be/src/runtime/bufferpool/buffer-allocator.h

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// to you under the Apache License, Version 2.0 (the
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//
//   http://www.apache.org/licenses/LICENSE-2.0
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#ifndef IMPALA_RUNTIME_BUFFER_ALLOCATOR_H
#define IMPALA_RUNTIME_BUFFER_ALLOCATOR_H

#include "common/status.h"

namespace impala {

/// The underlying memory allocator for the buffer pool. All buffers are allocated through
/// the BufferPool's BufferAllocator. The allocator only handles allocating buffers that
/// are power-of-two multiples of the minimum buffer length.
///
/// TODO:
/// * Allocate memory with mmap() instead of malloc().
/// * Implement free lists in the allocator or external to the allocator.
class BufferAllocator {
 public:
  BufferAllocator(int64_t min_buffer_len);

  /// Allocate memory for a buffer of 'len' bytes. 'len' must be a power-of-two multiple
  /// of the minimum buffer length.
  Status Allocate(int64_t len, uint8_t** buffer);

  /// Free the memory for a previously-allocated buffer.
  void Free(uint8_t* buffer, int64_t len);

 private:
  const int64_t min_buffer_len_;
};
}

#endif