// Copyright (c) 2013, Facebook, Inc. All rights reserved. // This source code is licensed under the BSD-style license found in the // LICENSE file in the root directory of this source tree. An additional grant // of patent rights can be found in the PATENTS file in the same directory. // // Copyright (c) 2011 The LevelDB Authors. All rights reserved. // Use of this source code is governed by a BSD-style license that can be // found in the LICENSE file. See the AUTHORS file for names of contributors. #include "db/db_impl.h" #ifndef __STDC_FORMAT_MACROS #define __STDC_FORMAT_MACROS #endif #include #include #include #include #include #include #include #include #include #include #include #include #include "db/builder.h" #include "db/db_iter.h" #include "db/dbformat.h" #include "db/filename.h" #include "db/log_reader.h" #include "db/log_writer.h" #include "db/memtable.h" #include "db/memtable_list.h" #include "db/merge_context.h" #include "db/merge_helper.h" #include "db/table_cache.h" #include "db/table_properties_collector.h" #include "db/forward_iterator.h" #include "db/transaction_log_impl.h" #include "db/version_set.h" #include "db/write_batch_internal.h" #include "port/port.h" #include "rocksdb/cache.h" #include "port/likely.h" #include "rocksdb/compaction_filter.h" #include "rocksdb/db.h" #include "rocksdb/env.h" #include "rocksdb/merge_operator.h" #include "rocksdb/statistics.h" #include "rocksdb/status.h" #include "rocksdb/table.h" #include "table/block.h" #include "table/block_based_table_factory.h" #include "table/merger.h" #include "table/table_builder.h" #include "table/two_level_iterator.h" #include "util/auto_roll_logger.h" #include "util/autovector.h" #include "util/build_version.h" #include "util/coding.h" #include "util/hash_skiplist_rep.h" #include "util/hash_linklist_rep.h" #include "util/logging.h" #include "util/log_buffer.h" #include "util/mutexlock.h" #include "util/perf_context_imp.h" #include "util/iostats_context_imp.h" #include "util/stop_watch.h" #include "util/sync_point.h" namespace rocksdb { const std::string kDefaultColumnFamilyName("default"); void DumpLeveldbBuildVersion(Logger * log); // Information kept for every waiting writer struct DBImpl::Writer { Status status; WriteBatch* batch; bool sync; bool disableWAL; bool in_batch_group; bool done; uint64_t timeout_hint_us; port::CondVar cv; explicit Writer(port::Mutex* mu) : cv(mu) { } }; struct DBImpl::WriteContext { autovector superversions_to_free_; autovector logs_to_free_; ~WriteContext() { for (auto& sv : superversions_to_free_) { delete sv; } for (auto& log : logs_to_free_) { delete log; } } }; struct DBImpl::CompactionState { Compaction* const compaction; // If there were two snapshots with seq numbers s1 and // s2 and s1 < s2, and if we find two instances of a key k1 then lies // entirely within s1 and s2, then the earlier version of k1 can be safely // deleted because that version is not visible in any snapshot. std::vector existing_snapshots; // Files produced by compaction struct Output { uint64_t number; uint32_t path_id; uint64_t file_size; InternalKey smallest, largest; SequenceNumber smallest_seqno, largest_seqno; }; std::vector outputs; std::list allocated_file_numbers; // State kept for output being generated unique_ptr outfile; unique_ptr builder; uint64_t total_bytes; Output* current_output() { return &outputs[outputs.size()-1]; } explicit CompactionState(Compaction* c) : compaction(c), total_bytes(0) { } // Create a client visible context of this compaction CompactionFilter::Context GetFilterContextV1() { CompactionFilter::Context context; context.is_full_compaction = compaction->IsFullCompaction(); context.is_manual_compaction = compaction->IsManualCompaction(); return context; } // Create a client visible context of this compaction CompactionFilterContext GetFilterContext() { CompactionFilterContext context; context.is_full_compaction = compaction->IsFullCompaction(); context.is_manual_compaction = compaction->IsManualCompaction(); return context; } std::vector key_str_buf_; std::vector existing_value_str_buf_; // new_value_buf_ will only be appended if a value changes std::vector new_value_buf_; // if values_changed_buf_[i] is true // new_value_buf_ will add a new entry with the changed value std::vector value_changed_buf_; // to_delete_buf_[i] is true iff key_buf_[i] is deleted std::vector to_delete_buf_; std::vector other_key_str_buf_; std::vector other_value_str_buf_; std::vector combined_key_buf_; std::vector combined_value_buf_; std::string cur_prefix_; // Buffers the kv-pair that will be run through compaction filter V2 // in the future. void BufferKeyValueSlices(const Slice& key, const Slice& value) { key_str_buf_.emplace_back(key.ToString()); existing_value_str_buf_.emplace_back(value.ToString()); } // Buffers the kv-pair that will not be run through compaction filter V2 // in the future. void BufferOtherKeyValueSlices(const Slice& key, const Slice& value) { other_key_str_buf_.emplace_back(key.ToString()); other_value_str_buf_.emplace_back(value.ToString()); } // Add a kv-pair to the combined buffer void AddToCombinedKeyValueSlices(const Slice& key, const Slice& value) { // The real strings are stored in the batch buffers combined_key_buf_.emplace_back(key); combined_value_buf_.emplace_back(value); } // Merging the two buffers void MergeKeyValueSliceBuffer(const InternalKeyComparator* comparator) { size_t i = 0; size_t j = 0; size_t total_size = key_str_buf_.size() + other_key_str_buf_.size(); combined_key_buf_.reserve(total_size); combined_value_buf_.reserve(total_size); while (i + j < total_size) { int comp_res = 0; if (i < key_str_buf_.size() && j < other_key_str_buf_.size()) { comp_res = comparator->Compare(key_str_buf_[i], other_key_str_buf_[j]); } else if (i >= key_str_buf_.size() && j < other_key_str_buf_.size()) { comp_res = 1; } else if (j >= other_key_str_buf_.size() && i < key_str_buf_.size()) { comp_res = -1; } if (comp_res > 0) { AddToCombinedKeyValueSlices(other_key_str_buf_[j], other_value_str_buf_[j]); j++; } else if (comp_res < 0) { AddToCombinedKeyValueSlices(key_str_buf_[i], existing_value_str_buf_[i]); i++; } } } void CleanupBatchBuffer() { to_delete_buf_.clear(); key_str_buf_.clear(); existing_value_str_buf_.clear(); new_value_buf_.clear(); value_changed_buf_.clear(); to_delete_buf_.shrink_to_fit(); key_str_buf_.shrink_to_fit(); existing_value_str_buf_.shrink_to_fit(); new_value_buf_.shrink_to_fit(); value_changed_buf_.shrink_to_fit(); other_key_str_buf_.clear(); other_value_str_buf_.clear(); other_key_str_buf_.shrink_to_fit(); other_value_str_buf_.shrink_to_fit(); } void CleanupMergedBuffer() { combined_key_buf_.clear(); combined_value_buf_.clear(); combined_key_buf_.shrink_to_fit(); combined_value_buf_.shrink_to_fit(); } }; Options SanitizeOptions(const std::string& dbname, const InternalKeyComparator* icmp, const Options& src) { auto db_options = SanitizeOptions(dbname, DBOptions(src)); auto cf_options = SanitizeOptions(icmp, ColumnFamilyOptions(src)); return Options(db_options, cf_options); } DBOptions SanitizeOptions(const std::string& dbname, const DBOptions& src) { DBOptions result = src; // result.max_open_files means an "infinite" open files. if (result.max_open_files != -1) { ClipToRange(&result.max_open_files, 20, 1000000); } if (result.info_log == nullptr) { Status s = CreateLoggerFromOptions(dbname, result.db_log_dir, src.env, result, &result.info_log); if (!s.ok()) { // No place suitable for logging result.info_log = nullptr; } } if (!result.rate_limiter) { if (result.bytes_per_sync == 0) { result.bytes_per_sync = 1024 * 1024; } } if (result.wal_dir.empty()) { // Use dbname as default result.wal_dir = dbname; } if (result.wal_dir.back() == '/') { result.wal_dir = result.wal_dir.substr(0, result.wal_dir.size() - 1); } if (result.db_paths.size() == 0) { result.db_paths.emplace_back(dbname, std::numeric_limits::max()); } return result; } namespace { Status SanitizeDBOptionsByCFOptions( const DBOptions* db_opts, const std::vector& column_families) { Status s; for (auto cf : column_families) { s = cf.options.table_factory->SanitizeDBOptions(db_opts); if (!s.ok()) { return s; } } return Status::OK(); } CompressionType GetCompressionFlush(const Options& options) { // Compressing memtable flushes might not help unless the sequential load // optimization is used for leveled compaction. Otherwise the CPU and // latency overhead is not offset by saving much space. bool can_compress; if (options.compaction_style == kCompactionStyleUniversal) { can_compress = (options.compaction_options_universal.compression_size_percent < 0); } else { // For leveled compress when min_level_to_compress == 0. can_compress = options.compression_per_level.empty() || options.compression_per_level[0] != kNoCompression; } if (can_compress) { return options.compression; } else { return kNoCompression; } } } // namespace DBImpl::DBImpl(const DBOptions& options, const std::string& dbname) : env_(options.env), dbname_(dbname), options_(SanitizeOptions(dbname, options)), stats_(options_.statistics.get()), db_lock_(nullptr), mutex_(options.use_adaptive_mutex), shutting_down_(nullptr), bg_cv_(&mutex_), logfile_number_(0), log_empty_(true), default_cf_handle_(nullptr), total_log_size_(0), max_total_in_memory_state_(0), tmp_batch_(), bg_schedule_needed_(false), bg_compaction_scheduled_(0), bg_manual_only_(0), bg_flush_scheduled_(0), manual_compaction_(nullptr), disable_delete_obsolete_files_(0), delete_obsolete_files_last_run_(options.env->NowMicros()), purge_wal_files_last_run_(0), last_stats_dump_time_microsec_(0), default_interval_to_delete_obsolete_WAL_(600), flush_on_destroy_(false), delayed_writes_(0), env_options_(options), bg_work_gate_closed_(false), refitting_level_(false), opened_successfully_(false) { env_->GetAbsolutePath(dbname, &db_absolute_path_); // Reserve ten files or so for other uses and give the rest to TableCache. // Give a large number for setting of "infinite" open files. const int table_cache_size = (options_.max_open_files == -1) ? 4194304 : options_.max_open_files - 10; // Reserve ten files or so for other uses and give the rest to TableCache. table_cache_ = NewLRUCache(table_cache_size, options_.table_cache_numshardbits, options_.table_cache_remove_scan_count_limit); versions_.reset( new VersionSet(dbname_, &options_, env_options_, table_cache_.get())); column_family_memtables_.reset( new ColumnFamilyMemTablesImpl(versions_->GetColumnFamilySet())); DumpLeveldbBuildVersion(options_.info_log.get()); DumpDBFileSummary(options_, dbname_); options_.Dump(options_.info_log.get()); LogFlush(options_.info_log); } DBImpl::~DBImpl() { mutex_.Lock(); if (flush_on_destroy_) { for (auto cfd : *versions_->GetColumnFamilySet()) { if (cfd->mem()->GetFirstSequenceNumber() != 0) { cfd->Ref(); mutex_.Unlock(); FlushMemTable(cfd, FlushOptions()); mutex_.Lock(); cfd->Unref(); } } versions_->GetColumnFamilySet()->FreeDeadColumnFamilies(); } // Wait for background work to finish shutting_down_.Release_Store(this); // Any non-nullptr value is ok while (bg_compaction_scheduled_ || bg_flush_scheduled_) { bg_cv_.Wait(); } if (default_cf_handle_ != nullptr) { // we need to delete handle outside of lock because it does its own locking mutex_.Unlock(); delete default_cf_handle_; mutex_.Lock(); } if (options_.allow_thread_local) { // Clean up obsolete files due to SuperVersion release. // (1) Need to delete to obsolete files before closing because RepairDB() // scans all existing files in the file system and builds manifest file. // Keeping obsolete files confuses the repair process. // (2) Need to check if we Open()/Recover() the DB successfully before // deleting because if VersionSet recover fails (may be due to corrupted // manifest file), it is not able to identify live files correctly. As a // result, all "live" files can get deleted by accident. However, corrupted // manifest is recoverable by RepairDB(). if (opened_successfully_) { DeletionState deletion_state; FindObsoleteFiles(deletion_state, true); // manifest number starting from 2 deletion_state.manifest_file_number = 1; if (deletion_state.HaveSomethingToDelete()) { PurgeObsoleteFiles(deletion_state); } } } // versions need to be destroyed before table_cache since it can hold // references