= buf.length - 8. Received value is: [offset]
2752     * @syscap SystemCapability.Utils.Lang
2753     * @since 9
2754     */
2755    /**
2756     * Writes a 64-bit, little-endian, double-precision floating-point number to this Buffer instance at the specified offset.
2757     *
2758     * @param { number } value - Data to write.
2759     * @param { number } [offset] - Number of bytes to skip before starting to write data. The default value is 0. The value range is [0, Buffer.length - 8].
2760     * @returns { number } offset plus the number of bytes written
2761     * @throws { BusinessError } 401 - Parameter error. Possible causes:
2762     * 1.Mandatory parameters are left unspecified;
2763     * 2.Incorrect parameter types.
2764     * @throws { BusinessError } 10200001 - The value of "offset" is out of range. It must be >= 0 and <= buf.length - 8. Received value is: [offset]
2765     * @syscap SystemCapability.Utils.Lang
2766     * @crossplatform
2767     * @since 10
2768     */
2769    /**
2770     * Writes a 64-bit, little-endian, double-precision floating-point number to this Buffer instance at the specified offset.
2771     *
2772     * @param { number } value - Data to write.
2773     * @param { number } [offset] - Number of bytes to skip before starting to write data. The default value is 0. The value range is [0, Buffer.length - 8].
2774     * @returns { number } offset plus the number of bytes written
2775     * @throws { BusinessError } 401 - Parameter error. Possible causes:
2776     * 1.Mandatory parameters are left unspecified;
2777     * 2.Incorrect parameter types.
2778     * @throws { BusinessError } 10200001 - The value of "offset" is out of range. It must be >= 0 and <= buf.length - 8. Received value is: [offset]
2779     * @syscap SystemCapability.Utils.Lang
2780     * @crossplatform
2781     * @atomicservice
2782     * @since arkts {'1.1':'11', '1.2':'20'}
2783     * @arkts 1.1&1.2
2784     */
2785    writeDoubleLE(value: number, offset?: number): number;
2786
2787    /**
2788     * Writes value to buf at the specified offset as big-endian.
2789     *
2790     * @param { number } value - value value Number to be written to buf
2791     * @param { number } [offset] - offset [offset = 0]  Number of bytes to skip before starting to write. Must satisfy: 0 <= offset <= buf.length - 4
2792     * @returns { number } offset plus the number of bytes written
2793     * @throws { BusinessError } 401 - Parameter error. Possible causes:
2794     * 1.Mandatory parameters are left unspecified;
2795     * 2.Incorrect parameter types.
2796     * @throws { BusinessError } 10200001 - The value of "offset" is out of range. It must be >= 0 and <= buf.length - 4. Received value is: [offset]
2797     * @syscap SystemCapability.Utils.Lang
2798     * @since 9
2799     */
2800    /**
2801     * Writes a 32-bit, big-endian, single-precision floating-point number to this Buffer instance at the specified offset.
2802     *
2803     * @param { number } value - Data to write.
2804     * @param { number } [offset] - Number of bytes to skip before starting to write data. The default value is 0. The value range is [0, Buffer.length - 4].
2805     * @returns { number } offset plus the number of bytes written
2806     * @throws { BusinessError } 401 - Parameter error. Possible causes:
2807     * 1.Mandatory parameters are left unspecified;
2808     * 2.Incorrect parameter types.
2809     * @throws { BusinessError } 10200001 - The value of "offset" is out of range. It must be >= 0 and <= buf.length - 4. Received value is: [offset]
2810     * @syscap SystemCapability.Utils.Lang
2811     * @crossplatform
2812     * @since 10
2813     */
2814    /**
2815     * Writes a 32-bit, big-endian, single-precision floating-point number to this Buffer instance at the specified offset.
2816     *
2817     * @param { number } value - Data to write.
2818     * @param { number } [offset] - Number of bytes to skip before starting to write data. The default value is 0. The value range is [0, Buffer.length - 4].
2819     * @returns { number } offset plus the number of bytes written
2820     * @throws { BusinessError } 401 - Parameter error. Possible causes:
2821     * 1.Mandatory parameters are left unspecified;
2822     * 2.Incorrect parameter types.
2823     * @throws { BusinessError } 10200001 - The value of "offset" is out of range. It must be >= 0 and <= buf.length - 4. Received value is: [offset]
2824     * @syscap SystemCapability.Utils.Lang
2825     * @crossplatform
2826     * @atomicservice
2827     * @since arkts {'1.1':'11', '1.2':'20'}
2828     * @arkts 1.1&1.2
2829     */
2830    writeFloatBE(value: number, offset?: number): number;
2831
2832    /**
2833     * Writes value to buf at the specified offset as little-endian.
2834     *
2835     * @param { number } value - value value Number to be written to buf
2836     * @param { number } [offset] - offset [offset = 0]  Number of bytes to skip before starting to write. Must satisfy: 0 <= offset <= buf.length - 4
2837     * @returns { number } offset plus the number of bytes written
2838     * @throws { BusinessError } 401 - Parameter error. Possible causes:
2839     * 1.Mandatory parameters are left unspecified;
2840     * 2.Incorrect parameter types.
2841     * @throws { BusinessError } 10200001 - The value of "offset" is out of range. It must be >= 0 and <= buf.length - 4. Received value is: [offset]
2842     * @syscap SystemCapability.Utils.Lang
2843     * @since 9
2844     */
2845    /**
2846     * Writes a 32-bit, little-endian, single-precision floating-point number to this Buffer instance at the specified offset.
2847     *
2848     * @param { number } value - Data to write.
2849     * @param { number } [offset] - Number of bytes to skip before starting to write data. The default value is 0. The value range is [0, Buffer.length - 4].
2850     * @returns { number } offset plus the number of bytes written
2851     * @throws { BusinessError } 401 - Parameter error. Possible causes:
2852     * 1.Mandatory parameters are left unspecified;
2853     * 2.Incorrect parameter types.
2854     * @throws { BusinessError } 10200001 - The value of "offset" is out of range. It must be >= 0 and <= buf.length - 4. Received value is: [offset]
2855     * @syscap SystemCapability.Utils.Lang
2856     * @crossplatform
2857     * @since 10
2858     */
2859    /**
2860     * Writes a 32-bit, little-endian, single-precision floating-point number to this Buffer instance at the specified offset.
2861     *
2862     * @param { number } value - Data to write.
2863     * @param { number } [offset] - Number of bytes to skip before starting to write data. The default value is 0. The value range is [0, Buffer.length - 4].
2864     * @returns { number } offset plus the number of bytes written
2865     * @throws { BusinessError } 401 - Parameter error. Possible causes:
2866     * 1.Mandatory parameters are left unspecified;
2867     * 2.Incorrect parameter types.
2868     * @throws { BusinessError } 10200001 - The value of "offset" is out of range. It must be >= 0 and <= buf.length - 4. Received value is: [offset]
2869     * @syscap SystemCapability.Utils.Lang
2870     * @crossplatform
2871     * @atomicservice
2872     * @since arkts {'1.1':'11', '1.2':'20'}
2873     * @arkts 1.1&1.2
2874     */
2875    writeFloatLE(value: number, offset?: number): number;
2876
2877    /**
2878     * Writes value to buf at the specified offset. value must be a valid signed 8-bit integer.
