fastarray.h

俄罗斯人开发的大名鼎鼎的Pocket Pc 阅读器haaliread的源代码,visual c

/*
 * Copyright (c) 2001,2002,2003 Mike Matsnev.  All Rights Reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice immediately at the beginning of the file, without modification,
 *    this list of conditions, and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Absolutely no warranty of function or purpose is made by the author
 *    Mike Matsnev.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 * 
 * $Id: FastArray.h,v 1.4.2.1 2003/04/12 22:52:32 mike Exp $
 * 
 */

#ifndef FASTARRAY_H
#define FASTARRAY_H

class FastArrayImp {
protected:
  HANDLE	m_heap;
  unsigned	m_item_size;
  char		**m_chunks;
  unsigned	m_nchunks;
  enum {
    CHUNK_BITS=10,    // 1<<10 items per chunk
    CHUNK_ITEMS=1<<CHUNK_BITS,
    CHUNK_MASK=CHUNK_ITEMS-1
  };
  unsigned	m_curchunk;
  unsigned	m_chunkptr;
  bool		m_dofree;

		FastArrayImp(unsigned item_size,HANDLE heap,bool dofree);
		~FastArrayImp();
  void		*Get() {
    if (m_chunkptr<CHUNK_ITEMS)
      return m_chunks[m_curchunk]+m_item_size*m_chunkptr++;
    return SlowGet();
  }
  int		Size() { return (m_curchunk<<CHUNK_BITS)+m_chunkptr; }
  void		*Item(unsigned ii) {
    return m_chunks[ii>>CHUNK_BITS]+m_item_size*(ii&CHUNK_MASK);
  }
  void		*SlowGet();
  void		RemoveAll() { m_chunkptr=m_curchunk=0; }
};

// WARNING: this is intended for use with structures _without_ constructors and
// destructors
template<class T>
class FastArray: public FastArrayImp {
public:
		FastArray(HANDLE heap,bool dofree=false) : FastArrayImp(sizeof(T),heap,dofree) { }

  T		*Get() { return (T*)FastArrayImp::Get(); }
  T&		operator[](int ii) { return *(T*)FastArrayImp::Item(ii); }
  int		GetSize() { return Size(); }
  void		Add(T& tt) { memcpy(Get(),&tt,sizeof(T)); }
  // does _not_ release memory
  void		RemoveAll() { FastArrayImp::RemoveAll(); }
};

#endif