Merge "Reuse buffer when reading bytes from files." (750d0f0c) · Commits · e / os / android_frameworks_base

packages/MtpDocumentsProvider/jni/com_android_mtp_AppFuse.cpp

+25 −14

Original line number	Diff line number	Diff line
		@@ -50,7 +50,8 @@ constexpr size_t MAX_REQUEST_SIZE = sizeof(struct fuse_in_header) +

		static jclass app_fuse_class;
		static jmethodID app_fuse_get_file_size;
		static jmethodID app_fuse_get_object_bytes;
		static jmethodID app_fuse_read_object_bytes;
		static jfieldID app_fuse_buffer;

		// NOTE:
		// FuseRequest and FuseResponse shares the same buffer to save memory usage, so the handlers must
		@@ -282,7 +283,7 @@ private:
		out->prepare_buffer(0);
		const int64_t result = get_object_bytes(it->second, offset, size, out->data());
		if (result < 0) {
		return -EIO;
		return result;
		}
		out->set_size(result);
		return 0;
		@@ -332,20 +333,24 @@ private:
		uint64_t offset,
		uint32_t size,
		void* buf) {
		ScopedLocalRef<jbyteArray> array(env_, static_cast<jbyteArray>(env_->CallObjectMethod(
		const jlong read_size = env_->CallLongMethod(
		self_,
		app_fuse_get_object_bytes,
		inode,
		offset,
		size)));
		app_fuse_read_object_bytes,
		static_cast<jint>(inode),
		static_cast<jlong>(offset),
		static_cast<jlong>(size));
		if (read_size <= 0) {
		return read_size;
		}
		ScopedLocalRef<jbyteArray> array(
		env_, static_cast<jbyteArray>(env_->GetObjectField(self_, app_fuse_buffer)));
		if (array.get() == nullptr) {
		return -1;
		return -EFAULT;
		}
		ScopedByteArrayRO bytes(env_, array.get());
		if (bytes.get() == nullptr) {
		return -1;
		return -ENOMEM;
		}
		const uint32_t read_size = std::min(static_cast<uint32_t>(bytes.size()), size);
		memcpy(buf, bytes.get(), read_size);
		return read_size;
		}
		@@ -451,10 +456,16 @@ jint JNI_OnLoad(JavaVM* vm, void* /* reserved */) {
		return -1;
		}

		app_fuse_get_object_bytes = env->GetMethodID(
		app_fuse_class, "getObjectBytes", "(IJI)[B");
		if (app_fuse_get_object_bytes == nullptr) {
		ALOGE("Can't find getObjectBytes");
		app_fuse_read_object_bytes = env->GetMethodID(
		app_fuse_class, "readObjectBytes", "(IJJ)J");
		if (app_fuse_read_object_bytes == nullptr) {
		ALOGE("Can't find readObjectBytes");
		return -1;
		}

		app_fuse_buffer = env->GetFieldID(app_fuse_class, "mBuffer", "[B");
		if (app_fuse_buffer == nullptr) {
		ALOGE("Can't find mBuffer");
		return -1;
		}

packages/MtpDocumentsProvider/src/com/android/mtp/AppFuse.java

+36 −7

Original line number	Diff line number	Diff line
		@@ -16,9 +16,11 @@

		package com.android.mtp;

		import android.annotation.WorkerThread;
		import android.os.ParcelFileDescriptor;
		import android.os.Process;
		import android.os.storage.StorageManager;
		import android.system.OsConstants;
		import android.util.Log;
		import com.android.internal.annotations.VisibleForTesting;
		import com.android.internal.util.Preconditions;
		@@ -40,6 +42,13 @@ public class AppFuse {

		private final String mName;
		private final Callback mCallback;

		/**
		* Buffer for read bytes request.
		* Don't use the buffer from the out of AppFuseMessageThread.
		*/
		private byte[] mBuffer = new byte[MAX_READ];

		private Thread mMessageThread;
		private ParcelFileDescriptor mDeviceFd;

		@@ -82,28 +91,48 @@ public class AppFuse {
		}

		static interface Callback {
		/**
		* Returns file size for the given inode.
		* @param inode
		* @return File size. Must not be negative.
		* @throws FileNotFoundException
		*/
		long getFileSize(int inode) throws FileNotFoundException;
		byte[] getObjectBytes(int inode, long offset, int size) throws IOException;

		/**
		* Returns flie bytes for the give inode.
		* @param inode
		* @param offset Offset for file bytes.
		* @param size Size for file bytes.
		* @param bytes Buffer to store file bytes.
		* @return Number of read bytes. Must not be negative.
		* @throws IOException
		*/
		long readObjectBytes(int inode, long offset, long size, byte[] bytes) throws IOException;
		}