2879     *
2880     * @param { number } value - value value Number to be written to buf
2881     * @param { number } [offset] - offset [offset = 0] Number of bytes to skip before starting to write. Must satisfy: 0 <= offset <= buf.length - 1
2882     * @returns { number } offset plus the number of bytes written
2883     * @throws { BusinessError } 401 - Parameter error. Possible causes:
2884     * 1.Mandatory parameters are left unspecified;
2885     * 2.Incorrect parameter types;
2886     * 3.Parameter verification failed.
2887     * @throws { BusinessError } 10200001 - The value of "[param]" is out of range. It must be >= [left range] and <= [right range]. Received value is: [param]
2888     * @syscap SystemCapability.Utils.Lang
2889     * @since 9
2890     */
2891    /**
2892     * Writes an 8-bit signed integer to this Buffer instance at the specified offset.
2893     *
2894     * @param { number } value - Data to write.
2895     * @param { number } [offset] - Number of bytes to skip before starting to write data. The default value is 0. The value range is [0, Buffer.length - 1].
2896     * @returns { number } offset plus the number of bytes written
2897     * @throws { BusinessError } 401 - Parameter error. Possible causes:
2898     * 1.Mandatory parameters are left unspecified;
2899     * 2.Incorrect parameter types;
2900     * 3.Parameter verification failed.
2901     * @throws { BusinessError } 10200001 - The value of "[param]" is out of range. It must be >= [left range] and <= [right range]. Received value is: [param]
2902     * @syscap SystemCapability.Utils.Lang
2903     * @crossplatform
2904     * @since 10
2905     */
2906    /**
2907     * Writes an 8-bit signed integer to this Buffer instance at the specified offset.
2908     *
2909     * @param { number } value - Data to write.
2910     * @param { number } [offset] - Number of bytes to skip before starting to write data. The default value is 0. The value range is [0, Buffer.length - 1].
2911     * @returns { number } offset plus the number of bytes written
2912     * @throws { BusinessError } 401 - Parameter error. Possible causes:
2913     * 1.Mandatory parameters are left unspecified;
2914     * 2.Incorrect parameter types;
2915     * 3.Parameter verification failed.
2916     * @throws { BusinessError } 10200001 - The value of "[param]" is out of range. It must be >= [left range] and <= [right range]. Received value is: [param]
2917     * @syscap SystemCapability.Utils.Lang
2918     * @crossplatform
2919     * @atomicservice
2920     * @since arkts {'1.1':'11', '1.2':'20'}
2921     * @arkts 1.1&1.2
2922     */
2923    writeInt8(value: number, offset?: number): number;
2924
2925    /**
2926     * Writes value to buf at the specified offset as big-endian. The value must be a valid signed 16-bit integer
2927     *
2928     * @param { number } value - value value Number to be written to buf
2929     * @param { number } [offset] - offset [offset = 0] Number of bytes to skip before starting to write. Must satisfy: 0 <= offset <= buf.length - 2
2930     * @returns { number } offset plus the number of bytes written
2931     * @throws { BusinessError } 401 - Parameter error. Possible causes:
2932     * 1.Mandatory parameters are left unspecified;
2933     * 2.Incorrect parameter types;
2934     * 3.Parameter verification failed.
2935     * @throws { BusinessError } 10200001 - The value of "[param]" is out of range. It must be >= [left range] and <= [right range]. Received value is: [param]
2936     * @syscap SystemCapability.Utils.Lang
2937     * @since 9
2938     */
2939    /**
2940     * Writes a 16-bit, big-endian, signed integer to this Buffer instance at the specified offset.
2941     *
2942     * @param { number } value - Data to write.
2943     * @param { number } [offset] - Number of bytes to skip before starting to write data. The default value is 0. The value range is [0, Buffer.length - 2].
2944     * @returns { number } offset plus the number of bytes written
2945     * @throws { BusinessError } 401 - Parameter error. Possible causes:
2946     * 1.Mandatory parameters are left unspecified;
2947     * 2.Incorrect parameter types;
2948     * 3.Parameter verification failed.
2949     * @throws { BusinessError } 10200001 - The value of "[param]" is out of range. It must be >= [left range] and <= [right range]. Received value is: [param]
2950     * @syscap SystemCapability.Utils.Lang
2951     * @crossplatform
2952     * @since 10
2953     */
2954    /**
2955     * Writes a 16-bit, big-endian, signed integer to this Buffer instance at the specified offset.
2956     *
2957     * @param { number } value - Data to write.
2958     * @param { number } [offset] - Number of bytes to skip before starting to write data. The default value is 0. The value range is [0, Buffer.length - 2].
2959     * @returns { number } offset plus the number of bytes written
2960     * @throws { BusinessError } 401 - Parameter error. Possible causes:
2961     * 1.Mandatory parameters are left unspecified;
2962     * 2.Incorrect parameter types;
2963     * 3.Parameter verification failed.
2964     * @throws { BusinessError } 10200001 - The value of "[param]" is out of range. It must be >= [left range] and <= [right range]. Received value is: [param]
2965     * @syscap SystemCapability.Utils.Lang
2966     * @crossplatform
2967     * @atomicservice
2968     * @since arkts {'1.1':'11', '1.2':'20'}
2969     * @arkts 1.1&1.2
2970     */
2971    writeInt16BE(value: number, offset?: number): number;
2972
2973    /**
2974     * Writes value to buf at the specified offset as little-endian. The value must be a valid signed 16-bit integer
2975     *
2976     * @param { number } value - value value Number to be written to buf
2977     * @param { number } [offset] - offset [offset = 0] Number of bytes to skip before starting to write. Must satisfy: 0 <= offset <= buf.length - 2
2978     * @returns { number } offset plus the number of bytes written
2979     * @throws { BusinessError } 401 - Parameter error. Possible causes:
2980     * 1.Mandatory parameters are left unspecified;
2981     * 2.Incorrect parameter types;
2982     * 3.Parameter verification failed.
2983     * @throws { BusinessError } 10200001 - The value of "[param]" is out of range. It must be >= [left range] and <= [right range]. Received value is: [param]
2984     * @syscap SystemCapability.Utils.Lang
2985     * @since 9
2986     */
2987    /**
2988     * Writes a 16-bit, little-endian, signed integer to this Buffer instance at the specified offset.
2989     *
2990     * @param { number } value - Data to write.
2991     * @param { number } [offset] - Number of bytes to skip before starting to write data. The default value is 0. The value range is [0, Buffer.length - 2].
2992     * @returns { number } offset plus the number of bytes written
2993     * @throws { BusinessError } 401 - Parameter error. Possible causes:
2994     * 1.Mandatory parameters are left unspecified;
2995     * 2.Incorrect parameter types;
2996     * 3.Parameter verification failed.
2997     * @throws { BusinessError } 10200001 - The value of "[param]" is out of range. It must be >= [left range] and <= [right range]. Received value is: [param]
2998     * @syscap SystemCapability.Utils.Lang
2999     * @crossplatform
3000     * @since 10
3001     */
3002    /**
3003     * Writes a 16-bit, little-endian, signed integer to this Buffer instance at the specified offset.
