edu.umass.cs.gigapaxos.paxosutil.PaxosPacketDemultiplexer.java Source code

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Here is the source code for edu.umass.cs.gigapaxos.paxosutil.PaxosPacketDemultiplexer.java

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/* Copyright (c) 2015 University of Massachusetts
 * 
 * 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.
 * 
 * Initial developer(s): V. Arun */
package edu.umass.cs.gigapaxos.paxosutil;

import org.json.JSONException;
import org.json.JSONObject;

import edu.umass.cs.gigapaxos.PaxosManager;
import edu.umass.cs.gigapaxos.PaxosConfig.PC;
import edu.umass.cs.gigapaxos.paxospackets.AcceptPacket;
import edu.umass.cs.gigapaxos.paxospackets.AcceptReplyPacket;
import edu.umass.cs.gigapaxos.paxospackets.BatchedAccept;
import edu.umass.cs.gigapaxos.paxospackets.BatchedAcceptReply;
import edu.umass.cs.gigapaxos.paxospackets.BatchedCommit;
import edu.umass.cs.gigapaxos.paxospackets.BatchedPaxosPacket;
import edu.umass.cs.gigapaxos.paxospackets.FailureDetectionPacket;
import edu.umass.cs.gigapaxos.paxospackets.FindReplicaGroupPacket;
import edu.umass.cs.gigapaxos.paxospackets.PValuePacket;
import edu.umass.cs.gigapaxos.paxospackets.PaxosPacket;
import edu.umass.cs.gigapaxos.paxospackets.PreparePacket;
import edu.umass.cs.gigapaxos.paxospackets.PrepareReplyPacket;
import edu.umass.cs.gigapaxos.paxospackets.ProposalPacket;
import edu.umass.cs.gigapaxos.paxospackets.RequestPacket;
import edu.umass.cs.gigapaxos.paxospackets.StatePacket;
import edu.umass.cs.gigapaxos.paxospackets.SyncDecisionsPacket;
import edu.umass.cs.nio.AbstractPacketDemultiplexer;
import edu.umass.cs.nio.interfaces.Stringifiable;
import edu.umass.cs.utils.Config;
import edu.umass.cs.utils.DelayProfiler;
import edu.umass.cs.utils.Util;

/**
 * @author V. Arun
 *         <p>
 *         Used to get NIO to send paxos packets to PaxosManager. This class has
 *         been merged into PaxosManager now and will be soon deprecated.
 */
public abstract class PaxosPacketDemultiplexer extends AbstractPacketDemultiplexer<JSONObject> {

    /**
     * @param json
     * @param unstringer
     * @return PaxosPacket parsed from JSON.
     * @throws JSONException
     */
    public static PaxosPacket toPaxosPacket(JSONObject json, Stringifiable<?> unstringer) throws JSONException {
        PaxosPacket.PaxosPacketType type = PaxosPacket.getPaxosPacketType(json);
        if (type == null)
            fatal(json);

        PaxosPacket paxosPacket = null;
        switch (type) {
        case REQUEST:
            paxosPacket = (new RequestPacket(json));
            break;
        case PROPOSAL:
            paxosPacket = (new ProposalPacket(json));
            break;
        case DECISION:
            paxosPacket = (new PValuePacket(json));
            break;
        case BATCHED_COMMIT:
            paxosPacket = (new BatchedCommit(json));
            break;
        case PREPARE:
            paxosPacket = (new PreparePacket(json));
            break;
        case PREPARE_REPLY:
            paxosPacket = (new PrepareReplyPacket(json));
            break;
        case ACCEPT:
            paxosPacket = (new AcceptPacket(json));
            break;
        case BATCHED_ACCEPT:
            paxosPacket = (new BatchedAccept(json));
            break;
        case BATCHED_PAXOS_PACKET:
            paxosPacket = (new BatchedPaxosPacket(json));
            break;
        case ACCEPT_REPLY:
            paxosPacket = (new AcceptReplyPacket(json));
            break;
        case BATCHED_ACCEPT_REPLY:
            long t = System.nanoTime();
            paxosPacket = (new BatchedAcceptReply(json));
            if (PaxosMessenger.INSTRUMENT_SERIALIZATION && Util.oneIn(100))
                DelayProfiler.updateDelayNano("batchedAcceptReplyPacketization", t,
                        ((BatchedAcceptReply) paxosPacket).size());
            break;
        case SYNC_DECISIONS_REQUEST:
            paxosPacket = (new SyncDecisionsPacket(json));
            break;
        case CHECKPOINT_STATE:
            paxosPacket = (new StatePacket(json));
            break;
        case FAILURE_DETECT:
            assert (unstringer != null);
            paxosPacket = new FailureDetectionPacket<>(json, unstringer);
            break;
        case FIND_REPLICA_GROUP:
            paxosPacket = new FindReplicaGroupPacket(json);
            break;
        default:
            fatal(json);
        }
        assert (paxosPacket != null) : json;
        return paxosPacket;
    }

    /**
     * @param json
     * @return PaxosPacket from {@code json}
     * @throws JSONException 
     */
    public static PaxosPacket toPaxosPacket(JSONObject json) throws JSONException {
        return toPaxosPacket(json, null);
    }

    private static final double THROTTLE_SLEEP = Config.getGlobalDouble(PC.THROTTLE_SLEEP);

    /**
     * 
     */
    public static void throttleExcessiveLoad() {
        try {
            Thread.sleep(THROTTLE_SLEEP >= 1 ? (long) THROTTLE_SLEEP : (Math.random() < THROTTLE_SLEEP ? 1 : 0));
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }

    private static void fatal(Object json) {
        PaxosManager.getLogger().severe(PaxosPacketDemultiplexer.class.getSimpleName() + " received " + json);
        throw new RuntimeException("PaxosPacketDemultiplexer recieved unrecognized paxos packet type");
    }
}