1 files changed, 71 insertions, 0 deletions
diff --git a/mobile/android/geckoview/src/main/java/org/mozilla/gecko/gfx/PanningPerfAPI.java b/mobile/android/geckoview/src/main/java/org/mozilla/gecko/gfx/PanningPerfAPI.java
new file mode 100644
index 0000000000..b8ceb74f0b
--- /dev/null
+++ b/mobile/android/geckoview/src/main/java/org/mozilla/gecko/gfx/PanningPerfAPI.java
@@ -0,0 +1,71 @@
+/* -*- Mode: Java; c-basic-offset: 4; tab-width: 20; indent-tabs-mode: nil; -*-
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package org.mozilla.gecko.gfx;
+
+import android.os.SystemClock;
+import android.util.Log;
+import java.util.ArrayList;
+import java.util.List;
+import org.mozilla.gecko.annotation.RobocopTarget;
+
+public final 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 mRecordingFrames;
+  private static List<Long> mFrameTimes;
+  private static long mFrameStartTime;
+
+  private static void initialiseRecordingArrays() {
+    if (mFrameTimes == null) {
+      mFrameTimes = new ArrayList<Long>(EXPECTED_FRAME_COUNT);
+    } else {
+      mFrameTimes.clear();
+    }
+  }
+
+  @RobocopTarget
+  public static void startFrameTimeRecording() {
+    if (mRecordingFrames) {
+      Log.e(LOGTAG, "Error: startFrameTimeRecording() called while already recording!");
+      return;
+    }
+    mRecordingFrames = true;
+    initialiseRecordingArrays();
+    mFrameStartTime = SystemClock.uptimeMillis();
+  }
+
+  @RobocopTarget
+  public static List<Long> stopFrameTimeRecording() {
+    if (!mRecordingFrames) {
+      Log.e(LOGTAG, "Error: stopFrameTimeRecording() called when not recording!");
+      return null;
+    }
+    mRecordingFrames = false;
+    return mFrameTimes;
+  }
+
+  public static void recordFrameTime() {
+    // this will be called often, so try to make it as quick as possible
+    if (mRecordingFrames) {
+      mFrameTimes.add(SystemClock.uptimeMillis() - mFrameStartTime);
+    }
+  }
+
+  @RobocopTarget
+  public static void startCheckerboardRecording() {
+    throw new UnsupportedOperationException();
+  }
+
+  @RobocopTarget
+  public static List<Float> stopCheckerboardRecording() {
+    throw new UnsupportedOperationException();
+  }
+}