Allowed MessageCodec's to specify if they want direct ByteBuffers.

gaaclarke · gaaclarke · commit 88aa46cf4fff · 2021-05-24T17:25:52.000-07:00
diff --git a/shell/platform/android/android_shell_holder.cc b/shell/platform/android/android_shell_holder.cc
@@ -303,4 +303,17 @@ std::optional<RunConfiguration> AndroidShellHolder::BuildRunConfiguration(
   }
   return config;
 }
+
+void AndroidShellHolder::ClearDirectByteBufferDecodingPreference(
+    const std::string& channel) {
+  jni_facade_->ClearDirectByteBufferDecodingPreference(channel);
+}
+
+void AndroidShellHolder::SetDirectByteBufferDecodingPreference(
+    const std::string& channel,
+    bool wants_direct_byte_buffer_for_decoding) {
+  jni_facade_->SetDirectByteBufferDecodingPreference(
+      channel, wants_direct_byte_buffer_for_decoding);
+}
+
 }  // namespace flutter
diff --git a/shell/platform/android/android_shell_holder.h b/shell/platform/android/android_shell_holder.h
@@ -96,6 +96,12 @@ class AndroidShellHolder {
 
   void NotifyLowMemoryWarning();
 
+  void ClearDirectByteBufferDecodingPreference(const std::string& channel);
+
+  void SetDirectByteBufferDecodingPreference(
+      const std::string& channel,
+      bool wants_direct_byte_buffer_for_decoding);
+
  private:
   const flutter::Settings settings_;
   const std::shared_ptr<PlatformViewAndroidJNI> jni_facade_;
diff --git a/shell/platform/android/io/flutter/embedding/engine/FlutterJNI.java b/shell/platform/android/io/flutter/embedding/engine/FlutterJNI.java
@@ -822,6 +822,32 @@ public void handlePlatformMessage(
     // (https://github.com/flutter/flutter/issues/25391)
   }
 
+  @SuppressWarnings("unused")
+  @VisibleForTesting
+  public void handleIndirectPlatformMessage(
+      @NonNull final String channel, ByteBuffer message, final int replyId) {
+    ByteBuffer indirectByteBuffer = ByteBuffer.allocate(message.capacity());
+    indirectByteBuffer.put(message);
+    indirectByteBuffer.rewind();
+    handlePlatformMessage(channel, indirectByteBuffer, replyId);
+  }
+
+  private native void nativeClearDirectByteBufferDecodingPreference(
+      long nativeShellHolderId, String channel);
+
+  public void clearDirectByteBufferDecodingPreference(@NonNull String channel) {
+    nativeClearDirectByteBufferDecodingPreference(nativeShellHolderId, channel);
+  }
+
+  private native void nativeSetDirectByteBufferDecodingPreference(
+      long nativeShellHolderId, String channel, boolean wantsDirectByteBufferForDecoding);
+
+  public void setDirectByteBufferDecodingPreference(
+      @NonNull String channel, boolean wantsDirectByteBufferForDecoding) {
+    nativeSetDirectByteBufferDecodingPreference(
+        nativeShellHolderId, channel, wantsDirectByteBufferForDecoding);
+  }
+
   // Called by native to respond to a platform message that we sent.
   // TODO(mattcarroll): determine if reply is nonull or nullable
   @SuppressWarnings("unused")
diff --git a/shell/platform/android/io/flutter/embedding/engine/dart/DartExecutor.java b/shell/platform/android/io/flutter/embedding/engine/dart/DartExecutor.java
@@ -59,7 +59,7 @@ public DartExecutor(@NonNull FlutterJNI flutterJNI, @NonNull AssetManager assetM
     this.flutterJNI = flutterJNI;
     this.assetManager = assetManager;
     this.dartMessenger = new DartMessenger(flutterJNI);
-    dartMessenger.setMessageHandler("flutter/isolate", isolateChannelMessageHandler);
+    dartMessenger.setMessageHandler("flutter/isolate", isolateChannelMessageHandler, true);
     this.binaryMessenger = new DefaultBinaryMessenger(dartMessenger);
     // The JNI might already be attached if coming from a spawned engine. If so, correctly report
     // that this DartExecutor is already running.
@@ -192,8 +192,10 @@ public void send(
   @Override
   @UiThread
   public void setMessageHandler(
-      @NonNull String channel, @Nullable BinaryMessenger.BinaryMessageHandler handler) {
-    binaryMessenger.setMessageHandler(channel, handler);
+      @NonNull String channel,
+      @Nullable BinaryMessenger.BinaryMessageHandler handler,
+      boolean wantsDirectByteBufferForDecoding) {
+    binaryMessenger.setMessageHandler(channel, handler, wantsDirectByteBufferForDecoding);
   }
   // ------ END BinaryMessenger -----
 
