/*
* Copyright 2013 Thomas Bocek, Maxat Pernebayev
*
* 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 net.tomp2p.synchronization;
import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import java.io.IOException;
import java.security.NoSuchAlgorithmException;
import java.security.PublicKey;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import java.util.NavigableMap;
import java.util.TreeMap;
import net.tomp2p.connection.ChannelCreator;
import net.tomp2p.connection.ConnectionBean;
import net.tomp2p.connection.PeerBean;
import net.tomp2p.connection.PeerConnection;
import net.tomp2p.connection.RequestHandler;
import net.tomp2p.connection.Responder;
import net.tomp2p.dht.ReplicationListener;
import net.tomp2p.dht.StorageLayer;
import net.tomp2p.dht.StorageLayer.PutStatus;
import net.tomp2p.futures.FutureResponse;
import net.tomp2p.message.DataMap;
import net.tomp2p.message.KeyCollection;
import net.tomp2p.message.KeyMap640Keys;
import net.tomp2p.message.Message;
import net.tomp2p.message.Message.Type;
import net.tomp2p.peers.Number160;
import net.tomp2p.peers.Number640;
import net.tomp2p.peers.PeerAddress;
import net.tomp2p.rpc.DispatchHandler;
import net.tomp2p.rpc.RPC;
import net.tomp2p.storage.Data;
import net.tomp2p.utils.Pair;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* This Synchronization RPC is used to synchronize data between peers by transferring only changes.
*
* @author Thomas Bocek
* @author Maxat Pernebayev
*
*/
public class SyncRPC extends DispatchHandler {
private static final Logger LOG = LoggerFactory.getLogger(SyncRPC.class);
public static final byte INFO_COMMAND = RPC.Commands.SYNC_INFO.getNr();
public static final byte SYNC_COMMAND = RPC.Commands.SYNC.getNr();
private final int blockSize;
private final StorageLayer storageLayer;
private final ReplicationListener replicationListener;
/**
* Constructor that registers this RPC with the message handler.
*
* @param peerBean
* The peer bean that contains data that is unique for each peer
* @param connectionBean
* The connection bean that is unique per connection (multiple peers can share a single connection)
* @param storageLayer
*/
public SyncRPC(final PeerBean peerBean, final ConnectionBean connectionBean, final int blockSize, StorageLayer storageLayer, ReplicationListener replicationListener) {
super(peerBean, connectionBean);
register(INFO_COMMAND, SYNC_COMMAND);
this.blockSize = blockSize;
this.storageLayer = storageLayer;
this.replicationListener = replicationListener;
}
/**
* Sends info message that asks whether the data is present at replica peer or not. If it is present whether it has
* changed. This is an RPC.
*
* @param remotePeer
* The remote peer to send this request
* @param synchronizationBuilder
* Used for keeping parameters that are sent
* @param channelCreator
* The channel creator that creates connections
* @return The future response to keep track of future events
*/
public FutureResponse infoMessage(final PeerAddress remotePeer,
final SyncBuilder synchronizationBuilder, final ChannelCreator channelCreator) {
final Message message = createMessage(remotePeer, INFO_COMMAND,
synchronizationBuilder.isSyncFromOldVersion() ? Type.REQUEST_2 : Type.REQUEST_1);
if (synchronizationBuilder.isSign()) {
message.publicKeyAndSign(synchronizationBuilder.keyPair());
}
KeyMap640Keys keyMap = new KeyMap640Keys(synchronizationBuilder.dataMapHash());
message.keyMap640Keys(keyMap);
FutureResponse futureResponse = new FutureResponse(message);
final RequestHandler requestHandler = new RequestHandler(futureResponse,
peerBean(), connectionBean(), synchronizationBuilder);
LOG.debug("Info sent {}", message);
return requestHandler.sendTCP(channelCreator);
}
/**
* Sends sync message that transfers the changed parts of data to a replica peer. This is an RPC
*
* @param remotePeer
* The remote peer to send this message
* @param synchronizationBuilder
* Used for keeping parameters that are sent
* @param channelCreator
* The channel creator that creates connections
* @return The future response to keep track of future events
* @throws IOException
*/
public FutureResponse syncMessage(final PeerAddress remotePeer,
final SyncBuilder synchronizationBuilder, final ChannelCreator channelCreator)
throws IOException {
final Message message = createMessage(remotePeer, SYNC_COMMAND, Type.REQUEST_1);
if (synchronizationBuilder.isSign()) {
message.publicKeyAndSign(synchronizationBuilder.keyPair());
}
DataMap dataMap = synchronizationBuilder.dataMap();
message.setDataMap(dataMap);
FutureResponse futureResponse = new FutureResponse(message);
final RequestHandler requestHandler = new RequestHandler(
futureResponse, peerBean(), connectionBean(), synchronizationBuilder);
LOG.debug("Sync sent {}", message);
return requestHandler.sendTCP(channelCreator);
}
@Override
public void handleResponse(final Message message, PeerConnection peerConnection, final boolean sign, Responder responder) throws Exception {
if (!(message.command() == INFO_COMMAND || message.command() == SYNC_COMMAND)) {
throw new IllegalArgumentException("Message content is wrong");
}
final Message responseMessage = createResponseMessage(message, Type.OK);
if(message.command() == INFO_COMMAND) {
handleInfo(message, responseMessage, responder);
} else if (message.command() == SYNC_COMMAND) {
handleSync(message, responseMessage, responder);
} else {
throw new IllegalArgumentException("Message content is wrong");
}
}
/**
* Handles the info message and returns a reply. This is an RPC.
