[Mojo Video Capture] Adapt video_capture service to refactored video capture stack

services/video_capture/public/cpp/receiver_media_to_mojo_adapter.cc

+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "services/video_capture/public/cpp/receiver_media_to_mojo_adapter.h"
+
+#include "media/capture/video/shared_memory_buffer_tracker.h"
+#include "mojo/public/cpp/bindings/strong_binding.h"
+#include "mojo/public/cpp/system/platform_handle.h"
+
+namespace {
+
+class MojoBufferHandleProvider
+    : public media::VideoCaptureDevice::Client::Buffer::HandleProvider {
+ public:
+  MojoBufferHandleProvider(mojo::ScopedSharedBufferHandle buffer_handle)
+      : buffer_handle_(std::move(buffer_handle)) {}
+
+  // Implementation of Buffer::HandleProvider:
+  mojo::ScopedSharedBufferHandle GetHandleForInterProcessTransit() override {
+    return buffer_handle_->Clone();
+  }
+  base::SharedMemoryHandle GetNonOwnedSharedMemoryHandleForLegacyIPC()
+      override {
+    LazyUnwrapHandleAndMapMemory();
+    return shared_memory_->handle();
+  }
+  std::unique_ptr<media::VideoCaptureBufferHandle> GetHandleForInProcessAccess()
+      override {
+    LazyUnwrapHandleAndMapMemory();
+    return base::MakeUnique<media::SharedMemoryBufferHandle>(
+        shared_memory_.get(), memory_size_);
+  }
+
+ private:
+  void LazyUnwrapHandleAndMapMemory() {
+    if (shared_memory_ != nullptr)
+      return;  // already done before

[emircan, 2017/04/19 18:16:48]

nit: You can also use base::Optional for this and keep the memory on stack.

[chfremer, 2017/04/19 23:03:37]

Done.

+
+    base::SharedMemoryHandle memory_handle;
+    const MojoResult result =
+        mojo::UnwrapSharedMemoryHandle(buffer_handle_->Clone(), &memory_handle,
+                                       &memory_size_, &read_only_flag_);
+    DCHECK_EQ(MOJO_RESULT_OK, result);
+    DCHECK_GT(memory_size_, 0u);
+
+    shared_memory_ =
+        base::MakeUnique<base::SharedMemory>(memory_handle, read_only_flag_);
+    if (!shared_memory_->Map(memory_size_)) {
+      DLOG(ERROR) << "LazyUnwrapHandleAndMapMemory: Map failed.";
+    }
+  }
+
+  mojo::ScopedSharedBufferHandle buffer_handle_;
+  std::unique_ptr<base::SharedMemory> shared_memory_;
+  size_t memory_size_ = 0;
+  bool read_only_flag_ = false;
+};
+
+class ScopedAccessPermissionMojoToMediaAdapter
+    : public media::VideoCaptureDevice::Client::Buffer::ScopedAccessPermission {
+ public:
+  ScopedAccessPermissionMojoToMediaAdapter(
+      video_capture::mojom::ScopedAccessPermissionPtr access_permission)
+      : access_permission_(std::move(access_permission)) {}
+
+ private:
+  video_capture::mojom::ScopedAccessPermissionPtr access_permission_;
+};
+
+}  // anonymous namespace
+
+namespace video_capture {
+
+ReceiverMediaToMojoAdapter::ReceiverMediaToMojoAdapter(
+    std::unique_ptr<media::VideoFrameReceiver> receiver)
+    : receiver_(std::move(receiver)) {}
+
+ReceiverMediaToMojoAdapter::~ReceiverMediaToMojoAdapter() = default;
+
+void ReceiverMediaToMojoAdapter::OnNewBufferHandle(
+    int32_t buffer_id,
+    mojo::ScopedSharedBufferHandle buffer_handle) {
+  receiver_->OnNewBufferHandle(
+      buffer_id,
+      base::MakeUnique<MojoBufferHandleProvider>(std::move(buffer_handle)));
+}
+
+void ReceiverMediaToMojoAdapter::OnFrameReadyInBuffer(
+    int32_t buffer_id,
+    int32_t frame_feedback_id,
+    mojom::ScopedAccessPermissionPtr access_permission,
+    media::mojom::VideoFrameInfoPtr frame_info) {
+  receiver_->OnFrameReadyInBuffer(
+      buffer_id, frame_feedback_id,
+      base::MakeUnique<ScopedAccessPermissionMojoToMediaAdapter>(
+          std::move(access_permission)),
+      std::move(frame_info));
+}
+
+void ReceiverMediaToMojoAdapter::OnBufferRetired(int32_t buffer_id) {
+  receiver_->OnBufferRetired(buffer_id);
+}
+
+void ReceiverMediaToMojoAdapter::OnError() {
+  receiver_->OnError();
+}
+
+void ReceiverMediaToMojoAdapter::OnLog(const std::string& message) {
+  receiver_->OnLog(message);
+}
+
+}  // namespace video_capture