@@ -413,8 +415,10 @@ public void send(
     @Override
     @UiThread
     public void setMessageHandler(
-        @NonNull String channel, @Nullable BinaryMessenger.BinaryMessageHandler handler) {
-      messenger.setMessageHandler(channel, handler);
+        @NonNull String channel,
+        @Nullable BinaryMessenger.BinaryMessageHandler handler,
+        boolean wantsDirectByteBufferForDecoding) {
+      messenger.setMessageHandler(channel, handler, wantsDirectByteBufferForDecoding);
     }
   }
 }
diff --git a/shell/platform/android/io/flutter/embedding/engine/dart/DartMessenger.java b/shell/platform/android/io/flutter/embedding/engine/dart/DartMessenger.java
@@ -38,12 +38,16 @@ class DartMessenger implements BinaryMessenger, PlatformMessageHandler {
 
   @Override
   public void setMessageHandler(
-      @NonNull String channel, @Nullable BinaryMessenger.BinaryMessageHandler handler) {
+      @NonNull String channel,
+      @Nullable BinaryMessenger.BinaryMessageHandler handler,
+      boolean wantsDirectByteBufferForDecoding) {
     if (handler == null) {
       Log.v(TAG, "Removing handler for channel '" + channel + "'");
+      flutterJNI.clearDirectByteBufferDecodingPreference(channel);
       messageHandlers.remove(channel);
     } else {
       Log.v(TAG, "Setting handler for channel '" + channel + "'");
+      flutterJNI.setDirectByteBufferDecodingPreference(channel, wantsDirectByteBufferForDecoding);
       messageHandlers.put(channel, handler);
     }
   }
diff --git a/shell/platform/android/io/flutter/plugin/common/BasicMessageChannel.java b/shell/platform/android/io/flutter/plugin/common/BasicMessageChannel.java
@@ -101,7 +101,10 @@ public void send(@Nullable T message, @Nullable final Reply<T> callback) {
    */
   @UiThread
   public void setMessageHandler(@Nullable final MessageHandler<T> handler) {
-    messenger.setMessageHandler(name, handler == null ? null : new IncomingMessageHandler(handler));
+    messenger.setMessageHandler(
+        name,
+        handler == null ? null : new IncomingMessageHandler(handler),
+        codec.wantsDirectByteBufferForDecoding());
   }
 
   /**
diff --git a/shell/platform/android/io/flutter/plugin/common/BinaryCodec.java b/shell/platform/android/io/flutter/plugin/common/BinaryCodec.java
@@ -18,8 +18,23 @@
 public final class BinaryCodec implements MessageCodec<ByteBuffer> {
   // This codec must match the Dart codec of the same name in package flutter/services.
   public static final BinaryCodec INSTANCE = new BinaryCodec();
+  /** A BinaryCodec that calls decodeMessage with direct ByteBuffers for better performance. */
+  public static final BinaryCodec INSTANCE_DIRECT = new BinaryCodec(true);
 
-  private BinaryCodec() {}
+  private final boolean wantsDirectByteBufferForDecoding;
+
+  private BinaryCodec() {
+    this.wantsDirectByteBufferForDecoding = false;
+  }
+
+  private BinaryCodec(boolean wantsDirectByteBufferForDecoding) {
+    this.wantsDirectByteBufferForDecoding = wantsDirectByteBufferForDecoding;
+  }
+
+  @Override
+  public boolean wantsDirectByteBufferForDecoding() {
+    return wantsDirectByteBufferForDecoding;
+  }
 
   @Override
   public ByteBuffer encodeMessage(ByteBuffer message) {
diff --git a/shell/platform/android/io/flutter/plugin/common/BinaryMessenger.java b/shell/platform/android/io/flutter/plugin/common/BinaryMessenger.java
@@ -4,6 +4,7 @@
 
 package io.flutter.plugin.common;
 
+import android.annotation.SuppressLint;
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 import androidx.annotation.UiThread;
@@ -50,6 +51,12 @@ public interface BinaryMessenger {
   @UiThread
   void send(@NonNull String channel, @Nullable ByteBuffer message, @Nullable BinaryReply callback);
 