*
* @param message
* The message from a responsible peer
* @param responseMessage
* The response message to a responsible peer
* @return The response message
* @throws IOException
* @throws ClassNotFoundException
* @throws NoSuchAlgorithmException
*/
private void handleInfo(final Message message, final Message responseMessage, Responder responder) {
LOG.debug("Info received from {} -> I'm {}", message.sender().peerId(), message.recipient()
.peerId());
final boolean isSyncFromOldVersion = message.type() == Type.REQUEST_2;
final KeyMap640Keys keysMap = message.keyMap640Keys(0);
final NavigableMap<Number640, Data> retVal = new TreeMap<Number640, Data>();
for (Map.Entry<Number640, Collection<Number160>> entry : keysMap.keysMap().entrySet()) {
Data data = storageLayer.get(entry.getKey());
if(entry.getValue().size() != 1) {
continue;
}
if (data != null) {
// found, check if same
if (entry.getValue().iterator().next().equals(data.hash())) {
retVal.put(entry.getKey(), new Data().flag1());
LOG.debug("no sync required");
} else {
// get the checksums
// TODO: don't copy data, toBytes does a copy!
List<Checksum> checksums = RSync.checksums(data.toBytes(), blockSize);
ByteBuf abuf = Unpooled.buffer();
ByteBuf dataBuffer = SyncUtils.encodeChecksum(checksums, entry.getKey().versionKey(), data.hash(), abuf);
//here we can release this buffer as encodeChecksum calls retain
//abuf.release();
retVal.put(entry.getKey(), new Data(dataBuffer));
LOG.debug("sync required hash = {}", data.hash());
}
} else {
if(isSyncFromOldVersion) {
//TODO: the client could send us his history to figure out what the latest version in this history is
Entry<Number640, Data> latest = storageLayer.
get(entry.getKey().minVersionKey(), entry.getKey().maxVersionKey(), 1, false).lastEntry();
// TODO: don't copy data, toBytes does a copy!
List<Checksum> checksums = RSync.checksums(latest.getValue().toBytes(), blockSize);
ByteBuf abuf = Unpooled.buffer();
ByteBuf dataBuffer = SyncUtils.encodeChecksum(checksums, latest.getKey().versionKey(),
latest.getValue().hash(), abuf);
//here we can release this buffer as encodeChecksum calls retain
//abuf.release();
retVal.put(entry.getKey(), new Data(dataBuffer));
LOG.debug("sync required for version");
} else {
// not found
retVal.put(entry.getKey(), new Data().flag2());
LOG.debug("copy required, not found on this peer {}", entry.getKey());
}
}
}
responseMessage.setDataMap(new DataMap(retVal));
responder.response(responseMessage);
}
/**
* Handles the sync message by putting the changed part of data into a hash table. This is an RPC.
*
* @param message
* The message from a responsible peer
* @param responseMessage
* The response message to a responsible peer
* @return The response message
* @throws IOException
* @throws ClassNotFoundException
*/
private void handleSync(final Message message, final Message responseMessage, Responder responder) {
LOG.debug("Sync received: got from {} -> I'm {}", message.sender().peerId(), message.recipient()
.peerId());
final DataMap dataMap = message.dataMap(0);
final PublicKey publicKey = message.publicKey(0);
final List<Number640> retVal = new ArrayList<Number640>(dataMap.size());
for (Map.Entry<Number640, Data> entry : dataMap.dataMap().entrySet()) {
if (entry.getValue().isFlag2()) {
LOG.debug("remove entry {}", entry.getKey());
Pair<Data, Enum<?>> result = storageLayer.remove(entry.getKey(), publicKey, false);
if (replicationListener != null && result.element1() == PutStatus.OK) {
replicationListener.dataRemoved(entry.getKey().locationKey());
}
} else if (entry.getValue().length() > 0) {
if (entry.getValue().isFlag1()) {
// diff
LOG.debug("handle diff {}", entry.getKey());
final ByteBuf buf = entry.getValue().buffer();
Number160 versionKey = SyncUtils.decodeHeader(buf);
Number160 hash = SyncUtils.decodeHeader(buf);
List<Instruction> instructions = SyncUtils.decodeInstructions(buf);
Data dataOld = storageLayer.get(new Number640(entry.getKey().locationAndDomainAndContentKey(), versionKey));
if (dataOld == null || !dataOld.hash().equals(hash)) {
continue;
}
// TODO: don't copy data, toBytes does a copy!
ByteBuf reconstructedValue = RSync.reconstruct(dataOld.toBytes(), instructions, blockSize);
//TODO: domain protection?, make the flags configurable
Enum<?> status = storageLayer.put(entry.getKey(), new Data(reconstructedValue), publicKey, false, false, false);
if (status == PutStatus.OK) {
retVal.add(entry.getKey());
if (replicationListener != null) {
replicationListener.dataInserted(
entry.getKey().locationKey());
}
}
} else {
// copy
LOG.debug("handle copy {}", entry.getKey());
//TODO: domain protection?, make the flags configurable
Enum<?> status = storageLayer.put(entry.getKey(), entry.getValue(),
message.publicKey(0), false, false, false);
if (status == PutStatus.OK) {
retVal.add(entry.getKey());
if (replicationListener != null) {
replicationListener.dataInserted(
entry.getKey().locationKey());
}
}
}
}
}
responseMessage.keyCollection(new KeyCollection(retVal));
responder.response(responseMessage);
}
}