Add getPartialObject to Java MtpDevice class. (52da3ad9) · Commits · e / os / android_frameworks_base

api/current.txt

+1 −0

Original line number	Diff line number	Diff line
		@@ -22452,6 +22452,7 @@ package android.mtp {
		method public int[] getObjectHandles(int, int, int);
		method public android.mtp.MtpObjectInfo getObjectInfo(int);
		method public long getParent(int);
		method public int getPartialObject(int, int, int, byte[]) throws java.io.IOException;
		method public long getStorageId(int);
		method public int[] getStorageIds();
		method public android.mtp.MtpStorageInfo getStorageInfo(int);

api/system-current.txt

+1 −0

Original line number	Diff line number	Diff line
		@@ -23998,6 +23998,7 @@ package android.mtp {
		method public int[] getObjectHandles(int, int, int);
		method public android.mtp.MtpObjectInfo getObjectInfo(int);
		method public long getParent(int);
		method public int getPartialObject(int, int, int, byte[]) throws java.io.IOException;
		method public long getStorageId(int);
		method public int[] getStorageIds();
		method public android.mtp.MtpStorageInfo getStorageInfo(int);

api/test-current.txt

+1 −0

Original line number	Diff line number	Diff line
		@@ -22460,6 +22460,7 @@ package android.mtp {
		method public int[] getObjectHandles(int, int, int);
		method public android.mtp.MtpObjectInfo getObjectInfo(int);
		method public long getParent(int);
		method public int getPartialObject(int, int, int, byte[]) throws java.io.IOException;
		method public long getStorageId(int);
		method public int[] getStorageIds();
		method public android.mtp.MtpStorageInfo getStorageInfo(int);

media/java/android/mtp/MtpDevice.java

+20 −1

Original line number	Diff line number	Diff line
		@@ -19,9 +19,10 @@ package android.mtp;
		import android.hardware.usb.UsbDevice;
		import android.hardware.usb.UsbDeviceConnection;
		import android.os.CancellationSignal;
		import android.os.OperationCanceledException;
		import android.os.ParcelFileDescriptor;

		import java.io.IOException;

		/**
		* This class represents an MTP or PTP device connected on the USB host bus. An application can
		* instantiate an object of this type, by referencing an attached {@link
		@@ -157,6 +158,22 @@ public final class MtpDevice {
		return native_get_object(objectHandle, objectSize);
		}

		/**
		* Obtains object bytes in the specified range and writes it to an array.
		* This call may block for an arbitrary amount of time depending on the size
		* of the data and speed of the devices.
		*
		* @param objectHandle handle of the object to read
		* @param offset Start index of reading range.
		* @param size Size of reading range.
		* @param buffer Array to write data.
		* @return Size of bytes that are actually read.
		*/
		public int getPartialObject(int objectHandle, int offset, int size, byte[] buffer)
		throws IOException {
		return native_get_partial_object(objectHandle, offset, size, buffer);
		}

		/**
		* Returns the thumbnail data for an object as a byte array.
		* The size and format of the thumbnail data can be determined via
		@@ -323,6 +340,8 @@ public final class MtpDevice {
		private native int[] native_get_object_handles(int storageId, int format, int objectHandle);
		private native MtpObjectInfo native_get_object_info(int objectHandle);
		private native byte[] native_get_object(int objectHandle, int objectSize);
		private native int native_get_partial_object(
		int objectHandle, int offset, int objectSize, byte[] buffer) throws IOException;
		private native byte[] native_get_thumbnail(int objectHandle);
		private native boolean native_delete_object(int objectHandle);
		private native long native_get_parent(int objectHandle);

media/jni/android_mtp_MtpDevice.cpp

+68 −23

Original line number	Diff line number	Diff line
		@@ -29,6 +29,7 @@
		#include "JNIHelp.h"
		#include "android_runtime/AndroidRuntime.h"
		#include "android_runtime/Log.h"
		#include "nativehelper/ScopedLocalRef.h"
		#include "private/android_filesystem_config.h"

		#include "MtpTypes.h"
		@@ -41,6 +42,8 @@ using namespace android;

