#ifndef SRC_TRACING_NODE_TRACE_BUFFER_H_

#define SRC_TRACING_NODE_TRACE_BUFFER_H_

#include "tracing/agent.h"

#include "node_mutex.h"

#include "libplatform/v8-tracing.h"

#include <atomic>

namespace node {

namespace tracing {

using v8::platform::tracing::TraceBuffer;

using v8::platform::tracing::TraceBufferChunk;

using v8::platform::tracing::TraceObject;

// forward declaration

class NodeTraceBuffer;

class InternalTraceBuffer {

 public:

  InternalTraceBuffer(size_t max_chunks, uint32_t id, Agent* agent);

  TraceObject* AddTraceEvent(uint64_t* handle);

  TraceObject* GetEventByHandle(uint64_t handle);

  void Flush(bool blocking);

  bool IsFull() const {

    return total_chunks_ == max_chunks_ && chunks_[total_chunks_ - 1]->IsFull();

  }

  bool IsFlushing() const {

    return flushing_;

  }

 private:

  uint64_t MakeHandle(size_t chunk_index, uint32_t chunk_seq,

                      size_t event_index) const;

  void ExtractHandle(uint64_t handle, uint32_t* buffer_id, size_t* chunk_index,

                     uint32_t* chunk_seq, size_t* event_index) const;

  size_t Capacity() const { return max_chunks_ * TraceBufferChunk::kChunkSize; }

  Mutex mutex_;

  bool flushing_;

  size_t max_chunks_;

  Agent* agent_;

  std::vector<std::unique_ptr<TraceBufferChunk>> chunks_;

  size_t total_chunks_ = 0;

  uint32_t current_chunk_seq_ = 1;

  uint32_t id_;

};

class NodeTraceBuffer : public TraceBuffer {

 public:

  NodeTraceBuffer(size_t max_chunks, Agent* agent, uv_loop_t* tracing_loop);

  ~NodeTraceBuffer() override;

  TraceObject* AddTraceEvent(uint64_t* handle) override;

  TraceObject* GetEventByHandle(uint64_t handle) override;

  bool Flush() override;

  static const size_t kBufferChunks = 1024;

 private:

  bool TryLoadAvailableBuffer();

  static void NonBlockingFlushSignalCb(uv_async_t* signal);

  static void ExitSignalCb(uv_async_t* signal);

  uv_loop_t* tracing_loop_;

  uv_async_t flush_signal_;

  uv_async_t exit_signal_;

  bool exited_ = false;

  // Used exclusively for exit logic.

  Mutex exit_mutex_;

  // Used to wait until async handles have been closed.

  ConditionVariable exit_cond_;

  std::atomic<InternalTraceBuffer*> current_buf_;

  InternalTraceBuffer buffer1_;

  InternalTraceBuffer buffer2_;

};

}  // namespace tracing

}  // namespace node

#endif  // SRC_TRACING_NODE_TRACE_BUFFER_H_