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 * Seek to the specified offset within the asset data. 'whence' uses the 98 * same constants as lseek()/fseek(). 99 * 100 * Uses 64-bit data type for large files as opposed to the 32-bit type used 101 * by AAsset_seek. 102 * 103 * Returns the new position on success, or (off64_t) -1 on error. 104 */ 105 off64_t AAsset_seek64(AAsset* asset, off64_t offset, int whence); 106 107 /** 108 * Close the asset, freeing all associated resources. 109 */ 110 void AAsset_close(AAsset* asset); 111 112 /** 113 * Get a pointer to a buffer holding the entire contents of the assset. 114 * 115 * Returns NULL on failure. 116 */ 117 const void* AAsset_getBuffer(AAsset* asset); 118 119 /** 120 * Report the total size of the asset data. 121 */ 122 off_t AAsset_getLength(AAsset* asset); 123 124 /** 125 * Report the total size of the asset data. Reports the size using a 64-bit 126 * number insted of 32-bit as AAsset_getLength. 127 */ 128 off64_t AAsset_getLength64(AAsset* asset); 129 130 /** 131 * Report the total amount of asset data that can be read from the current position. 132 */ 133 off_t AAsset_getRemainingLength(AAsset* asset); 134 135 /** 136 * Report the total amount of asset data that can be read from the current position. 137 * 138 * Uses a 64-bit number instead of a 32-bit number as AAsset_getRemainingLength does. 139 */ 140 off64_t AAsset_getRemainingLength64(AAsset* asset); 141 142 /** 143 * Open a new file descriptor that can be used to read the asset data. If the 144 * start or length cannot be represented by a 32-bit number, it will be 145 * truncated. If the file is large, use AAsset_openFileDescriptor64 instead. 146 * 147 * Returns < 0 if direct fd access is not possible (for example, if the asset is 148 * compressed). 149 */ 150 int AAsset_openFileDescriptor(AAsset* asset, off_t* outStart, off_t* outLength); 151 152 /** 153 * Open a new file descriptor that can be used to read the asset data. 154 * 155 * Uses a 64-bit number for the offset and length instead of 32-bit instead of 156 * as AAsset_openFileDescriptor does. 157 * 158 * Returns < 0 if direct fd access is not possible (for example, if the asset is 159 * compressed). 160 */ 161 int AAsset_openFileDescriptor64(AAsset* asset, off64_t* outStart, off64_t* outLength); 162 163 /** 164 * Returns whether this asset's internal buffer is allocated in ordinary RAM (i.e. not 165 * mmapped). 166 */ 167 int AAsset_isAllocated(AAsset* asset); 168 169 170 171 #ifdef __cplusplus 172 }; 173 #endif 174 175 #endif // ANDROID_ASSET_MANAGER_H 176
