com.alipay.sofa.jraft.test.atomic.server.AtomicStateMachine Maven / Gradle / Ivy
/*
* 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 com.alipay.sofa.jraft.test.atomic.server;
import java.io.File;
import java.io.IOException;
import java.nio.ByteBuffer;
import java.util.HashMap;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.atomic.AtomicLong;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import com.alipay.sofa.jraft.Closure;
import com.alipay.sofa.jraft.Iterator;
import com.alipay.sofa.jraft.Status;
import com.alipay.sofa.jraft.core.StateMachineAdapter;
import com.alipay.sofa.jraft.error.RaftError;
import com.alipay.sofa.jraft.error.RaftException;
import com.alipay.sofa.jraft.storage.snapshot.SnapshotReader;
import com.alipay.sofa.jraft.storage.snapshot.SnapshotWriter;
import com.alipay.sofa.jraft.test.atomic.KeyNotFoundException;
import com.alipay.sofa.jraft.test.atomic.command.BaseRequestCommand;
import com.alipay.sofa.jraft.test.atomic.command.BooleanCommand;
import com.alipay.sofa.jraft.test.atomic.command.CommandCodec;
import com.alipay.sofa.jraft.test.atomic.command.CompareAndSetCommand;
import com.alipay.sofa.jraft.test.atomic.command.GetCommand;
import com.alipay.sofa.jraft.test.atomic.command.IncrementAndGetCommand;
import com.alipay.sofa.jraft.test.atomic.command.SetCommand;
import com.alipay.sofa.jraft.test.atomic.command.ValueCommand;
import com.alipay.sofa.jraft.util.Utils;
/**
* Atomic state machine
* @author boyan ([email protected])
*
* 2018-Apr-25 1:47:50 PM
*/
public class AtomicStateMachine extends StateMachineAdapter {
private static final Logger LOG = LoggerFactory.getLogger(AtomicStateMachine.class);
//
private final ConcurrentHashMap counters = new ConcurrentHashMap<>();
/**
* leader term
*/
private final AtomicLong leaderTerm = new AtomicLong(-1);
public boolean isLeader() {
return this.leaderTerm.get() > 0;
}
@Override
public void onApply(Iterator iter) {
while (iter.hasNext()) {
final Closure done = iter.done();
CommandType cmdType;
final ByteBuffer data = iter.getData();
Object cmd = null;
LeaderTaskClosure closure = null;
if (done != null) {
closure = (LeaderTaskClosure) done;
cmdType = closure.getCmdType();
cmd = closure.getCmd();
} else {
final byte b = data.get();
final byte[] cmdBytes = new byte[data.remaining()];
data.get(cmdBytes);
cmdType = CommandType.parseByte(b);
switch (cmdType) {
case GET:
cmd = CommandCodec.decodeCommand(cmdBytes, GetCommand.class);
break;
case SET:
cmd = CommandCodec.decodeCommand(cmdBytes, SetCommand.class);
break;
case CAS:
cmd = CommandCodec.decodeCommand(cmdBytes, CompareAndSetCommand.class);
break;
case INC:
cmd = CommandCodec.decodeCommand(cmdBytes, IncrementAndGetCommand.class);
break;
}
}
final String key = ((BaseRequestCommand) cmd).getKey();
final AtomicLong counter = getCounter(key, true);
Object response = null;
switch (cmdType) {
case GET:
response = new ValueCommand(counter.get());
break;
case SET:
final SetCommand setCmd = (SetCommand) cmd;
counter.set(setCmd.getValue());
response = new BooleanCommand(true);
break;
case CAS:
final CompareAndSetCommand casCmd = (CompareAndSetCommand) cmd;
response = new BooleanCommand(counter.compareAndSet(casCmd.getExpect(), casCmd.getNewValue()));
break;
case INC:
final IncrementAndGetCommand incCmd = (IncrementAndGetCommand) cmd;
final long ret = counter.addAndGet(incCmd.getDetal());
response = new ValueCommand(ret);
break;
}
if (closure != null) {
closure.setResponse(response);
closure.run(Status.OK());
}
iter.next();
}
}
private AtomicLong getCounter(String key, boolean createWhenNotFound) {
AtomicLong ret = this.counters.get(key);
if (ret == null && createWhenNotFound) {
ret = new AtomicLong(0);
final AtomicLong old = this.counters.putIfAbsent(key, ret);
if (old != null) {
ret = old;
}
}
return ret;
}
public long getValue(String key) throws KeyNotFoundException {
final AtomicLong counter = getCounter(key, false);
if (counter == null) {
throw new KeyNotFoundException("Key `" + key + "` not found");
}
return counter.get();
}
@Override
public void onSnapshotSave(final SnapshotWriter writer, final Closure done) {
final Map values = new HashMap<>();
for (final Map.Entry entry : this.counters.entrySet()) {
values.put(entry.getKey(), entry.getValue().get());
}
Utils.runInThread(() -> {
final AtomicSnapshotFile snapshot = new AtomicSnapshotFile(writer.getPath() + File.separator + "data");
if (snapshot.save(values)) {
if (writer.addFile("data")) {
done.run(Status.OK());
} else {
done.run(new Status(RaftError.EIO, "Fail to add file to writer"));
}
} else {
done.run(new Status(RaftError.EIO, "Fail to save counter snapshot %s", snapshot.getPath()));
}
});
}
@Override
public void onError(RaftException e) {
LOG.error("Raft error: %s", e, e);
}
@Override
public boolean onSnapshotLoad(SnapshotReader reader) {
if (isLeader()) {
LOG.warn("Leader is not supposed to load snapshot");
return false;
}
if (reader.getFileMeta("data") == null) {
LOG.error("Fail to find data file in {}", reader.getPath());
return false;
}
final AtomicSnapshotFile snapshot = new AtomicSnapshotFile(reader.getPath() + File.separator + "data");
try {
final Map values = snapshot.load();
this.counters.clear();
if (values != null) {
for (final Map.Entry entry : values.entrySet()) {
this.counters.put(entry.getKey(), new AtomicLong(entry.getValue()));
}
}
return true;
} catch (final IOException e) {
LOG.error("Fail to load snapshot from {}", snapshot.getPath());
return false;
}
}
@Override
public void onLeaderStart(long term) {
this.leaderTerm.set(term);
super.onLeaderStart(term);
}
@Override
public void onLeaderStop(Status status) {
this.leaderTerm.set(-1);
super.onLeaderStop(status);
}
}