/* -*- Mode: Java; c-basic-offset: 4; tab-width: 20; indent-tabs-mode: nil; -*-
 * ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (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.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is Mozilla Android code.
 *
 * The Initial Developer of the Original Code is Mozilla Foundation.
 * Portions created by the Initial Developer are Copyright (C) 2011
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *   Kartikaya Gupta <kgupta@mozilla.com>
 *
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 * either the GNU General Public License Version 2 or later (the "GPL"), or
 * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
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package org.mozilla.gecko.gfx;

import java.util.ArrayList;
import java.util.List;
import android.os.SystemClock;
import android.util.Log;

public class PanningPerfAPI {
    private static final String LOGTAG = "GeckoPanningPerfAPI";

    // make this large enough to avoid having to resize the frame time
    // list, as that may be expensive and impact the thing we're trying
    // to measure.
    private static final int EXPECTED_FRAME_COUNT = 2048;

    private static boolean mRecording = false;
    private static List<Long> mFrameTimes;
    private static long mStartTime;

    public static void startFrameTimeRecording() {
        if (mRecording) {
            Log.e(LOGTAG, "Error: startFrameTimeRecording() called while already recording!");
            return;
        }
        mRecording = true;
        if (mFrameTimes == null) {
            mFrameTimes = new ArrayList<Long>(EXPECTED_FRAME_COUNT);
        } else {
            mFrameTimes.clear();
        }
        mStartTime = SystemClock.uptimeMillis();
    }

    public static List<Long> stopFrameTimeRecording() {
        if (!mRecording) {
            Log.e(LOGTAG, "Error: stopFrameTimeRecording() called when not recording!");
            return null;
        }
        mRecording = false;
        return mFrameTimes;
    }

    public static void recordFrameTime() {
        // this will be called often, so try to make it as quick as possible
        if (mRecording) {
            mFrameTimes.add(SystemClock.uptimeMillis() - mStartTime);
        }
    }
}