Add Message and MessageReceiver classes.

Those classes are utility class to handle mojo messages.

R=viettrungluu@chromium.org,rmcilroy@chromium.org

Review URL: https://codereview.chromium.org/311363003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@280785 0039d316-1c4b-4281-b951-d872f2087c98

5 files changed, 240 insertions, 0 deletions

diff --git a/mojo/android/javatests/src/org/chromium/mojo/TestUtils.java b/mojo/android/javatests/src/org/chromium/mojo/TestUtils.java
new file mode 100644
index 0000000..ad13ca9
--- /dev/null
+++ b/mojo/android/javatests/src/org/chromium/mojo/TestUtils.java
@@ -0,0 +1,30 @@
+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.mojo;
+
+import java.nio.ByteBuffer;
+import java.util.Random;
+
+/**
+ * Utilities methods for tests.
+ */
+public final class TestUtils {
+
+    private static final Random RANDOM = new Random();
+
+    /**
+     * Returns a new direct ByteBuffer of the given size with random (but reproducible) data.
+     */
+    public static ByteBuffer newRandomBuffer(int size) {
+        byte bytes[] = new byte[size];
+        RANDOM.setSeed(size);
+        RANDOM.nextBytes(bytes);
+        ByteBuffer data = ByteBuffer.allocateDirect(size);
+        data.put(bytes);
+        data.flip();
+        return data;
+    }
+
+}
diff --git a/mojo/android/javatests/src/org/chromium/mojo/bindings/MessageTest.java b/mojo/android/javatests/src/org/chromium/mojo/bindings/MessageTest.java
new file mode 100644
index 0000000..ee58979
--- /dev/null
+++ b/mojo/android/javatests/src/org/chromium/mojo/bindings/MessageTest.java
@@ -0,0 +1,123 @@
+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.mojo.bindings;
+
+import android.test.suitebuilder.annotation.SmallTest;
+
+import org.chromium.mojo.MojoTestCase;
+import org.chromium.mojo.TestUtils;
+import org.chromium.mojo.system.Core;
+import org.chromium.mojo.system.DataPipe;
+import org.chromium.mojo.system.Handle;
+import org.chromium.mojo.system.MessagePipeHandle;
+import org.chromium.mojo.system.MojoException;
+import org.chromium.mojo.system.MojoResult;
+import org.chromium.mojo.system.Pair;
+import org.chromium.mojo.system.impl.CoreImpl;
+
+import java.nio.ByteBuffer;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+
+/**
+ * Testing {@link Message}.
+ */
+public class MessageTest extends MojoTestCase {
+
+    static class RecordingMessageReceiver implements MessageReceiver {
+
+        public final List<Message> messages = new ArrayList<Message>();
+
+        /**
+         * @see MessageReceiver#accept(Message)
+         */
+        @Override
+        public boolean accept(Message message) {
+            messages.add(message);
+            return true;
+        }
+    }
+
+    private static final int DATA_SIZE = 1024;
+
+    private ByteBuffer mData;
+    private Pair<MessagePipeHandle, MessagePipeHandle> mHandles;
+    private List<Handle> mHandlesToSend = new ArrayList<Handle>();
+    private List<Handle> mHandlesToClose = new ArrayList<Handle>();
+    private RecordingMessageReceiver mMessageReceiver;
+
+    /**
+     * @see org.chromium.mojo.MojoTestCase#setUp()
+     */
+    @Override
+    protected void setUp() throws Exception {
+        super.setUp();
+        Core core = CoreImpl.getInstance();
+        mData = TestUtils.newRandomBuffer(DATA_SIZE);
+        mMessageReceiver = new RecordingMessageReceiver();
+        mHandles = core.createMessagePipe();
+        Pair<DataPipe.ProducerHandle, DataPipe.ConsumerHandle> datapipe = core.createDataPipe(null);
+        mHandlesToSend.addAll(Arrays.asList(datapipe.first, datapipe.second));
+        mHandlesToClose.addAll(Arrays.asList(mHandles.first, mHandles.second));
+        mHandlesToClose.addAll(mHandlesToSend);
+    }
+
+    /**
+     * @see org.chromium.mojo.MojoTestCase#tearDown()
+     */
+    @Override
+    protected void tearDown() throws Exception {
+        for (Handle handle : mHandlesToClose) {
+            handle.close();
+        }
+        super.tearDown();
+    }
+
+    /**
+     * Testing {@link Message#readAndDispatchMessage(MessagePipeHandle, MessageReceiver)}
+     */
+    @SmallTest
+    public void testReadAndDispatchMessage() {
+        mHandles.first.writeMessage(mData, mHandlesToSend, MessagePipeHandle.WriteFlags.NONE);
+        assertEquals(MojoResult.OK,
+                Message.readAndDispatchMessage(mHandles.second, mMessageReceiver));
+        assertEquals(1, mMessageReceiver.messages.size());
+        Message message = mMessageReceiver.messages.get(0);
+        mHandlesToClose.addAll(message.handles);
+        assertEquals(mData, message.buffer);
+        assertEquals(2, message.handles.size());
+        for (Handle handle : message.handles) {
