1 /* 2 * Copyright (C) 2010 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 18 #ifndef ANDROID_ASSET_MANAGER_H 19 #define ANDROID_ASSET_MANAGER_H 20 21 #ifdef __cplusplus 22 extern "C" { 23 #endif 24 25 struct AAssetManager; 26 typedef struct AAssetManager AAssetManager; 27 28 struct AAssetDir; 29 typedef struct AAssetDir AAssetDir; 30 31 struct AAsset; 32 typedef struct AAsset AAsset; 33 34 /* Available modes for opening assets */ 35 enum { 36 AASSET_MODE_UNKNOWN = 0, 37 AASSET_MODE_RANDOM = 1, 38 AASSET_MODE_STREAMING = 2, 39 AASSET_MODE_BUFFER = 3 40 }; 41 42 43 /** 44 * Open the named directory within the asset hierarchy. The directory can then 45 * be inspected with the AAssetDir functions. To open the top-level directory, 46 * pass in "" as the dirName. 47 * 48 * The object returned here should be freed by calling AAssetDir_close(). 49 */ 50 AAssetDir* AAssetManager_openDir(AAssetManager* mgr, const char* dirName); 51 52 /** 53 * Open an asset. 54 * 55 * The object returned here should be freed by calling AAsset_close(). 56 */ 57 AAsset* AAssetManager_open(AAssetManager* mgr, const char* filename, int mode); 58 59 /** 60 * Iterate over the files in an asset directory. A NULL string is returned 61 * when all the file names have been returned. 62 * 63 * The returned file name is suitable for passing to AAssetManager_open(). 64 * 65 * The string returned here is owned by the AssetDir implementation and is not 66 * guaranteed to remain valid if any other calls are made on this AAssetDir 67 * instance. 68 */ 69 const char* AAssetDir_getNextFileName(AAssetDir* assetDir); 70 71 /** 72 * Reset the iteration state of AAssetDir_getNextFileName() to the beginning. 73 */ 74 void AAssetDir_rewind(AAssetDir* assetDir); 75 76 /** 77 * Close an opened AAssetDir, freeing any related resources. 78 */ 79 void AAssetDir_close(AAssetDir* assetDir); 80 81 /** 82 * Attempt to read 'count' bytes of data from the current offset. 83 * 84 * Returns the number of bytes read, zero on EOF, or < 0 on error. 85 */ 86 int AAsset_read(AAsset* asset, void* buf, size_t count); 87 88 /** 89 * Seek to the specified offset within the asset data. 'whence' uses the 90 * same constants as lseek()/fseek(). 91 * 92 * Returns the new position on success, or (off_t) -1 on error. 93 */ 94 off_t AAsset_seek(AAsset* asset, off_t offset, int whence); 95 96 /** 97 * Close the asset, freeing all associated resources. 98 */ 99 void AAsset_close(AAsset* asset); 100 101 /** 102 * Get a pointer to a buffer holding the entire contents of the assset. 103 * 104 * Returns NULL on failure. 105 */ 106 const void* AAsset_getBuffer(AAsset* asset); 107 108 /** 109 * Report the total size of the asset data. 110 */ 111 off_t AAsset_getLength(AAsset* asset); 112 113 /** 114 * Report the total amount of asset data that can be read from the current position. 115 */ 116 off_t AAsset_getRemainingLength(AAsset* asset); 117 118 /** 119 * Open a new file descriptor that can be used to read the asset data. 120 * 121 * Returns < 0 if direct fd access is not possible (for example, if the asset is 122 * compressed). 123 */ 124 int AAsset_openFileDescriptor(AAsset* asset, off_t* outStart, off_t* outLength); 125 126 /** 127 * Returns whether this asset's internal buffer is allocated in ordinary RAM (i.e. not 128 * mmapped). 129 */ 130 int AAsset_isAllocated(AAsset* asset); 131 132 133 134 #ifdef __cplusplus 135 }; 136 #endif 137 138 #endif // ANDROID_ASSET_MANAGER_H 139