		@UsedByNative("com_android_mtp_AppFuse.cpp")
		@WorkerThread
		private long getFileSize(int inode) {
		try {
		return mCallback.getFileSize(inode);
		} catch (IOException e) {
		return -1;
		} catch (FileNotFoundException e) {
		return -OsConstants.ENOENT;
		}
		}

		@UsedByNative("com_android_mtp_AppFuse.cpp")
		private byte[] getObjectBytes(int inode, long offset, int size) {
		@WorkerThread
		private long readObjectBytes(int inode, long offset, long size) {
		if (offset < 0 \|\| size < 0 \|\| size > MAX_READ) {
		return null;
		return -OsConstants.EINVAL;
		}
		try {
		return mCallback.getObjectBytes(inode, offset, size);
		// It's OK to share the same mBuffer among requests because the requests are processed
		// by AppFuseMessageThread sequentially.
		return mCallback.readObjectBytes(inode, offset, size, mBuffer);
		} catch (IOException e) {
		return null;
		return -OsConstants.EIO;
		}
		}

packages/MtpDocumentsProvider/src/com/android/mtp/MtpDocumentsProvider.java

+4 −11

Original line number	Diff line number	Diff line
		@@ -16,8 +16,6 @@

		package com.android.mtp;

		import static com.android.internal.util.Preconditions.checkArgument;

		import android.content.ContentResolver;
		import android.content.res.AssetFileDescriptor;
		import android.content.res.Resources;
		@@ -40,7 +38,6 @@ import com.android.internal.annotations.VisibleForTesting;

		import java.io.FileNotFoundException;
		import java.io.IOException;
		import java.util.Arrays;
		import java.util.HashMap;
		import java.util.Map;

		@@ -391,16 +388,12 @@ public class MtpDocumentsProvider extends DocumentsProvider {
		}

		private class AppFuseCallback implements AppFuse.Callback {
		final byte[] mBytes = new byte[AppFuse.MAX_READ];

		@Override
		public byte[] getObjectBytes(int inode, long offset, int size) throws IOException {
		public long readObjectBytes(
		int inode, long offset, long size, byte[] buffer) throws IOException {
		final Identifier identifier = mDatabase.createIdentifier(Integer.toString(inode));
		final long readSize = mMtpManager.getPartialObject(
		identifier.mDeviceId, identifier.mObjectHandle, offset, size, mBytes);
		// TODO: Change signature so that getObjectBytes can return read size without copying
		// bytes.
		return Arrays.copyOf(mBytes, (int) readSize);
		return mMtpManager.getPartialObject(
		identifier.mDeviceId, identifier.mObjectHandle, offset, size, buffer);
		}

		@Override

packages/MtpDocumentsProvider/tests/src/com/android/mtp/AppFuseTest.java

+15 −10

Original line number	Diff line number	Diff line
		@@ -77,30 +77,35 @@ public class AppFuseTest extends AndroidTestCase {

		public void testReadFile() throws IOException {
		final StorageManager storageManager = getContext().getSystemService(StorageManager.class);
		final int INODE = 10;
		final byte[] BYTES = new byte[] { 'a', 'b', 'c', 'd', 'e' };
		final int fileInode = 10;
		final byte[] fileBytes = new byte[] { 'a', 'b', 'c', 'd', 'e' };
		final AppFuse appFuse = new AppFuse(
		"test",
		new TestCallback() {
		@Override
		public long getFileSize(int inode) throws FileNotFoundException {
		if (inode == INODE) {
		return BYTES.length;
		if (inode == fileInode) {
		return fileBytes.length;
		}
		return super.getFileSize(inode);
		}

		@Override
		public byte[] getObjectBytes(int inode, long offset, int size)
		public long readObjectBytes(int inode, long offset, long size, byte[] bytes)
		throws IOException {
		if (inode == INODE) {
		return Arrays.copyOfRange(BYTES, (int) offset, (int) offset + size);
		if (inode == fileInode) {
		int i = 0;
		while (i < size && i + offset < fileBytes.length) {
		bytes[i] = fileBytes[(int) (i + offset)];
		i++;
		}
		return i;
		}
		return super.getObjectBytes(inode, offset, size);
		return super.readObjectBytes(inode, offset, size, bytes);
		}
		});
		appFuse.mount(storageManager);
		final ParcelFileDescriptor fd = appFuse.openFile(INODE);
		final ParcelFileDescriptor fd = appFuse.openFile(fileInode);
		try (final ParcelFileDescriptor.AutoCloseInputStream stream =
		new ParcelFileDescriptor.AutoCloseInputStream(fd)) {
		final byte[] buffer = new byte[1024];
		@@ -117,7 +122,7 @@ public class AppFuseTest extends AndroidTestCase {
		}

		@Override
		public byte[] getObjectBytes(int inode, long offset, int size)
		public long readObjectBytes(int inode, long offset, long size, byte[] bytes)
		throws IOException {
		throw new IOException();
		}