to table_cache. versions_.reset(); mutex_.Unlock(); if (db_lock_ != nullptr) { env_->UnlockFile(db_lock_); } LogFlush(options_.info_log); } Status DBImpl::NewDB() { VersionEdit new_db; new_db.SetLogNumber(0); new_db.SetNextFile(2); new_db.SetLastSequence(0); Log(options_.info_log, "Creating manifest 1 \n"); const std::string manifest = DescriptorFileName(dbname_, 1); unique_ptr file; Status s = env_->NewWritableFile( manifest, &file, env_->OptimizeForManifestWrite(env_options_)); if (!s.ok()) { return s; } file->SetPreallocationBlockSize(options_.manifest_preallocation_size); { log::Writer log(std::move(file)); std::string record; new_db.EncodeTo(&record); s = log.AddRecord(record); } if (s.ok()) { // Make "CURRENT" file that points to the new manifest file. s = SetCurrentFile(env_, dbname_, 1, db_directory_.get()); } else { env_->DeleteFile(manifest); } return s; } void DBImpl::MaybeIgnoreError(Status* s) const { if (s->ok() || options_.paranoid_checks) { // No change needed } else { Log(options_.info_log, "Ignoring error %s", s->ToString().c_str()); *s = Status::OK(); } } const Status DBImpl::CreateArchivalDirectory() { if (options_.WAL_ttl_seconds > 0 || options_.WAL_size_limit_MB > 0) { std::string archivalPath = ArchivalDirectory(options_.wal_dir); return env_->CreateDirIfMissing(archivalPath); } return Status::OK(); } void DBImpl::PrintStatistics() { auto dbstats = options_.statistics.get(); if (dbstats) { Log(options_.info_log, "STATISTCS:\n %s", dbstats->ToString().c_str()); } } void DBImpl::MaybeDumpStats() { if (options_.stats_dump_period_sec == 0) return; const uint64_t now_micros = env_->NowMicros(); if (last_stats_dump_time_microsec_ + options_.stats_dump_period_sec * 1000000 <= now_micros) { // Multiple threads could race in here simultaneously. // However, the last one will update last_stats_dump_time_microsec_ // atomically. We could see more than one dump during one dump // period in rare cases. last_stats_dump_time_microsec_ = now_micros; bool tmp1 = false; bool tmp2 = false; DBPropertyType cf_property_type = GetPropertyType("rocksdb.cfstats", &tmp1, &tmp2); DBPropertyType db_property_type = GetPropertyType("rocksdb.dbstats", &tmp1, &tmp2); std::string stats; { MutexLock l(&mutex_); for (auto cfd : *versions_->GetColumnFamilySet()) { cfd->internal_stats()->GetStringProperty(cf_property_type, "rocksdb.cfstats", &stats); } default_cf_internal_stats_->GetStringProperty(db_property_type, "rocksdb.dbstats", &stats); } Log(options_.info_log, "------- DUMPING STATS -------"); Log(options_.info_log, "%s", stats.c_str()); PrintStatistics(); } } // Returns the list of live files in 'sst_live' and the list // of all files in the filesystem in 'candidate_files'. // no_full_scan = true -- never do the full scan using GetChildren() // force = false -- don't force the full scan, except every // options_.delete_obsolete_files_period_micros // force = true -- force the full scan void DBImpl::FindObsoleteFiles(DeletionState& deletion_state, bool force, bool no_full_scan) { mutex_.AssertHeld(); // if deletion is disabled, do nothing if (disable_delete_obsolete_files_ > 0) { return; } bool doing_the_full_scan = false; // logic for figurint out if we're doing the full scan if (no_full_scan) { doing_the_full_scan = false; } else if (force || options_.delete_obsolete_files_period_micros == 0) { doing_the_full_scan = true; } else { const uint64_t now_micros = env_->NowMicros(); if (delete_obsolete_files_last_run_ + options_.delete_obsolete_files_period_micros < now_micros) { doing_the_full_scan = true; delete_obsolete_files_last_run_ = now_micros; } } // get obsolete files versions_->GetObsoleteFiles(&deletion_state.sst_delete_files); // store the current filenum, lognum, etc deletion_state.manifest_file_number = versions_->ManifestFileNumber(); deletion_state.pending_manifest_file_number = versions_->PendingManifestFileNumber(); deletion_state.log_number = versions_->MinLogNumber(); deletion_state.prev_log_number = versions_->PrevLogNumber(); if (!doing_the_full_scan && !deletion_state.HaveSomethingToDelete()) { // avoid filling up sst_live if we're sure that we // are not going to do the full scan and that we don't have // anything to delete at the moment return; } // don't delete live files for (auto pair : pending_outputs_) { deletion_state.sst_live.emplace_back(pair.first, pair.second, 0); } /* deletion_state.sst_live.insert(pending_outputs_.begin(), pending_outputs_.end());*/ versions_->AddLiveFiles(&deletion_state.sst_live); if (doing_the_full_scan) { for (uint32_t path_id = 0; path_id < options_.db_paths.size(); path_id++) { // set of all files in the directory. We'll exclude files that are still // alive in the subsequent processings. std::vector files; env_->GetChildren(options_.db_paths[path_id].path, &files); // Ignore errors for (std::string file : files) { deletion_state.candidate_files.emplace_back(file, path_id); } } //Add log files in wal_dir if (options_.wal_dir != dbname_) { std::vector log_files; env_->GetChildren(options_.wal_dir, &log_files); // Ignore errors for (std::string log_file : log_files) { deletion_state.candidate_files.emplace_back(log_file, 0); } } // Add info log files in db_log_dir if (!options_.db_log_dir.empty() && options_.db_log_dir != dbname_) { std::vector info_log_files; env_->GetChildren(options_.db_log_dir, &info_log_files); // Ignore errors for (std::string log_file : info_log_files) { deletion_state.candidate_files.emplace_back(log_file, 0); } } } } namespace { bool CompareCandidateFile(const rocksdb::DBImpl::CandidateFileInfo& first, const rocksdb::DBImpl::CandidateFileInfo& second) { if (first.file_name > second.file_name) { return true; } else if (first.file_name < second.file_name) { return false; } else { return (first.path_id > second.path_id); } } }; // namespace // Diffs the files listed in filenames and those that do not // belong to live files are posibly removed. Also, removes all the // files in sst_delete_files and log_delete_files. // It is not necessary to hold the mutex when invoking this method. void DBImpl::PurgeObsoleteFiles(DeletionState& state) { // we'd better have sth to delete assert(state.HaveSomethingToDelete()); // this checks if FindObsoleteFiles() was run before. If not, don't do // PurgeObsoleteFiles(). If FindObsoleteFiles() was run, we need to also // run PurgeObsoleteFiles(), even if disable_delete_obsolete_files_ is true if (state.manifest_file_number == 0) { return; } // Now, convert live list to an unordered map, WITHOUT mutex held; // set is slow. std::unordered_map sst_live_map; for (FileDescriptor& fd : state.sst_live) { sst_live_map[fd.GetNumber()] = &fd; } auto& candidate_files = state.candidate_files; candidate_files.reserve( candidate_files.size() + state.sst_delete_files.size() + state.log_delete_files.size()); // We may ignore the dbname when generating the file names. const char* kDumbDbName = ""; for (auto file : state.sst_delete_files) { candidate_files.emplace_back( MakeTableFileName(kDumbDbName, file->fd.GetNumber()), file->fd.GetPathId()); delete file; } for (auto file_num : state.log_delete_files) { if (file_num > 0) { candidate_files.emplace_back(LogFileName(kDumbDbName, file_num).substr(1), 0); } } // dedup state.candidate_files so we don't try to delete the same // file twice sort(candidate_files.begin(), candidate_files.end(), CompareCandidateFile); candidate_files.erase(unique(candidate_files.begin(), candidate_files.end()), candidate_files.end()); std::vector old_info_log_files; InfoLogPrefix info_log_prefix(!options_.db_log_dir.empty(), dbname_); for (const auto& candidate_file : candidate_files) { std::string to_delete = candidate_file.file_name; uint32_t path_id = candidate_file.path_id; uint64_t number; FileType type; // Ignore file if we cannot recognize it. if (!ParseFileName(to_delete, &number, info_log_prefix.prefix, &type)) { continue; } bool keep = true; switch (type) { case kLogFile: keep = ((number >= state.log_number) || (number == state.prev_log_number)); break; case kDescriptorFile: // Keep my manifest file, and any newer incarnations' // (can happen during manifest roll) keep = (number >= state.manifest_file_number); break; case kTableFile: keep = (sst_live_map.find(number) != sst_live_map.end()); break; case kTempFile: // Any temp files that are currently being written to must // be recorded in pending_outputs_, which is inserted into "live". // Also, SetCurrentFile creates a temp file when writing out new // manifest, which is equal to state.pending_manifest_file_number. We // should not delete that file keep = (sst_live_map.find(number) != sst_live_map.end()) || (number == state.pending_manifest_file_number); break; case kInfoLogFile: keep = true; if (number != 0) { old_info_log_files.push_back(to_delete); } break; case kCurrentFile: case kDBLockFile: case kIdentityFile: case kMetaDatabase: keep = true; break; } if (keep) { continue; } std::string fname; if (type == kTableFile) { // evict from cache TableCache::Evict(table_cache_.get(), number); fname = TableFileName(options_.db_paths, number, path_id); } else { fname = ((type == kLogFile) ? options_.wal_dir : dbname_) + "/" + to_delete; } if (type == kLogFile && (options_.WAL_ttl_seconds > 0 || options_.WAL_size_limit_MB > 0)) { auto archived_log_name = ArchivedLogFileName(options_.wal_dir, number); // The sync point below is used in (DBTest,TransactionLogIteratorRace) TEST_SYNC_POINT("DBImpl::PurgeObsoleteFiles:1"); Status s = env_->RenameFile(fname, archived_log_name); // The sync point below is used in (DBTest,TransactionLogIteratorRace) TEST_SYNC_POINT("DBImpl::PurgeObsoleteFiles:2"); Log(options_.info_log, "Move log file %s to %s -- %s\n", fname.c_str(), archived_log_name.c_str(), s.ToString().c_str()); } else { Status s = env_->DeleteFile(fname); Log(options_.info_log, "Delete %s type=%d #%" PRIu64 " -- %s\n", fname.c_str(), type, number, s.ToString().c_str()); } } // Delete old info log files. size_t old_info_log_file_count = old_info_log_files.size(); if (old_info_log_file_count >= options_.keep_log_file_num) { std::sort(old_info_log_files.begin(), old_info_log_files.end()); size_t end = old_info_log_file_count - options_.keep_log_file_num; for (unsigned int i = 0; i <= end; i++) { std::string& to_delete = old_info_log_files.at(i); std::string full_path_to_delete = (options_.db_log_dir.empty() ? dbname_ : options_.db_log_dir) + "/" + to_delete; Log(options_.info_log, "Delete info log file %s\n", full_path_to_delete.c_str()); Status s = env_->DeleteFile(full_path_to_delete); if (!s.ok()) { Log(options_.info_log, "Delete info log file %s FAILED -- %s\n", to_delete.c_str(), s.ToString().c_str()); } } } PurgeObsoleteWALFiles(); LogFlush(options_.info_log); } void DBImpl::DeleteObsoleteFiles() { mutex_.AssertHeld(); DeletionState deletion_state; FindObsoleteFiles(deletion_state, true); if (deletion_state.HaveSomethingToDelete()) { PurgeObsoleteFiles(deletion_state); } } #ifndef ROCKSDB_LITE // 1. Go through all archived files and // a. if ttl is enabled, delete outdated files // b. if archive size limit is enabled, delete empty files, // compute file number and size. // 2. If size limit is enabled: // a. compute how many files should be deleted // b. get sorted non-empty archived logs // c. delete what should be deleted void DBImpl::PurgeObsoleteWALFiles() { bool const ttl_enabled = options_.WAL_ttl_seconds > 0; bool const size_limit_enabled = options_.WAL_size_limit_MB > 0; if (!ttl_enabled && !size_limit_enabled) { return; } int64_t current_time; Status s = env_->GetCurrentTime(¤t_time); if (!s.ok()) { Log(options_.info_log, "Can't get current time: %s", s.ToString().c_str()); assert(false); return; } uint64_t const now_seconds = static_cast(current_time); uint64_t const time_to_check = (ttl_enabled && !size_limit_enabled) ? options_.WAL_ttl_seconds / 2 : default_interval_to_delete_obsolete_WAL_; if (purge_wal_files_last_run_ + time_to_check > now_seconds) { return; } purge_wal_files_last_run_ = now_seconds; std::string archival_dir = ArchivalDirectory(options_.wal_dir); std::vector files; s = env_->GetChildren(archival_dir, &files); if (!s.ok()) { Log(options_.info_log, "Can't get archive files: %s", s.ToString().c_str()); assert(false); return; } size_t log_files_num = 0; uint64_t