include/android/asset_manager.h - platform/frameworks/native - Gitiles

 /*
  * 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

 #include <sys/cdefs.h>
 #include <sys/types.h>

 #ifdef __cplusplus
 extern "C" {
 #endif

 #if !defined(__ANDROID__) && !defined(__RENAME_IF_FILE_OFFSET64)
 #define __RENAME_IF_FILE_OFFSET64(x)
 #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)
     __RENAME_IF_FILE_OFFSET64(AAsset_seek64);

 /**
  * 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)
     __RENAME_IF_FILE_OFFSET64(AAsset_getLength64);

 /**
  * 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)
     __RENAME_IF_FILE_OFFSET64(AAsset_getRemainingLength64);

 /**
  * 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)
     __RENAME_IF_FILE_OFFSET64(AAsset_openFileDescriptor64);

 /**
  * 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

 /** @} */
	/*
	* 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

	#include <sys/cdefs.h>
	#include <sys/types.h>

	#ifdef __cplusplus
	extern "C" {
	#endif

	#if !defined(__ANDROID__) && !defined(__RENAME_IF_FILE_OFFSET64)
	#define __RENAME_IF_FILE_OFFSET64(x)
	#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)
	__RENAME_IF_FILE_OFFSET64(AAsset_seek64);

	/**
	* 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)
	__RENAME_IF_FILE_OFFSET64(AAsset_getLength64);

	/**
	* 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)
	__RENAME_IF_FILE_OFFSET64(AAsset_getRemainingLength64);

	/**
	* 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)
	__RENAME_IF_FILE_OFFSET64(AAsset_openFileDescriptor64);

	/**
	* 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

	/** @} */