org.apache.hama.bsp.Directive.java Source code

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Here is the source code for org.apache.hama.bsp.Directive.java

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/**
 * 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 org.apache.hama.bsp;

import java.io.DataInput;
import java.io.DataOutput;
import java.io.IOException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.io.Writable;
import org.apache.hadoop.io.WritableUtils;

/**
 * A generic directive from the {@link org.apache.hama.bsp.BSPMaster} to the
 * {@link org.apache.hama.bsp.GroomServer} to take some 'action'.
 */
public class Directive implements Writable {

    public static final Log LOG = LogFactory.getLog(Directive.class);

    private long timestamp;
    private Directive.Type type;
    private Map<String, String> groomServerPeers;
    private ArrayList<GroomServerAction> actionList;
    private GroomServerStatus status;

    public static enum Type {
        Request(1), Response(2);
        int t;

        Type(int t) {
            this.t = t;
        }

        public int value() {
            return this.t;
        }
    };

    public Directive() {
        this.timestamp = System.currentTimeMillis();
    }

    public Directive(Map<String, String> groomServerPeers, ArrayList<GroomServerAction> actionList) {
        this();
        this.type = Directive.Type.Request;
        this.groomServerPeers = groomServerPeers;
        this.actionList = actionList;
    }

    public Directive(GroomServerStatus status) {
        this();
        this.type = Directive.Type.Response;
        this.status = status;
    }

    public long getTimestamp() {
        return this.timestamp;
    }

    public Directive.Type getType() {
        return this.type;
    }

    public Map<String, String> getGroomServerPeers() {
        return this.groomServerPeers;
    }

    public ArrayList<GroomServerAction> getActionList() {
        return this.actionList;
    }

    public boolean addAction(GroomServerAction action) {
        if (!this.actionList.contains(action)) {
            this.actionList.add(action);
            return true;
        } else {
            return false;
        }
    }

    public GroomServerStatus getStatus() {
        return this.status;
    }

    public void write(DataOutput out) throws IOException {
        out.writeLong(this.timestamp);
        out.writeInt(this.type.value());
        if (getType().value() == Directive.Type.Request.value()) {
            if (this.actionList == null) {
                WritableUtils.writeVInt(out, 0);
            } else {
                WritableUtils.writeVInt(out, actionList.size());
                for (GroomServerAction action : this.actionList) {
                    WritableUtils.writeEnum(out, action.getActionType());
                    action.write(out);
                }
            }
            String[] groomServerNames = groomServerPeers.keySet().toArray(new String[0]);
            WritableUtils.writeCompressedStringArray(out, groomServerNames);

            List<String> groomServerAddresses = new ArrayList<String>(groomServerNames.length);
            for (String groomName : groomServerNames) {
                groomServerAddresses.add(groomServerPeers.get(groomName));
            }
            WritableUtils.writeCompressedStringArray(out, groomServerAddresses.toArray(new String[0]));
        } else if (getType().value() == Directive.Type.Response.value()) {
            this.status.write(out);
        } else {
            throw new IllegalStateException("Wrong directive type:" + getType());
        }

    }

    public void readFields(DataInput in) throws IOException {
        this.timestamp = in.readLong();
        int t = in.readInt();
        if (Directive.Type.Request.value() == t) {
            this.type = Directive.Type.Request;
            int length = WritableUtils.readVInt(in);
            if (length > 0) {
                this.actionList = new ArrayList<GroomServerAction>();
                for (int i = 0; i < length; ++i) {
                    GroomServerAction.ActionType actionType = WritableUtils.readEnum(in,
                            GroomServerAction.ActionType.class);
                    GroomServerAction action = GroomServerAction.createAction(actionType);
                    action.readFields(in);
                    actionList.add(action);
                }
            } else {
                this.actionList = null;
            }
            String[] groomServerNames = WritableUtils.readCompressedStringArray(in);
            String[] groomServerAddresses = WritableUtils.readCompressedStringArray(in);
            groomServerPeers = new HashMap<String, String>(groomServerNames.length);

            for (int i = 0; i < groomServerNames.length; i++) {
                groomServerPeers.put(groomServerNames[i], groomServerAddresses[i]);
            }
        } else if (Directive.Type.Response.value() == t) {
            this.type = Directive.Type.Response;
            this.status = new GroomServerStatus();
            this.status.readFields(in);
        } else {
            throw new IllegalStateException("Wrong directive type:" + t);
        }
    }
}