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-rw-r--r--src/erasure-code/shec/ErasureCodeShec.cc809
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diff --git a/src/erasure-code/shec/ErasureCodeShec.cc b/src/erasure-code/shec/ErasureCodeShec.cc
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+++ b/src/erasure-code/shec/ErasureCodeShec.cc
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+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
+// vim: ts=8 sw=2 smarttab
+/*
+ * Ceph - scalable distributed file system
+ *
+ * Copyright (C) 2014 FUJITSU LIMITED
+ * Copyright (C) 2013,2014 Cloudwatt <libre.licensing@cloudwatt.com>
+ * Copyright (C) 2014 Red Hat <contact@redhat.com>
+ *
+ * Author: Takanori Nakao <nakao.takanori@jp.fujitsu.com>
+ * Author: Takeshi Miyamae <miyamae.takeshi@jp.fujitsu.com>
+ * Author: Loic Dachary <loic@dachary.org>
+ *
+ * This library 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 2.1 of the License, or (at your option) any later version.
+ *
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <algorithm>
+using namespace std;
+
+#include "common/debug.h"
+#include "ErasureCodeShec.h"
+extern "C" {
+#include "jerasure/include/jerasure.h"
+#include "jerasure/include/galois.h"
+
+extern int calc_determinant(int *matrix, int dim);
+extern int* reed_sol_vandermonde_coding_matrix(int k, int m, int w);
+}
+
+#define dout_context g_ceph_context
+#define dout_subsys ceph_subsys_osd
+#undef dout_prefix
+#define dout_prefix _prefix(_dout)
+
+static ostream& _prefix(std::ostream* _dout)
+{
+ return *_dout << "ErasureCodeShec: ";
+}
+
+int ErasureCodeShec::init(ErasureCodeProfile &profile,
+ ostream *ss)
+{
+ int err = 0;
+ err |= parse(profile);
+ if (err)
+ return err;
+ prepare();
+ return ErasureCode::init(profile, ss);
+}
+
+unsigned int ErasureCodeShec::get_chunk_size(unsigned int object_size) const
+{
+ unsigned alignment = get_alignment();
+ unsigned tail = object_size % alignment;
+ unsigned padded_length = object_size + ( tail ? ( alignment - tail ) : 0 );
+
+ ceph_assert(padded_length % k == 0);
+ return padded_length / k;
+}
+
+int ErasureCodeShec::_minimum_to_decode(const set<int> &want_to_read,
+ const set<int> &available_chunks,
+ set<int> *minimum_chunks)
+{
+ if (!minimum_chunks) return -EINVAL;
+
+ for (set<int>::iterator it = available_chunks.begin(); it != available_chunks.end(); ++it){
+ if (*it < 0 || k+m <= *it) return -EINVAL;
+ }
+
+ for (set<int>::iterator it = want_to_read.begin(); it != want_to_read.end(); ++it){
+ if (*it < 0 || k+m <= *it) return -EINVAL;
+ }
+
+ int want[k + m];
+ int avails[k + m];
+ int minimum[k + m];
+
+ memset(want, 0, sizeof(want));
+ memset(avails, 0, sizeof(avails));
+ memset(minimum, 0, sizeof(minimum));
+ (*minimum_chunks).clear();
+
