196 lines
6.7 KiB
C
196 lines
6.7 KiB
C
/*
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* Copyright 2014 Tushar Gohad
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions are met:
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*
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* Redistributions of source code must retain the above copyright notice, this
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* list of conditions and the following disclaimer.
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*
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* Redistributions in binary form must reproduce the above copyright notice, this
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* list of conditions and the following disclaimer in the documentation and/or
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* other materials provided with the distribution. THIS SOFTWARE IS PROVIDED BY
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* THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED
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* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
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* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
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* EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
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* INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
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* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
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* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
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* OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
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* ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*
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* liberasurecode flat_xor_hd backend
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*
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* vi: set noai tw=79 ts=4 sw=4:
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*/
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#include <stdio.h>
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#include <stdlib.h>
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#include <xor_code.h>
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#include "erasurecode.h"
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#include "erasurecode_backend.h"
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#define FLAT_XOR_LIB_MAJOR 1
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#define FLAT_XOR_LIB_MINOR 0
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#define FLAT_XOR_LIB_REV 0
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#define FLAT_XOR_LIB_VER_STR "1.0"
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#define FLAT_XOR_LIB_NAME "flat_xor_hd"
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#if defined(__MACOS__) || defined(__MACOSX__) || defined(__OSX__) || defined(__APPLE__)
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#define FLAT_XOR_SO_NAME "libXorcode.dylib"
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#else
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#define FLAT_XOR_SO_NAME "libXorcode.so.1"
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#endif
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#define DEFAULT_W 32
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/* Forward declarations */
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struct ec_backend_op_stubs flat_xor_hd_ops;
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struct ec_backend flat_xor_hd;
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struct ec_backend_common backend_flat_xor_hd;
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typedef xor_code_t* (*init_xor_hd_code_func)(int, int, int);
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typedef void (*xor_code_encode_func)(xor_code_t *, char **, char **, int);
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typedef int (*xor_code_decode_func)(xor_code_t *, char **, char **, int *, int, int);
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typedef int (*xor_hd_fragments_needed_func)(xor_code_t *, int *, int *, int *);
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struct flat_xor_hd_descriptor {
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xor_code_t *xor_desc;
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init_xor_hd_code_func init_xor_hd_code;
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xor_code_encode_func xor_code_encode;
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xor_code_decode_func xor_code_decode;
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xor_hd_fragments_needed_func xor_hd_fragments_needed;
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};
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static int flat_xor_hd_encode(void *desc,
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char **data, char **parity, int blocksize)
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{
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struct flat_xor_hd_descriptor *xdesc =
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(struct flat_xor_hd_descriptor *) desc;
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xor_code_t *xor_desc = (xor_code_t *) xdesc->xor_desc;
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xor_desc->encode(xor_desc, data, parity, blocksize);
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return 0;
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}
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static int flat_xor_hd_decode(void *desc,
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char **data, char **parity, int *missing_idxs,
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int blocksize)
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{
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struct flat_xor_hd_descriptor *xdesc =
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(struct flat_xor_hd_descriptor *) desc;
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xor_code_t *xor_desc = (xor_code_t *) xdesc->xor_desc;
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return xor_desc->decode(xor_desc, data, parity, missing_idxs, blocksize, 1);
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}
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static int flat_xor_hd_reconstruct(void *desc,
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char **data, char **parity, int *missing_idxs,
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int destination_idx, int blocksize)
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{
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struct flat_xor_hd_descriptor *xdesc =
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(struct flat_xor_hd_descriptor *) desc;
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xor_code_t *xor_desc = (xor_code_t *) xdesc->xor_desc;
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xor_reconstruct_one(xor_desc, data, parity,
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missing_idxs, destination_idx, blocksize);
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return 0;
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}
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static int flat_xor_hd_min_fragments(void *desc,
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int *missing_idxs, int *fragments_to_exclude,
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int *fragments_needed)
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{
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struct flat_xor_hd_descriptor *xdesc =
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(struct flat_xor_hd_descriptor *) desc;
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xor_code_t *xor_desc = (xor_code_t *) xdesc->xor_desc;
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xor_desc->fragments_needed(xor_desc, missing_idxs, fragments_to_exclude, fragments_needed);
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return 0;
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}
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/**
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* Return the element-size, which is the number of bits stored
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* on a given device, per codeword. This is usually just 'w'.
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*/
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static int
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flar_xor_hd_element_size(void* desc)
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{
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return DEFAULT_W;
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}
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static void * flat_xor_hd_init(struct ec_backend_args *args, void *sohandle)
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{
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int k = args->uargs.k;
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int m = args->uargs.m;
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int hd = args->uargs.hd;
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xor_code_t *xor_desc = NULL;
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struct flat_xor_hd_descriptor *bdesc = NULL;
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/* store w back in args so upper layer can get to it */
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args->uargs.w = DEFAULT_W;
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/* init xor_code_t descriptor */
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xor_desc = init_xor_hd_code(k, m, hd);
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if (NULL == xor_desc) {
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return NULL;
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}
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/* fill in flat_xor_hd_descriptor */
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bdesc = (struct flat_xor_hd_descriptor *)
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malloc(sizeof(struct flat_xor_hd_descriptor));
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if (NULL == bdesc) {
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free (xor_desc);
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return NULL;
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}
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bdesc->xor_desc = xor_desc;
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return (void *) bdesc;
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}
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static int flat_xor_hd_exit(void *desc)
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{
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struct flat_xor_hd_descriptor *bdesc =
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(struct flat_xor_hd_descriptor *) desc;
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free (bdesc->xor_desc);
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free (bdesc);
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return 0;
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}
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/*
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* For the time being, we only claim compatibility with versions that
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* match exactly
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*/
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static bool flat_xor_is_compatible_with(uint32_t version) {
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return version == backend_flat_xor_hd.ec_backend_version;
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}
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struct ec_backend_op_stubs flat_xor_hd_op_stubs = {
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.INIT = flat_xor_hd_init,
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.EXIT = flat_xor_hd_exit,
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.ENCODE = flat_xor_hd_encode,
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.DECODE = flat_xor_hd_decode,
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.FRAGSNEEDED = flat_xor_hd_min_fragments,
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.RECONSTRUCT = flat_xor_hd_reconstruct,
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.ELEMENTSIZE = flar_xor_hd_element_size,
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.ISCOMPATIBLEWITH = flat_xor_is_compatible_with,
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.GETMETADATASIZE = get_backend_metadata_size_zero,
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.GETENCODEOFFSET = get_encode_offset_zero,
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};
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struct ec_backend_common backend_flat_xor_hd = {
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.id = EC_BACKEND_FLAT_XOR_HD,
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.name = FLAT_XOR_LIB_NAME,
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.soname = FLAT_XOR_SO_NAME,
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.soversion = FLAT_XOR_LIB_VER_STR,
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.ops = &flat_xor_hd_op_stubs,
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.ec_backend_version = _VERSION(FLAT_XOR_LIB_MAJOR,
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FLAT_XOR_LIB_MINOR,
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FLAT_XOR_LIB_REV),
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};
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