summaryrefslogtreecommitdiffstats
path: root/gfx/layers/ProfilerScreenshots.h
diff options
context:
space:
mode:
Diffstat (limited to '')
-rw-r--r--gfx/layers/ProfilerScreenshots.h120
1 files changed, 120 insertions, 0 deletions
diff --git a/gfx/layers/ProfilerScreenshots.h b/gfx/layers/ProfilerScreenshots.h
new file mode 100644
index 0000000000..8239c70403
--- /dev/null
+++ b/gfx/layers/ProfilerScreenshots.h
@@ -0,0 +1,120 @@
+/* -*- 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/. */
+
+#ifndef mozilla_layers_ProfilerScreenshots_h
+#define mozilla_layers_ProfilerScreenshots_h
+
+#include <functional>
+
+#include "mozilla/Mutex.h"
+#include "mozilla/RefPtr.h"
+#include "mozilla/TimeStamp.h"
+#include "nsCOMPtr.h"
+#include "nsTArray.h"
+
+#include "mozilla/gfx/Point.h"
+
+class nsIThread;
+
+namespace mozilla {
+
+namespace gfx {
+class DataSourceSurface;
+}
+
+namespace layers {
+
+/**
+ * Can be used to submit screenshots from the compositor to the profiler.
+ * Screenshots have a fixed bounding size. The user of this class will usually
+ * scale down the window contents first, ideally on the GPU, then read back the
+ * small scaled down image into main memory, and then call SubmitScreenshot to
+ * pass the data to the profiler.
+ * This class encodes each screenshot to a JPEG data URL, on a separate thread.
+ * This class manages that thread and recycles memory buffers.
+ * Users of ProfilerScreenshots should have one ProfilerScreenshot instance per
+ * window, as a unique window id is created by the constructor.
+ */
+class ProfilerScreenshots final {
+ NS_INLINE_DECL_THREADSAFE_REFCOUNTING(ProfilerScreenshots)
+
+ public:
+ ProfilerScreenshots();
+
+ /**
+ * Returns whether the profiler is currently active and is running with the
+ * "screenshots" feature enabled.
+ */
+ static bool IsEnabled();
+
+ /**
+ * Returns a fixed size that all screenshots should be resized to fit into.
+ */
+ static gfx::IntSize ScreenshotSize() { return gfx::IntSize(350, 350); }
+
+ /**
+ * The main functionality provided by this class.
+ * This method will synchronously invoke the supplied aPopulateSurface
+ * callback function with a DataSourceSurface in which the callback should
+ * store the pixel data. This surface may be larger than aScaledSize, but
+ * only the data in the rectangle (0, 0, aScaledSize.width,
+ * aScaledSize.height) will be read.
+ * @param aWindowIdentifier A pointer-sized integer that can be used to match
+ * up multiple screenshots from the same window.
+ * @param aOriginalSize The unscaled size of the snapshotted window.
+ * @param aScaledSize The scaled size, aScaled <= ScreenshotSize(), which the
+ * snapshot has been resized to.
+ * @param aTimeStamp The time at which the snapshot was taken. In
+ * asynchronous readback implementations, this is the time at which the
+ * readback / copy command was put into the command stream to the GPU, not
+ * the time at which the readback data was mapped into main memory.
+ * @param aPopulateSurface A callback that the caller needs to implement,
+ * which needs to copy the screenshot pixel data into the surface that's
+ * supplied to the callback. Called zero or one times, synchronously.
+ */
+ void SubmitScreenshot(
+ const gfx::IntSize& aOriginalSize, const gfx::IntSize& aScaledSize,
+ const TimeStamp& aTimeStamp,
+ const std::function<bool(gfx::DataSourceSurface*)>& aPopulateSurface);
+
+ private:
+ ~ProfilerScreenshots();
+
+ /**
+ * Recycle a surface from mAvailableSurfaces or create a new one if all
+ * surfaces are currently in use, up to some maximum limit.
+ * Returns null if the limit is reached.
+ * Can be called on any thread.
+ */
+ already_AddRefed<gfx::DataSourceSurface> TakeNextSurface();
+
+ /**
+ * Return aSurface back into the mAvailableSurfaces pool. Can be called on
+ * any thread.
+ */
+ void ReturnSurface(gfx::DataSourceSurface* aSurface);
+
+ // An array of surfaces ready to be recycled. Can be accessed from multiple
+ // threads, protected by mMutex.
+ nsTArray<RefPtr<gfx::DataSourceSurface>> mAvailableSurfaces;
+ // Protects mAvailableSurfaces.
+ Mutex mMutex MOZ_UNANNOTATED;
+ // The total number of surfaces created. If encoding is fast enough to happen
+ // entirely in the time between two calls to SubmitScreenshot, this should
+ // never exceed 1.
+ uint32_t mLiveSurfaceCount;
+
+ // Window identifier used to submit screenshots, created in the constructor.
+ uint32_t mWindowIdentifier;
+
+ // Counter incremented each time a new instance is constructed.
+ static uint32_t sWindowCounter;
+};
+
+} // namespace layers
+} // namespace mozilla
+
+#endif // mozilla_layers_ProfilerScreenshots_h