3004     *
3005     * @param { number } value - Data to write.
3006     * @param { number } [offset] - Number of bytes to skip before starting to write data. The default value is 0. The value range is [0, Buffer.length - 2].
3007     * @returns { number } offset plus the number of bytes written
3008     * @throws { BusinessError } 401 - Parameter error. Possible causes:
3009     * 1.Mandatory parameters are left unspecified;
3010     * 2.Incorrect parameter types;
3011     * 3.Parameter verification failed.
3012     * @throws { BusinessError } 10200001 - The value of "[param]" is out of range. It must be >= [left range] and <= [right range]. Received value is: [param]
3013     * @syscap SystemCapability.Utils.Lang
3014     * @crossplatform
3015     * @atomicservice
3016     * @since arkts {'1.1':'11', '1.2':'20'}
3017     * @arkts 1.1&1.2
3018     */
3019    writeInt16LE(value: number, offset?: number): number;
3020
3021    /**
3022     * Writes value to buf at the specified offset as big-endian. The value must be a valid signed 32-bit integer.
3023     *
3024     * @param { number } value - value value Number to be written to buf
3025     * @param { number } [offset] - offset [offset = 0] Number of bytes to skip before starting to write. Must satisfy: 0 <= offset <= buf.length - 4
3026     * @returns { number } offset plus the number of bytes written
3027     * @throws { BusinessError } 401 - Parameter error. Possible causes:
3028     * 1.Mandatory parameters are left unspecified;
3029     * 2.Incorrect parameter types;
3030     * 3.Parameter verification failed.
3031     * @throws { BusinessError } 10200001 - The value of "[param]" is out of range. It must be >= [left range] and <= [right range]. Received value is: [param]
3032     * @syscap SystemCapability.Utils.Lang
3033     * @since 9
3034     */
3035    /**
3036     * Writes a 32-bit, big-endian, signed integer to this Buffer instance at the specified offset.
3037     *
3038     * @param { number } value - Data to write.
3039     * @param { number } [offset] - Number of bytes to skip before starting to write data. The default value is 0. The value range is [0, Buffer.length - 4].
3040     * @returns { number } offset plus the number of bytes written
3041     * @throws { BusinessError } 401 - Parameter error. Possible causes:
3042     * 1.Mandatory parameters are left unspecified;
3043     * 2.Incorrect parameter types;
3044     * 3.Parameter verification failed.
3045     * @throws { BusinessError } 10200001 - The value of "[param]" is out of range. It must be >= [left range] and <= [right range]. Received value is: [param]
3046     * @syscap SystemCapability.Utils.Lang
3047     * @crossplatform
3048     * @since 10
3049     */
3050    /**
3051     * Writes a 32-bit, big-endian, signed integer to this Buffer instance at the specified offset.
3052     *
3053     * @param { number } value - Data to write.
3054     * @param { number } [offset] - Number of bytes to skip before starting to write data. The default value is 0. The value range is [0, Buffer.length - 4].
3055     * @returns { number } offset plus the number of bytes written
3056     * @throws { BusinessError } 401 - Parameter error. Possible causes:
3057     * 1.Mandatory parameters are left unspecified;
3058     * 2.Incorrect parameter types;
3059     * 3.Parameter verification failed.
3060     * @throws { BusinessError } 10200001 - The value of "[param]" is out of range. It must be >= [left range] and <= [right range]. Received value is: [param]
3061     * @syscap SystemCapability.Utils.Lang
3062     * @crossplatform
3063     * @atomicservice
3064     * @since arkts {'1.1':'11', '1.2':'20'}
3065     * @arkts 1.1&1.2
3066     */
3067    writeInt32BE(value: number, offset?: number): number;
3068
3069    /**
3070     * Writes value to buf at the specified offset as little-endian. The value must be a valid signed 32-bit integer.
3071     *
3072     * @param { number } value - value value Number to be written to buf
3073     * @param { number } [offset] - offset [offset = 0] Number of bytes to skip before starting to write. Must satisfy: 0 <= offset <= buf.length - 4
3074     * @returns { number } offset plus the number of bytes written
3075     * @throws { BusinessError } 401 - Parameter error. Possible causes:
3076     * 1.Mandatory parameters are left unspecified;
3077     * 2.Incorrect parameter types;
3078     * 3.Parameter verification failed.
3079     * @throws { BusinessError } 10200001 - The value of "[param]" is out of range. It must be >= [left range] and <= [right range]. Received value is: [param]
3080     * @syscap SystemCapability.Utils.Lang
3081     * @since 9
3082     */
3083    /**
3084     * Writes a 32-bit, little-endian, signed integer to this Buffer instance at the specified offset.
3085     *
3086     * @param { number } value - Data to write.
3087     * @param { number } [offset] - Number of bytes to skip before starting to write data. The default value is 0. The value range is [0, Buffer.length - 4].
3088     * @returns { number } offset plus the number of bytes written
3089     * @throws { BusinessError } 401 - Parameter error. Possible causes:
3090     * 1.Mandatory parameters are left unspecified;
3091     * 2.Incorrect parameter types;
3092     * 3.Parameter verification failed.
3093     * @throws { BusinessError } 10200001 - The value of "[param]" is out of range. It must be >= [left range] and <= [right range]. Received value is: [param]
3094     * @syscap SystemCapability.Utils.Lang
3095     * @crossplatform
3096     * @since 10
3097     */
3098    /**
3099     * Writes a 32-bit, little-endian, signed integer to this Buffer instance at the specified offset.
3100     *
3101     * @param { number } value - Data to write.
3102     * @param { number } [offset] - Number of bytes to skip before starting to write data. The default value is 0. The value range is [0, Buffer.length - 4].
3103     * @returns { number } offset plus the number of bytes written
3104     * @throws { BusinessError } 401 - Parameter error. Possible causes:
3105     * 1.Mandatory parameters are left unspecified;
3106     * 2.Incorrect parameter types;
3107     * 3.Parameter verification failed.
3108     * @throws { BusinessError } 10200001 - The value of "[param]" is out of range. It must be >= [left range] and <= [right range]. Received value is: [param]
3109     * @syscap SystemCapability.Utils.Lang
3110     * @crossplatform
3111     * @atomicservice
3112     * @since arkts {'1.1':'11', '1.2':'20'}
3113     * @arkts 1.1&1.2
3114     */
3115    writeInt32LE(value: number, offset?: number): number;
3116
3117    /**
3118     * Writes byteLength bytes of value to buf at the specified offset as big-endian
3119     *
3120     * @param { number } value - value value Number to be written to buf
3121     * @param { number } offset - offset offset Number of bytes to skip before starting to write. Must satisfy 0 <= offset <= buf.length - byteLength
3122     * @param { number } byteLength - byteLength byteLength Number of bytes to write. Must satisfy 0 < byteLength <= 6
3123     * @returns { number } offset plus the number of bytes written
3124     * @throws { BusinessError } 401 - Parameter error. Possible causes:
3125     * 1.Mandatory parameters are left unspecified;
3126     * 2.Incorrect parameter types.
