com.dangdang.ddframe.rdb.sharding.metrics.MetricsContext.java Source code

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Here is the source code for com.dangdang.ddframe.rdb.sharding.metrics.MetricsContext.java

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/**
 * Copyright 1999-2015 dangdang.com.
 * <p>
 * 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.
 * </p>
 */

package com.dangdang.ddframe.rdb.sharding.metrics;

import java.util.concurrent.TimeUnit;

import org.slf4j.LoggerFactory;

import com.codahale.metrics.MetricRegistry;
import com.codahale.metrics.Slf4jReporter;
import com.codahale.metrics.Slf4jReporter.LoggingLevel;
import com.codahale.metrics.Timer.Context;
import com.google.common.base.Joiner;
import com.google.common.base.Optional;

/**
 * ?.
 * 
 * @author gaohongtao
 */
public final class MetricsContext {

    private static final ThreadLocal<MetricsContext> CONTEXT = new ThreadLocal<>();

    private final Optional<MetricRegistry> metricRegistry;

    public MetricsContext(final boolean enable, final long period, final String packageName) {
        if (enable) {
            metricRegistry = Optional.of(new MetricRegistry());
            Slf4jReporter reporter = Slf4jReporter.forRegistry(metricRegistry.get())
                    .outputTo(LoggerFactory.getLogger(packageName)).convertRatesTo(TimeUnit.SECONDS)
                    .convertDurationsTo(TimeUnit.MILLISECONDS).withLoggingLevel(LoggingLevel.DEBUG).build();
            reporter.start(period, TimeUnit.SECONDS);
        } else {
            metricRegistry = Optional.absent();
        }
    }

    /**
     * ?.
     */
    public void register() {
        if (metricRegistry.isPresent() && !this.equals(CONTEXT.get())) {
            CONTEXT.set(this);
        }
    }

    /**
     * .
     *
     * @param name ???
     * 
     * @return 
     */
    public static Context start(final String... name) {
        return null == CONTEXT.get() ? null
                : CONTEXT.get().metricRegistry.get().timer(MetricRegistry.name(Joiner.on("-").join(name))).time();
    }

    /**
     * ?.
     *
     * @param context 
     */
    public static void stop(final Context context) {
        if (null != context) {
            context.stop();
        }
    }
}