AHeise commented on a change in pull request #11515: [FLINK-16744][task] implement channel state persistence for unaligned checkpoints URL: https://github.com/apache/flink/pull/11515#discussion_r400944368
########## File path: flink-runtime/src/main/java/org/apache/flink/runtime/checkpoint/channel/ChannelStateSerializer.java ########## @@ -0,0 +1,199 @@ +/* + * 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.flink.runtime.checkpoint.channel; + +import org.apache.flink.annotation.Internal; +import org.apache.flink.api.java.tuple.Tuple2; +import org.apache.flink.runtime.io.network.buffer.Buffer; +import org.apache.flink.runtime.io.network.buffer.BufferBuilder; +import org.apache.flink.util.Preconditions; + +import org.apache.flink.shaded.netty4.io.netty.buffer.ByteBuf; + +import javax.annotation.concurrent.NotThreadSafe; + +import java.io.DataInputStream; +import java.io.DataOutputStream; +import java.io.IOException; +import java.io.InputStream; + +import static java.lang.Math.addExact; +import static java.lang.Math.min; + +interface ChannelStateSerializer { + + void writeHeader(DataOutputStream dataStream) throws IOException; + + void writeData(DataOutputStream stream, Buffer... flinkBuffers) throws IOException; +} + +interface ChannelStateDeserializer { + + void readHeader(InputStream stream) throws IOException; + + /** + * Reads the length of state. + * + * @return size of state in bytes and offset of the current position resulted from reading. + */ + Tuple2<Integer, Integer> readLength(InputStream stream) throws IOException; + + int readData(InputStream stream, ChannelStateByteBuffer buffer, int bytes) throws IOException; +} + +/** + * Wrapper around various buffers to receive channel state data. + */ +@Internal +@NotThreadSafe +interface ChannelStateByteBuffer { + + boolean isWritable(); + + int writableBytes(); + + int writeBytes(InputStream input, int bytesToRead) throws IOException; + + static ChannelStateByteBuffer wrap(Buffer buffer) { + return new ChannelStateByteBuffer() { + + private ByteBuf byteBuf = buffer.asByteBuf(); + + @Override + public boolean isWritable() { + return byteBuf.isWritable(); + } + + @Override + public int writableBytes() { + return byteBuf.writableBytes(); + } + + @Override + public int writeBytes(InputStream input, int bytesToRead) throws IOException { + return byteBuf.writeBytes(input, Math.min(bytesToRead, byteBuf.writableBytes())); + } + }; + } + + static ChannelStateByteBuffer wrap(BufferBuilder bufferBuilder) { + final byte[] buf = new byte[1024]; + return new ChannelStateByteBuffer() { + @Override + public boolean isWritable() { + return !bufferBuilder.isFull(); + } + + @Override + public int writableBytes() { + return bufferBuilder.writableBytes(); + } + + @Override + public int writeBytes(InputStream input, int upToBytes) throws IOException { + int left = upToBytes; + for (int toRead = getToRead(left); toRead > 0; toRead = getToRead(left)) { + int read = input.read(buf, 0, toRead); + int copied = bufferBuilder.append(java.nio.ByteBuffer.wrap(buf, 0, read)); + Preconditions.checkState(copied == read); + left -= read; + } + bufferBuilder.commit(); + return upToBytes - left; + } + + private int getToRead(int bytesToRead) { + return min(bytesToRead, min(buf.length, writableBytes())); + } + }; + } + + static ChannelStateByteBuffer wrap(byte[] bytes) { + int written = 0; + return new ChannelStateByteBuffer() { + @Override + public boolean isWritable() { + return written < bytes.length; + } + + @Override + public int writableBytes() { + return bytes.length - written; + } + + @Override + public int writeBytes(InputStream input, int bytesToRead) throws IOException { + return input.read(bytes, written, writableBytes()); + } + }; + } +} + +class ChannelStateSerializerImpl implements ChannelStateSerializer, ChannelStateDeserializer { + private static final int LEN_SIZE = Integer.BYTES; + private static final int SERIALIZATION_VERSION = 0; + + @Override + public void writeHeader(DataOutputStream dataStream) throws IOException { + dataStream.writeInt(SERIALIZATION_VERSION); + } + + @Override + public void writeData(DataOutputStream stream, Buffer... flinkBuffers) throws IOException { + stream.writeInt(getSize(flinkBuffers)); + for (Buffer buffer : flinkBuffers) { + ByteBuf nettyByteBuf = buffer.asByteBuf(); + nettyByteBuf.getBytes(nettyByteBuf.readerIndex(), stream, nettyByteBuf.readableBytes()); // todo: review me Review comment: looks okay. anything particular to check? ---------------------------------------------------------------- This is an automated message from the Apache Git Service. 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