3127     * @throws { BusinessError } 10200001 - The value of "[param]" is out of range. It must be >= [left range] and <= [right range]. Received value is: [param]
3128     * @syscap SystemCapability.Utils.Lang
3129     * @since 9
3130     */
3131    /**
3132     * Writes a big-endian signed value of the specified length to this Buffer instance at the specified offset.
3133     *
3134     * @param { number } value - Data to write.
3135     * @param { number } offset - Number of bytes to skip before starting to write data.
3136     *     The default value is 0. The value range is [0, Buffer.length - byteLength].
3137     * @param { number } byteLength - Number of bytes to write.
3138     * @returns { number } offset plus the number of bytes written
3139     * @throws { BusinessError } 401 - Parameter error. Possible causes:
3140     * 1.Mandatory parameters are left unspecified;
3141     * 2.Incorrect parameter types.
3142     * @throws { BusinessError } 10200001 - The value of "[param]" is out of range. It must be >= [left range] and <= [right range]. Received value is: [param]
3143     * @syscap SystemCapability.Utils.Lang
3144     * @crossplatform
3145     * @since 10
3146     */
3147    /**
3148     * Writes a big-endian signed value of the specified length to this Buffer instance at the specified offset.
3149     *
3150     * @param { number } value - Data to write.
3151     * @param { number } offset - Number of bytes to skip before starting to write data.
3152     *     The default value is 0. The value range is [0, Buffer.length - byteLength].
3153     * @param { number } byteLength - Number of bytes to write.
3154     * @returns { number } offset plus the number of bytes written
3155     * @throws { BusinessError } 401 - Parameter error. Possible causes:
3156     * 1.Mandatory parameters are left unspecified;
3157     * 2.Incorrect parameter types.
3158     * @throws { BusinessError } 10200001 - The value of "[param]" is out of range. It must be >= [left range] and <= [right range]. Received value is: [param]
3159     * @syscap SystemCapability.Utils.Lang
3160     * @crossplatform
3161     * @atomicservice
3162     * @since arkts {'1.1':'11', '1.2':'20'}
3163     * @arkts 1.1&1.2
3164     */
3165    writeIntBE(value: number, offset: number, byteLength: number): number;
3166
3167    /**
3168     * Writes byteLength bytes of value to buf at the specified offset as little-endian
3169     *
3170     * @param { number } value - value value Number to be written to buf
3171     * @param { number } offset - offset offset  Number of bytes to skip before starting to write. Must satisfy 0 <= offset <= buf.length - byteLength
3172     * @param { number } byteLength - byteLength byteLength Number of bytes to write. Must satisfy 0 < byteLength <= 6
3173     * @returns { number } offset plus the number of bytes written
3174     * @throws { BusinessError } 401 - Parameter error. Possible causes:
3175     * 1.Mandatory parameters are left unspecified;
3176     * 2.Incorrect parameter types.
3177     * @throws { BusinessError } 10200001 - The value of "[param]" is out of range. It must be >= [left range] and <= [right range]. Received value is: [param]
3178     * @syscap SystemCapability.Utils.Lang
3179     * @since 9
3180     */
3181    /**
3182     * Writes a little-endian signed value of the specified length to this Buffer instance at the specified offset.
3183     *
3184     * @param { number } value - Data to write.
3185     * @param { number } offset - Number of bytes to skip before starting to write data. The default value is 0.
3186     *     The value range is [0, Buffer.length - byteLength].
3187     * @param { number } byteLength - Number of bytes to write.
3188     * @returns { number } offset plus the number of bytes written
3189     * @throws { BusinessError } 401 - Parameter error. Possible causes:
3190     * 1.Mandatory parameters are left unspecified;
3191     * 2.Incorrect parameter types.
3192     * @throws { BusinessError } 10200001 - The value of "[param]" is out of range. It must be >= [left range] and <= [right range]. Received value is: [param]
3193     * @syscap SystemCapability.Utils.Lang
3194     * @crossplatform
3195     * @since 10
3196     */
3197    /**
3198     * Writes a little-endian signed value of the specified length to this Buffer instance at the specified offset.
3199     *
3200     * @param { number } value - Data to write.
3201     * @param { number } offset - Number of bytes to skip before starting to write data.
3202     *     The default value is 0. The value range is [0, Buffer.length - byteLength].
3203     * @param { number } byteLength - Number of bytes to write.
3204     * @returns { number } offset plus the number of bytes written
3205     * @throws { BusinessError } 401 - Parameter error. Possible causes:
3206     * 1.Mandatory parameters are left unspecified;
3207     * 2.Incorrect parameter types.
3208     * @throws { BusinessError } 10200001 - The value of "[param]" is out of range. It must be >= [left range] and <= [right range]. Received value is: [param]
3209     * @syscap SystemCapability.Utils.Lang
3210     * @crossplatform
3211     * @atomicservice
3212     * @since arkts {'1.1':'11', '1.2':'20'}
3213     * @arkts 1.1&1.2
3214     */
3215    writeIntLE(value: number, offset: number, byteLength: number): number;
3216
3217    /**
3218     * Writes value to buf at the specified offset. value must be a valid unsigned 8-bit integer
3219     *
3220     * @param { number } value - value value Number to be written to buf
3221     * @param { number } [offset] - offset [offset = 0] Number of bytes to skip before starting to write. Must satisfy 0 <= offset <= buf.length - 1
3222     * @returns { number } offset plus the number of bytes written
3223     * @throws { BusinessError } 401 - Parameter error. Possible causes:
3224     * 1.Mandatory parameters are left unspecified;
3225     * 2.Incorrect parameter types;
3226     * 3.Parameter verification failed.
3227     * @throws { BusinessError } 10200001 - The value of "[param]" is out of range. It must be >= [left range] and <= [right range]. Received value is: [param]
3228     * @syscap SystemCapability.Utils.Lang
3229     * @since 9
3230     */
3231    /**
3232     * Writes an 8-bit unsigned integer to this Buffer instance at the specified offset.
3233     *
3234     * @param { number } value - Data to write.
3235     * @param { number } [offset] - Number of bytes to skip before starting to write data. The default value is 0. The value range is [0, Buffer.length - 1].
3236     * @returns { number } offset plus the number of bytes written
3237     * @throws { BusinessError } 401 - Parameter error. Possible causes:
3238     * 1.Mandatory parameters are left unspecified;
3239     * 2.Incorrect parameter types;
3240     * 3.Parameter verification failed.
3241     * @throws { BusinessError } 10200001 - The value of "[param]" is out of range. It must be >= [left range] and <= [right range]. Received value is: [param]
3242     * @syscap SystemCapability.Utils.Lang
3243     * @crossplatform
3244     * @since 10
3245     */
3246    /**
3247     * Writes an 8-bit unsigned integer to this Buffer instance at the specified offset.
3248     *
3249     * @param { number } value - Data to write.
3250     * @param { number } [offset] - Number of bytes to skip before starting to write data. The default value is 0. The value range is [0, Buffer.length - 1].
3251     * @returns { number } offset plus the number of bytes written
3252     * @throws { BusinessError } 401 - Parameter error. Possible causes:
3253     * 1.Mandatory parameters are left unspecified;
3254     * 2.Incorrect parameter types;
3255     * 3.Parameter verification failed.
