1 files changed, 107 insertions, 0 deletions
diff --git a/gfx/layers/CompositionRecorder.cpp b/gfx/layers/CompositionRecorder.cpp
new file mode 100644
index 0000000000..f668adcc02
--- /dev/null
+++ b/gfx/layers/CompositionRecorder.cpp
@@ -0,0 +1,107 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* 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/. */
+
+#include "CompositionRecorder.h"
+#include "gfxUtils.h"
+#include "mozilla/gfx/2D.h"
+#include "mozilla/gfx/gfxVars.h"
+#include "nsIInputStream.h"
+#include "nsIBinaryOutputStream.h"
+#include "nsIObjectOutputStream.h"
+#include "prtime.h"
+
+#include <ctime>
+#include <iomanip>
+#include "stdio.h"
+#ifdef XP_WIN
+#  include "direct.h"
+#else
+#  include <sys/types.h>
+#  include "sys/stat.h"
+#endif
+
+using namespace mozilla::gfx;
+
+namespace mozilla {
+namespace layers {
+
+CompositionRecorder::CompositionRecorder(TimeStamp aRecordingStart)
+    : mRecordingStart(aRecordingStart) {}
+
+void CompositionRecorder::RecordFrame(RecordedFrame* aFrame) {
+  mCollectedFrames.AppendElement(aFrame);
+}
+
+void CompositionRecorder::WriteCollectedFrames() {
+  // The directory has the format of
+  // "[LayersWindowRecordingPath]/windowrecording-[mRecordingStartTime as unix
+  // timestamp]". We need mRecordingStart as a unix timestamp here because we
+  // want the consumer of these files to be able to compute an absolute
+  // timestamp of each screenshot, so that we can align screenshots with timed
+  // data from other sources, such as Gecko profiler information. The time of
+  // each screenshot is part of the screenshot's filename, expressed as
+  // milliseconds *relative to mRecordingStart*. We want to compute the number
+  // of milliseconds between midnight 1 January 1970 UTC and mRecordingStart,
+  // unfortunately, mozilla::TimeStamp does not have a built-in way of doing
+  // that. However, PR_Now() returns the number of microseconds since midnight 1
+  // January 1970 UTC. We call PR_Now() and TimeStamp::Now() very
+  // closely to each other so that they return their representation of "the same
+  // time", and then compute (Now - (Now - mRecordingStart)).
+  std::stringstream str;
+  nsCString recordingStartTime;
+  TimeDuration delta = TimeStamp::Now() - mRecordingStart;
+  recordingStartTime.AppendFloat(
+      static_cast<double>(PR_Now() / 1000.0 - delta.ToMilliseconds()));
+  str << gfxVars::LayersWindowRecordingPath() << "windowrecording-"
+      << recordingStartTime;
+
+#ifdef XP_WIN
+  _mkdir(str.str().c_str());
+#else
+  mkdir(str.str().c_str(), 0777);
+#endif
+
+  uint32_t i = 1;
+  for (RefPtr<RecordedFrame>& frame : mCollectedFrames) {
+    RefPtr<DataSourceSurface> surf = frame->GetSourceSurface();
+    std::stringstream filename;
+    filename << str.str() << "/frame-" << i << "-"
+             << uint32_t(
+                    (frame->GetTimeStamp() - mRecordingStart).ToMilliseconds())
+             << ".png";
+    gfxUtils::WriteAsPNG(surf, filename.str().c_str());
+    i++;
+  }
+  mCollectedFrames.Clear();
+}
+
+CollectedFrames CompositionRecorder::GetCollectedFrames() {
+  nsTArray<CollectedFrame> frames;
+
+  TimeDuration delta = TimeStamp::Now() - mRecordingStart;
+  double recordingStart = PR_Now() / 1000.0 - delta.ToMilliseconds();
+
+  for (RefPtr<RecordedFrame>& frame : mCollectedFrames) {
+    nsCString buffer;
+
+    RefPtr<DataSourceSurface> surf = frame->GetSourceSurface();
+    double offset = (frame->GetTimeStamp() - mRecordingStart).ToMilliseconds();
+
+    gfxUtils::EncodeSourceSurface(surf, ImageType::PNG, u""_ns,
+                                  gfxUtils::eDataURIEncode, nullptr, &buffer);
+
+    frames.EmplaceBack(offset, std::move(buffer));
+  }
+
+  mCollectedFrames.Clear();
+
+  return CollectedFrames(recordingStart, std::move(frames));
+}
+
+void CompositionRecorder::ClearCollectedFrames() { mCollectedFrames.Clear(); }
+
+}  // namespace layers
+}  // namespace mozilla