com.badlogic.gdx.utils.PerformanceCounter.java Source code

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Here is the source code for com.badlogic.gdx.utils.PerformanceCounter.java

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/*******************************************************************************
 * Copyright 2011 See AUTHORS file.
 * 
 * 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 com.badlogic.gdx.utils;

import com.badlogic.gdx.Gdx;
import com.badlogic.gdx.math.FloatCounter;
import com.badlogic.gdx.math.WindowedMean;

/** Class to keep track of the time and load (percentage of total time) a specific task takes. Call {@link #start()} just before
 * starting the task and {@link #stop()} right after. You can do this multiple times if required. Every render or update call
 * {@link #tick()} to update the values. The {@link #time} {@link FloatCounter} provides access to the minimum, maximum, average,
 * total and current time the task takes. Likewise for the {@link #load} value, which is the percentage of the total time.
 * @author xoppa */
public class PerformanceCounter {
    private final static float nano2seconds = 1f / 1000000000.0f;
    private long startTime = 0L;
    private long lastTick = 0L;

    /** The time value of this counter */
    public final FloatCounter time;
    /** The load value of this counter */
    public final FloatCounter load;
    /** The name of this counter */
    public final String name;
    /** The current value, you can manually increase this using your own timing mechanism if needed, if you do so, you also need to
     * update {@link #valid}. */
    public float current = 0f;
    /** Flag to indicate that the current value is valid, you need to set this to true if using your own timing mechanism */
    public boolean valid = false;

    public PerformanceCounter(final String name) {
        this(name, 5);
    }

    public PerformanceCounter(final String name, final int windowSize) {
        this.name = name;
        this.time = new FloatCounter(windowSize);
        this.load = new FloatCounter(1);
    }

    /** Updates the time and load counters and resets the time. Call {@link #start()} to begin a new count. The values are only
     * valid after at least two calls to this method. */
    public void tick() {
        final long t = TimeUtils.nanoTime();
        if (lastTick > 0L)
            tick((t - lastTick) * nano2seconds);
        lastTick = t;
    }

    /** Updates the time and load counters and resets the time. Call {@link #start()} to begin a new count.
     * @param delta The time since the last call to this method */
    public void tick(final float delta) {
        if (!valid) {
            Gdx.app.error("PerformanceCounter", "Invalid data, check if you called PerformanceCounter#stop()");
            return;
        }

        time.put(current);

        final float currentLoad = delta == 0f ? 0f : current / delta;
        load.put((delta > 1f) ? currentLoad : delta * currentLoad + (1f - delta) * load.latest);

        current = 0f;
        valid = false;
    }

    /** Start counting, call this method just before performing the task you want to keep track of. Call {@link #stop()} when done. */
    public void start() {
        startTime = TimeUtils.nanoTime();
        valid = false;
    }

    /** Stop counting, call this method right after you performed the task you want to keep track of. Call {@link #start()} again
     * when you perform more of that task. */
    public void stop() {
        if (startTime > 0L) {
            current += (TimeUtils.nanoTime() - startTime) * nano2seconds;
            startTime = 0L;
            valid = true;
        }
    }

    /** Resets this performance counter to its defaults values. */
    public void reset() {
        time.reset();
        load.reset();
        startTime = 0L;
        lastTick = 0L;
        current = 0f;
        valid = false;
    }

    /** {@inheritDoc} */
    @Override
    public String toString() {
        final StringBuilder sb = new StringBuilder();
        return toString(sb).toString();
    }

    /** Creates a string in the form of "name [time: value, load: value]" */
    public StringBuilder toString(final StringBuilder sb) {
        sb.append(name).append(": [time: ").append(time.value).append(", load: ").append(load.value).append("]");
        return sb;
    }
}