3256     * @throws { BusinessError } 10200001 - The value of "[param]" is out of range. It must be >= [left range] and <= [right range]. Received value is: [param]
3257     * @syscap SystemCapability.Utils.Lang
3258     * @crossplatform
3259     * @atomicservice
3260     * @since arkts {'1.1':'11', '1.2':'20'}
3261     * @arkts 1.1&1.2
3262     */
3263    writeUInt8(value: number, offset?: number): number;
3264
3265    /**
3266     * Writes value to buf at the specified offset as big-endian. The value must be a valid unsigned 16-bit integer.
3267     *
3268     * @param { number } value - value value Number to be written to buf
3269     * @param { number } [offset] - offset [offset = 0] Number of bytes to skip before starting to write. Must satisfy 0 <= offset <= buf.length - 2
3270     * @returns { number } offset plus the number of bytes written
3271     * @throws { BusinessError } 401 - Parameter error. Possible causes:
3272     * 1.Mandatory parameters are left unspecified;
3273     * 2.Incorrect parameter types;
3274     * 3.Parameter verification failed.
3275     * @throws { BusinessError } 10200001 - The value of "[param]" is out of range. It must be >= [left range] and <= [right range]. Received value is: [param]
3276     * @syscap SystemCapability.Utils.Lang
3277     * @since 9
3278     */
3279    /**
3280     * Writes a 16-bit, big-endian, unsigned integer to this Buffer instance at the specified offset.
3281     *
3282     * @param { number } value - 	Data to write.
3283     * @param { number } [offset] - Number of bytes to skip before starting to write data. The default value is 0. The value range is [0, Buffer.length - 2].
3284     * @returns { number } offset plus the number of bytes written
3285     * @throws { BusinessError } 401 - Parameter error. Possible causes:
3286     * 1.Mandatory parameters are left unspecified;
3287     * 2.Incorrect parameter types;
3288     * 3.Parameter verification failed.
3289     * @throws { BusinessError } 10200001 - The value of "[param]" is out of range. It must be >= [left range] and <= [right range]. Received value is: [param]
3290     * @syscap SystemCapability.Utils.Lang
3291     * @crossplatform
3292     * @since 10
3293     */
3294    /**
3295     * Writes a 16-bit, big-endian, unsigned integer to this Buffer instance at the specified offset.
3296     *
3297     * @param { number } value - 	Data to write.
3298     * @param { number } [offset] - Number of bytes to skip before starting to write data. The default value is 0. The value range is [0, Buffer.length - 2].
3299     * @returns { number } offset plus the number of bytes written
3300     * @throws { BusinessError } 401 - Parameter error. Possible causes:
3301     * 1.Mandatory parameters are left unspecified;
3302     * 2.Incorrect parameter types;
3303     * 3.Parameter verification failed.
3304     * @throws { BusinessError } 10200001 - The value of "[param]" is out of range. It must be >= [left range] and <= [right range]. Received value is: [param]
3305     * @syscap SystemCapability.Utils.Lang
3306     * @crossplatform
3307     * @atomicservice
3308     * @since arkts {'1.1':'11', '1.2':'20'}
3309     * @arkts 1.1&1.2
3310     */
3311    writeUInt16BE(value: number, offset?: number): number;
3312
3313    /**
3314     * Writes value to buf at the specified offset as little-endian. The value must be a valid unsigned 16-bit integer.
3315     *
3316     * @param { number } value - value value Number to be written to buf
3317     * @param { number } [offset] - offset [offset = 0] Number of bytes to skip before starting to write. Must satisfy 0 <= offset <= buf.length - 2
3318     * @returns { number } offset plus the number of bytes written
3319     * @throws { BusinessError } 401 - Parameter error. Possible causes:
3320     * 1.Mandatory parameters are left unspecified;
3321     * 2.Incorrect parameter types;
3322     * 3.Parameter verification failed.
3323     * @throws { BusinessError } 10200001 - The value of "[param]" is out of range. It must be >= [left range] and <= [right range]. Received value is: [param]
3324     * @syscap SystemCapability.Utils.Lang
3325     * @since 9
3326     */
3327    /**
3328     * Writes a 16-bit, little-endian, unsigned integer to this Buffer instance at the specified offset.
3329     *
3330     * @param { number } value - Data to write.
3331     * @param { number } [offset] - Number of bytes to skip before starting to write data. The default value is 0. The value range is [0, Buffer.length - 2].
3332     * @returns { number } offset plus the number of bytes written
3333     * @throws { BusinessError } 401 - Parameter error. Possible causes:
3334     * 1.Mandatory parameters are left unspecified;
3335     * 2.Incorrect parameter types;
3336     * 3.Parameter verification failed.
3337     * @throws { BusinessError } 10200001 - The value of "[param]" is out of range. It must be >= [left range] and <= [right range]. Received value is: [param]
3338     * @syscap SystemCapability.Utils.Lang
3339     * @crossplatform
3340     * @since 10
3341     */
3342    /**
3343     * Writes a 16-bit, little-endian, unsigned integer to this Buffer instance at the specified offset.
3344     *
3345     * @param { number } value - Data to write.
3346     * @param { number } [offset] - Number of bytes to skip before starting to write data. The default value is 0. The value range is [0, Buffer.length - 2].
3347     * @returns { number } offset plus the number of bytes written
3348     * @throws { BusinessError } 401 - Parameter error. Possible causes:
3349     * 1.Mandatory parameters are left unspecified;
3350     * 2.Incorrect parameter types;
3351     * 3.Parameter verification failed.
3352     * @throws { BusinessError } 10200001 - The value of "[param]" is out of range. It must be >= [left range] and <= [right range]. Received value is: [param]
3353     * @syscap SystemCapability.Utils.Lang
3354     * @crossplatform
3355     * @atomicservice
3356     * @since arkts {'1.1':'11', '1.2':'20'}
3357     * @arkts 1.1&1.2
3358     */
3359    writeUInt16LE(value: number, offset?: number): number;
3360
3361    /**
3362     * Writes value to buf at the specified offset as big-endian. The value must be a valid unsigned 32-bit integer.
3363     *
3364     * @param { number } value - value value Number to be written to buf
3365     * @param { number } [offset] - offset [offset = 0] Number of bytes to skip before starting to write. Must satisfy 0 <= offset <= buf.length - 4
3366     * @returns { number } offset plus the number of bytes written
3367     * @throws { BusinessError } 401 - Parameter error. Possible causes:
3368     * 1.Mandatory parameters are left unspecified;
3369     * 2.Incorrect parameter types;
3370     * 3.Parameter verification failed.
3371     * @throws { BusinessError } 10200001 - The value of "[param]" is out of range. It must be >= [left range] and <= [right range]. Received value is: [param]
3372     * @syscap SystemCapability.Utils.Lang
3373     * @since 9
3374     */
3375    /**
3376     * Writes a 32-bit, big-endian, unsigned integer to this Buffer instance at the specified offset.
3377     *
3378     * @param { number } value - Data to write.
3379     * @param { number } [offset] - Number of bytes to skip before starting to write data. The default value is 0. The value range is [0, Buffer.length - 4].
