Java tutorial
/** * Copyright 2016 Yahoo Inc. * * Licensed 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 com.yahoo.pulsar.common.compression; import static org.testng.Assert.assertEquals; import static org.testng.Assert.assertTrue; import java.io.IOException; import java.nio.ByteBuffer; import org.testng.annotations.Test; import com.yahoo.pulsar.checksum.utils.Crc32cChecksum; import com.yahoo.pulsar.common.api.Commands; import com.yahoo.pulsar.common.api.Commands.ChecksumType; import com.yahoo.pulsar.common.api.DoubleByteBuf; import com.yahoo.pulsar.common.api.proto.PulsarApi.MessageMetadata; import com.yahoo.pulsar.common.util.protobuf.ByteBufCodedOutputStream; import io.netty.buffer.ByteBuf; import io.netty.buffer.PooledByteBufAllocator; import io.netty.buffer.Unpooled; public class CommandsTest { @Test public void testChecksumSendCommand() throws Exception { // test checksum in send command String producerName = "prod-name"; int sequenceId = 0; ByteBuf data = Unpooled.buffer(1024); MessageMetadata messageMetadata = MessageMetadata.newBuilder().setPublishTime(System.currentTimeMillis()) .setProducerName(producerName).setSequenceId(sequenceId).build(); int expectedChecksum = computeChecksum(messageMetadata, data); ByteBuf clientCommand = Commands.newSend(1, 0, 1, ChecksumType.Crc32c, messageMetadata, data); clientCommand.retain(); ByteBuffer inputBytes = clientCommand.nioBuffer(); ByteBuf receivedBuf = Unpooled.wrappedBuffer(inputBytes); receivedBuf.skipBytes(4); //skip [total-size] int cmdSize = (int) receivedBuf.readUnsignedInt(); receivedBuf.readerIndex(8 + cmdSize); int startMessagePos = receivedBuf.readerIndex(); /*** 1. verify checksum and metadataParsing ***/ boolean hasChecksum = Commands.hasChecksum(receivedBuf); int checksum = Commands.readChecksum(receivedBuf).intValue(); // verify checksum is present assertTrue(hasChecksum); // verify checksum value assertEquals(expectedChecksum, checksum); MessageMetadata metadata = Commands.parseMessageMetadata(receivedBuf); // verify metadata parsing assertEquals(metadata.getProducerName(), producerName); /** 2. parseMessageMetadata should skip checksum if present **/ receivedBuf.readerIndex(startMessagePos); metadata = Commands.parseMessageMetadata(receivedBuf); // verify metadata parsing assertEquals(metadata.getProducerName(), producerName); } private int computeChecksum(MessageMetadata msgMetadata, ByteBuf compressedPayload) throws IOException { int metadataSize = msgMetadata.getSerializedSize(); int metadataFrameSize = 4 + metadataSize; ByteBuf metaPayloadFrame = PooledByteBufAllocator.DEFAULT.buffer(metadataFrameSize, metadataFrameSize); ByteBufCodedOutputStream outStream = ByteBufCodedOutputStream.get(metaPayloadFrame); metaPayloadFrame.writeInt(metadataSize); msgMetadata.writeTo(outStream); ByteBuf payload = compressedPayload.copy(); ByteBuf metaPayloadBuf = DoubleByteBuf.get(metaPayloadFrame, payload); int computedChecksum = Crc32cChecksum.computeChecksum(metaPayloadBuf); outStream.recycle(); metaPayloadBuf.release(); return computedChecksum; } }