org.apache.hadoop.mapreduce.counters.GenericCounter.java Source code

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Here is the source code for org.apache.hadoop.mapreduce.counters.GenericCounter.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.hadoop.mapreduce.counters;

import java.io.DataInput;
import java.io.DataOutput;
import java.io.IOException;

import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.io.WritableUtils;
import org.apache.hadoop.mapreduce.Counter;
import org.apache.hadoop.util.StringInterner;

/**
 * A generic counter implementation
 */
@InterfaceAudience.Private
public class GenericCounter extends AbstractCounter {

    private String name;
    private String displayName;
    private long value = 0;

    public GenericCounter() {
        // mostly for readFields
    }

    public GenericCounter(String name, String displayName) {
        this.name = name;
        this.displayName = displayName;
    }

    public GenericCounter(String name, String displayName, long value) {
        this.name = name;
        this.displayName = displayName;
        this.value = value;
    }

    @Override
    @Deprecated
    public synchronized void setDisplayName(String displayName) {
        this.displayName = displayName;
    }

    @Override
    public synchronized void readFields(DataInput in) throws IOException {
        name = StringInterner.weakIntern(Text.readString(in));
        displayName = in.readBoolean() ? StringInterner.weakIntern(Text.readString(in)) : name;
        value = WritableUtils.readVLong(in);
    }

    /**
     * GenericCounter ::= keyName isDistinctDisplayName [displayName] value
     */
    @Override
    public synchronized void write(DataOutput out) throws IOException {
        Text.writeString(out, name);
        boolean distinctDisplayName = !name.equals(displayName);
        out.writeBoolean(distinctDisplayName);
        if (distinctDisplayName) {
            Text.writeString(out, displayName);
        }
        WritableUtils.writeVLong(out, value);
    }

    @Override
    public synchronized String getName() {
        return name;
    }

    @Override
    public synchronized String getDisplayName() {
        return displayName;
    }

    @Override
    public synchronized long getValue() {
        return value;
    }

    @Override
    public synchronized void setValue(long value) {
        this.value = value;
    }

    @Override
    public synchronized void increment(long incr) {
        value += incr;
    }

    @Override
    public Counter getUnderlyingCounter() {
        return this;
    }
}