jerasure/galois.h

112 lines
4.9 KiB
C
Executable File

/* Galois.h
* James S. Plank
Jerasure - A C/C++ Library for a Variety of Reed-Solomon and RAID-6 Erasure Coding Techniques
Revision 1.2A
May 24, 2011
James S. Plank
Department of Electrical Engineering and Computer Science
University of Tennessee
Knoxville, TN 37996
plank@cs.utk.edu
Copyright (c) 2011, James S. Plank
All rights reserved.
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>
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_log(int value, int w);
extern int galois_ilog(int value, int w);
extern int galois_create_log_tables(int w); /* Returns 0 on success, -1 on failure */
extern int galois_logtable_multiply(int x, int y, int w);
extern int galois_logtable_divide(int x, int y, int w);
extern int galois_create_mult_tables(int w); /* Returns 0 on success, -1 on failure */
extern int galois_multtable_multiply(int x, int y, int w);
extern int galois_multtable_divide(int x, int y, int w);
extern int galois_shift_multiply(int x, int y, int w);
extern int galois_shift_divide(int x, int y, int w);
extern int galois_create_split_w8_tables();
extern int galois_split_w8_multiply(int x, int y);
extern int galois_inverse(int x, int w);
extern int galois_shift_inverse(int y, int w);
extern int *galois_get_mult_table(int w);
extern int *galois_get_div_table(int w);
extern int *galois_get_log_table(int w);
extern int *galois_get_ilog_table(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 */
#endif