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d5ce2f6944
Remove option of providing Technique and handling errors based on that choose a matrix type automatically based on number of data blocks. INTEL recommends on using cauchy for consistent invertible matrices, while vandermonde is faster we should default to cauchy for large data blocks.
143 lines
4.8 KiB
C
143 lines
4.8 KiB
C
/*
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* Minio Cloud Storage, (C) 2014 Minio, Inc.
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include "ec.h"
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#include "ec_minio_common.h"
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static
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int32_t _minio_src_index_in_error (int r, int32_t *error_index, int errs)
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{
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int i;
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for (i = 0; i < errs; i++) {
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if (error_index[i] == r) {
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// true
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return 1;
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}
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}
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// false
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return 0;
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}
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// Separate out source data and target buffers
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int32_t minio_get_source_target (int errs, int k, int m,
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int32_t *error_index,
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uint32_t *decode_index,
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unsigned char **buffs,
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unsigned char ***source,
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unsigned char ***target)
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{
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int i;
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unsigned char *tmp_source[k];
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unsigned char *tmp_target[m];
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if (k < 0 || m < 0) {
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return -1;
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}
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memset (tmp_source, 0, k);
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memset (tmp_target, 0, m);
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for (i = 0; i < k; i++) {
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tmp_source[i] = (unsigned char *) buffs[decode_index[i]];
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}
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for (i = 0; i < m; i++) {
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if (i < errs)
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tmp_target[i] = (unsigned char *) buffs[error_index[i]];
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}
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*source = tmp_source;
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*target = tmp_target;
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return 0;
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}
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/*
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Generate decode matrix during the decoding phase
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*/
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int minio_init_decoder (int32_t *error_index,
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int k, int n, int errs,
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unsigned char *encode_matrix,
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unsigned char **decode_matrix,
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unsigned char **decode_tbls,
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uint32_t **decode_index)
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{
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int i, j, r, l;
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uint32_t *tmp_decode_index = (uint32_t *) malloc(sizeof(uint32_t) * k);
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unsigned char *input_matrix;
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unsigned char *inverse_matrix;
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unsigned char *tmp_decode_matrix;
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unsigned char *tmp_decode_tbls;
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input_matrix = (unsigned char *) malloc(sizeof(unsigned char) * k * n);
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inverse_matrix = (unsigned char *) malloc(sizeof(unsigned char) * k * n);
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tmp_decode_matrix = (unsigned char *) malloc(sizeof(unsigned char) * k * n);;
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tmp_decode_tbls = (unsigned char *) malloc(sizeof(unsigned char) * k * n * 32);
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for (i = 0, r = 0; i < k; i++, r++) {
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while (_minio_src_index_in_error(r, error_index, errs))
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r++;
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for (j = 0; j < k; j++) {
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input_matrix[k * i + j] = encode_matrix[k * r + j];
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}
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tmp_decode_index[i] = r;
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}
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// Not all vandermonde matrix can be inverted
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if (gf_invert_matrix(input_matrix, inverse_matrix, k) < 0) {
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free(tmp_decode_matrix);
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free(tmp_decode_tbls);
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free(tmp_decode_index);
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return -1;
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}
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for (l = 0; l < errs; l++) {
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if (error_index[l] < k) {
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// decoding matrix elements for data chunks
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for (j = 0; j < k; j++) {
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tmp_decode_matrix[k * l + j] =
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inverse_matrix[k *
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error_index[l] + j];
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}
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} else {
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// decoding matrix element for coding chunks
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for (i = 0; i < k; i++) {
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unsigned char s = 0;
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for (j = 0; j < k; j++) {
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s ^= gf_mul(inverse_matrix[j * k + i],
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encode_matrix[k *
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error_index[l] + j]);
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}
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tmp_decode_matrix[k * l + i] = s;
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}
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}
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}
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ec_init_tables (k, errs, tmp_decode_matrix, tmp_decode_tbls);
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*decode_matrix = tmp_decode_matrix;
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*decode_tbls = tmp_decode_tbls;
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*decode_index = tmp_decode_index;
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return 0;
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}
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