com.carrotgarden.nexus.aws.s3.publish.metrics.WatchQueueGuage.java Source code

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Here is the source code for com.carrotgarden.nexus.aws.s3.publish.metrics.WatchQueueGuage.java

Source

/**
 * Copyright (C) 2010-2012 Andrei Pozolotin <Andrei.Pozolotin@gmail.com>
 *
 * All rights reserved. Licensed under the OSI BSD License.
 *
 * http://www.opensource.org/licenses/bsd-license.php
 */
package com.carrotgarden.nexus.aws.s3.publish.metrics;

import org.apache.commons.collections.buffer.CircularFifoBuffer;

import com.yammer.metrics.core.Gauge;

/** inverse gauge */
public class WatchQueueGuage extends Gauge<String> implements Clearable {

    private final int size;
    private final CircularFifoBuffer buffer;

    public void add(final Object item) {
        buffer.add(item);
    }

    public WatchQueueGuage() {
        this(20);
    }

    public WatchQueueGuage(final int size) {
        this.size = size;
        this.buffer = new CircularFifoBuffer(size);
    }

    @Override
    public void clear() {
        buffer.clear();
    }

    @Override
    public String value() {

        final StringBuilder text = new StringBuilder(128);

        if (buffer.isEmpty()) {
            text.append("empty queue");
        } else {
            text.append("last ");
            text.append(size);
            text.append("\n");
            for (final Object item : buffer) {
                text.append(item);
                text.append("\n");
            }
        }

        return text.toString();

    }

}