-
Notifications
You must be signed in to change notification settings - Fork 0
Expand file tree
/
Copy pathErasureCode.cc
More file actions
254 lines (232 loc) · 7.58 KB
/
Copy pathErasureCode.cc
File metadata and controls
254 lines (232 loc) · 7.58 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
// vim: ts=8 sw=2 smarttab
/*
* Ceph distributed storage system
*
* Copyright (C) 2014 Cloudwatt <[email protected]>
* Copyright (C) 2014 Red Hat <[email protected]>
*
* Author: Loic Dachary <[email protected]>
*
* 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 <errno.h>
#include <vector>
#include <algorithm>
#include "common/strtol.h"
#include "ErasureCode.h"
const unsigned ErasureCode::SIMD_ALIGN = 32;
int ErasureCode::chunk_index(unsigned int i) const
{
return chunk_mapping.size() > i ? chunk_mapping[i] : i;
}
int ErasureCode::minimum_to_decode(const set<int> &want_to_read,
const set<int> &available_chunks,
set<int> *minimum)
{
if (includes(available_chunks.begin(), available_chunks.end(),
want_to_read.begin(), want_to_read.end())) {
*minimum = want_to_read;
} else {
unsigned int k = get_data_chunk_count();
if (available_chunks.size() < (unsigned)k)
return -EIO;
set<int>::iterator i;
unsigned j;
for (i = available_chunks.begin(), j = 0; j < (unsigned)k; ++i, j++)
minimum->insert(*i);
}
return 0;
}
int ErasureCode::minimum_to_decode_with_cost(const set<int> &want_to_read,
const map<int, int> &available,
set<int> *minimum)
{
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);
}
int ErasureCode::encode_prepare(const bufferlist &raw,
map<int, bufferlist> &encoded) const
{
unsigned int k = get_data_chunk_count();
unsigned int m = get_chunk_count() - k;
unsigned blocksize = get_chunk_size(raw.length());
unsigned padded_chunks = k - raw.length() / blocksize;
bufferlist prepared = raw;
for (unsigned int i = 0; i < k - padded_chunks; i++) {
bufferlist &chunk = encoded[chunk_index(i)];
chunk.substr_of(prepared, i * blocksize, blocksize);
chunk.rebuild_aligned_size_and_memory(blocksize, SIMD_ALIGN);
assert(chunk.is_contiguous());
}
if (padded_chunks) {
unsigned remainder = raw.length() - (k - padded_chunks) * blocksize;
bufferptr buf(buffer::create_aligned(blocksize, SIMD_ALIGN));
raw.copy((k - padded_chunks) * blocksize, remainder, buf.c_str());
buf.zero(remainder, blocksize - remainder);
encoded[chunk_index(k-padded_chunks)].push_back(buf);
for (unsigned int i = k - padded_chunks + 1; i < k; i++) {
bufferptr buf(buffer::create_aligned(blocksize, SIMD_ALIGN));
buf.zero();
encoded[chunk_index(i)].push_back(buf);
}
}
for (unsigned int i = k; i < k + m; i++) {
bufferlist &chunk = encoded[chunk_index(i)];
chunk.push_back(buffer::create_aligned(blocksize, SIMD_ALIGN));
}
return 0;
}
int ErasureCode::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;
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 ErasureCode::encode_chunks(const set<int> &want_to_encode,
map<int, bufferlist> *encoded)
{
assert("ErasureCode::encode_chunks not implemented" == 0);
}
int ErasureCode::decode(const set<int> &want_to_read,
const map<int, bufferlist> &chunks,
map<int, bufferlist> *decoded)
{
vector<int> have;
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()) {
bufferptr ptr(buffer::create_aligned(blocksize, SIMD_ALIGN));
(*decoded)[i].push_front(ptr);
} else {
(*decoded)[i] = chunks.find(i)->second;
(*decoded)[i].rebuild_aligned(SIMD_ALIGN);
}
}
return decode_chunks(want_to_read, chunks, decoded);
}
int ErasureCode::decode_chunks(const set<int> &want_to_read,
const map<int, bufferlist> &chunks,
map<int, bufferlist> *decoded)
{
assert("ErasureCode::decode_chunks not implemented" == 0);
}
int ErasureCode::parse(const map<std::string,std::string> ¶meters,
ostream *ss)
{
return to_mapping(parameters, ss);
}
const vector<int> &ErasureCode::get_chunk_mapping() const {
return chunk_mapping;
}
int ErasureCode::to_mapping(const map<std::string,std::string> ¶meters,
ostream *ss)
{
if (parameters.find("mapping") != parameters.end()) {
std::string mapping = parameters.find("mapping")->second;
int position = 0;
vector<int> coding_chunk_mapping;
for(std::string::iterator it = mapping.begin(); it != mapping.end(); ++it) {
if (*it == 'D')
chunk_mapping.push_back(position);
else
coding_chunk_mapping.push_back(position);
position++;
}
chunk_mapping.insert(chunk_mapping.end(),
coding_chunk_mapping.begin(),
coding_chunk_mapping.end());
}
return 0;
}
int ErasureCode::to_int(const std::string &name,
const map<std::string,std::string> ¶meters,
int *value,
int default_value,
ostream *ss)
{
if (parameters.find(name) == parameters.end() ||
parameters.find(name)->second.size() == 0) {
*value = default_value;
return 0;
}
std::string p = parameters.find(name)->second;
std::string err;
int r = strict_strtol(p.c_str(), 10, &err);
if (!err.empty()) {
*ss << "could not convert " << name << "=" << p
<< " to int because " << err
<< ", set to default " << default_value << std::endl;
*value = default_value;
return -EINVAL;
}
*value = r;
return 0;
}
int ErasureCode::to_bool(const std::string &name,
const map<std::string,std::string> ¶meters,
bool *value,
bool default_value,
ostream *ss)
{
if (parameters.find(name) == parameters.end() ||
parameters.find(name)->second.size() == 0) {
*value = default_value;
return 0;
}
const std::string p = parameters.find(name)->second;
*value = (p == "yes") || (p == "true");
return 0;
}
int ErasureCode::decode_concat(const map<int, bufferlist> &chunks,
bufferlist *decoded)
{
set<int> want_to_read;
for (unsigned int i = 0; i < get_data_chunk_count(); i++) {
want_to_read.insert(chunk_index(i));
}
map<int, bufferlist> decoded_map;
int r = decode(want_to_read, chunks, &decoded_map);
if (r == 0) {
for (unsigned int i = 0; i < get_data_chunk_count(); i++) {
decoded->claim_append(decoded_map[chunk_index(i)]);
}
}
return r;
}