log_file_size = 0; for (auto& f : files) { uint64_t number; FileType type; if (ParseFileName(f, &number, &type) && type == kLogFile) { std::string const file_path = archival_dir + "/" + f; if (ttl_enabled) { uint64_t file_m_time; Status const s = env_->GetFileModificationTime(file_path, &file_m_time); if (!s.ok()) { Log(options_.info_log, "Can't get file mod time: %s: %s", file_path.c_str(), s.ToString().c_str()); continue; } if (now_seconds - file_m_time > options_.WAL_ttl_seconds) { Status const s = env_->DeleteFile(file_path); if (!s.ok()) { Log(options_.info_log, "Can't delete file: %s: %s", file_path.c_str(), s.ToString().c_str()); continue; } else { MutexLock l(&read_first_record_cache_mutex_); read_first_record_cache_.erase(number); } continue; } } if (size_limit_enabled) { uint64_t file_size; Status const s = env_->GetFileSize(file_path, &file_size); if (!s.ok()) { Log(options_.info_log, "Can't get file size: %s: %s", file_path.c_str(), s.ToString().c_str()); return; } else { if (file_size > 0) { log_file_size = std::max(log_file_size, file_size); ++log_files_num; } else { Status s = env_->DeleteFile(file_path); if (!s.ok()) { Log(options_.info_log, "Can't delete file: %s: %s", file_path.c_str(), s.ToString().c_str()); continue; } else { MutexLock l(&read_first_record_cache_mutex_); read_first_record_cache_.erase(number); } } } } } } if (0 == log_files_num || !size_limit_enabled) { return; } size_t const files_keep_num = options_.WAL_size_limit_MB * 1024 * 1024 / log_file_size; if (log_files_num <= files_keep_num) { return; } size_t files_del_num = log_files_num - files_keep_num; VectorLogPtr archived_logs; GetSortedWalsOfType(archival_dir, archived_logs, kArchivedLogFile); if (files_del_num > archived_logs.size()) { Log(options_.info_log, "Trying to delete more archived log files than " "exist. Deleting all"); files_del_num = archived_logs.size(); } for (size_t i = 0; i < files_del_num; ++i) { std::string const file_path = archived_logs[i]->PathName(); Status const s = DeleteFile(file_path); if (!s.ok()) { Log(options_.info_log, "Can't delete file: %s: %s", file_path.c_str(), s.ToString().c_str()); continue; } else { MutexLock l(&read_first_record_cache_mutex_); read_first_record_cache_.erase(archived_logs[i]->LogNumber()); } } } namespace { struct CompareLogByPointer { bool operator()(const unique_ptr& a, const unique_ptr& b) { LogFileImpl* a_impl = dynamic_cast(a.get()); LogFileImpl* b_impl = dynamic_cast(b.get()); return *a_impl < *b_impl; } }; } Status DBImpl::GetSortedWalsOfType(const std::string& path, VectorLogPtr& log_files, WalFileType log_type) { std::vector all_files; const Status status = env_->GetChildren(path, &all_files); if (!status.ok()) { return status; } log_files.reserve(all_files.size()); for (const auto& f : all_files) { uint64_t number; FileType type; if (ParseFileName(f, &number, &type) && type == kLogFile) { SequenceNumber sequence; Status s = ReadFirstRecord(log_type, number, &sequence); if (!s.ok()) { return s; } if (sequence == 0) { // empty file continue; } // Reproduce the race condition where a log file is moved // to archived dir, between these two sync points, used in // (DBTest,TransactionLogIteratorRace) TEST_SYNC_POINT("DBImpl::GetSortedWalsOfType:1"); TEST_SYNC_POINT("DBImpl::GetSortedWalsOfType:2"); uint64_t size_bytes; s = env_->GetFileSize(LogFileName(path, number), &size_bytes); // re-try in case the alive log file has been moved to archive. if (!s.ok() && log_type == kAliveLogFile && env_->FileExists(ArchivedLogFileName(path, number))) { s = env_->GetFileSize(ArchivedLogFileName(path, number), &size_bytes); } if (!s.ok()) { return s; } log_files.push_back(std::move(unique_ptr( new LogFileImpl(number, log_type, sequence, size_bytes)))); } } CompareLogByPointer compare_log_files; std::sort(log_files.begin(), log_files.end(), compare_log_files); return status; } Status DBImpl::RetainProbableWalFiles(VectorLogPtr& all_logs, const SequenceNumber target) { int64_t start = 0; // signed to avoid overflow when target is < first file. int64_t end = static_cast(all_logs.size()) - 1; // Binary Search. avoid opening all files. while (end >= start) { int64_t mid = start + (end - start) / 2; // Avoid overflow. SequenceNumber current_seq_num = all_logs.at(mid)->StartSequence(); if (current_seq_num == target) { end = mid; break; } else if (current_seq_num < target) { start = mid + 1; } else { end = mid - 1; } } // end could be -ve. size_t start_index = std::max(static_cast(0), end); // The last wal file is always included all_logs.erase(all_logs.begin(), all_logs.begin() + start_index); return Status::OK(); } Status DBImpl::ReadFirstRecord(const WalFileType type, const uint64_t number, SequenceNumber* sequence) { if (type != kAliveLogFile && type != kArchivedLogFile) { return Status::NotSupported("File Type Not Known " + std::to_string(type)); } { MutexLock l(&read_first_record_cache_mutex_); auto itr = read_first_record_cache_.find(number); if (itr != read_first_record_cache_.end()) { *sequence = itr->second; return Status::OK(); } } Status s; if (type == kAliveLogFile) { std::string fname = LogFileName(options_.wal_dir, number); s = ReadFirstLine(fname, sequence); if (env_->FileExists(fname) && !s.ok()) { // return any error that is not caused by non-existing file return s; } } if (type == kArchivedLogFile || !s.ok()) { // check if the file got moved to archive. std::string archived_file = ArchivedLogFileName(options_.wal_dir, number); s = ReadFirstLine(archived_file, sequence); } if (s.ok() && *sequence != 0) { MutexLock l(&read_first_record_cache_mutex_); read_first_record_cache_.insert({number, *sequence}); } return s; } // the function returns status.ok() and sequence == 0 if the file exists, but is // empty Status DBImpl::ReadFirstLine(const std::string& fname, SequenceNumber* sequence) { struct LogReporter : public log::Reader::Reporter { Env* env; Logger* info_log; const char* fname; Status* status; bool ignore_error; // true if options_.paranoid_checks==false virtual void Corruption(size_t bytes, const Status& s) { Log(info_log, "%s%s: dropping %d bytes; %s", (this->ignore_error ? "(ignoring error) " : ""), fname, static_cast(bytes), s.ToString().c_str()); if (this->status->ok()) { // only keep the first error *this->status = s; } } }; unique_ptr file; Status status = env_->NewSequentialFile(fname, &file, env_options_); if (!status.ok()) { return status; } LogReporter reporter; reporter.env = env_; reporter.info_log = options_.info_log.get(); reporter.fname = fname.c_str(); reporter.status = &status; reporter.ignore_error = !options_.paranoid_checks; log::Reader reader(std::move(file), &reporter, true /*checksum*/, 0 /*initial_offset*/); std::string scratch; Slice record; if (reader.ReadRecord(&record, &scratch) && (status.ok() || !options_.paranoid_checks)) { if (record.size() < 12) { reporter.Corruption(record.size(), Status::Corruption("log record too small")); // TODO read record's till the first no corrupt entry? } else { WriteBatch batch; WriteBatchInternal::SetContents(&batch, record); *sequence = WriteBatchInternal::Sequence(&batch); return Status::OK(); } } // ReadRecord returns false on EOF, which means that the log file is empty. we // return status.ok() in that case and set sequence number to 0 *sequence = 0; return status; } #endif // ROCKSDB_LITE Status DBImpl::Recover( const std::vector& column_families, bool read_only, bool error_if_log_file_exist) { mutex_.AssertHeld(); bool is_new_db = false; assert(db_lock_ == nullptr); if (!read_only) { // We call CreateDirIfMissing() as the directory may already exist (if we // are reopening a DB), when this happens we don't want creating the // directory to cause an error. However, we need to check if creating the // directory fails or else we may get an obscure message about the lock // file not existing. One real-world example of this occurring is if // env->CreateDirIfMissing() doesn't create intermediate directories, e.g. // when dbname_ is "dir/db" but when "dir" doesn't exist. Status s = env_->CreateDirIfMissing(dbname_); if (!s.ok()) { return s; } for (auto& db_path : options_.db_paths) { s = env_->CreateDirIfMissing(db_path.path); if (!s.ok()) { return s; } } s = env_->NewDirectory(dbname_, &db_directory_); if (!s.ok()) { return s; } s = env_->LockFile(LockFileName(dbname_), &db_lock_); if (!s.ok()) { return s; } if (!env_->FileExists(CurrentFileName(dbname_))) { if (options_.create_if_missing) { s = NewDB(); is_new_db = true; if (!s.ok()) { return s; } } else { return Status::InvalidArgument( dbname_, "does not exist (create_if_missing is false)"); } } else { if (options_.error_if_exists) { return Status::InvalidArgument( dbname_, "exists (error_if_exists is true)"); } } // Check for the IDENTITY file and create it if not there if (!env_->FileExists(IdentityFileName(dbname_))) { s = SetIdentityFile(env_, dbname_); if (!s.ok()) { return s; } } } Status s = versions_->Recover(column_families, read_only); if (options_.paranoid_checks && s.ok()) { s = CheckConsistency(); } if (s.ok()) { SequenceNumber max_sequence(0); default_cf_handle_ = new ColumnFamilyHandleImpl( versions_->GetColumnFamilySet()->GetDefault(), this, &mutex_); default_cf_internal_stats_ = default_cf_handle_->cfd()->internal_stats(); single_column_family_mode_ = versions_->GetColumnFamilySet()->NumberOfColumnFamilies() == 1; // Recover from all newer log files than the ones named in the // descriptor (new log files may have been added by the previous // incarnation without registering them in the descriptor). // // Note that PrevLogNumber() is no longer used, but we pay // attention to it in case we are recovering a database // produced by an older version of rocksdb. const uint64_t min_log = versions_->MinLogNumber(); const uint64_t prev_log = versions_->PrevLogNumber(); std::vector filenames; s = env_->GetChildren(options_.wal_dir, &filenames); if (!s.ok()) { return s; } std::vector logs; for (size_t i = 0; i < filenames.size(); i++) { uint64_t number; FileType type; if (ParseFileName(filenames[i], &number, &type) && type == kLogFile) { if (is_new_db) { return Status::Corruption( "While creating a new Db, wal_dir contains " "existing log file: ", filenames[i]); } else if ((number >= min_log) || (number == prev_log)) { logs.push_back(number); } } } if (logs.size() > 0 && error_if_log_file_exist) { return Status::Corruption("" "The db was opened in readonly mode with error_if_log_file_exist" "flag but a log file already exists"); } // Recover in the order in which the logs were generated std::sort(logs.begin(), logs.end()); for (const auto& log : logs) { // The previous incarnation may not have written any MANIFEST // records after allocating this log number. So we manually // update the file number allocation counter in VersionSet. versions_->MarkFileNumberUsed(log); s = RecoverLogFile(log, &max_sequence, read_only); } SetTickerCount(stats_, SEQUENCE_NUMBER, versions_->LastSequence()); } for (auto cfd : *versions_->GetColumnFamilySet()) { max_total_in_memory_state_ += cfd->options()->write_buffer_size * cfd->options()->max_write_buffer_number; } return s; } Status DBImpl::RecoverLogFile(uint64_t log_number, SequenceNumber* max_sequence, bool read_only) { struct LogReporter : public log::Reader::Reporter { Env* env; Logger* info_log; const char* fname; Status* status; // nullptr if options_.paranoid_checks==false or // options_.skip_log_error_on_recovery==true virtual void Corruption(size_t bytes, const Status& s) { Log(info_log, "%s%s: dropping %d bytes; %s", (this->status == nullptr ? "(ignoring error) " : ""), fname, static_cast(bytes), s.ToString().c_str()); if (this->status != nullptr && this->status->ok()) *this->status = s; } }; mutex_.AssertHeld(); std::unordered_map version_edits; // no need to refcount because iteration is under mutex for (auto cfd : *versions_->GetColumnFamilySet()) { VersionEdit edit; edit.SetColumnFamily(cfd->GetID()); version_edits.insert({cfd->GetID(), edit}); } // Open the log file std::string fname = LogFileName(options_.wal_dir, log_number); unique_ptr file; Status status = env_->NewSequentialFile(fname, &file, env_options_); if (!status.ok()) { MaybeIgnoreError(&status); return status; } // Create the log reader. LogReporter reporter; reporter.env = env_; reporter.info_log = options_.info_log.get(); reporter.fname = fname.c_str(); reporter.status = (options_.paranoid_checks && !options_.skip_log_error_on_recovery ? &status : nullptr); // We intentially make log::Reader do checksumming even if // paranoid_checks==false so that corruptions cause entire commits // to be skipped instead of propagating bad information (like overly // large sequence numbers). log::Reader reader(std::move(file), &reporter, true/*checksum*/, 0/*initial_offset*/); Log(options_.info_log, "Recovering log #%" PRIu64 "", log_number); // Read all the records and add to a memtable std::string scratch; Slice record; WriteBatch batch; while (reader.ReadRecord(&record, &scratch)) { if (record.size() < 12) { reporter.Corruption(record.size(), Status::Corruption("log record too small")); continue; } WriteBatchInternal::SetContents(&batch, record); // If column family was not found, it might mean that the WAL write // batch references to the column family that was dropped after the // insert. We don't want to fail the whole write batch in that case -- we // just ignore the update. That's why we set ignore missing column families // to true status = WriteBatchInternal::InsertInto( &batch, column_family_memtables_.get(), true /* ignore missing column families */, log_number); MaybeIgnoreError(&status); if (!status.ok()) { return status; } const SequenceNumber last_seq = WriteBatchInternal::Sequence(&batch) + WriteBatchInternal::Count(&batch) - 1; if (last_seq > *max_sequence) { *max_sequence = last_seq; } if (!read_only) { // no need to refcount since client still doesn't have access // to the DB and can not drop column families while we iterate for (auto cfd : *versions_->GetColumnFamilySet()) { if (cfd->mem()->ShouldFlush()) { // If this asserts, it means that InsertInto failed in // filtering updates to already-flushed column families assert(cfd->GetLogNumber() <= log_number); auto iter = version_edits.find(cfd->GetID()); assert(iter != version_edits.end()); VersionEdit* edit = &iter->second; status = WriteLevel0TableForRecovery(cfd, cfd->mem(), edit); // we still want to clear the memtable, even if the recovery failed cfd->CreateNewMemtable(); if (!status.ok()) { // Reflect errors immediately so that conditions like full // file-systems cause the DB::Open() to fail. return status; } } } } } if (versions_->LastSequence() < *max_sequence) { versions_->SetLastSequence(*max_sequence); } if (!read_only) { // no need to refcount since client still doesn't have access // to the DB and can not drop column families while we iterate for (auto cfd : *versions_->GetColumnFamilySet()) { auto iter = version_edits.find(cfd->GetID()); assert(iter != version_edits.end()); VersionEdit* edit = &iter->second; if (cfd->GetLogNumber() > log_number) { // Column family cfd has already flushed the data // from log_number. Memtable has to be empty because // we filter the updates based on log_number // (in WriteBatch::InsertInto) assert(cfd->mem()->GetFirstSequenceNumber() == 0); assert(edit->NumEntries() == 0); continue; } // flush the final memtable (if non-empty) if (cfd->mem()->GetFirstSequenceNumber() != 0) { status = WriteLevel0TableForRecovery(cfd, cfd->mem(), edit); } // we still want to clear the memtable, even if the recovery failed cfd->CreateNewMemtable(); if (!status.ok()) { return status; } // write MANIFEST with update // writing log number in the manifest means that any log file // with number strongly less than (log_number + 1) is already // recovered and should be ignored on next reincarnation. // Since we already recovered log_number, we want all logs // with numbers `<= log_number` (includes this one) to be ignored edit->SetLogNumber(log_number + 1); // we must mark the next log number as used, even though it's // not actually used. that is because VersionSet assumes // VersionSet::next_file_number_ always to be strictly greater than any // log number versions_->MarkFileNumberUsed(log_number + 1); status = versions_->LogAndApply(cfd, edit, &mutex_); if (!status.ok()) { return status; } } } return status; } Status DBImpl::WriteLevel0TableForRecovery(ColumnFamilyData* cfd, MemTable* mem, VersionEdit* edit) { mutex_.AssertHeld(); const uint64_t start_micros = env_->NowMicros(); FileMetaData meta; meta.fd = FileDescriptor(versions_->NewFileNumber(), 0, 0); pending_outputs_[meta.fd.GetNumber()] = 0; // path 0 for level 0 file. ReadOptions ro; ro.total_order_seek = true; Arena arena; Status s; { ScopedArenaIterator iter(mem->NewIterator(ro, &arena)); const SequenceNumber newest_snapshot = snapshots_.GetNewest(); const SequenceNumber earliest_seqno_in_memtable = mem->GetFirstSequenceNumber(); Log(options_.info_log, "[%s] Level-0 table #%" PRIu64 ": started", cfd->GetName().c_str(), meta.fd.GetNumber()); { mutex_.Unlock(); s = BuildTable( dbname_, env_, *cfd->ioptions(), env_options_, cfd->table_cache(), iter.get(), &meta, cfd->internal_comparator(), newest_snapshot, earliest_seqno_in_memtable, GetCompressionFlush(*cfd->options()), cfd->options()->compression_opts, Env::IO_HIGH); LogFlush(options_.info_log); mutex_.Lock(); } Log(options_.info_log, "[%s] Level-0 table #%" PRIu64 ": %" PRIu64 " bytes %s", cfd->GetName().c_str(), meta.fd.GetNumber(), meta.fd.GetFileSize(), s.ToString().c_str()); } pending_outputs_.erase(meta.fd.GetNumber()); // Note that if file_size is zero, the file has been deleted and // should not be added to the manifest. int level = 0; if (s.ok() && meta.fd.GetFileSize() > 0) { edit->AddFile(level, meta.fd.GetNumber(), meta.fd.GetPathId(), meta.fd.GetFileSize(), meta.smallest, meta.largest, meta.smallest_seqno, meta.largest_seqno); } InternalStats::CompactionStats stats(1); stats.micros = env_->NowMicros() - start_micros; stats.bytes_written = meta.fd.GetFileSize(); stats.files_out_levelnp1 = 1; cfd->internal_stats()->AddCompactionStats(level, stats); cfd->internal_stats()->AddCFStats( InternalStats::BYTES_FLUSHED, meta.fd.GetFileSize()); RecordTick(stats_, COMPACT_WRITE_BYTES, meta.fd.GetFileSize()); return s; } Status DBImpl::WriteLevel0Table(ColumnFamilyData* cfd, autovector& mems, VersionEdit* edit, uint64_t* filenumber, LogBuffer* log_buffer) { mutex_.AssertHeld(); const uint64_t start_micros = env_->NowMicros(); FileMetaData meta; meta.fd = FileDescriptor(versions_->NewFileNumber(), 0, 0); *filenumber = meta.fd.GetNumber(); pending_outputs_[meta.fd.GetNumber()] = 0; // path 0 for level 0 file. const SequenceNumber newest_snapshot = snapshots_.GetNewest(); const SequenceNumber earliest_seqno_in_memtable = mems[0]->GetFirstSequenceNumber(); Version* base = cfd->current(); base->Ref(); // it is likely that we do not need this reference Status s; { mutex_.Unlock(); log_buffer->FlushBufferToLog(); std::vector memtables; ReadOptions ro; ro.total_order_seek = true; Arena arena; for (MemTable* m : mems) { Log(options_.info_log, "[%s] Flushing memtable with next log file: %" PRIu64 "\n", cfd->GetName().c_str(), m->GetNextLogNumber()); memtables.push_back(m->NewIterator(ro, &arena)); } { ScopedArenaIterator iter(NewMergingIterator(&cfd->internal_comparator(), &memtables[0], memtables.size(), &arena)); Log(options_.info_log, "[%s] Level-0 flush table #%" PRIu64 ": started", cfd->GetName().c_str(), meta.fd.GetNumber()); s = BuildTable( dbname_, env_, *cfd->ioptions(), env_options_, cfd->table_cache(), iter.get(), &meta, cfd->internal_comparator(), newest_snapshot, earliest_seqno_in_memtable, GetCompressionFlush(*cfd->options()), cfd->options()->compression_opts, Env::IO_HIGH); LogFlush(options_.info_log); } Log(options_.info_log, "[%s] Level-0 flush table #%" PRIu64 ": %" PRIu64 " bytes %s", cfd->GetName().c_str(), meta.fd.GetNumber(), meta.fd.GetFileSize(), s.ToString().c_str()); if (!options_.disableDataSync) { db_directory_->Fsync(); } mutex_.Lock(); } base->Unref(); // re-acquire the most current version base = cfd->current(); // There could be multiple threads writing to its own level-0 file. // The pending_outputs cannot be cleared here, otherwise this newly // created file might not be considered as a live-file by another // compaction thread that is concurrently deleting obselete files. // The pending_outputs can be cleared only after the new version is // committed so that other threads can recognize this file as a // valid one. // pending_outputs_.erase(meta.number); // Note that if file_size is zero, the file has been deleted and // should not be added to the manifest. int level = 0; if (s.ok() && meta.fd.GetFileSize() > 0) { const Slice min_user_key = meta.smallest.user_key(); const Slice max_user_key = meta.largest.user_key(); // if we have more than 1 background thread, then we cannot // insert files directly into higher levels because some other // threads could be concurrently producing compacted files for // that key range. if (base != nullptr && options_.max_background_compactions <= 1 && cfd->options()->compaction_style == kCompactionStyleLevel) { level = base->PickLevelForMemTableOutput(min_user_key, max_user_key); } edit->AddFile(level, meta.fd.GetNumber(), meta.fd.GetPathId(), meta.fd.GetFileSize(), meta.smallest, meta.largest, meta.smallest_seqno, meta.largest_seqno); } InternalStats::CompactionStats stats(1); stats.micros = env_->NowMicros() - start_micros; stats.bytes_written = meta.fd.GetFileSize(); cfd->internal_stats()->AddCompactionStats(level, stats); cfd->internal_stats()->AddCFStats( InternalStats::BYTES_FLUSHED, meta.fd.GetFileSize()); RecordTick(stats_, COMPACT_WRITE_BYTES, meta.fd.GetFileSize()); return s; } Status DBImpl::FlushMemTableToOutputFile(ColumnFamilyData* cfd, bool* madeProgress, DeletionState& deletion_state, LogBuffer* log_buffer) { mutex_.AssertHeld(); assert(cfd->imm()->size() != 0); assert(cfd->imm()->IsFlushPending()); // Save the contents of the earliest memtable as a new Table uint64_t file_number; autovector mems; cfd->imm()->PickMemtablesToFlush(&mems); if (mems.empty()) { LogToBuffer(log_buffer, "[%s] Nothing in memtable to flush", cfd->GetName().c_str()); return Status::OK(); } // record the logfile_number_ before we release the mutex // entries mems are (implicitly) sorted in ascending order by their created // time. We will use the first memtable's `edit` to keep the meta info for // this flush. MemTable* m = mems[0]; VersionEdit* edit = m->GetEdits(); edit->SetPrevLogNumber(0); // SetLogNumber(log_num) indicates logs with number smaller than log_num // will no longer be picked up for recovery. edit->SetLogNumber(mems.back()->GetNextLogNumber()); edit->SetColumnFamily(cfd->GetID()); // This will release and re-acquire the mutex. Status s = WriteLevel0Table(cfd, mems, edit, &file_number, log_buffer); if (s.ok() && shutting_down_.Acquire_Load() && cfd->IsDropped()) { s = Status::ShutdownInProgress( "Database shutdown or Column family drop during flush"); } if (!s.ok()) { cfd->imm()->RollbackMemtableFlush(mems, file_number, &pending_outputs_); } else { // Replace immutable memtable with the generated Table s = cfd->imm()->InstallMemtableFlushResults( cfd, mems, versions_.get(), &mutex_, options_.info_log.get(), file_number, &pending_outputs_, &deletion_state.memtables_to_free, db_directory_.get(), log_buffer); } if (s.ok()) { InstallSuperVersion(cfd, deletion_state); if (madeProgress) { *madeProgress = 1; } Version::LevelSummaryStorage tmp; LogToBuffer(log_buffer, "[%s] Level summary: %s\n", cfd->GetName().c_str(), cfd->current()->LevelSummary(&tmp)); if (disable_delete_obsolete_files_ == 0) { // add to deletion state while (alive_log_files_.size() && alive_log_files_.begin()->number < versions_->MinLogNumber()) { const auto& earliest = *alive_log_files_.begin(); deletion_state.log_delete_files.push_back(earliest.number); total_log_size_ -= earliest.size; alive_log_files_.pop_front(); } } } if (!s.ok() && !s.IsShutdownInProgress() && options_.paranoid_checks && bg_error_.ok()) { // if a bad error happened (not ShutdownInProgress) and paranoid_checks is // true, mark DB read-only bg_error_ = s; } RecordFlushIOStats(); return s; } Status DBImpl::CompactRange(ColumnFamilyHandle* column_family, const Slice* begin, const Slice* end, bool reduce_level, int target_level, uint32_t target_path_id) { if (target_path_id >= options_.db_paths.size()) { return Status::InvalidArgument("Invalid