/* * Copyright (C) 2010 The Android Open Source Project * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ /** * @addtogroup Asset * @{ */ /** * @file asset_manager.h */ #ifndef ANDROID_ASSET_MANAGER_H #define ANDROID_ASSET_MANAGER_H #ifdef __cplusplus extern "C" { #endif struct AAssetManager; /** * {@link AAssetManager} provides access to an application's raw assets by * creating {@link AAsset} objects. * * AAssetManager is a wrapper to the low-level native implementation * of the java {@link AAssetManager}, a pointer can be obtained using * AAssetManager_fromJava(). * * The asset hierarchy may be examined like a filesystem, using * {@link AAssetDir} objects to peruse a single directory. * * A native {@link AAssetManager} pointer may be shared across multiple threads. */ typedef struct AAssetManager AAssetManager; struct AAssetDir; /** * {@link AAssetDir} provides access to a chunk of the asset hierarchy as if * it were a single directory. The contents are populated by the * {@link AAssetManager}. * * The list of files will be sorted in ascending order by ASCII value. */ typedef struct AAssetDir AAssetDir; struct AAsset; /** * {@link AAsset} provides access to a read-only asset. * * {@link AAsset} objects are NOT thread-safe, and should not be shared across * threads. */ typedef struct AAsset AAsset; /** Available access modes for opening assets with {@link AAssetManager_open} */ enum { /** No specific information about how data will be accessed. **/ AASSET_MODE_UNKNOWN = 0, /** Read chunks, and seek forward and backward. */ AASSET_MODE_RANDOM = 1, /** Read sequentially, with an occasional forward seek. */ AASSET_MODE_STREAMING = 2, /** Caller plans to ask for a read-only buffer with all data. */ AASSET_MODE_BUFFER = 3 }; /** * Open the named directory within the asset hierarchy. The directory can then * be inspected with the AAssetDir functions. To open the top-level directory, * pass in "" as the dirName. * * The object returned here should be freed by calling AAssetDir_close(). */ AAssetDir* AAssetManager_openDir(AAssetManager* mgr, const char* dirName); /** * Open an asset. * * The object returned here should be freed by calling AAsset_close(). */ AAsset* AAssetManager_open(AAssetManager* mgr, const char* filename, int mode); /** * Iterate over the files in an asset directory. A NULL string is returned * when all the file names have been returned. * * The returned file name is suitable for passing to AAssetManager_open(). * * The string returned here is owned by the AssetDir implementation and is not * guaranteed to remain valid if any other calls are made on this AAssetDir * instance. */ const char* AAssetDir_getNextFileName(AAssetDir* assetDir); /** * Reset the iteration state of AAssetDir_getNextFileName() to the beginning. */ void AAssetDir_rewind(AAssetDir* assetDir); /** * Close an opened AAssetDir, freeing any related resources. */ void AAssetDir_close(AAssetDir* assetDir); /** * Attempt to read 'count' bytes of data from the current offset. * * Returns the number of bytes read, zero on EOF, or < 0 on error. */ int AAsset_read(AAsset* asset, void* buf, size_t count); /** * Seek to the specified offset within the asset data. 'whence' uses the * same constants as lseek()/fseek(). * * Returns the new position on success, or (off_t) -1 on error. */ off_t AAsset_seek(AAsset* asset, off_t offset, int whence); /** * Seek to the specified offset within the asset data. 'whence' uses the * same constants as lseek()/fseek(). * * Uses 64-bit data type for large files as opposed to the 32-bit type used * by AAsset_seek. * * Returns the new position on success, or (off64_t) -1 on error. */ off64_t AAsset_seek64(AAsset* asset, off64_t offset, int whence); /** * Close the asset, freeing all associated resources. */ void AAsset_close(AAsset* asset); /** * Get a pointer to a buffer holding the entire contents of the assset. * * Returns NULL on failure. */ const void* AAsset_getBuffer(AAsset* asset); /** * Report the total size of the asset data. */ off_t AAsset_getLength(AAsset* asset); /** * Report the total size of the asset data. Reports the size using a 64-bit * number insted of 32-bit as AAsset_getLength. */ off64_t AAsset_getLength64(AAsset* asset); /** * Report the total amount of asset data that can be read from the current position. */ off_t AAsset_getRemainingLength(AAsset* asset); /** * Report the total amount of asset data that can be read from the current position. * * Uses a 64-bit number instead of a 32-bit number as AAsset_getRemainingLength does. */ off64_t AAsset_getRemainingLength64(AAsset* asset); /** * Open a new file descriptor that can be used to read the asset data. If the * start or length cannot be represented by a 32-bit number, it will be * truncated. If the file is large, use AAsset_openFileDescriptor64 instead. * * Returns < 0 if direct fd access is not possible (for example, if the asset is * compressed). */ int AAsset_openFileDescriptor(AAsset* asset, off_t* outStart, off_t* outLength); /** * Open a new file descriptor that can be used to read the asset data. * * Uses a 64-bit number for the offset and length instead of 32-bit instead of * as AAsset_openFileDescriptor does. * * Returns < 0 if direct fd access is not possible (for example, if the asset is * compressed). */ int AAsset_openFileDescriptor64(AAsset* asset, off64_t* outStart, off64_t* outLength); /** * Returns whether this asset's internal buffer is allocated in ordinary RAM (i.e. not * mmapped). */ int AAsset_isAllocated(AAsset* asset); #ifdef __cplusplus }; #endif #endif // ANDROID_ASSET_MANAGER_H /** @} */