CoolVLViewer/indra/llcommon/llcrc.h

/**
 * @file llcrc.h
 * @brief LLCRC class header file.
 *
 * $LicenseInfo:firstyear=2002&license=viewergpl$
 *
 * Copyright (c) 2002-2009, Linden Research, Inc.
 *
 * Second Life Viewer Source Code
 * The source code in this file ("Source Code") is provided by Linden Lab
 * to you under the terms of the GNU General Public License, version 2.0
 * ("GPL"), unless you have obtained a separate licensing agreement
 * ("Other License"), formally executed by you and Linden Lab.  Terms of
 * the GPL can be found in doc/GPL-license.txt in this distribution, or
 * online at http://secondlifegrid.net/programs/open_source/licensing/gplv2
 *
 * There are special exceptions to the terms and conditions of the GPL as
 * it is applied to this Source Code. View the full text of the exception
 * in the file doc/FLOSS-exception.txt in this software distribution, or
 * online at
 * http://secondlifegrid.net/programs/open_source/licensing/flossexception
 *
 * By copying, modifying or distributing this software, you acknowledge
 * that you have read and understood your obligations described above,
 * and agree to abide by those obligations.
 *
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 * $/LicenseInfo$
 */

#ifndef LL_LLCRC_H
#define LL_LLCRC_H

#include <string>

#include "llpreprocessor.h"
#include "stdtypes.h"

// Simple 32 bits crc. To use, instantiate an LLCRC instance and feed it the
// bytes you want to check. It will update the internal crc as you go, and you
// can qery it at the end. As a horribly inefficient example (don't try this at
// work kids):
//
//  LLCRC crc;
//  FILE* fp = LLFile::open(filename,"rb");
//  while(!feof(fp))
//	{
//    crc.update(fgetc(fp));
//  }
//  LLFile::close(fp);
//  llinfos << "File crc: " << crc.getCRC() << llendl;

class LLCRC
{
protected:
	LOG_CLASS(LLCRC);

public:
	LLCRC();

	U32 getCRC() const;
	void update(U8 next_byte);
	void update(const U8* buffer, size_t buffer_size);
	void update(const std::string& filename);

protected:
	U32 mCurrent;
};

#endif // LL_LLCRC_H