xref: /aosp_15_r20/external/lzma/CPP/Common/MyBuffer2.h (revision f6dc9357d832569d4d1f5d24eacdb3935a1ae8e6)

// Common/MyBuffer2.h

#ifndef ZIP7_INC_COMMON_MY_BUFFER2_H
#define ZIP7_INC_COMMON_MY_BUFFER2_H

#include "../../C/Alloc.h"

#include "MyTypes.h"

class CMidBuffer
{
  Byte *_data;
  size_t _size;

  Z7_CLASS_NO_COPY(CMidBuffer)

public:
  CMidBuffer(): _data(NULL), _size(0) {}
  ~CMidBuffer() { ::MidFree(_data); }

  void Free() { ::MidFree(_data); _data = NULL; _size = 0; }

  bool IsAllocated() const { return _data != NULL; }
  operator       Byte *()       { return _data; }
  operator const Byte *() const { return _data; }
  size_t Size() const { return _size; }

  void Alloc(size_t size)
  {
    if (!_data || size != _size)
    {
      ::MidFree(_data);
      _size = 0;
      _data = NULL;
      _data = (Byte *)::MidAlloc(size);
      if (_data)
        _size = size;
    }
  }

  void AllocAtLeast(size_t size)
  {
    if (!_data || size > _size)
    {
      ::MidFree(_data);
      const size_t kMinSize = (size_t)1 << 16;
      if (size < kMinSize)
        size = kMinSize;
      _size = 0;
      _data = NULL;
      _data = (Byte *)::MidAlloc(size);
      if (_data)
        _size = size;
    }
  }
};


class CAlignedBuffer1
{
  Byte *_data;

  Z7_CLASS_NO_COPY(CAlignedBuffer1)

public:
  ~CAlignedBuffer1()
  {
    z7_AlignedFree(_data);
  }

  CAlignedBuffer1(size_t size)
  {
    _data = NULL;
    _data = (Byte *)z7_AlignedAlloc(size);
    if (!_data)
      throw 1;
  }

  operator       Byte *()       { return _data; }
  operator const Byte *() const { return _data; }
};


class CAlignedBuffer
{
  Byte *_data;
  size_t _size;

  Z7_CLASS_NO_COPY(CAlignedBuffer)

public:
  CAlignedBuffer(): _data(NULL), _size(0) {}
  ~CAlignedBuffer()
  {
    z7_AlignedFree(_data);
  }

  /*
  CAlignedBuffer(size_t size): _size(0)
  {
    _data = NULL;
    _data = (Byte *)z7_AlignedAlloc(size);
    if (!_data)
      throw 1;
    _size = size;
  }
  */

  void Free()
  {
    z7_AlignedFree(_data);
    _data = NULL;
    _size = 0;
  }

  bool IsAllocated() const { return _data != NULL; }
  operator       Byte *()       { return _data; }
  operator const Byte *() const { return _data; }
  size_t Size() const { return _size; }

  void Alloc(size_t size)
  {
    if (!_data || size != _size)
    {
      z7_AlignedFree(_data);
      _size = 0;
      _data = NULL;
      _data = (Byte *)z7_AlignedAlloc(size);
      if (_data)
        _size = size;
    }
  }

  void AllocAtLeast(size_t size)
  {
    if (!_data || size > _size)
    {
      z7_AlignedFree(_data);
      _size = 0;
      _data = NULL;
      _data = (Byte *)z7_AlignedAlloc(size);
      if (_data)
        _size = size;
    }
  }

  // (size <= size_max)
  void AllocAtLeast_max(size_t size, size_t size_max)
  {
    if (!_data || size > _size)
    {
      z7_AlignedFree(_data);
      _size = 0;
      _data = NULL;
      if (size_max < size) size_max = size; // optional check
      const size_t delta = size / 2;
      size += delta;
      if (size < delta || size > size_max)
        size = size_max;
      _data = (Byte *)z7_AlignedAlloc(size);
      if (_data)
        _size = size;
    }
  }
};

/*
  CMidAlignedBuffer must return aligned pointer.
   - in Windows it uses CMidBuffer(): MidAlloc() : VirtualAlloc()
       VirtualAlloc(): Memory allocated is automatically initialized to zero.
       MidAlloc(0) returns NULL
   - in non-Windows systems it uses g_AlignedAlloc.
     g_AlignedAlloc::Alloc(size = 0) can return non NULL.
*/

typedef
#ifdef _WIN32
  CMidBuffer
#else
  CAlignedBuffer
#endif
  CMidAlignedBuffer;


#endif