+            assertTrue(handle.isValid());
+        }
+    }
+
+    /**
+     * Testing {@link Message#readAndDispatchMessage(MessagePipeHandle, MessageReceiver)} with no
+     * message available.
+     */
+    @SmallTest
+    public void testReadAndDispatchMessageOnEmptyHandle() {
+        assertEquals(MojoResult.SHOULD_WAIT,
+                Message.readAndDispatchMessage(mHandles.second, mMessageReceiver));
+        assertEquals(0, mMessageReceiver.messages.size());
+    }
+
+    /**
+     * Testing {@link Message#readAndDispatchMessage(MessagePipeHandle, MessageReceiver)} on closed
+     * handle.
+     */
+    @SmallTest
+    public void testReadAndDispatchMessageOnClosedHandle() {
+        mHandles.first.close();
+        try {
+            Message.readAndDispatchMessage(mHandles.second, mMessageReceiver);
+            fail("MojoException should have been thrown");
+        } catch (MojoException expected) {
+            assertEquals(MojoResult.FAILED_PRECONDITION, expected.getMojoResult());
+        }
+        assertEquals(0, mMessageReceiver.messages.size());
+    }
+}
diff --git a/mojo/bindings/java/src/org/chromium/mojo/bindings/Message.java b/mojo/bindings/java/src/org/chromium/mojo/bindings/Message.java
new file mode 100644
index 0000000..f826a8e
--- /dev/null
+++ b/mojo/bindings/java/src/org/chromium/mojo/bindings/Message.java
@@ -0,0 +1,63 @@
+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.mojo.bindings;
+
+import org.chromium.mojo.system.Handle;
+import org.chromium.mojo.system.MessagePipeHandle;
+import org.chromium.mojo.system.MessagePipeHandle.ReadMessageResult;
+import org.chromium.mojo.system.MojoResult;
+
+import java.nio.ByteBuffer;
+import java.util.List;
+
+import javax.annotation.Nullable;
+
+/**
+ * A raw message to be sent/received from a {@link MessagePipeHandle}.
+ */
+public final class Message {
+
+    /**
+     * The data of the message.
+     */
+    public final ByteBuffer buffer;
+
+    /**
+     * The handles of the message.
+     */
+    public final List<? extends Handle> handles;
+
+    /**
+     * Constructor.
+     *
+     * @param buffer The buffer containing the bytes to send. This must be a direct buffer.
+     * @param handles The list of handles to send.
+     */
+    public Message(ByteBuffer buffer, List<? extends Handle> handles) {
+        assert buffer.isDirect();
+        this.buffer = buffer;
+        this.handles = handles;
+    }
+
+    /**
+     * Read a message, and pass it to the given |MessageReceiver| if not null. If the
+     * |MessageReceiver| is null, the message is lost.
+     */
+    public static int readAndDispatchMessage(MessagePipeHandle handle,
+            @Nullable MessageReceiver receiver) {
+        // TODO(qsr) Allow usage of a pool of pre-allocated buffer for performance.
+        ReadMessageResult result = handle.readMessage(null, 0, MessagePipeHandle.ReadFlags.NONE);
+        if (result.getMojoResult() != MojoResult.RESOURCE_EXHAUSTED) {
+            return result.getMojoResult();
+        }
+        ByteBuffer buffer = ByteBuffer.allocateDirect(result.getMessageSize());
+        result = handle.readMessage(buffer, result.getHandlesCount(),
+                MessagePipeHandle.ReadFlags.NONE);
+        if (receiver != null && result.getMojoResult() == MojoResult.OK) {
+            receiver.accept(new Message(buffer, result.getHandles()));
+        }
+        return result.getMojoResult();
+    }
+}
diff --git a/mojo/bindings/java/src/org/chromium/mojo/bindings/MessageReceiver.java b/mojo/bindings/java/src/org/chromium/mojo/bindings/MessageReceiver.java
new file mode 100644
index 0000000..1736bc6
--- /dev/null
+++ b/mojo/bindings/java/src/org/chromium/mojo/bindings/MessageReceiver.java
@@ -0,0 +1,17 @@
+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.mojo.bindings;
+
+/**
+ * A class which implements this interface can receive {@link Message} objects.
+ */
+public interface MessageReceiver {
+
+    /**
+     * Receive a {@link Message}. The {@link MessageReceiver} is allowed to mutable the message.
+     * Returns |true| if the message has been handled, |false| otherwise.
+     */
+    boolean accept(Message message);
+}
diff --git a/mojo/mojo_public.gypi b/mojo/mojo_public.gypi
index 8f3c9d9..6797821a4 100644
--- a/mojo/mojo_public.gypi
+++ b/mojo/mojo_public.gypi
@@ -426,6 +426,13 @@
             'java_in_dir': 'public/java',
           },
           'includes': [ '../build/java.gypi' ],
+          'conditions': [
+            ['android_webview_build==0', {
+              'dependencies': [
+                '../third_party/jsr-305/jsr-305.gyp:jsr_305_javalib',
+              ],
+            }]
+          ],
         },
         {
           'target_name': 'mojo_bindings_java',