Asset

Files
file	asset_manager.h
file	asset_manager_jni.h

Typedefs
typedef struct AAssetManager	AAssetManager
typedef struct AAssetDir	AAssetDir
typedef struct AAsset	AAsset

Enumerations
enum	{ AASSET_MODE_UNKNOWN = 0, AASSET_MODE_RANDOM = 1, AASSET_MODE_STREAMING = 2, AASSET_MODE_BUFFER = 3 }

Functions
AAssetDir *	AAssetManager_openDir (AAssetManager *mgr, const char *dirName)
AAsset *	AAssetManager_open (AAssetManager *mgr, const char *filename, int mode)
const char *	AAssetDir_getNextFileName (AAssetDir *assetDir)
void	AAssetDir_rewind (AAssetDir *assetDir)
void	AAssetDir_close (AAssetDir *assetDir)
int	AAsset_read (AAsset *asset, void *buf, size_t count)
off_t	AAsset_seek (AAsset *asset, off_t offset, int whence)
off64_t	AAsset_seek64 (AAsset *asset, off64_t offset, int whence)
void	AAsset_close (AAsset *asset)
const void *	AAsset_getBuffer (AAsset *asset)
off_t	AAsset_getLength (AAsset *asset)
off64_t	AAsset_getLength64 (AAsset *asset)
off_t	AAsset_getRemainingLength (AAsset *asset)
off64_t	AAsset_getRemainingLength64 (AAsset *asset)
int	AAsset_openFileDescriptor (AAsset *asset, off_t *outStart, off_t *outLength)
int	AAsset_openFileDescriptor64 (AAsset *asset, off64_t *outStart, off64_t *outLength)
int	AAsset_isAllocated (AAsset *asset)
AAssetManager *	AAssetManager_fromJava (JNIEnv *env, jobject assetManager)

Detailed Description

Typedef Documentation

typedef struct AAsset AAsset

AAsset provides access to a read-only asset.

AAsset objects are NOT thread-safe, and should not be shared across threads.

typedef struct AAssetDir AAssetDir

AAssetDir provides access to a chunk of the asset hierarchy as if it were a single directory. The contents are populated by the AAssetManager.

The list of files will be sorted in ascending order by ASCII value.

typedef struct AAssetManager AAssetManager

AAssetManager provides access to an application's raw assets by creating AAsset objects.

AAssetManager is a wrapper to the low-level native implementation of the java AAssetManager, a pointer can be obtained using AAssetManager_fromJava().

The asset hierarchy may be examined like a filesystem, using AAssetDir objects to peruse a single directory.

A native AAssetManager pointer may be shared across multiple threads.

Enumeration Type Documentation

anonymous enum

Available access modes for opening assets with AAssetManager_open

Enumerator
AASSET_MODE_UNKNOWN	No specific information about how data will be accessed.
AASSET_MODE_RANDOM	Read chunks, and seek forward and backward.
AASSET_MODE_STREAMING	Read sequentially, with an occasional forward seek.
AASSET_MODE_BUFFER	Caller plans to ask for a read-only buffer with all data.

Function Documentation

void AAsset_close

(

AAsset *

asset

)

Close the asset, freeing all associated resources.

const void* AAsset_getBuffer

(

AAsset *

asset

)

Get a pointer to a buffer holding the entire contents of the assset.

Returns NULL on failure.

off_t AAsset_getLength

(

AAsset *

asset

)

Report the total size of the asset data.

off64_t AAsset_getLength64

(

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.

off_t AAsset_getRemainingLength

(

AAsset *

asset

)

Report the total amount of asset data that can be read from the current position.

off64_t AAsset_getRemainingLength64

(

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.

int AAsset_isAllocated

(

AAsset *

asset

)

Returns whether this asset's internal buffer is allocated in ordinary RAM (i.e. not mmapped).

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. 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_openFileDescriptor64	(	AAsset *	asset,
		off64_t *	outStart,
		off64_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_read	(	AAsset *	asset,
		void *	buf,
		size_t	count
	)

Attempt to read 'count' bytes of data from the current offset.

Returns the number of bytes read, zero on EOF, or < 0 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().

Returns the new position on success, or (off_t) -1 on error.

off64_t AAsset_seek64	(	AAsset *	asset,
		off64_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.

void AAssetDir_close

(

AAssetDir *

assetDir

)

Close an opened AAssetDir, freeing any related resources.

const char* AAssetDir_getNextFileName

(

AAssetDir *

assetDir

)

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.

void AAssetDir_rewind

(

AAssetDir *

assetDir

)

Reset the iteration state of AAssetDir_getNextFileName() to the beginning.

AAssetManager* AAssetManager_fromJava	(	JNIEnv *	env,
		jobject	assetManager
	)

Given a Dalvik AssetManager object, obtain the corresponding native AAssetManager object. Note that the caller is responsible for obtaining and holding a VM reference to the jobject to prevent its being garbage collected while the native object is in use.

AAsset* AAssetManager_open	(	AAssetManager *	mgr,
		const char *	filename,
		int	mode
	)

Open an asset.

The object returned here should be freed by calling AAsset_close().

AAssetDir* AAssetManager_openDir	(	AAssetManager *	mgr,
		const char *	dirName
	)

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().