TaskJniUtils

public class TaskJniUtils

JNI utils for Task API.

Nested Classes

| interface | TaskJniUtils.EmptyHandleProvider | Syntax sugar to get nativeHandle from empty param list. | | interface | TaskJniUtils.FdAndOptionsHandleProvider<T> | Syntax sugar to get nativeHandle from file descriptor and options. | | interface | TaskJniUtils.MultipleBuffersHandleProvider | Syntax sugar to get nativeHandle from an array of ByteBuffers. |

Constants

| long | INVALID_POINTER | |

Public Methods

| static <T> long | createHandleFromFdAndOptions(Context context, FdAndOptionsHandleProvider<T> provider, String libName, String filePath, T options) Initializes the JNI and returns C++ handle with file descriptor and options for task API.

| | static long | createHandleFromLibrary(TaskJniUtils.EmptyHandleProvider provider, String libName) Initializes the JNI and returns C++ handle by first loading the C++ library and then invokes TaskJniUtils.EmptyHandleProvider.createHandle().

| | static long | createHandleWithMultipleAssetFilesFromLibrary(Context context, TaskJniUtils.MultipleBuffersHandleProvider provider, String libName, String... filePaths) Initializes the JNI and returns C++ handle by first loading the C++ library and then invokes TaskJniUtils.MultipleBuffersHandleProvider.createHandle(ByteBuffer).

| | static long | createProtoBaseOptionsHandle(BaseOptions baseOptions) | | static long | createProtoBaseOptionsHandleWithLegacyNumThreads(BaseOptions baseOptions, int legacyNumThreads) | | static MappedByteBuffer | loadMappedFile(Context context, String filePath) Loads a file from the asset folder through memory mapping.

| | static void | tryLoadLibrary(String libName) Try loading a native library, if it's already loaded return directly.

|

Inherited Methods

From class java.lang.Object

| boolean | equals(Object arg0) | | final Class<?> | getClass() | | int | hashCode() | | final void | notify() | | final void | notifyAll() | | String | toString() | | final void | wait(long arg0, int arg1) | | final void | wait(long arg0) | | final void | wait() |

Constants

public static final long INVALID_POINTER

Constant Value: 0

Public Methods

public static long createHandleFromFdAndOptions (Context context, FdAndOptionsHandleProvider<T> provider, String libName, String filePath, T options)

Initializes the JNI and returns C++ handle with file descriptor and options for task API.

Parameters

| context | the Android app context | | provider | provider to get C++ handle, usually returned from native call | | libName | name of C++ lib to be loaded | | filePath | path of the file to be loaded | | options | options to set up the task API, used by the provider |

Returns

• C++ handle as long

Throws

| IOException | If model file fails to load. |

public static long createHandleFromLibrary (TaskJniUtils.EmptyHandleProvider provider, String libName)

Initializes the JNI and returns C++ handle by first loading the C++ library and then invokes TaskJniUtils.EmptyHandleProvider.createHandle().

Parameters

| provider | provider to get C++ handle, usually returned from native call | | libName | |

Returns

• C++ handle as long

public static long createHandleWithMultipleAssetFilesFromLibrary (Context context, TaskJniUtils.MultipleBuffersHandleProvider provider, String libName, String... filePaths)

Initializes the JNI and returns C++ handle by first loading the C++ library and then invokes TaskJniUtils.MultipleBuffersHandleProvider.createHandle(ByteBuffer).

Parameters

| context | app context | | provider | provider to get C++ pointer, usually returned from native call | | libName | name of C++ lib to load | | filePaths | file paths to load |

Returns

• C++ pointer as long

Throws

| IOException | If model file fails to load. |

public static long createProtoBaseOptionsHandle (BaseOptions baseOptions)

Parameters

| baseOptions | |

public static long createProtoBaseOptionsHandleWithLegacyNumThreads (BaseOptions baseOptions, int legacyNumThreads)

Parameters

| baseOptions | | | legacyNumThreads | |

public static MappedByteBuffer loadMappedFile (Context context, String filePath)

Loads a file from the asset folder through memory mapping.

Parameters

| context | Application context to access assets. | | filePath | Asset path of the file. |

Returns

• the loaded memory mapped file.

Throws

| IOException | If model file fails to load. |

public static void tryLoadLibrary (String libName)

Try loading a native library, if it's already loaded return directly.

Parameters

| libName | name of the lib |