+ for (set<int>::const_iterator i = want_to_read.begin();
+ i != want_to_read.end();
+ ++i) {
+ want[*i] = 1;
+ }
+
+ for (set<int>::const_iterator i = available_chunks.begin();
+ i != available_chunks.end();
+ ++i) {
+ avails[*i] = 1;
+ }
+
+ {
+ int decoding_matrix[k*k];
+ int dm_row[k];
+ int dm_column[k];
+ memset(decoding_matrix, 0, sizeof(decoding_matrix));
+ memset(dm_row, 0, sizeof(dm_row));
+ memset(dm_column, 0, sizeof(dm_column));
+ if (shec_make_decoding_matrix(true, want, avails, decoding_matrix, dm_row, dm_column, minimum) < 0) {
+ return -EIO;
+ }
+ }
+
+ for (int i = 0; i < k + m; i++) {
+ if (minimum[i] == 1) minimum_chunks->insert(i);
+ }
+
+ return 0;
+}
+
+int ErasureCodeShec::minimum_to_decode_with_cost(const set<int> &want_to_read,
+ const map<int, int> &available,
+ set<int> *minimum_chunks)
+{
+ set <int> available_chunks;
+
+ for (map<int, int>::const_iterator i = available.begin();
+ i != available.end();
+ ++i)
+ available_chunks.insert(i->first);
+
+ return _minimum_to_decode(want_to_read, available_chunks, minimum_chunks);
+}
+
+int ErasureCodeShec::encode(const set<int> &want_to_encode,
+ const bufferlist &in,
+ map<int, bufferlist> *encoded)
+{
+ unsigned int k = get_data_chunk_count();
+ unsigned int m = get_chunk_count() - k;
+ bufferlist out;
+
+ if (!encoded || !encoded->empty()){
+ return -EINVAL;
+ }
+
+ int err = encode_prepare(in, *encoded);
+ if (err)
+ return err;
+ encode_chunks(want_to_encode, encoded);
+ for (unsigned int i = 0; i < k + m; i++) {
+ if (want_to_encode.count(i) == 0)
+ encoded->erase(i);
+ }
+ return 0;
+}
+
+int ErasureCodeShec::encode_chunks(const set<int> &want_to_encode,
+ map<int, bufferlist> *encoded)
+{
+ char *chunks[k + m];
+ for (int i = 0; i < k + m; i++){
+ chunks[i] = (*encoded)[i].c_str();
+ }
+ shec_encode(&chunks[0], &chunks[k], (*encoded)[0].length());
+ return 0;
+}
+
+int ErasureCodeShec::_decode(const set<int> &want_to_read,
+ const map<int, bufferlist> &chunks,
+ map<int, bufferlist> *decoded)
+{
+ vector<int> have;
+
+ if (!decoded || !decoded->empty()){
+ return -EINVAL;
+ }
+
+ have.reserve(chunks.size());
+ for (map<int, bufferlist>::const_iterator i = chunks.begin();
+ i != chunks.end();
+ ++i) {
+ have.push_back(i->first);
+ }
+ if (includes(
+ have.begin(), have.end(), want_to_read.begin(), want_to_read.end())) {
+ for (set<int>::iterator i = want_to_read.begin();
+ i != want_to_read.end();
+ ++i) {
+ (*decoded)[*i] = chunks.find(*i)->second;
+ }
+ return 0;
+ }
+ unsigned int k = get_data_chunk_count();
+ unsigned int m = get_chunk_count() - k;
+ unsigned blocksize = (*chunks.begin()).second.length();
+ for (unsigned int i = 0; i < k + m; i++) {
+ if (chunks.find(i) == chunks.end()) {
+ bufferlist tmp;
+ bufferptr ptr(buffer::create_aligned(blocksize, SIMD_ALIGN));
