Improvement

apps/LoopThroughWithOpenGLCompositing/videoio/SystemOutputFramePool.h

@@ -0,0 +1,90 @@
+#pragma once
+
+#include "VideoIOTypes.h"
+
+#include <cstddef>
+#include <cstdint>
+#include <deque>
+#include <mutex>
+#include <vector>
+
+enum class OutputFrameSlotState
+{
+	Free,
+	Acquired,
+	Ready,
+	Consumed,
+	Scheduled
+};
+
+struct SystemOutputFramePoolConfig
+{
+	unsigned width = 0;
+	unsigned height = 0;
+	VideoIOPixelFormat pixelFormat = VideoIOPixelFormat::Bgra8;
+	unsigned rowBytes = 0;
+	std::size_t capacity = 0;
+};
+
+struct OutputFrameSlot
+{
+	VideoIOOutputFrame frame;
+	std::size_t index = 0;
+	uint64_t generation = 0;
+};
+
+struct SystemOutputFramePoolMetrics
+{
+	std::size_t capacity = 0;
+	std::size_t freeCount = 0;
+	std::size_t acquiredCount = 0;
+	std::size_t readyCount = 0;
+	std::size_t consumedCount = 0;
+	std::size_t scheduledCount = 0;
+	uint64_t acquireMissCount = 0;
+	uint64_t readyUnderrunCount = 0;
+};
+
+class SystemOutputFramePool
+{
+public:
+	SystemOutputFramePool() = default;
+	explicit SystemOutputFramePool(const SystemOutputFramePoolConfig& config);
+
+	void Configure(const SystemOutputFramePoolConfig& config);
+	SystemOutputFramePoolConfig Config() const;
+
+	bool AcquireFreeSlot(OutputFrameSlot& slot);
+	bool PublishReadySlot(const OutputFrameSlot& slot);
+	bool ConsumeReadySlot(OutputFrameSlot& slot);
+	bool MarkScheduled(const OutputFrameSlot& slot);
+	bool MarkScheduledByBuffer(void* bytes);
+	bool ReleaseSlot(const OutputFrameSlot& slot);
+	bool ReleaseScheduledSlot(const OutputFrameSlot& slot);
+	bool ReleaseSlotByBuffer(void* bytes);
+	void Clear();
+
+	SystemOutputFramePoolMetrics GetMetrics() const;
+
+private:
+	struct StoredSlot
+	{
+		std::vector<unsigned char> bytes;
+		OutputFrameSlotState state = OutputFrameSlotState::Free;
+		uint64_t generation = 1;
+	};
+
+	bool IsValidSlotLocked(const OutputFrameSlot& slot) const;
+	bool TransitionSlotLocked(const OutputFrameSlot& slot, OutputFrameSlotState expectedState, OutputFrameSlotState nextState);
+	void FillOutputSlotLocked(std::size_t index, OutputFrameSlot& slot);
+	void RemoveReadyIndexLocked(std::size_t index);
+	bool ReleaseSlotByIndexLocked(std::size_t index);
+	std::size_t FrameByteCount() const;
+
+	mutable std::mutex mMutex;
+	SystemOutputFramePoolConfig mConfig;
+	std::vector<StoredSlot> mSlots;
+	std::deque<std::size_t> mReadySlots;
+	uint64_t mAcquireMissCount = 0;
+	uint64_t mReadyUnderrunCount = 0;
+};