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

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Here is the source code for edu.umass.cs.gigapaxos.paxospackets.PreparePacket.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 org.json.JSONException;
import org.json.JSONObject;

import edu.umass.cs.gigapaxos.paxosutil.Ballot;

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

    /**
     * Ballot in the PREPARE message.
     */
    public final Ballot ballot;
    /**
     * First undecided slot at coordinator. Only used as an optimization, not
     * for safety.
     */
    public final int firstUndecidedSlot;

    // non-final because AbstractPaxosLogger.rollForward needs to set it
    private boolean recovery;

    public PreparePacket(Ballot b) {
        this(b, -1);
    }

    public PreparePacket(Ballot b, int firstUndecidedSlot) {
        super((PaxosPacket) null);
        this.ballot = b;
        this.packetType = PaxosPacketType.PREPARE;
        this.firstUndecidedSlot = firstUndecidedSlot;
        this.recovery = false;
    }

    public PreparePacket(int coordinatorID, int receiverID, Ballot ballot, int slotNumber) {
        super((PaxosPacket) null);
        this.ballot = ballot;
        this.firstUndecidedSlot = slotNumber;
        this.packetType = PaxosPacketType.PREPARE;
        this.recovery = false;
    }

    public PreparePacket(JSONObject json) throws JSONException {
        super(json);
        assert (PaxosPacket.getPaxosPacketType(json) == PaxosPacketType.PREPARE);
        this.packetType = PaxosPacket.getPaxosPacketType(json);
        this.ballot = new Ballot(json.getString(PaxosPacket.NodeIDKeys.B.toString()));
        this.firstUndecidedSlot = json.getInt(PaxosPacket.Keys.PREP_MIN.toString());
        this.recovery = json.optBoolean(PaxosPacket.Keys.RCVRY.toString());
    }

    @Override
    public JSONObject toJSONObjectImpl() throws JSONException {
        JSONObject json = new JSONObject();
        json.put(PaxosPacket.NodeIDKeys.B.toString(), ballot.toString());
        json.put(PaxosPacket.Keys.PREP_MIN.toString(), firstUndecidedSlot);
        if (this.recovery)
            json.put(PaxosPacket.Keys.RCVRY.toString(), recovery);

        return json;
    }

    public boolean isRecovery() {
        return this.recovery;
    }

    public void setRecovery() {
        this.recovery = true;
    }

    @Override
    protected String getSummaryString() {
        return ballot + "(" + this.firstUndecidedSlot + ")";
    }
}