+ tmp.push_back(ptr);
+ tmp.claim_append((*decoded)[i]);
+ (*decoded)[i].swap(tmp);
+ } else {
+ (*decoded)[i] = chunks.find(i)->second;
+ (*decoded)[i].rebuild_aligned(SIMD_ALIGN);
+ }
+ }
+ return decode_chunks(want_to_read, chunks, decoded);
+}
+
+int ErasureCodeShec::decode_chunks(const set<int> &want_to_read,
+ const map<int, bufferlist> &chunks,
+ map<int, bufferlist> *decoded)
+{
+ unsigned blocksize = (*chunks.begin()).second.length();
+ int erased[k + m];
+ int erased_count = 0;
+ int avails[k + m];
+ char *data[k];
+ char *coding[m];
+
+ for (int i = 0; i < k + m; i++) {
+ erased[i] = 0;
+ if (chunks.find(i) == chunks.end()) {
+ if (want_to_read.count(i) > 0) {
+ erased[i] = 1;
+ erased_count++;
+ }
+ avails[i] = 0;
+ } else {
+ avails[i] = 1;
+ }
+ if (i < k)
+ data[i] = (*decoded)[i].c_str();
+ else
+ coding[i - k] = (*decoded)[i].c_str();
+ }
+
+ if (erased_count > 0) {
+ return shec_decode(erased, avails, data, coding, blocksize);
+ } else {
+ return 0;
+ }
+}
+
+//
+// ErasureCodeShecReedSolomonVandermonde
+//
+
+void ErasureCodeShecReedSolomonVandermonde::shec_encode(char **data,
+ char **coding,
+ int blocksize)
+{
+ jerasure_matrix_encode(k, m, w, matrix, data, coding, blocksize);
+}
+
+int ErasureCodeShecReedSolomonVandermonde::shec_decode(int *erased,
+ int *avails,
+ char **data,
+ char **coding,
+ int blocksize)
+{
+ return shec_matrix_decode(erased, avails, data, coding, blocksize);
+}
+
+unsigned ErasureCodeShecReedSolomonVandermonde::get_alignment() const
+{
+ return k*w*sizeof(int);
+}
+
+int ErasureCodeShecReedSolomonVandermonde::parse(const ErasureCodeProfile &profile)
+{
+ int err = 0;
+ // k, m, c
+ if (profile.find("k") == profile.end() &&
+ profile.find("m") == profile.end() &&
+ profile.find("c") == profile.end()){
+ dout(10) << "(k, m, c) default to " << "(" << DEFAULT_K
+ << ", " << DEFAULT_M << ", " << DEFAULT_C << ")" << dendl;
+ k = DEFAULT_K; m = DEFAULT_M; c = DEFAULT_C;
+ } else if (profile.find("k") == profile.end() ||
+ profile.find("m") == profile.end() ||
+ profile.find("c") == profile.end()){
+ dout(10) << "(k, m, c) must be chosen" << dendl;
+ err = -EINVAL;
+ } else {
+ std::string err_k, err_m, err_c, value_k, value_m, value_c;
+ value_k = profile.find("k")->second;
+ value_m = profile.find("m")->second;
+ value_c = profile.find("c")->second;
+ k = strict_strtol(value_k.c_str(), 10, &err_k);
+ m = strict_strtol(value_m.c_str(), 10, &err_m);
+ c = strict_strtol(value_c.c_str(), 10, &err_c);
+
+ if (!err_k.empty() || !err_m.empty() || !err_c.empty()){
+ if (!err_k.empty()){
+ derr << "could not convert k=" << value_k << "to int" << dendl;
+ } else if (!err_m.empty()){
+ derr << "could not convert m=" << value_m << "to int" << dendl;
+ } else if (!err_c.empty()){
+ derr << "could not convert c=" << value_c << "to int" << dendl;
