Stopwatch.java

/*
 * Copyright (C) 2011 The Android Open Source Project
 *
 * 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.
 */

package me.xiaopan.sketch.util;

import java.text.DecimalFormat;

import me.xiaopan.sketch.SLogType;
import me.xiaopan.sketch.SLog;

public class Stopwatch {
    private static Stopwatch instance;
    private long startTime;
    private long lastTime;
    private long decodeCount;
    private long useTimeCount;
    private StringBuilder builder;
    private String logName;
    private DecimalFormat decimalFormat = new DecimalFormat("#.##");

    public static Stopwatch with() {
        if (instance == null) {
            synchronized (Stopwatch.class) {
                if (instance == null) {
                    instance = new Stopwatch();
                }
            }
        }
        return instance;
    }

    public void start(String logName) {
        this.logName = logName;
        startTime = System.currentTimeMillis();
        lastTime = startTime;
        builder = new StringBuilder();
    }

    public void record(String nodeName) {
        if (builder != null) {
            long currentTime = System.currentTimeMillis();
            long useTime = currentTime - lastTime;
            lastTime = currentTime;

            if (builder.length() > 0) {
                builder.append(", ");
            }
            builder.append(nodeName).append(":").append(useTime).append("ms");
        }
    }

    public void print(String requestId) {
        if (builder != null) {
            long totalTime = System.currentTimeMillis() - startTime;

            if (builder.length() > 0) {
                builder.append(". ");
            }

            builder.append("useTime=").append(totalTime).append("ms");

            if ((Long.MAX_VALUE - decodeCount) < 1 || (Long.MAX_VALUE - useTimeCount) < totalTime) {
                decodeCount = 0;
                useTimeCount = 0;
            }
            decodeCount++;
            useTimeCount += totalTime;

            SLog.d(SLogType.TIME, logName, "%s, average=%sms. %s",
                    builder.toString(), decimalFormat.format((double) useTimeCount / decodeCount), requestId);
            builder = null;
        }
    }
}