+  @UiThread
+  @SuppressLint("NewApi")
+  default void setMessageHandler(@NonNull String channel, @Nullable BinaryMessageHandler handler) {
+    setMessageHandler(channel, handler, true);
+  }
+
   /**
    * Registers a handler to be invoked when the Flutter application sends a message to its host
    * platform.
@@ -64,7 +71,10 @@ public interface BinaryMessenger {
    * @param handler a {@link BinaryMessageHandler} to be invoked on incoming messages, or null.
    */
   @UiThread
-  void setMessageHandler(@NonNull String channel, @Nullable BinaryMessageHandler handler);
+  void setMessageHandler(
+      @NonNull String channel,
+      @Nullable BinaryMessageHandler handler,
+      boolean wantsDirectByteBufferForDecoding);
 
   /** Handler for incoming binary messages from Flutter. */
   interface BinaryMessageHandler {
diff --git a/shell/platform/android/io/flutter/plugin/common/EventChannel.java b/shell/platform/android/io/flutter/plugin/common/EventChannel.java
@@ -84,7 +84,9 @@ public EventChannel(BinaryMessenger messenger, String name, MethodCodec codec) {
   @UiThread
   public void setStreamHandler(final StreamHandler handler) {
     messenger.setMessageHandler(
-        name, handler == null ? null : new IncomingStreamRequestHandler(handler));
+        name,
+        handler == null ? null : new IncomingStreamRequestHandler(handler),
+        /*wantsDirectByteBufferForDecoding=*/ true);
   }
 
   /**
diff --git a/shell/platform/android/io/flutter/plugin/common/JSONMessageCodec.java b/shell/platform/android/io/flutter/plugin/common/JSONMessageCodec.java
@@ -27,6 +27,11 @@ public final class JSONMessageCodec implements MessageCodec<Object> {
 
   private JSONMessageCodec() {}
 
+  @Override
+  public boolean wantsDirectByteBufferForDecoding() {
+    return true;
+  }
+
   @Override
   public ByteBuffer encodeMessage(Object message) {
     if (message == null) {
diff --git a/shell/platform/android/io/flutter/plugin/common/MessageCodec.java b/shell/platform/android/io/flutter/plugin/common/MessageCodec.java
@@ -13,6 +13,15 @@
  * <p>Both operations throw {@link IllegalArgumentException}, if conversion fails.
  */
 public interface MessageCodec<T> {
+
+  /**
+   * Controls the ByteBuffer parameter for `decodeMessage`.
+   *
+   * @return true if the MessageCodec wants the ByteBuffer parameter to decodeMessage to be a direct
+   *     ByteBuffer.
+   */
+  boolean wantsDirectByteBufferForDecoding();
+
   /**
    * Encodes the specified message into binary.
    *
@@ -26,9 +35,9 @@ public interface MessageCodec<T> {
   /**
    * Decodes the specified message from binary.
    *
-   * <p><b>Warning:</b> The ByteBuffer may be `direct`. Do not retain references to the ByteBuffer
-   * without checking `ByteBuffer.isDirect()`. See also:
-   * https://docs.oracle.com/javase/7/docs/api/java/nio/ByteBuffer.html
+   * <p><b>Warning:</b> The ByteBuffer may be `direct` if `wantsDirectByteBufferForDecoding` returns
+   * `true. Do not retain references to the ByteBuffer without checking `ByteBuffer.isDirect()`. See
+   * also: https://docs.oracle.com/javase/7/docs/api/java/nio/ByteBuffer.html
    *
    * @param message the {@link ByteBuffer} message, possibly null.
    * @return a T value representation of the bytes between the given buffer's current position and
diff --git a/shell/platform/android/io/flutter/plugin/common/MethodChannel.java b/shell/platform/android/io/flutter/plugin/common/MethodChannel.java
@@ -117,7 +117,9 @@ public void invokeMethod(String method, @Nullable Object arguments, @Nullable Re
   @UiThread
   public void setMethodCallHandler(final @Nullable MethodCallHandler handler) {
     messenger.setMessageHandler(
-        name, handler == null ? null : new IncomingMethodCallHandler(handler));
+        name,
+        handler == null ? null : new IncomingMethodCallHandler(handler),
+        /*wantsDirectByteBufferForDecoding=*/ true);
   }
 
