The Tor Browser: mobile/android/base/gfx/PanningPerfAPI.java@b8a032363ba2

Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6

     1 /* -*- Mode: Java; c-basic-offset: 4; tab-width: 20; indent-tabs-mode: nil; -*-

     2  * This Source Code Form is subject to the terms of the Mozilla Public

     3  * License, v. 2.0. If a copy of the MPL was not distributed with this

     4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

     6 package org.mozilla.gecko.gfx;

     8 import org.mozilla.gecko.mozglue.RobocopTarget;

    10 import android.os.SystemClock;

    11 import android.util.Log;

    13 import java.util.ArrayList;

    14 import java.util.List;

    16 public class PanningPerfAPI {

    17     private static final String LOGTAG = "GeckoPanningPerfAPI";

    19     // make this large enough to avoid having to resize the frame time

    20     // list, as that may be expensive and impact the thing we're trying

    21     // to measure.

    22     private static final int EXPECTED_FRAME_COUNT = 2048;

    24     private static boolean mRecordingFrames = false;

    25     private static List<Long> mFrameTimes;

    26     private static long mFrameStartTime;

    28     private static boolean mRecordingCheckerboard = false;

    29     private static List<Float> mCheckerboardAmounts;

    30     private static long mCheckerboardStartTime;

    32     private static void initialiseRecordingArrays() {

    33         if (mFrameTimes == null) {

    34             mFrameTimes = new ArrayList<Long>(EXPECTED_FRAME_COUNT);

    35         } else {

    36             mFrameTimes.clear();

    37         }

    38         if (mCheckerboardAmounts == null) {

    39             mCheckerboardAmounts = new ArrayList<Float>(EXPECTED_FRAME_COUNT);

    40         } else {

    41             mCheckerboardAmounts.clear();

    42         }

    43     }

    45     @RobocopTarget

    46     public static void startFrameTimeRecording() {

    47         if (mRecordingFrames || mRecordingCheckerboard) {

    48             Log.e(LOGTAG, "Error: startFrameTimeRecording() called while already recording!");

    49             return;

    50         }

    51         mRecordingFrames = true;

    52         initialiseRecordingArrays();

    53         mFrameStartTime = SystemClock.uptimeMillis();

    54     }

    56     @RobocopTarget

    57     public static List<Long> stopFrameTimeRecording() {

    58         if (!mRecordingFrames) {

    59             Log.e(LOGTAG, "Error: stopFrameTimeRecording() called when not recording!");

    60             return null;

    61         }

    62         mRecordingFrames = false;

    63         return mFrameTimes;

    64     }

    66     public static void recordFrameTime() {

    67         // this will be called often, so try to make it as quick as possible

    68         if (mRecordingFrames) {

    69             mFrameTimes.add(SystemClock.uptimeMillis() - mFrameStartTime);

    70         }

    71     }

    73     public static boolean isRecordingCheckerboard() {

    74         return mRecordingCheckerboard;

    75     }

    77     @RobocopTarget

    78     public static void startCheckerboardRecording() {

    79         if (mRecordingCheckerboard || mRecordingFrames) {

    80             Log.e(LOGTAG, "Error: startCheckerboardRecording() called while already recording!");

    81             return;

    82         }

    83         mRecordingCheckerboard = true;

    84         initialiseRecordingArrays();

    85         mCheckerboardStartTime = SystemClock.uptimeMillis();

    86     }

    88     @RobocopTarget

    89     public static List<Float> stopCheckerboardRecording() {

    90         if (!mRecordingCheckerboard) {

    91             Log.e(LOGTAG, "Error: stopCheckerboardRecording() called when not recording!");

    92             return null;

    93         }

    94         mRecordingCheckerboard = false;

    96         // We take the number of values in mCheckerboardAmounts here, as there's

    97         // the possibility that this function is called while recordCheckerboard

    98         // is still executing. As values are added to this list last, we use

    99         // this number as the canonical number of recordings.

   100         int values = mCheckerboardAmounts.size();

   102         // The score will be the sum of all the values in mCheckerboardAmounts,

   103         // so weight the checkerboard values by time so that frame-rate and

   104         // run-length don't affect score.

   105         long lastTime = 0;

   106         float totalTime = mFrameTimes.get(values - 1);

   107         for (int i = 0; i < values; i++) {

   108             long elapsedTime = mFrameTimes.get(i) - lastTime;

   109             mCheckerboardAmounts.set(i, mCheckerboardAmounts.get(i) * elapsedTime / totalTime);

   110             lastTime += elapsedTime;

   111         }

   113         return mCheckerboardAmounts;

   114     }

   116     public static void recordCheckerboard(float amount) {

   117         // this will be called often, so try to make it as quick as possible

   118         if (mRecordingCheckerboard) {

   119             mFrameTimes.add(SystemClock.uptimeMillis() - mCheckerboardStartTime);

   120             mCheckerboardAmounts.add(amount);

   121         }

   122     }

   123 }

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