buffer.h

虚拟打印机

/*
 *
 * buffer.h

   Copyright (C) 2006 Michael H. Overlin

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
   
   Contact at [e-mail]

 *
 */

#ifndef BUFFER_H
#define BUFFER_H

#include "utils.h"


class Buffer {
public:
	enum errcode { eAllocateFail };

	Buffer(DWORD dwSize)  throw(.../*errcode*/) {
		this->pBuff = this->MyRealloc(NULL, dwSize);
		this->dwSize = dwSize;
	}

	~Buffer() { MyFree(this->pBuff); }

	VOID RequireMinSize(DWORD dwNewSize)  {
		if (this->dwSize < dwNewSize) {
			this->pBuff = MyRealloc(this->pBuff, dwNewSize);
			this->dwSize = dwNewSize;
		}
	}

	PVOID GetPtr(VOID) const { return this->pBuff; }
	DWORD GetSize(VOID) const { return this->dwSize; }

private:
	static PVOID MyRealloc(PVOID pvOld, DWORD dwNewSize) throw(.../*errcode*/) {
		PVOID pvRetValue = NULL;
		if (dwNewSize != 0) {
			if (pvOld != NULL) {
				pvRetValue = realloc(pvOld, dwNewSize);
			} else {
				pvRetValue = malloc(dwNewSize);
			}
			if (pvRetValue == NULL) {
				throw(eAllocateFail);
			}
		} else {
			MyFree(pvOld);
		}
		return pvRetValue;
	}

	static VOID MyFree(PVOID pv) {
		if (pv != NULL) {
			free(pv);
		}
	}
			
	PVOID pBuff;
	DWORD dwSize;
};

class ItemBuffer {
public:
	ItemBuffer(DWORD dwItemCount, DWORD dwItemSize)  throw(.../*Buffer::errcode*/) 
		:	dwItemSize(dwItemSize),
			buff(dwItemCount * dwItemSize)  { 
		this->dwItemCount = dwItemCount;
	}

	~ItemBuffer() {}

	VOID RequireMinCount(DWORD dwNewItemCount)  throw(.../*Buffer::errcode*/) { 
		this->buff.RequireMinSize(dwNewItemCount * this->dwItemSize);
		this->dwItemCount = dwNewItemCount;
	}

	PVOID GetPtr(VOID) const { return this->buff.GetPtr(); }
	DWORD GetCount(VOID) const { return this->dwItemCount; }

private:
	const DWORD dwItemSize;
	DWORD dwItemCount;
	Buffer buff;
};

#endif