3380     * @returns { number } offset plus the number of bytes written
3381     * @throws { BusinessError } 401 - Parameter error. Possible causes:
3382     * 1.Mandatory parameters are left unspecified;
3383     * 2.Incorrect parameter types;
3384     * 3.Parameter verification failed.
3385     * @throws { BusinessError } 10200001 - The value of "[param]" is out of range. It must be >= [left range] and <= [right range]. Received value is: [param]
3386     * @syscap SystemCapability.Utils.Lang
3387     * @crossplatform
3388     * @since 10
3389     */
3390    /**
3391     * Writes a 32-bit, big-endian, unsigned integer to this Buffer instance at the specified offset.
3392     *
3393     * @param { number } value - Data to write.
3394     * @param { number } [offset] - Number of bytes to skip before starting to write data. The default value is 0. The value range is [0, Buffer.length - 4].
3395     * @returns { number } offset plus the number of bytes written
3396     * @throws { BusinessError } 401 - Parameter error. Possible causes:
3397     * 1.Mandatory parameters are left unspecified;
3398     * 2.Incorrect parameter types;
3399     * 3.Parameter verification failed.
3400     * @throws { BusinessError } 10200001 - The value of "[param]" is out of range. It must be >= [left range] and <= [right range]. Received value is: [param]
3401     * @syscap SystemCapability.Utils.Lang
3402     * @crossplatform
3403     * @atomicservice
3404     * @since arkts {'1.1':'11', '1.2':'20'}
3405     * @arkts 1.1&1.2
3406     */
3407    writeUInt32BE(value: number, offset?: number): number;
3408
3409    /**
3410     * Writes value to buf at the specified offset as little-endian. The value must be a valid unsigned 32-bit integer.
3411     *
3412     * @param { number } value - value value Number to be written to buf
3413     * @param { number } [offset] - offset [offset = 0] Number of bytes to skip before starting to write. Must satisfy 0 <= offset <= buf.length - 4
3414     * @returns { number } offset plus the number of bytes written
3415     * @throws { BusinessError } 401 - Parameter error. Possible causes:
3416     * 1.Mandatory parameters are left unspecified;
3417     * 2.Incorrect parameter types;
3418     * 3.Parameter verification failed.
3419     * @throws { BusinessError } 10200001 - The value of "[param]" is out of range. It must be >= [left range] and <= [right range]. Received value is: [param]
3420     * @syscap SystemCapability.Utils.Lang
3421     * @since 9
3422     */
3423    /**
3424     * Writes a 32-bit, little-endian, unsigned integer to this Buffer instance at the specified offset.
3425     *
3426     * @param { number } value - Data to write.
3427     * @param { number } [offset] - Number of bytes to skip before starting to write data. The default value is 0. The value range is [0, Buffer.length - 4].
3428     * @returns { number } offset plus the number of bytes written
3429     * @throws { BusinessError } 401 - Parameter error. Possible causes:
3430     * 1.Mandatory parameters are left unspecified;
3431     * 2.Incorrect parameter types;
3432     * 3.Parameter verification failed.
3433     * @throws { BusinessError } 10200001 - The value of "[param]" is out of range. It must be >= [left range] and <= [right range]. Received value is: [param]
3434     * @syscap SystemCapability.Utils.Lang
3435     * @crossplatform
3436     * @since 10
3437     */
3438    /**
3439     * Writes a 32-bit, little-endian, unsigned integer to this Buffer instance at the specified offset.
3440     *
3441     * @param { number } value - Data to write.
3442     * @param { number } [offset] - Number of bytes to skip before starting to write data. The default value is 0. The value range is [0, Buffer.length - 4].
3443     * @returns { number } offset plus the number of bytes written
3444     * @throws { BusinessError } 401 - Parameter error. Possible causes:
3445     * 1.Mandatory parameters are left unspecified;
3446     * 2.Incorrect parameter types;
3447     * 3.Parameter verification failed.
3448     * @throws { BusinessError } 10200001 - The value of "[param]" is out of range. It must be >= [left range] and <= [right range]. Received value is: [param]
3449     * @syscap SystemCapability.Utils.Lang
3450     * @crossplatform
3451     * @atomicservice
3452     * @since arkts {'1.1':'11', '1.2':'20'}
3453     * @arkts 1.1&1.2
3454     */
3455    writeUInt32LE(value: number, offset?: number): number;
3456
3457    /**
3458     * Writes byteLength bytes of value to buf at the specified offset as big-endian
3459     *
3460     * @param { number } value - value value Number to be written to buf
3461     * @param { number } offset - offset offset Number of bytes to skip before starting to write. Must satisfy 0 <= offset <= buf.length - byteLength
3462     * @param { number } byteLength - byteLength byteLength Number of bytes to write. Must satisfy 0 < byteLength <= 6
3463     * @returns { number } offset plus the number of bytes written
3464     * @throws { BusinessError } 401 - Parameter error. Possible causes:
3465     * 1.Mandatory parameters are left unspecified;
3466     * 2.Incorrect parameter types.
3467     * @throws { BusinessError } 10200001 - The value of "[param]" is out of range. It must be >= [left range] and <= [right range]. Received value is: [param]
3468     * @syscap SystemCapability.Utils.Lang
3469     * @since 9
3470     */
3471    /**
3472     * Writes an unsigned big-endian value of the specified length to this Buffer instance at the specified offset.
3473     *
3474     * @param { number } value - Data to write.
3475     * @param { number } offset - Number of bytes to skip before starting to write data.
3476     *     The default value is 0. The value range is [0, Buffer.length - byteLength].
3477     * @param { number } byteLength - Number of bytes to write.
3478     * @returns { number } offset plus the number of bytes written
3479     * @throws { BusinessError } 401 - Parameter error. Possible causes:
3480     * 1.Mandatory parameters are left unspecified;
3481     * 2.Incorrect parameter types.
3482     * @throws { BusinessError } 10200001 - The value of "[param]" is out of range. It must be >= [left range] and <= [right range]. Received value is: [param]
3483     * @syscap SystemCapability.Utils.Lang
3484     * @crossplatform
3485     * @since 10
3486     */
3487    /**
3488     * Writes an unsigned big-endian value of the specified length to this Buffer instance at the specified offset.
3489     *
3490     * @param { number } value - Data to write.
3491     * @param { number } offset - Number of bytes to skip before starting to write data.
3492     *     The default value is 0. The value range is [0, Buffer.length - byteLength].
3493     * @param { number } byteLength - Number of bytes to write.
3494     * @returns { number } offset plus the number of bytes written
3495     * @throws { BusinessError } 401 - Parameter error. Possible causes:
3496     * 1.Mandatory parameters are left unspecified;
3497     * 2.Incorrect parameter types.
