1 files changed, 114 insertions, 0 deletions
diff --git a/gfx/layers/CompositionRecorder.cpp b/gfx/layers/CompositionRecorder.cpp
new file mode 100644
index 0000000000..61d43330e9
--- /dev/null
+++ b/gfx/layers/CompositionRecorder.cpp
@@ -0,0 +1,114 @@
+/* -*- 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) {
+  mRecordedFrames.AppendElement(aFrame);
+}
+
+Maybe<FrameRecording> CompositionRecorder::GetRecording() {
+  FrameRecording recording;
+
+  recording.startTime() = mRecordingStart;
+
+  nsTArray<uint8_t> bytes;
+  for (RefPtr<RecordedFrame>& recordedFrame : mRecordedFrames) {
+    RefPtr<DataSourceSurface> surf = recordedFrame->GetSourceSurface();
+    if (!surf) {
+      return Nothing();
+    }
+
+    nsCOMPtr<nsIInputStream> imgStream;
+    nsresult rv = gfxUtils::EncodeSourceSurfaceAsStream(
+        surf, ImageType::PNG, u""_ns, getter_AddRefs(imgStream));
+    if (NS_FAILED(rv)) {
+      return Nothing();
+    }
+
+    uint64_t bufSize64;
+    rv = imgStream->Available(&bufSize64);
+    if (NS_FAILED(rv) || bufSize64 > UINT32_MAX) {
+      return Nothing();
+    }
+
+    const uint32_t frameLength = static_cast<uint32_t>(bufSize64);
+    size_t startIndex = bytes.Length();
+    bytes.SetLength(startIndex + frameLength);
+
+    uint8_t* bytePtr = &bytes[startIndex];
+    uint32_t bytesLeft = frameLength;
+
+    while (bytesLeft > 0) {
+      uint32_t bytesRead = 0;
+      rv = imgStream->Read(reinterpret_cast<char*>(bytePtr), bytesLeft,
+                           &bytesRead);
+      if (NS_FAILED(rv) || bytesRead == 0) {
+        return Nothing();
+      }
+
+      bytePtr += bytesRead;
+      bytesLeft -= bytesRead;
+    }
+
+#ifdef DEBUG
+
+    // Currently, all implementers of imgIEncoder report their exact size
+    // through nsIInputStream::Available(), but let's explicitly state that we
+    // rely on that behavior for the algorithm above.
+
+    char dummy = 0;
+    uint32_t bytesRead = 0;
+    rv = imgStream->Read(&dummy, 1, &bytesRead);
+    MOZ_ASSERT(NS_SUCCEEDED(rv) && bytesRead == 0);
+
+#endif
+
+    RecordedFrameData frameData;
+
+    frameData.timeOffset() = recordedFrame->GetTimeStamp();
+    frameData.length() = frameLength;
+
+    recording.frames().AppendElement(std::move(frameData));
+
+    // Now that we're done, release the frame so we can free up its memory
+    recordedFrame = nullptr;
+  }
+
+  mRecordedFrames.Clear();
+
+  recording.bytes() = ipc::BigBuffer(bytes);
+
+  return Some(std::move(recording));
+}
+
+}  // namespace layers
+}  // namespace mozilla