#ifndef __XRDOUCCRC_HH__
#define __XRDOUCCRC_HH__
/******************************************************************************/
/* */
/* X r d O u c C R C . h h */
/* */
/* (c) 2007 by the Board of Trustees of the Leland Stanford, Jr., University */
/* All Rights Reserved */
/* Produced by Andrew Hanushevsky for Stanford University under contract */
/* DE-AC02-76-SFO0515 with the Department of Energy */
/* */
/* This file is part of the XRootD software suite. */
/* */
/* XRootD is free software: you can redistribute it and/or modify it under */
/* the terms of the GNU Lesser General Public License as published by the */
/* Free Software Foundation, either version 3 of the License, or (at your */
/* option) any later version. */
/* */
/* XRootD 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 Lesser General Public */
/* License for more details. */
/* */
/* You should have received a copy of the GNU Lesser General Public License */
/* along with XRootD in a file called COPYING.LESSER (LGPL license) and file */
/* COPYING (GPL license). If not, see . */
/* */
/* The copyright holder's institutional names and contributor's names may not */
/* be used to endorse or promote products derived from this software without */
/* specific prior written permission of the institution or contributor. */
/******************************************************************************/
#include
#include
#include "XrdSys/XrdSysPageSize.hh"
class XrdOucCRC
{
public:
//------------------------------------------------------------------------------
//! Compute a CRC32 checksum.
//!
//! @note This is a historical method as it uses the very slow CRC32 algoritm.
// It is now better to use the CRC32C hardware assisted methods.
//!
//! @param data Pointer to the data whose checksum it to be computed.
//! @param count The number of bytes pointed to by data.
//!
//! @return The CRC32 checksum.
//------------------------------------------------------------------------------
static uint32_t CRC32(const unsigned char *data, int count);
//------------------------------------------------------------------------------
//! Compute a CRC32C checksum using hardware assist if available.
//!
//! @param data Pointer to the data whose checksum it to be computed.
//! @param count The number of bytes pointed to by data.
//! @param prevcs The previous checksum value. The initial checksum of
//! checksum sequence should be zero, the default.
//!
//! @return The CRC32C checksum.
//------------------------------------------------------------------------------
static uint32_t Calc32C(const void* data, size_t count, uint32_t prevcs=0);
//------------------------------------------------------------------------------
//! Compute a CRC32C page checksums using hardware assist if available.
//!
//! @param data Pointer to the data whose checksum it to be computed.
//! @param count The number of bytes pointed to by data.
//! @param csval Pointer to a vector to hold individual page checksums. The
//! vector must be sized:
//! (count/XrdSys::PageSize + (count%XrdSys::PageSize != 0)).
//! On return, each element of csval holds the checksum for
//! the associated page.
//------------------------------------------------------------------------------
static void Calc32C(const void* data, size_t count, uint32_t* csval);
//------------------------------------------------------------------------------
//! Verify a CRC32C checksum using hardware assist if available.
//!
//! @param data Pointer to the data whose checksum it to be verified.
//! @param count The number of bytes pointed to by data.
//! @param csval The expected checksum.
//! @param csbad If csbad is not nil, the computed checksum is returned.
//!
//! @return True if the expected checksum equals the actual checksum;
//! otherwise, false is returned.
//------------------------------------------------------------------------------
static bool Ver32C(const void* data, size_t count,
const uint32_t csval, uint32_t* csbad=0);
//------------------------------------------------------------------------------
//! Verify a CRC32C page checksums using hardware assist if available.
//!
//! @param data Pointer to the data whose checksum it to be verified.
//! @param count The number of bytes pointed to by data.
//! @param csval Pointer to a vector of expected page checksums. The
//! vector must be sized:
//! (count/XrdSys::PageSize + (count%XrdSys::PageSize != 0)).
//! @param valcs Where the computed checksum is returned for the page
//! whose verification failed; otherwise it is untouched.
//!
//! @return -1 if all the checksums match. Otherwise, the non-negative index
//! into csval whose checksum does not match.
//------------------------------------------------------------------------------
static int Ver32C(const void* data, size_t count,
const uint32_t* csval, uint32_t& valcs);
//------------------------------------------------------------------------------
//! Verify a CRC32C page checksums using hardware assist if available.
//!
//! @param data Pointer to the data whose checksum it to be verified.
//! @param count The number of bytes pointed to by data.
//! @param csval Pointer to a vector of expected page checksums. The
//! vector must be sized (count/PageSize+(count%PageSize != 0)).
//! @param valok Pointer to a vector of the same size as csval to hold
//! the results of the comparison (true matches, o/w false).
//!
//! @return True if all the checksums match with each element of valok set to
//! true. Otherwise, false is returned and false is set in valok for
//! each page that did not match the expected checksum.
//------------------------------------------------------------------------------
static bool Ver32C(const void* data, size_t count,
const uint32_t* csval, bool* valok);
//------------------------------------------------------------------------------
//! Verify a CRC32C page checksums using hardware assist if available.
//!
//! @param data Pointer to the data whose checksum it to be verified.
//! @param count The number of bytes pointed to by data.
//! @param csval Pointer to a vector of expected page checksums. The
//! vector must be sized (count/PageSize+(count%PageSize != 0)).
//! @param valcs Pointer to a vector of the same size as csval to hold
//! the computed checksum.
//!
//! @return True if all the checksums match; false otherwise.
//------------------------------------------------------------------------------
static bool Ver32C(const void* data, size_t count,
const uint32_t* csval, uint32_t* valcs);
XrdOucCRC() {}
~XrdOucCRC() {}
private:
static unsigned int crctable[256];
};
#endif