jerasure/galois.h

103 lines
4.7 KiB
C

/* *
* Copyright (c) 2013, James S. Plank and Kevin Greenan
* All rights reserved.
*
* Jerasure - A C/C++ Library for a Variety of Reed-Solomon and RAID-6 Erasure
* Coding Techniques
*
* Revision 2.0: Galois Field backend now links to GF-Complete
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* - 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.
*
* - Neither the name of the University of Tennessee nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "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 COPYRIGHT
* HOLDER OR CONTRIBUTORS 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.
*/
#ifndef _GALOIS_H
#define _GALOIS_H
#include <stdio.h>
#include <stdlib.h>
#include <gf_complete.h>
extern void galois_change_technique(gf_t *gf, int w);
extern int galois_single_multiply(int a, int b, int w);
extern int galois_single_divide(int a, int b, int w);
extern int galois_inverse(int x, int w);
void galois_region_xor( char *r1, /* Region 1 */
char *r2, /* Region 2 */
char *r3, /* Sum region (r3 = r1 ^ r2) -- can be r1 or r2 */
int nbytes); /* Number of bytes in region */
/* These multiply regions in w=8, w=16 and w=32. They are much faster
than calling galois_single_multiply. The regions must be long word aligned. */
void galois_w08_region_multiply(char *region, /* Region to multiply */
int multby, /* Number to multiply by */
int nbytes, /* Number of bytes in region */
char *r2, /* If r2 != NULL, products go here.
Otherwise region is overwritten */
int add); /* If (r2 != NULL && add) the produce is XOR'd with r2 */
void galois_w16_region_multiply(char *region, /* Region to multiply */
int multby, /* Number to multiply by */
int nbytes, /* Number of bytes in region */
char *r2, /* If r2 != NULL, products go here.
Otherwise region is overwritten */
int add); /* If (r2 != NULL && add) the produce is XOR'd with r2 */
void galois_w32_region_multiply(char *region, /* Region to multiply */
int multby, /* Number to multiply by */
int nbytes, /* Number of bytes in region */
char *r2, /* If r2 != NULL, products go here.
Otherwise region is overwritten */
int add); /* If (r2 != NULL && add) the produce is XOR'd with r2 */
int galois_init_base_field(int w,
int mult_type,
int region_type,
int divide_type,
uint64_t prim_poly,
int arg1,
int arg2);
int galois_init_composite_field(int w,
int region_type,
int divide_type,
uint64_t prim_poly,
int arg1,
int arg2,
gf_t* base_gf);
gf_t * galois_get_field_ptr(int w);
#endif