target path ID"); } auto cfh = reinterpret_cast(column_family); auto cfd = cfh->cfd(); Status s = FlushMemTable(cfd, FlushOptions()); if (!s.ok()) { LogFlush(options_.info_log); return s; } int max_level_with_files = 0; { MutexLock l(&mutex_); Version* base = cfd->current(); for (int level = 1; level < cfd->NumberLevels(); level++) { if (base->OverlapInLevel(level, begin, end)) { max_level_with_files = level; } } } for (int level = 0; level <= max_level_with_files; level++) { // in case the compaction is unversal or if we're compacting the // bottom-most level, the output level will be the same as input one. // level 0 can never be the bottommost level (i.e. if all files are in level // 0, we will compact to level 1) if (cfd->options()->compaction_style == kCompactionStyleUniversal || cfd->options()->compaction_style == kCompactionStyleFIFO || (level == max_level_with_files && level > 0)) { s = RunManualCompaction(cfd, level, level, target_path_id, begin, end); } else { s = RunManualCompaction(cfd, level, level + 1, target_path_id, begin, end); } if (!s.ok()) { LogFlush(options_.info_log); return s; } } if (reduce_level) { s = ReFitLevel(cfd, max_level_with_files, target_level); } LogFlush(options_.info_log); { MutexLock l(&mutex_); // an automatic compaction that has been scheduled might have been // preempted by the manual compactions. Need to schedule it back. MaybeScheduleFlushOrCompaction(); } return s; } // return the same level if it cannot be moved int DBImpl::FindMinimumEmptyLevelFitting(ColumnFamilyData* cfd, int level) { mutex_.AssertHeld(); Version* current = cfd->current(); int minimum_level = level; for (int i = level - 1; i > 0; --i) { // stop if level i is not empty if (current->NumLevelFiles(i) > 0) break; // stop if level i is too small (cannot fit the level files) if (cfd->compaction_picker()->MaxBytesForLevel(i) < current->NumLevelBytes(level)) { break; } minimum_level = i; } return minimum_level; } Status DBImpl::ReFitLevel(ColumnFamilyData* cfd, int level, int target_level) { assert(level < cfd->NumberLevels()); SuperVersion* superversion_to_free = nullptr; SuperVersion* new_superversion = new SuperVersion(); mutex_.Lock(); // only allow one thread refitting if (refitting_level_) { mutex_.Unlock(); Log(options_.info_log, "ReFitLevel: another thread is refitting"); delete new_superversion; return Status::NotSupported("another thread is refitting"); } refitting_level_ = true; // wait for all background threads to stop bg_work_gate_closed_ = true; while (bg_compaction_scheduled_ > 0 || bg_flush_scheduled_) { Log(options_.info_log, "RefitLevel: waiting for background threads to stop: %d %d", bg_compaction_scheduled_, bg_flush_scheduled_); bg_cv_.Wait(); } // move to a smaller level int to_level = target_level; if (target_level < 0) { to_level = FindMinimumEmptyLevelFitting(cfd, level); } assert(to_level <= level); Status status; if (to_level < level) { Log(options_.info_log, "[%s] Before refitting:\n%s", cfd->GetName().c_str(), cfd->current()->DebugString().data()); VersionEdit edit; edit.SetColumnFamily(cfd->GetID()); for (const auto& f : cfd->current()->files_[level]) { edit.DeleteFile(level, f->fd.GetNumber()); edit.AddFile(to_level, f->fd.GetNumber(), f->fd.GetPathId(), f->fd.GetFileSize(), f->smallest, f->largest, f->smallest_seqno, f->largest_seqno); } Log(options_.info_log, "[%s] Apply version edit:\n%s", cfd->GetName().c_str(), edit.DebugString().data()); status = versions_->LogAndApply(cfd, &edit, &mutex_, db_directory_.get()); superversion_to_free = cfd->InstallSuperVersion(new_superversion, &mutex_); new_superversion = nullptr; Log(options_.info_log, "[%s] LogAndApply: %s\n", cfd->GetName().c_str(), status.ToString().data()); if (status.ok()) { Log(options_.info_log, "[%s] After refitting:\n%s", cfd->GetName().c_str(), cfd->current()->DebugString().data()); } } refitting_level_ = false; bg_work_gate_closed_ = false; mutex_.Unlock(); delete superversion_to_free; delete new_superversion; return status; } int DBImpl::NumberLevels(ColumnFamilyHandle* column_family) { auto cfh = reinterpret_cast(column_family); return cfh->cfd()->NumberLevels(); } int DBImpl::MaxMemCompactionLevel(ColumnFamilyHandle* column_family) { auto cfh = reinterpret_cast(column_family); return cfh->cfd()->options()->max_mem_compaction_level; } int DBImpl::Level0StopWriteTrigger(ColumnFamilyHandle* column_family) { auto cfh = reinterpret_cast(column_family); return cfh->cfd()->options()->level0_stop_writes_trigger; } Status DBImpl::Flush(const FlushOptions& options, ColumnFamilyHandle* column_family) { auto cfh = reinterpret_cast(column_family); return FlushMemTable(cfh->cfd(), options); } SequenceNumber DBImpl::GetLatestSequenceNumber() const { return versions_->LastSequence(); } Status DBImpl::RunManualCompaction(ColumnFamilyData* cfd, int input_level, int output_level, uint32_t output_path_id, const Slice* begin, const Slice* end) { assert(input_level >= 0); InternalKey begin_storage, end_storage; ManualCompaction manual; manual.cfd = cfd; manual.input_level = input_level; manual.output_level = output_level; manual.output_path_id = output_path_id; manual.done = false; manual.in_progress = false; // For universal compaction, we enforce every manual compaction to compact // all files. if (begin == nullptr || cfd->options()->compaction_style == kCompactionStyleUniversal || cfd->options()->compaction_style == kCompactionStyleFIFO) { manual.begin = nullptr; } else { begin_storage = InternalKey(*begin, kMaxSequenceNumber, kValueTypeForSeek); manual.begin = &begin_storage; } if (end == nullptr || cfd->options()->compaction_style == kCompactionStyleUniversal || cfd->options()->compaction_style == kCompactionStyleFIFO) { manual.end = nullptr; } else { end_storage = InternalKey(*end, 0, static_cast(0)); manual.end = &end_storage; } MutexLock l(&mutex_); // When a manual compaction arrives, temporarily disable scheduling of // non-manual compactions and wait until the number of scheduled compaction // jobs drops to zero. This is needed to ensure that this manual compaction // can compact any range of keys/files. // // bg_manual_only_ is non-zero when at least one thread is inside // RunManualCompaction(), i.e. during that time no other compaction will // get scheduled (see MaybeScheduleFlushOrCompaction). // // Note that the following loop doesn't stop more that one thread calling // RunManualCompaction() from getting to the second while loop below. // However, only one of them will actually schedule compaction, while // others will wait on a condition variable until it completes. ++bg_manual_only_; while (bg_compaction_scheduled_ > 0) { Log(options_.info_log, "[%s] Manual compaction waiting for all other scheduled background " "compactions to finish", cfd->GetName().c_str()); bg_cv_.Wait(); } Log(options_.info_log, "[%s] Manual compaction starting", cfd->GetName().c_str()); while (!manual.done && !shutting_down_.Acquire_Load() && bg_error_.ok()) { assert(bg_manual_only_ > 0); if (manual_compaction_ != nullptr) { // Running either this or some other manual compaction bg_cv_.Wait(); } else { manual_compaction_ = &manual; assert(bg_compaction_scheduled_ == 0); bg_compaction_scheduled_++; env_->Schedule(&DBImpl::BGWorkCompaction, this, Env::Priority::LOW); } } assert(!manual.in_progress); assert(bg_manual_only_ > 0); --bg_manual_only_; return manual.status; } Status DBImpl::FlushMemTable(ColumnFamilyData* cfd, const FlushOptions& options) { Writer w(&mutex_); w.batch = nullptr; w.sync = false; w.disableWAL = false; w.in_batch_group = false; w.done = false; w.timeout_hint_us = kNoTimeOut; Status s; { WriteContext context; MutexLock guard_lock(&mutex_); s = BeginWrite(&w, 0); assert(s.ok() && !w.done); // No timeout and nobody should do our job // SetNewMemtableAndNewLogFile() will release and reacquire mutex // during execution s = SetNewMemtableAndNewLogFile(cfd, &context); cfd->imm()->FlushRequested(); MaybeScheduleFlushOrCompaction(); assert(!writers_.empty()); assert(writers_.front() == &w); EndWrite(&w, &w, s); } if (s.ok() && options.wait) { // Wait until the compaction completes s = WaitForFlushMemTable(cfd); } return s; } Status DBImpl::WaitForFlushMemTable(ColumnFamilyData* cfd) { Status s; // Wait until the compaction completes MutexLock l(&mutex_); while (cfd->imm()->size() > 0 && bg_error_.ok()) { bg_cv_.Wait(); } if (!bg_error_.ok()) { s = bg_error_; } return s; } void DBImpl::MaybeScheduleFlushOrCompaction() { mutex_.AssertHeld(); bg_schedule_needed_ = false; if (bg_work_gate_closed_) { // gate closed for backgrond work } else if (shutting_down_.Acquire_Load()) { // DB is being deleted; no more background compactions } else { bool is_flush_pending = false; // no need to refcount since we're under a mutex for (auto cfd : *versions_->GetColumnFamilySet()) { if (cfd->imm()->IsFlushPending()) { is_flush_pending = true; } } if (is_flush_pending) { // memtable flush needed if (bg_flush_scheduled_ < options_.max_background_flushes) { bg_flush_scheduled_++; env_->Schedule(&DBImpl::BGWorkFlush, this, Env::Priority::HIGH); } else if (options_.max_background_flushes > 0) { bg_schedule_needed_ = true; } } bool is_compaction_needed = false; // no need to refcount since we're under a mutex for (auto cfd : *versions_->GetColumnFamilySet()) { if (cfd->current()->NeedsCompaction()) { is_compaction_needed = true; break; } } // Schedule BGWorkCompaction if there's a compaction pending (or a memtable // flush, but the HIGH pool is not enabled) // Do it only if max_background_compactions hasn't been reached and // bg_manual_only_ == 0 if (!bg_manual_only_ && (is_compaction_needed || (is_flush_pending && options_.max_background_flushes == 0))) { if (bg_compaction_scheduled_ < options_.max_background_compactions) { bg_compaction_scheduled_++; env_->Schedule(&DBImpl::BGWorkCompaction, this, Env::Priority::LOW); } else { bg_schedule_needed_ = true; } } } } void DBImpl::RecordFlushIOStats() { RecordTick(stats_, FLUSH_WRITE_BYTES, IOSTATS(bytes_written)); IOSTATS_RESET(bytes_written); } void DBImpl::RecordCompactionIOStats() { RecordTick(stats_, COMPACT_READ_BYTES, IOSTATS(bytes_read)); IOSTATS_RESET(bytes_read); RecordTick(stats_, COMPACT_WRITE_BYTES, IOSTATS(bytes_written)); IOSTATS_RESET(bytes_written); } void DBImpl::BGWorkFlush(void* db) { IOSTATS_SET_THREAD_POOL_ID(Env::Priority::HIGH); reinterpret_cast(db)->BackgroundCallFlush(); } void DBImpl::BGWorkCompaction(void* db) { IOSTATS_SET_THREAD_POOL_ID(Env::Priority::LOW); reinterpret_cast(db)->BackgroundCallCompaction(); } Status DBImpl::BackgroundFlush(bool* madeProgress, DeletionState& deletion_state, LogBuffer* log_buffer) { mutex_.AssertHeld(); // call_status is failure if at least one flush was a failure. even if // flushing one column family reports a failure, we will continue flushing // other column families. however, call_status will be a failure in that case. Status call_status; // refcounting in iteration for (auto cfd : *versions_->GetColumnFamilySet()) { cfd->Ref(); Status flush_status; while (flush_status.ok() && cfd->imm()->IsFlushPending()) { LogToBuffer( log_buffer, "BackgroundCallFlush doing FlushMemTableToOutputFile with column " "family [%s], flush slots available %d", cfd->GetName().c_str(), options_.max_background_flushes - bg_flush_scheduled_); flush_status = FlushMemTableToOutputFile(cfd, madeProgress, deletion_state, log_buffer); } if (call_status.ok() && !flush_status.ok()) { call_status = flush_status; } cfd->Unref(); } versions_->GetColumnFamilySet()->FreeDeadColumnFamilies(); return call_status; } void DBImpl::BackgroundCallFlush() { bool madeProgress = false; DeletionState deletion_state(true); assert(bg_flush_scheduled_); LogBuffer log_buffer(InfoLogLevel::INFO_LEVEL, options_.info_log.get()); { MutexLock l(&mutex_); Status s; if (!shutting_down_.Acquire_Load()) { s = BackgroundFlush(&madeProgress, deletion_state, &log_buffer); if (!s.ok()) { // Wait a little bit before retrying background compaction in // case this is an environmental problem and we do not want to // chew up resources for failed compactions for the duration of // the problem. uint64_t error_cnt = default_cf_internal_stats_->BumpAndGetBackgroundErrorCount(); bg_cv_.SignalAll(); // In case a waiter can proceed despite