/*
* Copyright (c) 2014 Cisco Systems, Inc. and others. All rights reserved.
*
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License v1.0 which accompanies this distribution,
* and is available at http://www.eclipse.org/legal/epl-v10.html
*/
package org.opendaylight.controller.cluster.raft.behaviors;
import com.google.common.base.Optional;
import com.google.common.base.Preconditions;
import com.google.common.io.ByteSource;
import java.io.BufferedOutputStream;
import java.io.IOException;
import java.util.Arrays;
import org.opendaylight.controller.cluster.io.FileBackedOutputStream;
import org.opendaylight.controller.cluster.raft.RaftActorContext;
import org.slf4j.Logger;
/**
* Helper class that maintains state for a snapshot that is being installed in chunks on a Follower.
*/
class SnapshotTracker implements AutoCloseable {
private final Logger log;
private final int totalChunks;
private final String leaderId;
private final BufferedOutputStream bufferedStream;
private final FileBackedOutputStream fileBackedStream;
private int lastChunkIndex = LeaderInstallSnapshotState.FIRST_CHUNK_INDEX - 1;
private boolean sealed = false;
private int lastChunkHashCode = LeaderInstallSnapshotState.INITIAL_LAST_CHUNK_HASH_CODE;
private long count;
SnapshotTracker(Logger log, int totalChunks, String leaderId, RaftActorContext context) {
this.log = log;
this.totalChunks = totalChunks;
this.leaderId = Preconditions.checkNotNull(leaderId);
fileBackedStream = context.newFileBackedOutputStream();
bufferedStream = new BufferedOutputStream(fileBackedStream);
}
/**
* Adds a chunk to the tracker.
*
* @param chunkIndex the index of the chunk
* @param chunk the chunk data
* @param lastChunkHashCode the optional hash code for the chunk
* @return true if this is the last chunk is received
* @throws InvalidChunkException if the chunk index is invalid or out of order
*/
boolean addChunk(int chunkIndex, byte[] chunk, Optional<Integer> maybeLastChunkHashCode)
throws InvalidChunkException, IOException {
log.debug("addChunk: chunkIndex={}, lastChunkIndex={}, collectedChunks.size={}, lastChunkHashCode={}",
chunkIndex, lastChunkIndex, count, this.lastChunkHashCode);
if (sealed) {
throw new InvalidChunkException("Invalid chunk received with chunkIndex " + chunkIndex
+ " all chunks already received");
}
if (lastChunkIndex + 1 != chunkIndex) {
throw new InvalidChunkException("Expected chunkIndex " + (lastChunkIndex + 1) + " got " + chunkIndex);
}
if (maybeLastChunkHashCode.isPresent() && maybeLastChunkHashCode.get() != this.lastChunkHashCode) {
throw new InvalidChunkException("The hash code of the recorded last chunk does not match "
+ "the senders hash code, expected " + this.lastChunkHashCode + " was "
+ maybeLastChunkHashCode.get());
}
bufferedStream.write(chunk);
count += chunk.length;
sealed = chunkIndex == totalChunks;
lastChunkIndex = chunkIndex;
this.lastChunkHashCode = Arrays.hashCode(chunk);
return sealed;
}
ByteSource getSnapshotBytes() throws IOException {
if (!sealed) {
throw new IllegalStateException("lastChunk not received yet");
}
bufferedStream.close();
return fileBackedStream.asByteSource();
}
String getLeaderId() {
return leaderId;
}
@Override
public void close() {
fileBackedStream.cleanup();
}
public static class InvalidChunkException extends IOException {
private static final long serialVersionUID = 1L;
InvalidChunkException(String message) {
super(message);
}
}
}