content: /*
   * Licensed to the Apache Software Foundation (ASF) under one or more
   * contributor license agreements.  See the NOTICE file distributed with
   * this work for additional information regarding copyright ownership.
   * The ASF licenses this file to You under the Apache License, Version 2.0
   * (the "License"); you may not use this file except in compliance with
   * the License.  You may obtain a copy of the License at
   *
   *    http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package org.apache.spark.network.util;
  
  import java.nio.ByteBuffer;
  import java.util.ArrayList;
  import java.util.List;
  import java.util.Random;
  import java.util.concurrent.atomic.AtomicInteger;
  
  import io.netty.buffer.ByteBuf;
  import io.netty.buffer.Unpooled;
  import io.netty.channel.ChannelHandlerContext;
  import org.junit.AfterClass;
  import org.junit.Test;
  import org.mockito.invocation.InvocationOnMock;
  import org.mockito.stubbing.Answer;
  import static org.junit.Assert.*;
  import static org.mockito.Mockito.*;
  
  public class TransportFrameDecoderSuite {
  
    private static Random RND = new Random();
  
    @AfterClass
    public static void cleanup() {
      RND = null;
    }
  
    @Test
    public void testFrameDecoding() throws Exception {
      TransportFrameDecoder decoder = new TransportFrameDecoder();
      ChannelHandlerContext ctx = mockChannelHandlerContext();
      ByteBuf data = createAndFeedFrames(100, decoder, ctx);
      verifyAndCloseDecoder(decoder, ctx, data);
    }
  
    @Test
    public void testInterception() throws Exception {
      final int interceptedReads = 3;
      TransportFrameDecoder decoder = new TransportFrameDecoder();
      TransportFrameDecoder.Interceptor interceptor = spy(new MockInterceptor(interceptedReads));
      ChannelHandlerContext ctx = mockChannelHandlerContext();
  
      byte[] data = new byte[8];
      ByteBuf len = Unpooled.copyLong(8 + data.length);
      ByteBuf dataBuf = Unpooled.wrappedBuffer(data);
  
      try {
        decoder.setInterceptor(interceptor);
        for (int i = 0; i < interceptedReads; i++) {
          decoder.channelRead(ctx, dataBuf);
          assertEquals(0, dataBuf.refCnt());
          dataBuf = Unpooled.wrappedBuffer(data);
        }
        decoder.channelRead(ctx, len);
        decoder.channelRead(ctx, dataBuf);
        verify(interceptor, times(interceptedReads)).handle(any(ByteBuf.class));
        verify(ctx).fireChannelRead(any(ByteBuffer.class));
        assertEquals(0, len.refCnt());
        assertEquals(0, dataBuf.refCnt());
      } finally {
        release(len);
        release(dataBuf);
      }
    }
  
    @Test
    public void testRetainedFrames() throws Exception {
      TransportFrameDecoder decoder = new TransportFrameDecoder();
  
      final AtomicInteger count = new AtomicInteger();
      final List<ByteBuf> retained = new ArrayList<>();
  
      ChannelHandlerContext ctx = mock(ChannelHandlerContext.class);
      when(ctx.fireChannelRead(any())).thenAnswer(new Answer<Void>() {
        @Override
        public Void answer(InvocationOnMock in) {
          // Retain a few frames but not others.
          ByteBuf buf = (ByteBuf) in.getArguments()[0];
          if (count.incrementAndGet() % 2 == 0) {
            retained.add(buf);
          } else {
            buf.release();
          }
          return null;
        }
      });
  
      ByteBuf data = createAndFeedFrames(100, decoder, ctx);
      try {
        // Verify all retained buffers are readable.
        for (ByteBuf b : retained) {
          byte[] tmp = new byte[b.readableBytes()];
          b.readBytes(tmp);
          b.release();
        }
        verifyAndCloseDecoder(decoder, ctx, data);
      } finally {
        for (ByteBuf b : retained) {
          release(b);
        }
      }
    }
  
    @Test
    public void testSplitLengthField() throws Exception {
      byte[] frame = new byte[1024 * (RND.nextInt(31) + 1)];
      ByteBuf buf = Unpooled.buffer(frame.length + 8);
      buf.writeLong(frame.length + 8);
      buf.writeBytes(frame);
  