the error mutex_.Unlock(); Log(options_.info_log, "Waiting after background flush error: %s" "Accumulated background error counts: %" PRIu64, s.ToString().c_str(), error_cnt); log_buffer.FlushBufferToLog(); LogFlush(options_.info_log); env_->SleepForMicroseconds(1000000); mutex_.Lock(); } } // If !s.ok(), this means that Flush failed. In that case, we want // to delete all obsolete files and we force FindObsoleteFiles() FindObsoleteFiles(deletion_state, !s.ok()); // delete unnecessary files if any, this is done outside the mutex if (deletion_state.HaveSomethingToDelete() || !log_buffer.IsEmpty()) { mutex_.Unlock(); // Have to flush the info logs before bg_flush_scheduled_-- // because if bg_flush_scheduled_ becomes 0 and the lock is // released, the deconstructor of DB can kick in and destroy all the // states of DB so info_log might not be available after that point. // It also applies to access other states that DB owns. log_buffer.FlushBufferToLog(); if (deletion_state.HaveSomethingToDelete()) { PurgeObsoleteFiles(deletion_state); } mutex_.Lock(); } bg_flush_scheduled_--; // Any time the mutex is released After finding the work to do, another // thread might execute MaybeScheduleFlushOrCompaction(). It is possible // that there is a pending job but it is not scheduled because of the // max thread limit. if (madeProgress || bg_schedule_needed_) { MaybeScheduleFlushOrCompaction(); } RecordFlushIOStats(); bg_cv_.SignalAll(); // IMPORTANT: there should be no code after calling SignalAll. This call may // signal the DB destructor that it's OK to proceed with destruction. In // that case, all DB variables will be dealloacated and referencing them // will cause trouble. } } void DBImpl::BackgroundCallCompaction() { bool madeProgress = false; DeletionState deletion_state(true); MaybeDumpStats(); LogBuffer log_buffer(InfoLogLevel::INFO_LEVEL, options_.info_log.get()); { MutexLock l(&mutex_); assert(bg_compaction_scheduled_); Status s; if (!shutting_down_.Acquire_Load()) { s = BackgroundCompaction(&madeProgress, deletion_state, &log_buffer); if (!s.ok()) { // Wait a little bit before retrying background compaction in // case this is an environmental problem and we do not want to // chew up resources for failed compactions for the duration of // the problem. uint64_t error_cnt = default_cf_internal_stats_->BumpAndGetBackgroundErrorCount(); bg_cv_.SignalAll(); // In case a waiter can proceed despite the error mutex_.Unlock(); log_buffer.FlushBufferToLog(); Log(options_.info_log, "Waiting after background compaction error: %s, " "Accumulated background error counts: %" PRIu64, s.ToString().c_str(), error_cnt); LogFlush(options_.info_log); env_->SleepForMicroseconds(1000000); mutex_.Lock(); } } // If !s.ok(), this means that Compaction failed. In that case, we want // to delete all obsolete files we might have created and we force // FindObsoleteFiles(). This is because deletion_state does not catch // all created files if compaction failed. FindObsoleteFiles(deletion_state, !s.ok()); // delete unnecessary files if any, this is done outside the mutex if (deletion_state.HaveSomethingToDelete() || !log_buffer.IsEmpty()) { mutex_.Unlock(); // Have to flush the info logs before bg_compaction_scheduled_-- // because if bg_flush_scheduled_ becomes 0 and the lock is // released, the deconstructor of DB can kick in and destroy all the // states of DB so info_log might not be available after that point. // It also applies to access other states that DB owns. log_buffer.FlushBufferToLog(); if (deletion_state.HaveSomethingToDelete()) { PurgeObsoleteFiles(deletion_state); } mutex_.Lock(); } bg_compaction_scheduled_--; versions_->GetColumnFamilySet()->FreeDeadColumnFamilies(); // Previous compaction may have produced too many files in a level, // So reschedule another compaction if we made progress in the // last compaction. // // Also, any time the mutex is released After finding the work to do, // another thread might execute MaybeScheduleFlushOrCompaction(). It is // possible that there is a pending job but it is not scheduled because of // the max thread limit. if (madeProgress || bg_schedule_needed_) { MaybeScheduleFlushOrCompaction(); } if (madeProgress || bg_compaction_scheduled_ == 0 || bg_manual_only_ > 0) { // signal if // * madeProgress -- need to wakeup MakeRoomForWrite // * bg_compaction_scheduled_ == 0 -- need to wakeup ~DBImpl // * bg_manual_only_ > 0 -- need to wakeup RunManualCompaction // If none of this is true, there is no need to signal since nobody is // waiting for it bg_cv_.SignalAll(); } // IMPORTANT: there should be no code after calling SignalAll. This call may // signal the DB destructor that it's OK to proceed with destruction. In // that case, all DB variables will be dealloacated and referencing them // will cause trouble. } } Status DBImpl::BackgroundCompaction(bool* madeProgress, DeletionState& deletion_state, LogBuffer* log_buffer) { *madeProgress = false; mutex_.AssertHeld(); bool is_manual = (manual_compaction_ != nullptr) && (manual_compaction_->in_progress == false); if (is_manual) { // another thread cannot pick up the same work manual_compaction_->in_progress = true; } else if (manual_compaction_ != nullptr) { // there should be no automatic compactions running when manual compaction // is running return Status::OK(); } // FLUSH preempts compaction Status flush_stat; for (auto cfd : *versions_->GetColumnFamilySet()) { while (cfd->imm()->IsFlushPending()) { LogToBuffer( log_buffer, "BackgroundCompaction doing FlushMemTableToOutputFile, " "compaction slots available %d", options_.max_background_compactions - bg_compaction_scheduled_); cfd->Ref(); flush_stat = FlushMemTableToOutputFile(cfd, madeProgress, deletion_state, log_buffer); cfd->Unref(); if (!flush_stat.ok()) { if (is_manual) { manual_compaction_->status = flush_stat; manual_compaction_->done = true; manual_compaction_->in_progress = false; manual_compaction_ = nullptr; } return flush_stat; } } } unique_ptr c; InternalKey manual_end_storage; InternalKey* manual_end = &manual_end_storage; if (is_manual) { ManualCompaction* m = manual_compaction_; assert(m->in_progress); c.reset(m->cfd->CompactRange(m->input_level, m->output_level, m->output_path_id, m->begin, m->end, &manual_end)); if (!c) { m->done = true; } LogToBuffer(log_buffer, "[%s] Manual compaction from level-%d to level-%d from %s .. " "%s; will stop at %s\n", m->cfd->GetName().c_str(), m->input_level, m->output_level, (m->begin ? m->begin->DebugString().c_str() : "(begin)"), (m->end ? m->end->DebugString().c_str() : "(end)"), ((m->done || manual_end == nullptr) ? "(end)" : manual_end->DebugString().c_str())); } else { // no need to refcount in iteration since it's always under a mutex for (auto cfd : *versions_->GetColumnFamilySet()) { if (!cfd->options()->disable_auto_compactions) { c.reset(cfd->PickCompaction(log_buffer)); if (c != nullptr) { // update statistics MeasureTime(stats_, NUM_FILES_IN_SINGLE_COMPACTION, c->inputs(0)->size()); break; } } } } Status status; if (!c) { // Nothing to do LogToBuffer(log_buffer, "Compaction nothing to do"); } else if (c->IsDeletionCompaction()) { // TODO(icanadi) Do we want to honor snapshots here? i.e. not delete old // file if there is alive snapshot pointing to it assert(c->num_input_files(1) == 0); assert(c->level() == 0); assert(c->column_family_data()->options()->compaction_style == kCompactionStyleFIFO); for (const auto& f : *c->inputs(0)) { c->edit()->DeleteFile(c->level(), f->fd.GetNumber()); } status = versions_->LogAndApply(c->column_family_data(), c->edit(), &mutex_, db_directory_.get()); InstallSuperVersion(c->column_family_data(), deletion_state); LogToBuffer(log_buffer, "[%s] Deleted %d files\n", c->column_family_data()->GetName().c_str(), c->num_input_files(0)); c->ReleaseCompactionFiles(status); *madeProgress = true; } else if (!is_manual && c->IsTrivialMove()) { // Move file to next level assert(c->num_input_files(0) == 1); FileMetaData* f = c->input(0, 0); c->edit()->DeleteFile(c->level(), f->fd.GetNumber()); c->edit()->AddFile(c->level() + 1, f->fd.GetNumber(), f->fd.GetPathId(), f->fd.GetFileSize(), f->smallest, f->largest, f->smallest_seqno, f->largest_seqno); status = versions_->LogAndApply(c->column_family_data(), c->edit(), &mutex_, db_directory_.get()); InstallSuperVersion(c->column_family_data(), deletion_state); Version::LevelSummaryStorage tmp; LogToBuffer( log_buffer, "[%s] Moved #%lld to level-%d %lld bytes %s: %s\n", c->column_family_data()->GetName().c_str(), static_cast(f->fd.GetNumber()), c->level() + 1, static_cast(f->fd.GetFileSize()), status.ToString().c_str(), c->input_version()->LevelSummary(&tmp)); c->ReleaseCompactionFiles(status); *madeProgress = true; } else { MaybeScheduleFlushOrCompaction(); // do more compaction work in parallel. CompactionState* compact = new CompactionState(c.get()); status = DoCompactionWork(compact, deletion_state, log_buffer); CleanupCompaction(compact, status); c->ReleaseCompactionFiles(status); c->ReleaseInputs(); *madeProgress = true; } c.reset(); if (status.ok()) { // Done } else if (status.IsShutdownInProgress()) { // Ignore compaction errors found during shutting down } else { Log(InfoLogLevel::WARN_LEVEL, options_.info_log, "Compaction error: %s", status.ToString().c_str()); if (options_.paranoid_checks && bg_error_.ok()) { bg_error_ = status; } } if (is_manual) { ManualCompaction* m = manual_compaction_; if (!status.ok()) { m->status = status; m->done = true; } // For universal compaction: // Because universal compaction always happens at level 0, so one // compaction will pick up all overlapped files. No files will be // filtered out due to size limit and left for a successive compaction. // So we can safely conclude the current compaction. // // Also note that, if we don't stop here, then the current compaction // writes a new file back to level 0, which will be used in successive // compaction. Hence the manual compaction will never finish. // // Stop the compaction if manual_end points to nullptr -- this means // that we compacted the whole range. manual_end should always point // to nullptr in case of universal compaction if (manual_end == nullptr) { m->done = true; } if (!m->done) { // We only compacted part of the requested range. Update *m // to the range that is left to be compacted. // Universal and FIFO compactions should always compact the whole range assert(m->cfd->options()->compaction_style != kCompactionStyleUniversal); assert(m->cfd->options()->compaction_style != kCompactionStyleFIFO); m->tmp_storage = *manual_end; m->begin = &m->tmp_storage; } m->in_progress = false; // not being processed anymore manual_compaction_ = nullptr; } return status; } void DBImpl::CleanupCompaction(CompactionState* compact, Status status) { mutex_.AssertHeld(); if (compact->builder != nullptr) { // May happen if we get a shutdown call in the middle of compaction compact->builder->Abandon(); compact->builder.reset(); } else { assert(compact->outfile == nullptr); } for (size_t i = 0; i < compact->outputs.size(); i++) { const CompactionState::Output& out = compact->outputs[i]; pending_outputs_.erase(out.number); // If this file was inserted into the table cache then remove // them here because this compaction was not committed. if (!status.ok()) { TableCache::Evict(table_cache_.get(), out.number); } } delete compact; } // Allocate the file numbers for the output file. We allocate as // many output file numbers as there are files in level+1 (at least one) // Insert them into pending_outputs so that they do not get deleted. void DBImpl::AllocateCompactionOutputFileNumbers(CompactionState* compact) { mutex_.AssertHeld(); assert(compact != nullptr); assert(compact->builder == nullptr); int filesNeeded = compact->compaction->num_input_files(1); for (int i = 0; i < std::max(filesNeeded, 1); i++) { uint64_t file_number = versions_->NewFileNumber(); pending_outputs_[file_number] = compact->compaction->GetOutputPathId(); compact->allocated_file_numbers.push_back(file_number); } } // Frees up unused file number. void DBImpl::ReleaseCompactionUnusedFileNumbers(CompactionState* compact) { mutex_.AssertHeld(); for (const auto file_number : compact->allocated_file_numbers) { pending_outputs_.erase(file_number); } } Status