+ }
+ err = -EINVAL;
+ } else if (k <= 0){
+ derr << "k=" << k
+ << " must be a positive number" << dendl;
+ err = -EINVAL;
+ } else if (m <= 0){
+ derr << "m=" << m
+ << " must be a positive number" << dendl;
+ err = -EINVAL;
+ } else if (c <= 0){
+ derr << "c=" << c
+ << " must be a positive number" << dendl;
+ err = -EINVAL;
+ } else if (m < c){
+ derr << "c=" << c
+ << " must be less than or equal to m=" << m << dendl;
+ err = -EINVAL;
+ } else if (k > 12){
+ derr << "k=" << k
+ << " must be less than or equal to 12" << dendl;
+ err = -EINVAL;
+ } else if (k+m > 20){
+ derr << "k+m=" << k+m
+ << " must be less than or equal to 20" << dendl;
+ err = -EINVAL;
+ } else if (k<m){
+ derr << "m=" << m
+ << " must be less than or equal to k=" << k << dendl;
+ err = -EINVAL;
+ }
+ }
+
+ if (err) {
+ derr << "(k, m, c)=(" << k << ", " << m << ", " << c
+ << ") is not a valid parameter." << dendl;
+ return err;
+ }
+
+ dout(10) << "(k, m, c) set to " << "(" << k << ", " << m << ", "
+ << c << ")"<< dendl;
+
+ // w
+ if (profile.find("w") == profile.end()){
+ dout(10) << "w default to " << DEFAULT_W << dendl;
+ w = DEFAULT_W;
+ } else {
+ std::string err_w, value_w;
+ value_w = profile.find("w")->second;
+ w = strict_strtol(value_w.c_str(), 10, &err_w);
+
+ if (!err_w.empty()){
+ derr << "could not convert w=" << value_w << "to int" << dendl;
+ dout(10) << "w default to " << DEFAULT_W << dendl;
+ w = DEFAULT_W;
+
+ } else if (w != 8 && w != 16 && w != 32) {
+ derr << "w=" << w
+ << " must be one of {8, 16, 32}" << dendl;
+ dout(10) << "w default to " << DEFAULT_W << dendl;
+ w = DEFAULT_W;
+
+ } else {
+ dout(10) << "w set to " << w << dendl;
+ }
+ }
+ return 0;
+}
+
+void ErasureCodeShecReedSolomonVandermonde::prepare()
+{
+ // setup shared encoding table
+ int** p_enc_table =
+ tcache.getEncodingTable(technique, k, m, c, w);
+
+ if (!*p_enc_table) {
+ dout(10) << "[ cache tables ] creating coeff for k=" <<
+ k << " m=" << m << " c=" << c << " w=" << w << dendl;
+
+ matrix = shec_reedsolomon_coding_matrix(technique);
+
+ // either our new created table is stored or if it has been
+ // created in the meanwhile the locally allocated table will be
+ // freed by setEncodingTable
+ matrix = tcache.setEncodingTable(technique, k, m, c, w, matrix);
+
+ dout(10) << "matrix = " << dendl;
+ for (int i=0; i<m; i++) {
+ char mat[k+1];
+ for (int j=0; j<k; j++) {
+ if (matrix[i*k+j] > 0) {
+ mat[j] = '1';
+ } else {
+ mat[j] = '0';
+ }
+ }
+ mat[k] = '\0';
+ dout(10) << mat << dendl;
+ }
+ } else {
+ matrix = *p_enc_table;
+ }
+
+ dout(10) << " [ technique ] = " <<
+ ((technique == MULTIPLE) ? "multiple" : "single") << dendl;
+
+ ceph_assert((technique == SINGLE) || (technique == MULTIPLE));
+
+}
+
+// ErasureCodeShec::
+// Mearged from shec.cc.
