YugabyteDB (2.13.0.0-b42, bfc6a6643e7399ac8a0e81d06a3ee6d6571b33ab)

// Copyright (c) YugaByte, Inc.

//

// Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except

// in compliance with the License.  You may obtain a copy of the License at

//

// http://www.apache.org/licenses/LICENSE-2.0

//

// Unless required by applicable law or agreed to in writing, software distributed under the License

// is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express

// or implied.  See the License for the specific language governing permissions and limitations

// under the License.

//

#ifndef YB_RPC_CIRCULAR_READ_BUFFER_H

#define YB_RPC_CIRCULAR_READ_BUFFER_H

#include "yb/rpc/stream.h"

#include "yb/util/mem_tracker.h"

namespace yb {

namespace rpc {

struct FreeMemory {

  void operator()(void* data) const {

    free(data);

  }

};

// StreamReadBuffer implementation that is based on circular buffer of fixed capacity.

class CircularReadBuffer : public StreamReadBuffer {

 public:

  explicit CircularReadBuffer(size_t capacity, const MemTrackerPtr& parent_tracker);

  bool ReadyToRead() override;

  bool Empty() override;

  void Reset() override;

  Result<IoVecs> PrepareAppend() override;

  std::string ToString() const override;

  void DataAppended(size_t len) override;

  IoVecs AppendedVecs() override;

  bool Full() override;

  void Consume(size_t count, const Slice& prepend) override;

  size_t DataAvailable() override;

 private:

  ScopedTrackedConsumption consumption_;

  std::unique_ptr<char, FreeMemory> buffer_;

  const size_t capacity_;

  size_t pos_ = 0;

  size_t size_ = 0;

  Slice prepend_;

  bool had_prepend_ = false;

};

} // namespace rpc

} // namespace yb

#endif // YB_RPC_CIRCULAR_READ_BUFFER_H