3498     * @throws { BusinessError } 10200001 - The value of "[param]" is out of range. It must be >= [left range] and <= [right range]. Received value is: [param]
3499     * @syscap SystemCapability.Utils.Lang
3500     * @crossplatform
3501     * @atomicservice
3502     * @since arkts {'1.1':'11', '1.2':'20'}
3503     * @arkts 1.1&1.2
3504     */
3505    writeUIntBE(value: number, offset: number, byteLength: number): number;
3506
3507    /**
3508     * Writes byteLength bytes of value to buf at the specified offset as little-endian
3509     *
3510     * @param { number } value - value value Number to be written to buf
3511     * @param { number } offset - offset offset Number of bytes to skip before starting to write. Must satisfy 0 <= offset <= buf.length - byteLength
3512     * @param { number } byteLength - byteLength byteLength Number of bytes to write. Must satisfy 0 < byteLength <= 6
3513     * @returns { number } offset plus the number of bytes written
3514     * @throws { BusinessError } 401 - Parameter error. Possible causes:
3515     * 1.Mandatory parameters are left unspecified;
3516     * 2.Incorrect parameter types.
3517     * @throws { BusinessError } 10200001 - The value of "[param]" is out of range. It must be >= [left range] and <= [right range]. Received value is: [param]
3518     * @syscap SystemCapability.Utils.Lang
3519     * @since 9
3520     */
3521    /**
3522     * Writes an unsigned little-endian value of the specified length to this Buffer instance at the specified offset.
3523     *
3524     * @param { number } value - Data to write.
3525     * @param { number } offset - Number of bytes to skip before starting to write data.
3526     *     The default value is 0. The value range is [0, Buffer.length - byteLength].
3527     * @param { number } byteLength - Number of bytes to write.
3528     * @returns { number } offset plus the number of bytes written
3529     * @throws { BusinessError } 401 - Parameter error. Possible causes:
3530     * 1.Mandatory parameters are left unspecified;
3531     * 2.Incorrect parameter types.
3532     * @throws { BusinessError } 10200001 - The value of "[param]" is out of range. It must be >= [left range] and <= [right range]. Received value is: [param]
3533     * @syscap SystemCapability.Utils.Lang
3534     * @crossplatform
3535     * @since 10
3536     */
3537    /**
3538     * Writes an unsigned little-endian value of the specified length to this Buffer instance at the specified offset.
3539     *
3540     * @param { number } value - Data to write.
3541     * @param { number } offset - Number of bytes to skip before starting to write data.
3542     *     The default value is 0. The value range is [0, Buffer.length - byteLength].
3543     * @param { number } byteLength - Number of bytes to write.
3544     * @returns { number } offset plus the number of bytes written
3545     * @throws { BusinessError } 401 - Parameter error. Possible causes:
3546     * 1.Mandatory parameters are left unspecified;
3547     * 2.Incorrect parameter types.
3548     * @throws { BusinessError } 10200001 - The value of "[param]" is out of range. It must be >= [left range] and <= [right range]. Received value is: [param]
3549     * @syscap SystemCapability.Utils.Lang
3550     * @crossplatform
3551     * @atomicservice
3552     * @since arkts {'1.1':'11', '1.2':'20'}
3553     * @arkts 1.1&1.2
3554     */
3555    writeUIntLE(value: number, offset: number, byteLength: number): number;
3556
3557    /**
3558     * Returns the byte at the specified index.
3559     *
3560     * @param { number } index - byte index to read
3561     * @returns { number | undefined } Returns the byte value at `index`
3562     * @syscap SystemCapability.Utils.Lang
3563     * @crossplatform
3564     * @atomicservice
3565     * @since 20
3566     * @arkts 1.2
3567     */
3568    $_get(index: number): number | undefined;
3569
3570    /**
3571     * Sets the byte at the specified index.
3572     *
3573     * @param { number } index – byte index to write
3574     * @param { number } value – byte value (0–255)
3575     * @syscap SystemCapability.Utils.Lang
3576     * @crossplatform
3577     * @atomicservice
3578     * @since 20
3579     * @arkts 1.2
3580     */
3581    $_set(index: number, value: number): void;
3582  }
3583
3584  /**
3585   * Defines the Blob related options parameters.
3586   *
3587   * @interface BlobOptions
3588   * @syscap SystemCapability.Utils.Lang
3589   * @crossplatform
3590   * @atomicservice
3591   * @since 20
3592   * @arkts 1.2
3593   */
3594  interface BlobOptions {
3595    /**
3596     * Blob content type. The default parameter is' '.
3597     * @type { ?string }
3598     * @syscap SystemCapability.Utils.Lang
3599     * @crossplatform
3600     * @atomicservice
3601     * @since 20
3602     * @arkts 1.2
3603     */
3604    type?: string;
3605
3606    /**
3607     * How to output a string ending with '\ n' as' transparent or native . The default value is transparent.
3608     * @type { ?string }
3609     * @syscap SystemCapability.Utils.Lang
3610     * @crossplatform
3611     * @atomicservice
3612     * @since 20
3613     * @arkts 1.2
3614     */
3615    endings?: string;
3616  }
3617
3618  /**
3619   * Process data as blob type
3620   *
3621   * @syscap SystemCapability.Utils.Lang
3622   * @since 9
3623   */
3624  /**
3625   * Process data as blob type
3626   *
3627   * @syscap SystemCapability.Utils.Lang
3628   * @crossplatform
3629   * @since 10
3630   */
3631  /**
3632   * Process data as blob type
3633   *
3634   * @syscap SystemCapability.Utils.Lang
3635   * @crossplatform
3636   * @atomicservice
3637   * @since arkts {'1.1':'11', '1.2':'20'}
3638   * @arkts 1.1&1.2
3639   */
3640  class Blob {
3641    /**
3642     * Creates a new Blob object containing a concatenation of the given sources.
3643     *
3644     * @param { string[] | ArrayBuffer[] | TypedArray[] | DataView[] | Blob[] } sources - sources sources An array of string, <ArrayBuffer>,
3645     * <TypedArray>, <DataView>, or <Blob> objects, or any mix of such objects, that will be stored within the Blob
3646     * @param { Object } [options] - options options {endings: string, type: string}
3647     *                 endings:  One of either 'transparent' or 'native'.
3648     *                 type: The Blob content-type
3649     * @throws { BusinessError } 401 - Parameter error. Possible causes:
3650     * 1.Mandatory parameters are left unspecified;
3651     * 2.Incorrect parameter types.
3652     * @syscap SystemCapability.Utils.Lang
3653     * @since 9
3654     */
3655    /**
3656     * Creates a new Blob object containing a concatenation of the given sources.
3657     *
3658     * @param { string[] | ArrayBuffer[] | TypedArray[] | DataView[] | Blob[] } sources - sources sources An array of string, <ArrayBuffer>,
3659     * <TypedArray>, <DataView>, or <Blob> objects, or any mix of such objects, that will be stored within the Blob
3660     * @param { Object } [options] - options options {endings: string, type: string}
3661     *                 endings:  One of either 'transparent' or 'native'.
3662     *                 type: The Blob content-type
3663     * @throws { BusinessError } 401 - Parameter error. Possible causes:
3664     * 1.Mandatory parameters are left unspecified;
3665     * 2.Incorrect parameter types.
3666     * @syscap SystemCapability.Utils.Lang
3667     * @crossplatform
3668     * @since 10
3669     */
3670    /**
3671     * Creates a new Blob object containing a concatenation of the given sources.
