Merge "Cache least recently used output buffer." (6eb27ef9) · Commits · e / os / android_frameworks_base

apct-tests/perftests/core/src/com/android/internal/util/FastDataPerfTest.java

+7 −3

Original line number	Diff line number	Diff line
		@@ -64,9 +64,13 @@ public class FastDataPerfTest {
		final BenchmarkState state = mPerfStatusReporter.getBenchmarkState();
		while (state.keepRunning()) {
		os.reset();
		final FastDataOutput out = new FastDataOutput(os, BUFFER_SIZE);
		final FastDataOutput out = FastDataOutput.obtain(os);
		try {
		doWrite(out);
		out.flush();
		} finally {
		out.release();
		}
		}
		}

core/java/com/android/internal/util/BinaryXmlSerializer.java

+7 −2

Original line number	Diff line number	Diff line
		@@ -124,7 +124,7 @@ public final class BinaryXmlSerializer implements TypedXmlSerializer {
		throw new UnsupportedOperationException();
		}

		mOut = new FastDataOutput(os, BUFFER_SIZE);
		mOut = FastDataOutput.obtain(os);
		mOut.write(PROTOCOL_MAGIC_VERSION_0);

		mTagCount = 0;
		@@ -138,8 +138,10 @@ public final class BinaryXmlSerializer implements TypedXmlSerializer {

		@Override
		public void flush() throws IOException {
		if (mOut != null) {
		mOut.flush();
		}
		}

		@Override
		public void startDocument(@Nullable String encoding, @Nullable Boolean standalone)
		@@ -157,6 +159,9 @@ public final class BinaryXmlSerializer implements TypedXmlSerializer {
		public void endDocument() throws IOException {
		mOut.writeByte(END_DOCUMENT \| TYPE_NULL);
		flush();

		mOut.release();
		mOut = null;
		}

		@Override

core/java/com/android/internal/util/FastDataOutput.java

+50 −3

Original line number	Diff line number	Diff line
		@@ -30,6 +30,7 @@ import java.io.IOException;
		import java.io.OutputStream;
		import java.util.HashMap;
		import java.util.Objects;
		import java.util.concurrent.atomic.AtomicReference;

		/**
		* Optimized implementation of {@link DataOutput} which buffers data in memory
		@@ -41,23 +42,26 @@ import java.util.Objects;
		public class FastDataOutput implements DataOutput, Flushable, Closeable {
		private static final int MAX_UNSIGNED_SHORT = 65_535;

		private static final int BUFFER_SIZE = 32_768;

		private static AtomicReference<FastDataOutput> sOutCache = new AtomicReference<>();

		private final VMRuntime mRuntime;
		private final OutputStream mOut;

		private final byte[] mBuffer;
		private final long mBufferPtr;
		private final int mBufferCap;

		private OutputStream mOut;
		private int mBufferPos;

		/**
		* Values that have been "interned" by {@link #writeInternedUTF(String)}.
		*/
		private HashMap<String, Short> mStringRefs = new HashMap<>();
		private final HashMap<String, Short> mStringRefs = new HashMap<>();

		public FastDataOutput(@NonNull OutputStream out, int bufferSize) {
		mRuntime = VMRuntime.getRuntime();
		mOut = Objects.requireNonNull(out);
		if (bufferSize < 8) {
		throw new IllegalArgumentException();
		}
		@@ -65,6 +69,48 @@ public class FastDataOutput implements DataOutput, Flushable, Closeable {
		mBuffer = (byte[]) mRuntime.newNonMovableArray(byte.class, bufferSize);
		mBufferPtr = mRuntime.addressOf(mBuffer);
		mBufferCap = mBuffer.length;

		setOutput(out);
		}

		/**
		* Create a new FastDataOutput object or retrieve one from cache.
		*/
		public static FastDataOutput obtain(@NonNull OutputStream out) {
		FastDataOutput instance = sOutCache.getAndSet(null);
		if (instance != null) {
		instance.setOutput(out);
		return instance;
		}
		return new FastDataOutput(out, BUFFER_SIZE);
		}

		/**
		* Put a FastDataOutput object back into the cache.
		* You must not touch the object after this call.
		*/
		public void release() {
		if (mBufferPos > 0) {
		throw new IllegalStateException("Lingering data, call flush() before releasing.");
		}

		mOut = null;
		mBufferPos = 0;
		mStringRefs.clear();

		if (mBufferCap == BUFFER_SIZE) {
		// Try to return to the cache.
		sOutCache.compareAndSet(null, this);
		}
		}

		/**
		* Re-initializes the object for the new output.
		*/
		private void setOutput(@NonNull OutputStream out) {
		mOut = Objects.requireNonNull(out);
		mBufferPos = 0;
		mStringRefs.clear();
		}

		private void drain() throws IOException {
		@@ -83,6 +129,7 @@ public class FastDataOutput implements DataOutput, Flushable, Closeable {
		@Override
		public void close() throws IOException {
		mOut.close();
		release();
		}

		@Override