Modify ScreenCaptureFrameQueue into a template

webrtc/modules/desktop_capture/win/screen_capturer_win_gdi.cc

 /*
  *  Copyright (c) 2014 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
 #include "webrtc/modules/desktop_capture/win/screen_capturer_win_gdi.h"
 
 #include <assert.h>
 
 #include <utility>
 
+#include "webrtc/base/checks.h"
 #include "webrtc/modules/desktop_capture/desktop_capture_options.h"
 #include "webrtc/modules/desktop_capture/desktop_frame.h"
 #include "webrtc/modules/desktop_capture/desktop_frame_win.h"
 #include "webrtc/modules/desktop_capture/desktop_region.h"
 #include "webrtc/modules/desktop_capture/differ.h"
 #include "webrtc/modules/desktop_capture/mouse_cursor.h"
 #include "webrtc/modules/desktop_capture/win/cursor.h"
 #include "webrtc/modules/desktop_capture/win/desktop.h"
 #include "webrtc/modules/desktop_capture/win/screen_capture_utils.h"
 #include "webrtc/system_wrappers/include/logging.h"
@@ skipping 63 matching lines @@
 
 void ScreenCapturerWinGdi::SetSharedMemoryFactory(
     rtc::scoped_ptr<SharedMemoryFactory> shared_memory_factory) {
   shared_memory_factory_ =
       rtc::ScopedToUnique(std::move(shared_memory_factory));
 }
 
 void ScreenCapturerWinGdi::Capture(const DesktopRegion& region) {
   TickTime capture_start_time = TickTime::Now();
 
-  queue_.MoveToNextFrame();
+  queue_.MoveToNext();
+  RTC_DCHECK(!queue_.current() || !queue_.current()->IsShared());
 
   // Request that the system not power-down the system, or the display hardware.
   if (!SetThreadExecutionState(ES_DISPLAY_REQUIRED | ES_SYSTEM_REQUIRED)) {
     if (!set_thread_execution_state_failed_) {
       set_thread_execution_state_failed_ = true;
       LOG_F(LS_WARNING) << "Failed to make system & display power assertion: "
                         << GetLastError();
     }
   }
 
   // Make sure the GDI capture resources are up-to-date.
   PrepareCaptureResources();
 
   if (!CaptureImage()) {
     callback_->OnCaptureCompleted(NULL);
     return;
   }
 
-  const DesktopFrame* current_frame = queue_.current_frame();
-  const DesktopFrame* last_frame = queue_.previous_frame();
+  const DesktopFrame* current_frame = queue_.current();
+  const DesktopFrame* last_frame = queue_.previous();
   if (last_frame && last_frame->size().equals(current_frame->size())) {
     // Make sure the differencer is set up correctly for these previous and
     // current screens.
     if (!differ_.get() ||
         (differ_->width() != current_frame->size().width()) ||
         (differ_->height() != current_frame->size().height()) ||
         (differ_->bytes_per_row() != current_frame->stride())) {
       differ_.reset(new Differ(current_frame->size().width(),
                                current_frame->size().height(),
                                DesktopFrame::kBytesPerPixel,
                                current_frame->stride()));
     }
 
     // Calculate difference between the two last captured frames.
     DesktopRegion region;
     differ_->CalcDirtyRegion(last_frame->data(), current_frame->data(),
                              &region);
     helper_.InvalidateRegion(region);
   } else {
     // No previous frame is available, or the screen is resized. Invalidate the
     // whole screen.
     helper_.InvalidateScreen(current_frame->size());
   }
 
   helper_.set_size_most_recent(current_frame->size());
 
   // Emit the current frame.
-  DesktopFrame* frame = queue_.current_frame()->Share();
+  DesktopFrame* frame = queue_.current()->Share();
   frame->set_dpi(DesktopVector(
       GetDeviceCaps(desktop_dc_, LOGPIXELSX),
       GetDeviceCaps(desktop_dc_, LOGPIXELSY)));
   frame->mutable_updated_region()->Clear();
   helper_.TakeInvalidRegion(frame->mutable_updated_region());
   frame->set_capture_time_ms(
       (TickTime::Now() - capture_start_time).Milliseconds());
   callback_->OnCaptureCompleted(frame);
 }
 
@@ skipping 92 matching lines @@
 bool ScreenCapturerWinGdi::CaptureImage() {
   DesktopRect screen_rect =
       GetScreenRect(current_screen_id_, current_device_key_);
   if (screen_rect.is_empty())
     return false;
 
   DesktopSize size = screen_rect.size();
   // If the current buffer is from an older generation then allocate a new one.
   // Note that we can't reallocate other buffers at this point, since the caller
   // may still be reading from them.
-  if (!queue_.current_frame() ||
-      !queue_.current_frame()->size().equals(screen_rect.size())) {
+  if (!queue_.current() ||
+      !queue_.current()->size().equals(screen_rect.size())) {
     assert(desktop_dc_ != NULL);
     assert(memory_dc_ != NULL);
 
     std::unique_ptr<DesktopFrame> buffer(DesktopFrameWin::Create(
         size, shared_memory_factory_.get(), desktop_dc_));
-    if (!buffer.get())
+    if (!buffer)
       return false;
-    queue_.ReplaceCurrentFrame(buffer.release());
+    queue_.ReplaceCurrent(SharedDesktopFrame::Wrap(std::move(buffer)));
   }
 
   // Select the target bitmap into the memory dc and copy the rect from desktop
   // to memory.
   DesktopFrameWin* current = static_cast<DesktopFrameWin*>(
-      queue_.current_frame()->GetUnderlyingFrame());
+      queue_.current()->GetUnderlyingFrame());
   HGDIOBJ previous_object = SelectObject(memory_dc_, current->bitmap());
   if (previous_object != NULL) {
     BitBlt(memory_dc_,
            0, 0, screen_rect.width(), screen_rect.height(),
            desktop_dc_,
            screen_rect.left(), screen_rect.top(),
            SRCCOPY | CAPTUREBLT);
 
     // Select back the previously selected object to that the device contect
     // could be destroyed independently of the bitmap if needed.
     SelectObject(memory_dc_, previous_object);
   }
   return true;
 }
 
 }  // namespace webrtc