+
+double ErasureCodeShec::shec_calc_recovery_efficiency1(int k, int m1, int m2, int c1, int c2){
+ int r_eff_k[k];
+ double r_e1;
+ int i, rr, cc, start, end;
+ int first_flag;
+
+ if (m1 < c1 || m2 < c2) return -1;
+ if ((m1 == 0 && c1 != 0) || (m2 == 0 && c2 != 0)) return -1;
+
+ for (i=0; i<k; i++) r_eff_k[i] = 100000000;
+ r_e1 = 0;
+
+ for (rr=0; rr<m1; rr++){
+ start = ((rr*k)/m1) % k;
+ end = (((rr+c1)*k)/m1) % k;
+ for (cc=start, first_flag=1; first_flag || cc!=end; cc=(cc+1)%k){
+ first_flag = 0;
+ r_eff_k[cc] = std::min(r_eff_k[cc], ((rr+c1)*k)/m1 - (rr*k)/m1);
+ }
+ r_e1 += ((rr+c1)*k)/m1 - (rr*k)/m1;
+ }
+
+ for (rr=0; rr<m2; rr++){
+ start = ((rr*k)/m2) % k;
+ end = (((rr+c2)*k)/m2) % k;
+ for (cc=start, first_flag=1; first_flag || cc!=end; cc=(cc+1)%k){
+ first_flag = 0;
+ r_eff_k[cc] = std::min(r_eff_k[cc], ((rr+c2)*k)/m2 - (rr*k)/m2);
+ }
+ r_e1 += ((rr+c2)*k)/m2 - (rr*k)/m2;
+ }
+
+ for (i=0; i<k; i++){
+ r_e1 += r_eff_k[i];
+ }
+
+ r_e1 /= (k+m1+m2);
+
+ return r_e1;
+}
+
+int* ErasureCodeShec::shec_reedsolomon_coding_matrix(int is_single)
+{
+ int *matrix;
+ int rr, cc, start, end;
+ int m1, m2, c1, c2;
+
+ if (w != 8 && w != 16 && w != 32) return NULL;
+
+ if (!is_single){
+ int c1_best = -1, m1_best = -1;
+ double min_r_e1 = 100.0;
+
+ // create all multiple shec pattern and choose best.
+
+ for (c1=0; c1 <= c/2; c1++){
+ for (m1=0; m1 <= m; m1++){
+ c2 = c-c1;
+ m2 = m-m1;
+
+ if (m1 < c1 || m2 < c2) continue;
+ if ((m1 == 0 && c1 != 0) || (m2 == 0 && c2 != 0)) continue;
+ if ((m1 != 0 && c1 == 0) || (m2 != 0 && c2 == 0)) continue;
+
+ // minimize r_e1
+
+ if (true) {
+ double r_e1;
+ r_e1 = shec_calc_recovery_efficiency1(k, m1, m2, c1, c2);
+ if (min_r_e1 - r_e1 > std::numeric_limits<double>::epsilon() &&
+ r_e1 < min_r_e1) {
+ min_r_e1 = r_e1;
+ c1_best = c1;
+ m1_best = m1;
+ }
+ }
+ }
+ }
+ m1 = m1_best;
+ c1 = c1_best;
+ m2 = m - m1_best;
+ c2 = c - c1_best;
+ } else {
+ m1 = 0;
+ c1 = 0;
+ m2 = m;
+ c2 = c;
+ }
+
+ // create matrix
+ matrix = reed_sol_vandermonde_coding_matrix(k, m, w);
+
+ for (rr=0; rr<m1; rr++){
+ end = ((rr*k)/m1) % k;
+ start = (((rr+c1)*k)/m1) % k;
+ for (cc=start; cc!=end; cc=(cc+1)%k){
+ matrix[cc + rr*k] = 0;
+ }
+ }
+
+ for (rr=0; rr<m2; rr++){
+ end = ((rr*k)/m2) % k;
+ start = (((rr+c2)*k)/m2) % k;
+ for (cc=start; cc!=end; cc=(cc+1)%k){
+ matrix[cc + (rr+m1)*k] = 0;
+ }
+ }
+
+ return matrix;
+}
+
+int ErasureCodeShec::shec_make_decoding_matrix(bool prepare, int *want_, int *avails,
+ int *decoding_matrix, int *dm_row, int *dm_column,
+ int *minimum)
+{
+ int mindup = k+1, minp = k+1;
+ int want[k + m];
+
+ memset(want, 0, sizeof(want));
+
+ for (int i = 0; i < k + m; ++i) {
+ want[i] = want_[i];
+ }
+
+ for (int i = 0; i < m; ++i) {
+ if (want[i + k] && !avails[i + k]) {
+ for (int j=0; j < k; ++j) {
+ if (matrix[i * k + j] > 0) {
+ want[j] = 1;
+ }
+ }
+ }
+ }
+
+ if (tcache.getDecodingTableFromCache(decoding_matrix,
+ dm_row, dm_column, minimum,
+ technique,
+ k, m, c, w,
+ want, avails)) {
+ return 0;
+ }
+
+ for (unsigned long long pp = 0; pp < (1ull << m); ++pp) {
+
+ // select parity chunks
+ int ek = 0;
+ int p[m];
+ for (int i=0; i < m; ++i) {
+ if (pp & (1ull << i)) {
+ p[ek++] = i;
+ }
+ }
+ if (ek > minp) {
+ continue;
+ }
+
+ // Are selected parity chunks avail?