		// ----------------------------------------------------------------------------

		namespace {

		static jfieldID field_context;

		jclass clazz_deviceInfo;
		@@ -93,6 +96,28 @@ static jfieldID field_objectInfo_keywords;
		// MtpEvent fields
		static jfieldID field_event_eventCode;

		class JavaArrayWriter {
		JNIEnv* mEnv;
		jbyteArray mArray;
		jsize mSize;

		public:
		JavaArrayWriter(JNIEnv* env, jbyteArray array) :
		mEnv(env), mArray(array), mSize(mEnv->GetArrayLength(mArray)) {}
		bool write(void* data, uint32_t offset, uint32_t length) {
		if (static_cast<uint32_t>(mSize) < offset + length) {
		return false;
		}
		mEnv->SetByteArrayRegion(mArray, offset, length, static_cast<jbyte*>(data));
		return true;
		}
		static bool writeTo(void* data, uint32_t offset, uint32_t length, void* clientData) {
		return static_cast<JavaArrayWriter*>(clientData)->write(data, offset, length);
		}
		};

		}

		MtpDevice* get_device_from_object(JNIEnv* env, jobject javaDevice)
		{
		return (MtpDevice*)env->GetLongField(javaDevice, field_context);
		@@ -307,38 +332,57 @@ android_mtp_MtpDevice_get_object_info(JNIEnv *env, jobject thiz, jint objectID)
		return info;
		}

		struct get_object_callback_data {
		JNIEnv *env;
		jbyteArray array;
		};

		static bool get_object_callback(void* data, int offset, int length, void* clientData)
		{
		get_object_callback_data* cbData = (get_object_callback_data *)clientData;
		cbData->env->SetByteArrayRegion(cbData->array, offset, length, (jbyte *)data);
		return true;
		}

		static jbyteArray
		android_mtp_MtpDevice_get_object(JNIEnv *env, jobject thiz, jint objectID, jint objectSize)
		{
		MtpDevice* device = get_device_from_object(env, thiz);
		if (!device)
		return NULL;
		if (!device) {
		return nullptr;
		}

		jbyteArray array = env->NewByteArray(objectSize);
		if (!array) {
		ScopedLocalRef<jbyteArray> array(env, env->NewByteArray(objectSize));
		if (!array.get()) {
		jniThrowException(env, "java/lang/OutOfMemoryError", NULL);
		return NULL;
		return nullptr;
		}

		get_object_callback_data data;
		data.env = env;
		data.array = array;
		JavaArrayWriter writer(env, array.get());

		if (device->readObject(objectID, get_object_callback, objectSize, &data))
		return array;
		return NULL;
		if (device->readObject(objectID, JavaArrayWriter::writeTo, objectSize, &writer)) {
		return array.release();
		}
		return nullptr;
		}

		static jint
		android_mtp_MtpDevice_get_partial_object(JNIEnv *env,
		jobject thiz,
		jint objectID,
		jint offset,
		jint size,
		jbyteArray array)
		{
		if (array == nullptr) {
		jniThrowException(env, "java/lang/IllegalArgumentException", "Array must not be null.");
		return -1;
		}

		MtpDevice* const device = get_device_from_object(env, thiz);
		if (!device) {
		jniThrowException(env, "java/io/IOException", "Failed to obtain MtpDevice.");
		return -1;
		}

		JavaArrayWriter writer(env, array);
		const int64_t result = device->readPartialObject(
		objectID, offset, size, JavaArrayWriter::writeTo, &writer);

		if (result >= 0) {
		return static_cast<jint>(result);
		} else {
		jniThrowException(env, "java/io/IOException", "Failed to read data.");
		return -1;
		}
		}

		static jbyteArray
		@@ -547,6 +591,7 @@ static const JNINativeMethod gMethods[] = {
		{"native_get_object_info", "(I)Landroid/mtp/MtpObjectInfo;",
		(void *)android_mtp_MtpDevice_get_object_info},
		{"native_get_object", "(II)[B",(void *)android_mtp_MtpDevice_get_object},
		{"native_get_partial_object", "(III[B)I", (void *) android_mtp_MtpDevice_get_partial_object},
		{"native_get_thumbnail", "(I)[B",(void *)android_mtp_MtpDevice_get_thumbnail},
		{"native_delete_object", "(I)Z", (void *)android_mtp_MtpDevice_delete_object},
		{"native_get_parent", "(I)J", (void *)android_mtp_MtpDevice_get_parent},