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Diffstat (limited to 'src/erasure-code/ErasureCode.cc')
| -rw-r--r-- | src/erasure-code/ErasureCode.cc | 349 |
1 files changed, 349 insertions, 0 deletions
diff --git a/src/erasure-code/ErasureCode.cc b/src/erasure-code/ErasureCode.cc new file mode 100644 index 000000000..0cebf9a98 --- /dev/null +++ b/src/erasure-code/ErasureCode.cc @@ -0,0 +1,349 @@ +// -*- 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 <libre.licensing@cloudwatt.com> + * Copyright (C) 2014 Red Hat <contact@redhat.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 <algorithm> +#include <cerrno> + +#include "ErasureCode.h" + +#include "common/strtol.h" +#include "include/buffer.h" +#include "crush/CrushWrapper.h" +#include "osd/osd_types.h" + +#define DEFAULT_RULE_ROOT "default" +#define DEFAULT_RULE_FAILURE_DOMAIN "host" + +using std::make_pair; +using std::map; +using std::ostream; +using std::pair; +using std::set; +using std::string; +using std::vector; + +using ceph::bufferlist; + +namespace ceph { +const unsigned ErasureCode::SIMD_ALIGN = 32; + +int ErasureCode::init( + ErasureCodeProfile &profile, + std::ostream *ss) +{ + int err = 0; + err |= to_string("crush-root", profile, + &rule_root, + DEFAULT_RULE_ROOT, ss); + err |= to_string("crush-failure-domain", profile, + &rule_failure_domain, + DEFAULT_RULE_FAILURE_DOMAIN, ss); + err |= to_string("crush-device-class", profile, + &rule_device_class, + "", ss); + if (err) + return err; + _profile = profile; + return 0; +} + +int ErasureCode::create_rule( + const std::string &name, + CrushWrapper &crush, + std::ostream *ss) const +{ + int ruleid = crush.add_simple_rule( + name, + rule_root, + rule_failure_domain, + rule_device_class, + "indep", + pg_pool_t::TYPE_ERASURE, + ss); + + if (ruleid < 0) + return ruleid; + + crush.set_rule_mask_max_size(ruleid, get_chunk_count()); + return ruleid; +} + +int ErasureCode::sanity_check_k_m(int k, int m, ostream *ss) +{ + if (k < 2) { + *ss << "k=" << k << " must be >= 2" << std::endl; + return -EINVAL; + } + if (m < 1) { + *ss << "m=" << m << " must be >= 1" << std::endl; + return -EINVAL; + } + return 0; +} + +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(const set<int> &want_to_read, + const set<int> &available_chunks, + map<int, vector<pair<int, int>>> *minimum) +{ + set<int> minimum_shard_ids; + int r = _minimum_to_decode(want_to_read, available_chunks, &minimum_shard_ids); + if (r != 0) { + return r; + } + vector<pair<int, int>> default_subchunks; + default_subchunks.push_back(make_pair(0, get_sub_chunk_count())); + for (auto &&id : minimum_shard_ids) { + minimum->insert(make_pair(id, default_subchunks)); + } + 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); + ceph_assert(chunk.is_contiguous()); + } + if (padded_chunks) { + unsigned remainder = raw.length() - (k - padded_chunks) * blocksize; + bufferptr buf(buffer::create_aligned(blocksize, SIMD_ALIGN)); + + raw.begin((k - padded_chunks) * blocksize).copy(remainder, buf.c_str()); + buf.zero(remainder, blocksize - remainder); + encoded[chunk_index(k-padded_chunks)].push_back(std::move(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(std::move(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::_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()) { + 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 ErasureCode::decode(const set<int> &want_to_read, + const map<int, bufferlist> &chunks, + map<int, bufferlist> *decoded, int chunk_size) +{ + return _decode(want_to_read, chunks, decoded); +} + +int ErasureCode::parse(const ErasureCodeProfile &profile, + ostream *ss) +{ + return to_mapping(profile, ss); +} + +const vector<int> &ErasureCode::get_chunk_mapping() const { + return chunk_mapping; +} + +int ErasureCode::to_mapping(const ErasureCodeProfile &profile, + ostream *ss) +{ + if (profile.find("mapping") != profile.end()) { + std::string mapping = profile.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, + ErasureCodeProfile &profile, + int *value, + const std::string &default_value, + ostream *ss) +{ + if (profile.find(name) == profile.end() || + profile.find(name)->second.size() == 0) + profile[name] = default_value; + std::string p = profile.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 = strict_strtol(default_value.c_str(), 10, &err); + return -EINVAL; + } + *value = r; + return 0; +} + +int ErasureCode::to_bool(const std::string &name, + ErasureCodeProfile &profile, + bool *value, + const std::string &default_value, + ostream *ss) +{ + if (profile.find(name) == profile.end() || + profile.find(name)->second.size() == 0) + profile[name] = default_value; + const std::string p = profile.find(name)->second; + *value = (p == "yes") || (p == "true"); + return 0; +} + +int ErasureCode::to_string(const std::string &name, + ErasureCodeProfile &profile, + std::string *value, + const std::string &default_value, + ostream *ss) +{ + if (profile.find(name) == profile.end() || + profile.find(name)->second.size() == 0) + profile[name] = default_value; + *value = profile[name]; + 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; +} +} |