      TransportFrameDecoder decoder = new TransportFrameDecoder();
      ChannelHandlerContext ctx = mockChannelHandlerContext();
      try {
        decoder.channelRead(ctx, buf.readSlice(RND.nextInt(7)).retain());
        verify(ctx, never()).fireChannelRead(any(ByteBuf.class));
        decoder.channelRead(ctx, buf);
        verify(ctx).fireChannelRead(any(ByteBuf.class));
        assertEquals(0, buf.refCnt());
      } finally {
        decoder.channelInactive(ctx);
        release(buf);
      }
    }
  
    @Test(expected = IllegalArgumentException.class)
    public void testNegativeFrameSize() throws Exception {
      testInvalidFrame(-1);
    }
  
    @Test(expected = IllegalArgumentException.class)
    public void testEmptyFrame() throws Exception {
      // 8 because frame size includes the frame length.
      testInvalidFrame(8);
    }
  
    @Test(expected = IllegalArgumentException.class)
    public void testLargeFrame() throws Exception {
      // Frame length includes the frame size field, so need to add a few more bytes.
      testInvalidFrame(Integer.MAX_VALUE + 9);
    }
  
    /**
     * Creates a number of randomly sized frames and feed them to the given decoder, verifying
     * that the frames were read.
     */
    private ByteBuf createAndFeedFrames(
        int frameCount,
        TransportFrameDecoder decoder,
        ChannelHandlerContext ctx) throws Exception {
      ByteBuf data = Unpooled.buffer();
      for (int i = 0; i < frameCount; i++) {
        byte[] frame = new byte[1024 * (RND.nextInt(31) + 1)];
        data.writeLong(frame.length + 8);
        data.writeBytes(frame);
      }
  
      try {
        while (data.isReadable()) {
          int size = RND.nextInt(4 * 1024) + 256;
          decoder.channelRead(ctx, data.readSlice(Math.min(data.readableBytes(), size)).retain());
        }
  
        verify(ctx, times(frameCount)).fireChannelRead(any(ByteBuf.class));
      } catch (Exception e) {
        release(data);
        throw e;
      }
      return data;
    }
  
    private void verifyAndCloseDecoder(
        TransportFrameDecoder decoder,
        ChannelHandlerContext ctx,
        ByteBuf data) throws Exception {
      try {
        decoder.channelInactive(ctx);
        assertTrue("There shouldn't be dangling references to the data.", data.release());
      } finally {
        release(data);
      }
    }
  
    private void testInvalidFrame(long size) throws Exception {
      TransportFrameDecoder decoder = new TransportFrameDecoder();
      ChannelHandlerContext ctx = mock(ChannelHandlerContext.class);
      ByteBuf frame = Unpooled.copyLong(size);
      try {
        decoder.channelRead(ctx, frame);
      } finally {
        release(frame);
      }
    }
  
    private ChannelHandlerContext mockChannelHandlerContext() {
      ChannelHandlerContext ctx = mock(ChannelHandlerContext.class);
      when(ctx.fireChannelRead(any())).thenAnswer(new Answer<Void>() {
        @Override
        public Void answer(InvocationOnMock in) {
          ByteBuf buf = (ByteBuf) in.getArguments()[0];
          buf.release();
          return null;
        }
      });
      return ctx;
    }
  
    private void release(ByteBuf buf) {
      if (buf.refCnt() > 0) {
        buf.release(buf.refCnt());
      }
    }
  
    private static class MockInterceptor implements TransportFrameDecoder.Interceptor {
  
      private int remainingReads;
  
      MockInterceptor(int readCount) {
        this.remainingReads = readCount;
      }
  
      @Override
      public boolean handle(ByteBuf data) throws Exception {
        data.readerIndex(data.readerIndex() + data.readableBytes());
        assertFalse(data.isReadable());
        remainingReads -= 1;
        return remainingReads != 0;
      }
  
      @Override
      public void exceptionCaught(Throwable cause) throws Exception {
  
      }
  
      @Override
      public void channelInactive() throws Exception {
  
      }
  
    }
  
  }
  