3672     *
3673     * @param { string[] | ArrayBuffer[] | TypedArray[] | DataView[] | Blob[] } sources - sources sources An array of string, <ArrayBuffer>,
3674     * <TypedArray>, <DataView>, or <Blob> objects, or any mix of such objects, that will be stored within the Blob
3675     * @param { Object } [options] - options options {endings: string, type: string}
3676     *                 endings:  One of either 'transparent' or 'native'.
3677     *                 type: The Blob content-type
3678     * @throws { BusinessError } 401 - Parameter error. Possible causes:
3679     * 1.Mandatory parameters are left unspecified;
3680     * 2.Incorrect parameter types.
3681     * @syscap SystemCapability.Utils.Lang
3682     * @crossplatform
3683     * @atomicservice
3684     * @since 11
3685     */
3686    constructor(sources: string[] | ArrayBuffer[] | TypedArray[] | DataView[] | Blob[], options?: Object);
3687
3688    /**
3689     * Creates a new Blob object containing a concatenation of the given sources.
3690     *
3691     * @param { Array<TypedArray> | Array<string> | Array<ArrayBuffer> | Array<DataView> | Array<Blob> } sources - sources sources An array of string, <ArrayBuffer>,
3692     * <TypedArray>, <DataView>, or <Blob> objects, or any mix of such objects, that will be stored within the Blob
3693     * @param { BlobOptions } [options] - options options {endings: string, type: string}
3694     *                 endings:  One of either 'transparent' or 'native'.
3695     *                 type: The Blob content-type
3696     * @throws { BusinessError } 401 - Parameter error. Possible causes:
3697     * 1.Mandatory parameters are left unspecified;
3698     * 2.Incorrect parameter types.
3699     * @syscap SystemCapability.Utils.Lang
3700     * @crossplatform
3701     * @atomicservice
3702     * @since 20
3703     * @arkts 1.2
3704     */
3705    constructor(sources: Array<TypedArray> | Array<string> | Array<ArrayBuffer> | Array<DataView> | Array<Blob>, options?: BlobOptions);
3706
3707    /**
3708     * The total size of the Blob in bytes
3709     *
3710     * @type { number }
3711     * @syscap SystemCapability.Utils.Lang
3712     * @since 9
3713     */
3714    /**
3715     * Total size of the Blob instance, in bytes.
3716     *
3717     * @type { number }
3718     * @syscap SystemCapability.Utils.Lang
3719     * @crossplatform
3720     * @since 10
3721     */
3722    /**
3723     * Total size of the Blob instance, in bytes.
3724     *
3725     * @type { number }
3726     * @syscap SystemCapability.Utils.Lang
3727     * @crossplatform
3728     * @atomicservice
3729     * @since arkts {'1.1':'11', '1.2':'20'}
3730     * @arkts 1.1&1.2
3731     */
3732    size: number;
3733
3734    /**
3735     * The content-type of the Blob
3736     *
3737     * @type { string }
3738     * @syscap SystemCapability.Utils.Lang
3739     * @since 9
3740     */
3741    /**
3742     * Type of the data in the Blob instance.
3743     *
3744     * @type { string }
3745     * @syscap SystemCapability.Utils.Lang
3746     * @crossplatform
3747     * @since 10
3748     */
3749    /**
3750     * Type of the data in the Blob instance.
3751     *
3752     * @type { string }
3753     * @syscap SystemCapability.Utils.Lang
3754     * @crossplatform
3755     * @atomicservice
3756     * @since arkts {'1.1':'11', '1.2':'20'}
3757     * @arkts 1.1&1.2
3758     */
3759    type: string;
3760
3761    /**
3762     * Returns a promise that fulfills with an <ArrayBuffer> containing a copy of the Blob data.
3763     *
3764     * @returns { Promise<ArrayBuffer> }
3765     * @syscap SystemCapability.Utils.Lang
3766     * @since 9
3767     */
3768    /**
3769     * Puts the Blob data into an ArrayBuffer instance. This API uses a promise to return the result.
3770     *
3771     * @returns { Promise<ArrayBuffer> }
3772     * @syscap SystemCapability.Utils.Lang
3773     * @crossplatform
3774     * @since 10
3775     */
3776    /**
3777     * Puts the Blob data into an ArrayBuffer instance. This API uses a promise to return the result.
3778     *
3779     * @returns { Promise<ArrayBuffer> }
3780     * @syscap SystemCapability.Utils.Lang
3781     * @crossplatform
3782     * @atomicservice
3783     * @since arkts {'1.1':'11', '1.2':'20'}
3784     * @arkts 1.1&1.2
3785     */
3786    arrayBuffer(): Promise<ArrayBuffer>;
3787
3788    /**
3789     * Creates and returns a new Blob containing a subset of this Blob objects data. The original Blob is not altered
3790     *
3791     * @param { number } [start] - start start The starting index
3792     * @param { number } [end] - end end The ending index
3793     * @param { string } [type] - type type The content-type for the new Blob
3794     * @returns { Blob }
3795     * @syscap SystemCapability.Utils.Lang
3796     * @since 9
3797     */
3798    /**
3799     * Creates a Blob instance by copying specified data from this Blob instance.
3800     *
3801     * @param { number } [start] - Offset to the start position of the data to copy. The default value is 0.
3802     * @param { number } [end] - Offset to the end position of the data to copy. The default value is the data length in the original Blob instance.
3803     * @param { string } [type] - Type of the data in the new Blob instance. The default value is ''.
3804     * @returns { Blob }
3805     * @syscap SystemCapability.Utils.Lang
3806     * @crossplatform
3807     * @since 10
3808     */
3809    /**
3810     * Creates a Blob instance by copying specified data from this Blob instance.
3811     *
3812     * @param { number } [start] - Offset to the start position of the data to copy. The default value is 0.
3813     * @param { number } [end] - Offset to the end position of the data to copy. The default value is the data length in the original Blob instance.
3814     * @param { string } [type] - Type of the data in the new Blob instance. The default value is ''.
3815     * @returns { Blob }
3816     * @syscap SystemCapability.Utils.Lang
3817     * @crossplatform
3818     * @atomicservice
3819     * @since arkts {'1.1':'11', '1.2':'20'}
3820     * @arkts 1.1&1.2
3821     */
3822    slice(start?: number, end?: number, type?: string): Blob;
3823
3824    /**
3825     * Returns a promise that fulfills with the contents of the Blob decoded as a UTF-8 string.
3826     *
3827     * @returns { Promise<string> }
3828     * @syscap SystemCapability.Utils.Lang
3829     * @since 9
3830     */
3831    /**
3832     * Returns text in UTF-8 format. This API uses a promise to return the result.
3833     *
3834     * @returns { Promise<string> }
3835     * @syscap SystemCapability.Utils.Lang
3836     * @crossplatform
3837     * @since 10
3838     */
3839    /**
3840     * Returns text in UTF-8 format. This API uses a promise to return the result.
3841     *
3842     * @returns { Promise<string> }
3843     * @syscap SystemCapability.Utils.Lang
3844     * @crossplatform
3845     * @atomicservice
3846     * @since arkts {'1.1':'11', '1.2':'20'}
3847     * @arkts 1.1&1.2
3848     */
3849    text(): Promise<string>;
3850  }
3851}
3852export default buffer;
3853