+ bool ok = true;
+ for (int i = 0; i < ek && ok; i++) {
+ if (!avails[k+p[i]]) {
+ ok = false;
+ break;
+ }
+ }
+
+ if (!ok) {
+ continue;
+ }
+
+ int tmprow[k + m];
+ int tmpcolumn[k];
+ for (int i = 0; i < k + m; i++) {
+ tmprow[i] = 0;
+ }
+ for (int i = 0; i < k; i++) {
+ tmpcolumn[i] = 0;
+ }
+
+ for (int i=0; i < k; i++) {
+ if (want[i] && !avails[i]) {
+ tmpcolumn[i] = 1;
+ }
+ }
+
+ // Parity chunks which are used to recovery erased data chunks, are added to tmprow.
+ for (int i = 0; i < ek; i++) {
+ tmprow[k + p[i]] = 1;
+ for (int j = 0; j < k; j++) {
+ int element = matrix[(p[i]) * k + j];
+ if (element != 0) {
+ tmpcolumn[j] = 1;
+ }
+ if (element != 0 && avails[j] == 1) {
+ tmprow[j] = 1;
+ }
+ }
+ }
+
+ int dup_row = 0, dup_column = 0, dup = 0;
+ for (int i = 0; i < k + m; i++) {
+ if (tmprow[i]) {
+ dup_row++;
+ }
+ }
+
+ for (int i = 0; i < k; i++) {
+ if (tmpcolumn[i]) {
+ dup_column++;
+ }
+ }
+
+ if (dup_row != dup_column) {
+ continue;
+ }
+ dup = dup_row;
+ if (dup == 0) {
+ mindup = dup;
+ for (int i = 0; i < k; i++) {
+ dm_row[i] = -1;
+ }
+ for (int i = 0; i < k; i++) {
+ dm_column[i] = -1;
+ }
+ break;
+ }
+
+ // minimum is updated.
+ if (dup < mindup) {
+ int tmpmat[dup * dup];
+ {
+ for (int i = 0, row = 0; i < k + m; i++) {
+ if (tmprow[i]) {
+ for (int j = 0, column = 0; j < k; j++) {
+ if (tmpcolumn[j]) {
+ if (i < k) {
+ tmpmat[row * dup + column] = (i == j ? 1 : 0);
+ } else {
+ tmpmat[row * dup + column] = matrix[(i - k) * k + j];
+ }
+ column++;
+ }
+ }
+ row++;
+ }
+ }
+ }
+ int det = calc_determinant(tmpmat, dup);
+
+ if (det != 0) {
+ int row_id = 0;
+ int column_id = 0;
+ for (int i = 0; i < k; i++) {
+ dm_row[i] = -1;
+ }
+ for (int i = 0; i < k; i++) {
+ dm_column[i] = -1;
+ }
+
+ mindup = dup;
+ for (int i=0; i < k + m; i++) {
+ if (tmprow[i]) {
+ dm_row[row_id++] = i;
+ }
+ }
+ for (int i=0; i < k; i++) {
+ if (tmpcolumn[i]) {
+ dm_column[column_id++] = i;
+ }
+ }
+ minp = ek;
+ }
+ }
+ }
+
+
+ if (mindup == k+1) {
+ fprintf(stderr, "shec_make_decoding_matrix(): can't find recover matrix.\n");
+ return -1;
+ }
+
+ for (int i = 0; i < k + m; i++) {
+ minimum[i] = 0;
+ }
+
+ for (int i=0; i < k && dm_row[i] != -1; i++) {
+ minimum[dm_row[i]] = 1;
+ }
+
+ for (int i = 0; i < k; ++i) {
+ if (want[i] && avails[i]) {
