/**
* 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.hadoop.hdfs.protocol.datatransfer;
import static org.apache.hadoop.hdfs.protocolPB.PBHelper.vintPrefixed;
import static org.apache.hadoop.hdfs.protocol.datatransfer.DataTransferProtoUtil.fromProto;
import java.io.DataInputStream;
import java.io.IOException;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.classification.InterfaceStability;
import org.apache.hadoop.hdfs.protocol.proto.DataTransferProtos.OpBlockChecksumProto;
import org.apache.hadoop.hdfs.protocol.proto.DataTransferProtos.OpCopyBlockProto;
import org.apache.hadoop.hdfs.protocol.proto.DataTransferProtos.OpReadBlockProto;
import org.apache.hadoop.hdfs.protocol.proto.DataTransferProtos.OpReplaceBlockProto;
import org.apache.hadoop.hdfs.protocol.proto.DataTransferProtos.OpTransferBlockProto;
import org.apache.hadoop.hdfs.protocol.proto.DataTransferProtos.OpRequestShortCircuitAccessProto;
import org.apache.hadoop.hdfs.protocol.proto.DataTransferProtos.CachingStrategyProto;
import org.apache.hadoop.hdfs.protocol.proto.DataTransferProtos.OpWriteBlockProto;
import org.apache.hadoop.hdfs.protocolPB.PBHelper;
import org.apache.hadoop.hdfs.server.datanode.CachingStrategy;
/** Receiver */
@InterfaceAudience.Private
@InterfaceStability.Evolving
public abstract class Receiver implements DataTransferProtocol {
protected DataInputStream in;
/** Initialize a receiver for DataTransferProtocol with a socket. */
protected void initialize(final DataInputStream in) {
this.in = in;
}
/** Read an Op. It also checks protocol version. */
protected final Op readOp() throws IOException {
final short version = in.readShort();
if (version != DataTransferProtocol.DATA_TRANSFER_VERSION) {
throw new IOException( "Version Mismatch (Expected: " +
DataTransferProtocol.DATA_TRANSFER_VERSION +
", Received: " + version + " )");
}
return Op.read(in);
}
/** Process op by the corresponding method. */
protected final void processOp(Op op) throws IOException {
switch(op) {
case READ_BLOCK:
opReadBlock();
break;
case WRITE_BLOCK:
opWriteBlock(in);
break;
case REPLACE_BLOCK:
opReplaceBlock(in);
break;
case COPY_BLOCK:
opCopyBlock(in);
break;
case BLOCK_CHECKSUM:
opBlockChecksum(in);
break;
case TRANSFER_BLOCK:
opTransferBlock(in);
break;
case REQUEST_SHORT_CIRCUIT_FDS:
opRequestShortCircuitFds(in);
break;
default:
throw new IOException("Unknown op " + op + " in data stream");
}
}
static private CachingStrategy getCachingStrategy(CachingStrategyProto strategy) {
Boolean dropBehind = strategy.hasDropBehind() ?
strategy.getDropBehind() : null;
Long readahead = strategy.hasReadahead() ?
strategy.getReadahead() : null;
return new CachingStrategy(dropBehind, readahead);
}
/** Receive OP_READ_BLOCK */
private void opReadBlock() throws IOException {
OpReadBlockProto proto = OpReadBlockProto.parseFrom(vintPrefixed(in));
readBlock(PBHelper.convert(proto.getHeader().getBaseHeader().getBlock()),
PBHelper.convert(proto.getHeader().getBaseHeader().getToken()),
proto.getHeader().getClientName(),
proto.getOffset(),
proto.getLen(),
proto.getSendChecksums(),
(proto.hasCachingStrategy() ?
getCachingStrategy(proto.getCachingStrategy()) :
CachingStrategy.newDefaultStrategy()));
}
/** Receive OP_WRITE_BLOCK */
private void opWriteBlock(DataInputStream in) throws IOException {
final OpWriteBlockProto proto = OpWriteBlockProto.parseFrom(vintPrefixed(in));
writeBlock(PBHelper.convert(proto.getHeader().getBaseHeader().getBlock()),
PBHelper.convert(proto.getHeader().getBaseHeader().getToken()),
proto.getHeader().getClientName(),
PBHelper.convert(proto.getTargetsList()),
PBHelper.convert(proto.getSource()),
fromProto(proto.getStage()),
proto.getPipelineSize(),
proto.getMinBytesRcvd(), proto.getMaxBytesRcvd(),
proto.getLatestGenerationStamp(),
fromProto(proto.getRequestedChecksum()),
(proto.hasCachingStrategy() ?
getCachingStrategy(proto.getCachingStrategy()) :
CachingStrategy.newDefaultStrategy()));
}
/** Receive {@link Op#TRANSFER_BLOCK} */
private void opTransferBlock(DataInputStream in) throws IOException {
final OpTransferBlockProto proto =
OpTransferBlockProto.parseFrom(vintPrefixed(in));
transferBlock(PBHelper.convert(proto.getHeader().getBaseHeader().getBlock()),
PBHelper.convert(proto.getHeader().getBaseHeader().getToken()),
proto.getHeader().getClientName(),
PBHelper.convert(proto.getTargetsList()));
}
/** Receive {@link Op#REQUEST_SHORT_CIRCUIT_FDS} */
private void opRequestShortCircuitFds(DataInputStream in) throws IOException {
final OpRequestShortCircuitAccessProto proto =
OpRequestShortCircuitAccessProto.parseFrom(vintPrefixed(in));
requestShortCircuitFds(PBHelper.convert(proto.getHeader().getBlock()),
PBHelper.convert(proto.getHeader().getToken()),
proto.getMaxVersion());
}
/** Receive OP_REPLACE_BLOCK */
private void opReplaceBlock(DataInputStream in) throws IOException {
OpReplaceBlockProto proto = OpReplaceBlockProto.parseFrom(vintPrefixed(in));
replaceBlock(PBHelper.convert(proto.getHeader().getBlock()),
PBHelper.convert(proto.getHeader().getToken()),
proto.getDelHint(),
PBHelper.convert(proto.getSource()));
}
/** Receive OP_COPY_BLOCK */
private void opCopyBlock(DataInputStream in) throws IOException {
OpCopyBlockProto proto = OpCopyBlockProto.parseFrom(vintPrefixed(in));
copyBlock(PBHelper.convert(proto.getHeader().getBlock()),
PBHelper.convert(proto.getHeader().getToken()));
}
/** Receive OP_BLOCK_CHECKSUM */
private void opBlockChecksum(DataInputStream in) throws IOException {
OpBlockChecksumProto proto = OpBlockChecksumProto.parseFrom(vintPrefixed(in));
blockChecksum(PBHelper.convert(proto.getHeader().getBlock()),
PBHelper.convert(proto.getHeader().getToken()));
}
}