   /**
diff --git a/shell/platform/android/io/flutter/plugin/common/StandardMessageCodec.java b/shell/platform/android/io/flutter/plugin/common/StandardMessageCodec.java
@@ -63,6 +63,11 @@ public class StandardMessageCodec implements MessageCodec<Object> {
   private static final String TAG = "StandardMessageCodec#";
   public static final StandardMessageCodec INSTANCE = new StandardMessageCodec();
 
+  @Override
+  public boolean wantsDirectByteBufferForDecoding() {
+    return true;
+  }
+
   @Override
   public ByteBuffer encodeMessage(Object message) {
     if (message == null) {
diff --git a/shell/platform/android/io/flutter/plugin/common/StringCodec.java b/shell/platform/android/io/flutter/plugin/common/StringCodec.java
@@ -20,6 +20,11 @@ public final class StringCodec implements MessageCodec<String> {
 
   private StringCodec() {}
 
+  @Override
+  public boolean wantsDirectByteBufferForDecoding() {
+    return true;
+  }
+
   @Override
   public ByteBuffer encodeMessage(String message) {
     if (message == null) {
diff --git a/shell/platform/android/io/flutter/view/FlutterNativeView.java b/shell/platform/android/io/flutter/view/FlutterNativeView.java
@@ -140,8 +140,11 @@ public void send(String channel, ByteBuffer message, BinaryReply callback) {
 
   @Override
   @UiThread
-  public void setMessageHandler(String channel, BinaryMessageHandler handler) {
-    dartExecutor.getBinaryMessenger().setMessageHandler(channel, handler);
+  public void setMessageHandler(
+      String channel, BinaryMessageHandler handler, boolean wantsDirectByteBufferForDecoding) {
+    dartExecutor
+        .getBinaryMessenger()
+        .setMessageHandler(channel, handler, wantsDirectByteBufferForDecoding);
   }
 
   /*package*/ FlutterJNI getFlutterJNI() {
diff --git a/shell/platform/android/io/flutter/view/FlutterView.java b/shell/platform/android/io/flutter/view/FlutterView.java
@@ -863,8 +863,9 @@ public void send(String channel, ByteBuffer message, BinaryReply callback) {
 
   @Override
   @UiThread
-  public void setMessageHandler(String channel, BinaryMessageHandler handler) {
-    mNativeView.setMessageHandler(channel, handler);
+  public void setMessageHandler(
+      String channel, BinaryMessageHandler handler, boolean wantsDirectByteBufferForDecoding) {
+    mNativeView.setMessageHandler(channel, handler, wantsDirectByteBufferForDecoding);
   }
 
   /** Listener will be called on the Android UI thread once when Flutter renders the first frame. */
diff --git a/shell/platform/android/jni/jni_mock.h b/shell/platform/android/jni/jni_mock.h
@@ -101,6 +101,16 @@ class JNIMock final : public PlatformViewAndroidJNI {
               RequestDartDeferredLibrary,
               (int loading_unit_id),
               (override));
+
+  MOCK_METHOD(void,
+              ClearDirectByteBufferDecodingPreference,
+              (const std::string& channel),
+              (override));
+
+  MOCK_METHOD(void,
+              SetDirectByteBufferDecodingPreference,
+              (const std::string&, bool),
+              (override));
 };
 
 }  // namespace flutter
diff --git a/shell/platform/android/jni/platform_view_android_jni.h b/shell/platform/android/jni/platform_view_android_jni.h
@@ -197,6 +197,13 @@ class PlatformViewAndroidJNI {
   virtual double GetDisplayRefreshRate() = 0;
 
   virtual bool RequestDartDeferredLibrary(int loading_unit_id) = 0;
+
+  virtual void ClearDirectByteBufferDecodingPreference(
+      const std::string& channel) = 0;
+
+  virtual void SetDirectByteBufferDecodingPreference(
+      const std::string& channel,
+      bool wants_direct_byte_buffer_for_decoding) = 0;
 };
 
 }  // namespace flutter
diff --git a/shell/platform/android/platform_view_android_jni_impl.cc b/shell/platform/android/platform_view_android_jni_impl.cc
diff --git a/shell/platform/android/platform_view_android_jni_impl.h b/shell/platform/android/platform_view_android_jni_impl.h
diff --git a/shell/platform/android/test/io/flutter/embedding/engine/dart/DartMessengerTest.java b/shell/platform/android/test/io/flutter/embedding/engine/dart/DartMessengerTest.java
