edu.umass.cs.gigapaxos.paxospackets.StatePacket.java Source code

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Here is the source code for edu.umass.cs.gigapaxos.paxospackets.StatePacket.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.paxospackets;

import edu.umass.cs.gigapaxos.paxosutil.Ballot;
import edu.umass.cs.gigapaxos.paxosutil.SlotBallotState;
import edu.umass.cs.utils.Util;

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

/**
 * @author arun
 *
 */
@SuppressWarnings("javadoc")
public final class StatePacket extends PaxosPacket {

    /**
     * Ballot in which the request at the checkpointed slot was committed.
     */
    public final Ballot ballot;
    /**
     * Slot number of the request immediately after executing which the checkpoint was taken.
     */
    public final int slotNumber;
    /**
     * The checkpoint state encoded as a string.
     */
    public final String state;
    /*
     * Whether the checkpoint is large. If so, checkpoint/restore or remote
     * checkpoint transfers will use the file system instead of memory.
     */
    public final boolean isLargeCheckpoint;

    public StatePacket(Ballot b, int slotNumber, String state) {
        this(b, slotNumber, state, false);
    }

    private StatePacket(Ballot b, int slotNumber, String state, boolean isLargeCheckpoint) {
        super((PaxosPacket) null);
        this.ballot = b;
        this.slotNumber = slotNumber;
        this.state = state;
        this.packetType = PaxosPacketType.CHECKPOINT_STATE;
        this.isLargeCheckpoint = isLargeCheckpoint;
    }

    public StatePacket(JSONObject json) throws JSONException {
        super(json);
        assert (PaxosPacket.getPaxosPacketType(json) == PaxosPacketType.CHECKPOINT_STATE);
        this.packetType = PaxosPacketType.CHECKPOINT_STATE;
        this.slotNumber = json.getInt(PaxosPacket.Keys.S.toString());
        this.ballot = new Ballot(json.getString(PaxosPacket.NodeIDKeys.B.toString()));
        this.state = json.getString(PaxosPacket.Keys.STATE.toString());
        this.isLargeCheckpoint = json.optBoolean(PaxosPacket.Keys.BIG_CP.toString());
    }

    @Override
    public JSONObject toJSONObjectImpl() throws JSONException {
        JSONObject json = new JSONObject();
        json.put(PaxosPacket.Keys.S.toString(), this.slotNumber);
        json.put(PaxosPacket.NodeIDKeys.B.toString(), this.ballot.ballotNumber + ":" + this.ballot.coordinatorID);
        json.put(PaxosPacket.Keys.STATE.toString(), this.state);
        json.put(PaxosPacket.Keys.BIG_CP.toString(), this.isLargeCheckpoint);
        return json;
    }

    public static StatePacket getStatePacket(SlotBallotState sbs) {
        return new StatePacket(new Ballot(sbs.ballotnum, sbs.coordinator), sbs.slot, sbs.state);
    }

    @Override
    protected String getSummaryString() {
        return ballot + ", " + slotNumber + ", [" + Util.truncate(state, 16, 16) + "]";
    }
}