+ minimum[i] = 1;
+ }
+ }
+
+ for (int i = 0; i < m; ++i) {
+ if (want[k + i] && avails[k + i] && !minimum[k + i]) {
+ for (int j = 0; j < k; ++j) {
+ if (matrix[i * k + j] > 0 && !want[j]) {
+ minimum[k + i] = 1;
+ break;
+ }
+ }
+ }
+ }
+
+ if (mindup == 0) {
+ return 0;
+ }
+
+ int tmpmat[mindup * mindup];
+ for (int i=0; i < mindup; i++) {
+ for (int j=0; j < mindup; j++) {
+ if (dm_row[i] < k) {
+ tmpmat[i * mindup + j] = (dm_row[i] == dm_column[j] ? 1 : 0);
+ } else {
+ tmpmat[i * mindup + j] = matrix[(dm_row[i] - k) * k + dm_column[j]];
+ }
+ }
+ if (dm_row[i] < k) {
+ for (int j = 0; j < mindup; j++) {
+ if (dm_row[i] == dm_column[j]) {
+ dm_row[i] = j;
+ }
+ }
+ } else {
+ dm_row[i] -= (k - mindup);
+ }
+ }
+
+ if (prepare) {
+ return 0;
+ }
+
+ int ret = jerasure_invert_matrix(tmpmat, decoding_matrix, mindup, w);
+
+ tcache.putDecodingTableToCache(decoding_matrix, dm_row, dm_column, minimum, technique,
+ k, m, c, w, want, avails);
+
+ return ret;
+}
+
+int ErasureCodeShec::shec_matrix_decode(int *want, int *avails, char **data_ptrs,
+ char **coding_ptrs, int size)
+{
+ int decoding_matrix[k*k];
+ int dm_row[k], dm_column[k];
+ int minimum[k + m];
+
+ memset(decoding_matrix, 0, sizeof(decoding_matrix));
+ memset(dm_row, -1, sizeof(dm_row));
+ memset(dm_column, -1, sizeof(dm_column));
+ memset(minimum, -1, sizeof(minimum));
+
+ if (w != 8 && w != 16 && w != 32) return -1;
+
+ if (shec_make_decoding_matrix(false, want, avails, decoding_matrix,
+ dm_row, dm_column, minimum) < 0) {
+ return -1;
+ }
+
+ // Get decoding matrix size
+ int dm_size = 0;
+ for (int i = 0; i < k; i++) {
+ if (dm_row[i] == -1) {
+ break;
+ }
+ dm_size++;
+ }
+
+ char *dm_data_ptrs[dm_size];
+ for (int i = 0; i < dm_size; i++) {
+ dm_data_ptrs[i] = data_ptrs[dm_column[i]];
+ }
+
+ // Decode the data drives
+ for (int i = 0; i < dm_size; i++) {
+ if (!avails[dm_column[i]]) {
+ jerasure_matrix_dotprod(dm_size, w, decoding_matrix + (i * dm_size),
+ dm_row, i, dm_data_ptrs, coding_ptrs, size);
+ }
+ }
+
+ // Re-encode any erased coding devices
+ for (int i = 0; i < m; i++) {
+ if (want[k+i] && !avails[k+i]) {
+ jerasure_matrix_dotprod(k, w, matrix + (i * k), NULL, i+k,
+ data_ptrs, coding_ptrs, size);
+ }
+ }
+
+ return 0;
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-30 13:04:41 +0000