DBImpl::OpenCompactionOutputFile(CompactionState* compact) { assert(compact != nullptr); assert(compact->builder == nullptr); uint64_t file_number; // If we have not yet exhausted the pre-allocated file numbers, // then use the one from the front. Otherwise, we have to acquire // the heavyweight lock and allocate a new file number. if (!compact->allocated_file_numbers.empty()) { file_number = compact->allocated_file_numbers.front(); compact->allocated_file_numbers.pop_front(); } else { mutex_.Lock(); file_number = versions_->NewFileNumber(); pending_outputs_[file_number] = compact->compaction->GetOutputPathId(); mutex_.Unlock(); } CompactionState::Output out; out.number = file_number; out.path_id = compact->compaction->GetOutputPathId(); out.smallest.Clear(); out.largest.Clear(); out.smallest_seqno = out.largest_seqno = 0; compact->outputs.push_back(out); // Make the output file std::string fname = TableFileName(options_.db_paths, file_number, compact->compaction->GetOutputPathId()); Status s = env_->NewWritableFile(fname, &compact->outfile, env_options_); if (s.ok()) { compact->outfile->SetIOPriority(Env::IO_LOW); compact->outfile->SetPreallocationBlockSize( compact->compaction->OutputFilePreallocationSize()); ColumnFamilyData* cfd = compact->compaction->column_family_data(); compact->builder.reset(NewTableBuilder( *cfd->ioptions(), cfd->internal_comparator(), compact->outfile.get(), compact->compaction->OutputCompressionType(), cfd->options()->compression_opts)); } LogFlush(options_.info_log); return s; } Status DBImpl::FinishCompactionOutputFile(CompactionState* compact, Iterator* input) { assert(compact != nullptr); assert(compact->outfile); assert(compact->builder != nullptr); const uint64_t output_number = compact->current_output()->number; const uint32_t output_path_id = compact->current_output()->path_id; assert(output_number != 0); // Check for iterator errors Status s = input->status(); const uint64_t current_entries = compact->builder->NumEntries(); if (s.ok()) { s = compact->builder->Finish(); } else { compact->builder->Abandon(); } const uint64_t current_bytes = compact->builder->FileSize(); compact->current_output()->file_size = current_bytes; compact->total_bytes += current_bytes; compact->builder.reset(); // Finish and check for file errors if (s.ok() && !options_.disableDataSync) { if (options_.use_fsync) { StopWatch sw(env_, stats_, COMPACTION_OUTFILE_SYNC_MICROS); s = compact->outfile->Fsync(); } else { StopWatch sw(env_, stats_, COMPACTION_OUTFILE_SYNC_MICROS); s = compact->outfile->Sync(); } } if (s.ok()) { s = compact->outfile->Close(); } compact->outfile.reset(); if (s.ok() && current_entries > 0) { // Verify that the table is usable ColumnFamilyData* cfd = compact->compaction->column_family_data(); FileDescriptor fd(output_number, output_path_id, current_bytes); Iterator* iter = cfd->table_cache()->NewIterator( ReadOptions(), env_options_, cfd->internal_comparator(), fd); s = iter->status(); delete iter; if (s.ok()) { Log(options_.info_log, "[%s] Generated table #%" PRIu64 ": %" PRIu64 " keys, %" PRIu64 " bytes", cfd->GetName().c_str(), output_number, current_entries, current_bytes); } } return s; } Status DBImpl::InstallCompactionResults(CompactionState* compact, LogBuffer* log_buffer) { mutex_.AssertHeld(); // paranoia: verify that the files that we started with // still exist in the current version and in the same original level. // This ensures that a concurrent compaction did not erroneously // pick the same files to compact. if (!versions_->VerifyCompactionFileConsistency(compact->compaction)) { Log(options_.info_log, "[%s] Compaction %d@%d + %d@%d files aborted", compact->compaction->column_family_data()->GetName().c_str(), compact->compaction->num_input_files(0), compact->compaction->level(), compact->compaction->num_input_files(1), compact->compaction->output_level()); return Status::Corruption("Compaction input files inconsistent"); } LogToBuffer(log_buffer, "[%s] Compacted %d@%d + %d@%d files => %lld bytes", compact->compaction->column_family_data()->GetName().c_str(), compact->compaction->num_input_files(0), compact->compaction->level(), compact->compaction->num_input_files(1), compact->compaction->output_level(), static_cast(compact->total_bytes)); // Add compaction outputs compact->compaction->AddInputDeletions(compact->compaction->edit()); for (size_t i = 0; i < compact->outputs.size(); i++) { const CompactionState::Output& out = compact->outputs[i]; compact->compaction->edit()->AddFile(compact->compaction->output_level(), out.number, out.path_id, out.file_size, out.smallest, out.largest, out.smallest_seqno, out.largest_seqno); } return versions_->LogAndApply(compact->compaction->column_family_data(), compact->compaction->edit(), &mutex_, db_directory_.get()); } // Given a sequence number, return the sequence number of the // earliest snapshot that this sequence number is visible in. // The snapshots themselves are arranged in ascending order of // sequence numbers. // Employ a sequential search because the total number of // snapshots are typically small. inline SequenceNumber DBImpl::findEarliestVisibleSnapshot( SequenceNumber in, std::vector& snapshots, SequenceNumber* prev_snapshot) { SequenceNumber prev __attribute__((unused)) = 0; for (const auto cur : snapshots) { assert(prev <= cur); if (cur >= in) { *prev_snapshot = prev; return cur; } prev = cur; // assignment assert(prev); } Log(options_.info_log, "Looking for seqid %" PRIu64 " but maxseqid is %" PRIu64 "", in, snapshots[snapshots.size() - 1]); assert(0); return 0; } uint64_t DBImpl::CallFlushDuringCompaction(ColumnFamilyData* cfd, DeletionState& deletion_state, LogBuffer* log_buffer) { if (options_.max_background_flushes > 0) { // flush thread will take care of this return 0; } if (cfd->imm()->imm_flush_needed.NoBarrier_Load() != nullptr) { const uint64_t imm_start = env_->NowMicros(); mutex_.Lock(); if (cfd->imm()->IsFlushPending()) { cfd->Ref(); FlushMemTableToOutputFile(cfd, nullptr, deletion_state, log_buffer); cfd->Unref(); bg_cv_.SignalAll(); // Wakeup MakeRoomForWrite() if necessary } mutex_.Unlock(); log_buffer->FlushBufferToLog(); return env_->NowMicros() - imm_start; } return 0; } Status DBImpl::ProcessKeyValueCompaction( bool is_snapshot_supported, SequenceNumber visible_at_tip, SequenceNumber earliest_snapshot, SequenceNumber latest_snapshot, DeletionState& deletion_state, bool bottommost_level, int64_t& imm_micros, Iterator* input, CompactionState* compact, bool is_compaction_v2, LogBuffer* log_buffer) { size_t combined_idx = 0; Status status; std::string compaction_filter_value; ParsedInternalKey ikey; IterKey current_user_key; bool has_current_user_key = false; IterKey delete_key; SequenceNumber last_sequence_for_key __attribute__((unused)) = kMaxSequenceNumber; SequenceNumber visible_in_snapshot = kMaxSequenceNumber; ColumnFamilyData* cfd = compact->compaction->column_family_data(); MergeHelper merge( cfd->user_comparator(), cfd->options()->merge_operator.get(), options_.info_log.get(), cfd->options()->min_partial_merge_operands, false /* internal key corruption is expected */); auto compaction_filter = cfd->options()->compaction_filter; std::unique_ptr compaction_filter_from_factory = nullptr; if (!compaction_filter) { auto context = compact->GetFilterContextV1(); compaction_filter_from_factory = cfd->options()->compaction_filter_factory->CreateCompactionFilter( context); compaction_filter = compaction_filter_from_factory.get(); } int64_t key_drop_user = 0; int64_t key_drop_newer_entry = 0; int64_t key_drop_obsolete = 0; int64_t loop_cnt = 0; while (input->Valid() && !shutting_down_.Acquire_Load() && !cfd->IsDropped()) { if (++loop_cnt > 1000) { if (key_drop_user > 0) { RecordTick(stats_, COMPACTION_KEY_DROP_USER, key_drop_user); key_drop_user = 0; } if (key_drop_newer_entry > 0) { RecordTick(stats_, COMPACTION_KEY_DROP_NEWER_ENTRY, key_drop_newer_entry); key_drop_newer_entry = 0; } if (key_drop_obsolete > 0) { RecordTick(stats_, COMPACTION_KEY_DROP_OBSOLETE, key_drop_obsolete); key_drop_obsolete = 0; } RecordCompactionIOStats(); loop_cnt = 0; } // FLUSH preempts compaction // TODO(icanadi) this currently only checks if flush is necessary on // compacting column family. we should also check if flush is necessary on // other column families, too imm_micros += CallFlushDuringCompaction(cfd, deletion_state, log_buffer); Slice key; Slice value; // If is_compaction_v2 is on, kv-pairs are reset to the prefix batch. // This prefix batch should contain results after calling // compaction_filter_v2. // // If is_compaction_v2 is off, this function will go through all the // kv-pairs in input. if (!is_compaction_v2) { key = input->key(); value = input->value(); } else { if (combined_idx >= compact->combined_key_buf_.size()) { break; } assert(combined_idx < compact->combined_key_buf_.size()); key = compact->combined_key_buf_[combined_idx]; value = compact->combined_value_buf_[combined_idx]; ++combined_idx; } if (compact->compaction->ShouldStopBefore(key) && compact->builder != nullptr) { status = FinishCompactionOutputFile(compact, input); if (!status.ok()) { break; } } // Handle key/value, add to state, etc. bool drop = false; bool current_entry_is_merging = false; if (!ParseInternalKey(key, &ikey)) { // Do not hide error keys // TODO: error key stays in db forever? Figure out the intention/rationale // v10 error v8 : we cannot hide v8 even though it's pretty obvious. current_user_key.Clear(); has_current_user_key = false; last_sequence_for_key = kMaxSequenceNumber; visible_in_snapshot = kMaxSequenceNumber; } else { if (!has_current_user_key || cfd->user_comparator()->Compare(ikey.user_key, current_user_key.GetKey()) != 0) { // First occurrence of this user key current_user_key.SetKey(ikey.user_key); has_current_user_key = true; last_sequence_for_key = kMaxSequenceNumber; visible_in_snapshot = kMaxSequenceNumber; // apply the compaction filter to the first occurrence of the user key if (compaction_filter && !is_compaction_v2 && ikey.type == kTypeValue && (visible_at_tip || ikey.sequence > latest_snapshot)) { // If the user has specified a compaction filter and the sequence // number is greater than any external snapshot, then invoke the // filter. // If the return value of the compaction filter is true, replace // the entry with a delete marker. bool value_changed = false; compaction_filter_value.clear(); bool to_delete = compaction_filter->Filter( compact->compaction->level(), ikey.user_key, value, &compaction_filter_value, &value_changed); if (to_delete) { // make a copy of the original key and convert it to a delete delete_key.SetInternalKey(ExtractUserKey(key), ikey.sequence, kTypeDeletion); // anchor the key again key = delete_key.GetKey(); // needed because ikey is backed by key ParseInternalKey(key, &ikey); // no value associated with delete value.clear(); ++key_drop_user; } else if (value_changed) { value = compaction_filter_value; } } } // If there are no snapshots, then this kv affect visibility at tip. // Otherwise, search though all existing snapshots to find // the earlist snapshot that is affected by this kv. SequenceNumber prev_snapshot = 0; // 0 means no previous snapshot SequenceNumber visible = visible_at_tip ? visible_at_tip : is_snapshot_supported ? findEarliestVisibleSnapshot(ikey.sequence, compact->existing_snapshots, &prev_snapshot) : 0; if (visible_in_snapshot == visible) { // If the earliest snapshot is which this key is visible in // is the same as the visibily of a previous instance of the // same key, then this kv is not visible in any snapshot. // Hidden by an newer entry for same user key // TODO: why not > ? assert(last_sequence_for_key >= ikey.sequence); drop = true; // (A) ++key_drop_newer_entry; } else if (ikey.type == kTypeDeletion && ikey.sequence <= earliest_snapshot && compact->compaction->KeyNotExistsBeyondOutputLevel(ikey.user_key)) { // For this user key: // (1) there is no data in higher levels // (2) data in lower levels will have larger sequence numbers // (3) data in layers that are being compacted here and have // smaller sequence numbers will be dropped in the next // few iterations of this loop (by rule (A) above). // Therefore this deletion marker is obsolete and can be dropped. drop = true; ++key_drop_obsolete; } else if (ikey.type == kTypeMerge) { if (!merge.HasOperator()) { LogToBuffer(log_buffer, "Options::merge_operator is null."); status = Status::InvalidArgument( "merge_operator is not properly initialized."); break; } // We know the merge type entry is not hidden, otherwise we would // have hit (A) // We encapsulate the merge related state machine in a different // object to minimize change to the existing flow. Turn out this // logic could also be nicely re-used for memtable flush purge // optimization in BuildTable. int steps = 0; merge.MergeUntil(input, prev_snapshot, bottommost_level, options_.statistics.get(), &steps); // Skip the Merge ops combined_idx = combined_idx - 1 + steps; current_entry_is_merging = true; if (merge.IsSuccess()) { // Successfully found Put/Delete/(end-of-key-range) while merging // Get the merge result key = merge.key(); ParseInternalKey(key, &ikey); value = merge.value(); } else { // Did not find a Put/Delete/(end-of-key-range) while merging // We now have some stack of merge operands to write out. // NOTE: key,value, and ikey are now referring to old entries. // These will be correctly set below. assert(!merge.keys().empty()); assert(merge.keys().size() == merge.values().size()); // Hack to make sure last_sequence_for_key is correct ParseInternalKey(merge.keys().front(), &ikey); } } last_sequence_for_key = ikey.sequence; visible_in_snapshot = visible; } if (!drop) { // We may write a single key (e.g.: for Put/Delete or successful merge). // Or we may instead have to write a sequence/list of keys. // We have to write a sequence iff we have an unsuccessful merge bool has_merge_list = current_entry_is_merging && !merge.IsSuccess(); const std::deque* keys = nullptr; const std::deque* values = nullptr; std::deque::const_reverse_iterator key_iter; std::deque::const_reverse_iterator value_iter; if (has_merge_list) { keys = &merge.keys(); values = &merge.values(); key_iter = keys->rbegin(); // The back (*rbegin()) is the first key value_iter = values->rbegin(); key = Slice(*key_iter); value = Slice(*value_iter); } // If we have a list of keys to write, traverse the list. // If we have a single key to write, simply write that key. while (true) { // Invariant: key,value,ikey will always be the next entry to write char* kptr = (char*)key.data(); std::string kstr; // Zeroing out the sequence number leads to better compression. // If this is the bottommost level (no files in lower levels) // and the earliest snapshot is larger than this seqno // then we can squash the seqno to zero. if (bottommost_level && ikey.sequence < earliest_snapshot && ikey.type != kTypeMerge) { assert(ikey.type != kTypeDeletion); // make a copy because updating in place would cause problems // with the priority queue that is managing the input key iterator kstr.assign(key.data(), key.size()); kptr = (char *)kstr.c_str(); UpdateInternalKey(kptr, key.size(), (uint64_t)0, ikey.type); } Slice newkey(kptr, key.size()); assert((key.clear(), 1)); // we do not need 'key' anymore // Open output file if necessary if (compact->builder == nullptr) { status = OpenCompactionOutputFile(compact); if (!status.ok()) { break; } } SequenceNumber seqno = GetInternalKeySeqno(newkey); if (compact->builder->NumEntries() == 0) { compact->current_output()->smallest.DecodeFrom(newkey); compact->current_output()->smallest_seqno = seqno; } else { compact->current_output()->smallest_seqno = std::min(compact->current_output()->smallest_seqno, seqno); } compact->current_output()->largest.DecodeFrom(newkey); compact->builder->Add(newkey, value); compact->current_output()->largest_seqno = std::max(compact->current_output()->largest_seqno, seqno); // Close output file if it is big enough if (compact->builder->FileSize() >= compact->compaction->MaxOutputFileSize()) { status = FinishCompactionOutputFile(compact, input); if (!status.ok()) { break; } } // If we have a list of entries, move to next element // If we only had one entry, then break the loop. if (has_merge_list) { ++key_iter; ++value_iter; // If at end of list if (key_iter == keys->rend() || value_iter == values->rend()) { // Sanity Check: if one ends, then both end assert(key_iter == keys->rend() && value_iter == values->rend()); break; } // Otherwise not at end of list. Update key, value, and ikey. key = Slice(*key_iter); value = Slice(*value_iter); ParseInternalKey(key, &ikey); } else{ // Only had one item to begin with (Put/Delete) break; } } } // MergeUntil has moved input to the next entry if (!current_entry_is_merging) { input->Next(); } } if (key_drop_user > 0) { RecordTick(stats_, COMPACTION_KEY_DROP_USER, key_drop_user); } if (key_drop_newer_entry > 0) { RecordTick(stats_, COMPACTION_KEY_DROP_NEWER_ENTRY, key_drop_newer_entry); } if (key_drop_obsolete > 0) { RecordTick(stats_, COMPACTION_KEY_DROP_OBSOLETE, key_drop_obsolete); } RecordCompactionIOStats(); return status; } void DBImpl::CallCompactionFilterV2(CompactionState* compact, CompactionFilterV2* compaction_filter_v2) { if (compact == nullptr || compaction_filter_v2 == nullptr) { return; } // Assemble slice vectors for user keys and existing values. // We also keep track of our parsed internal key structs because // we may need to access the sequence number in the event that // keys are garbage collected during the filter process. std::vector ikey_buf; std::vector user_key_buf; std::vector existing_value_buf; for (const auto& key : compact->key_str_buf_) { ParsedInternalKey ikey; ParseInternalKey(Slice(key), &ikey); ikey_buf.emplace_back(ikey); user_key_buf.emplace_back(ikey.user_key); } for (const auto& value : compact->existing_value_str_buf_) { existing_value_buf.emplace_back(Slice(value)); } // If the user has specified a compaction filter and the sequence // number is greater than any external snapshot, then invoke the // filter. // If the return value of the compaction filter is true, replace // the entry with a delete marker. compact->to_delete_buf_ = compaction_filter_v2->Filter( compact->compaction->level(), user_key_buf, existing_value_buf, &compact->new_value_buf_, &compact->value_changed_buf_); // new_value_buf_.size() <= to_delete__buf_.size(). "=" iff all // kv-pairs in this compaction run needs to be deleted. assert(compact->to_delete_buf_.size() == compact->key_str_buf_.size()); assert(compact->to_delete_buf_.size() == compact->existing_value_str_buf_.size()); assert(compact->to_delete_buf_.size() == compact->value_changed_buf_.size()); int new_value_idx = 0; for (unsigned int i = 0; i < compact->to_delete_buf_.size(); ++i) { if (compact->to_delete_buf_[i]) { // update the string buffer directly // the Slice buffer points to the updated buffer UpdateInternalKey(&compact->key_str_buf_[i][0], compact->key_str_buf_[i].size(), ikey_buf[i].sequence, kTypeDeletion); // no value associated with delete compact->existing_value_str_buf_[i].clear(); RecordTick(stats_, COMPACTION_KEY_DROP_USER); } else if (compact->value_changed_buf_[i]) { compact->existing_value_str_buf_[i] = compact->new_value_buf_[new_value_idx++]; } } // for } Status DBImpl::DoCompactionWork(CompactionState* compact, DeletionState& deletion_state, LogBuffer* log_buffer) { assert(compact); compact->CleanupBatchBuffer(); compact->CleanupMergedBuffer(); bool prefix_initialized = false; // Generate file_levels_ for compaction berfore making Iterator compact->compaction->GenerateFileLevels(); int64_t imm_micros = 0; // Micros spent doing imm_ compactions ColumnFamilyData* cfd = compact->compaction->column_family_data(); LogToBuffer( log_buffer, "[%s] Compacting %d@%d + %d@%d files, score %.2f slots available %d", cfd->GetName().c_str(), compact->compaction->num_input_files(0), compact->compaction->level(), compact->compaction->num_input_files(1), compact->compaction->output_level(), compact->compaction->score(), options_.max_background_compactions - bg_compaction_scheduled_); char scratch[2345]; compact->compaction->Summary(scratch, sizeof(scratch)); LogToBuffer(log_buffer, "[%s] Compaction start summary: %s\n", cfd->GetName().c_str(), scratch); assert(cfd->current()->NumLevelFiles(compact->compaction->level()) > 0); assert(compact->builder == nullptr); assert(!compact->outfile); SequenceNumber visible_at_tip = 0; SequenceNumber earliest_snapshot; SequenceNumber latest_snapshot = 0; snapshots_.getAll(compact->existing_snapshots); if (compact->existing_snapshots.size() == 0) { // optimize for fast path if there are no snapshots visible_at_tip = versions_->LastSequence(); earliest_snapshot = visible_at_tip; } else { latest_snapshot = compact->existing_snapshots.back(); // Add the current seqno as the 'latest' virtual // snapshot to the end of this list. compact->existing_snapshots.push_back(versions_->LastSequence()); earliest_snapshot = compact->existing_snapshots[0]; } // Is this compaction producing files at the bottommost level? bool bottommost_level = compact->compaction->BottomMostLevel(); // Allocate the output file numbers before we release the lock AllocateCompactionOutputFileNumbers(compact); bool is_snapshot_supported = IsSnapshotSupported(); // Release mutex while we're actually doing the compaction work mutex_.Unlock(); log_buffer->FlushBufferToLog(); const uint64_t start_micros = env_->NowMicros(); unique_ptr input(versions_->MakeInputIterator(compact->compaction)); input->SeekToFirst(); shared_ptr backup_input( versions_->MakeInputIterator(compact->compaction)); backup_input->SeekToFirst(); Status status; ParsedInternalKey ikey; std::unique_ptr compaction_filter_from_factory_v2 = nullptr; auto context = compact->GetFilterContext(); compaction_filter_from_factory_v2 = cfd->options()->compaction_filter_factory_v2->CreateCompactionFilterV2( context); auto compaction_filter_v2 = compaction_filter_from_factory_v2.get(); // temp_backup_input always point to the start of the current buffer // temp_backup_input = backup_input; // iterate through input, // 1) buffer ineligible keys and value keys into 2 separate buffers; // 2) send value_buffer to compaction filter and alternate the values; // 3) merge value_buffer with ineligible_value_buffer; // 4) run the modified "compaction" using the old for loop. if (compaction_filter_v2) { while (backup_input->Valid() && !shutting_down_.Acquire_Load() && !cfd->IsDropped()) { // FLUSH preempts compaction // TODO(icanadi) this currently only checks if flush is necessary on // compacting column family. we should also check if flush is necessary on // other column families, too imm_micros += CallFlushDuringCompaction(cfd, deletion_state, log_buffer); Slice key = backup_input->key(); Slice value = backup_input->value(); if (!ParseInternalKey(key, &ikey)) { // log error Log(options_.info_log, "[%s] Failed to parse key: %s", cfd->GetName().c_str(), key.ToString().c_str()); continue; } else { const SliceTransform* transformer = cfd->options()->compaction_filter_factory_v2->GetPrefixExtractor(); const auto key_prefix = transformer->Transform(ikey.user_key); if (!prefix_initialized) { compact->cur_prefix_ = key_prefix.ToString(); prefix_initialized = true; } // If the prefix remains the same, keep buffering if (key_prefix.compare(Slice(compact->cur_prefix_)) == 0) { // Apply the compaction filter V2 to all the kv pairs sharing // the same prefix if (ikey.type == kTypeValue && (visible_at_tip || ikey.sequence > latest_snapshot)) { // Buffer all keys sharing the same prefix for CompactionFilterV2 // Iterate through keys to check prefix compact->BufferKeyValueSlices(key, value); } else { // buffer ineligible keys compact->BufferOtherKeyValueSlices(key, value); } backup_input->Next(); continue; // finish changing values for eligible keys } else { // Now prefix changes, this batch is done. // Call compaction filter on the buffered values to change the value if (compact->key_str_buf_.size() > 0) { CallCompactionFilterV2(compact, compaction_filter_v2); } compact->cur_prefix_ = key_prefix.ToString(); } } // Merge this batch of data (values + ineligible keys) compact->MergeKeyValueSliceBuffer(&cfd->internal_comparator()); // Done buffering for the current prefix. Spit it out to disk // Now just iterate through all the kv-pairs status = ProcessKeyValueCompaction( is_snapshot_supported, visible_at_tip, earliest_snapshot, latest_snapshot, deletion_state, bottommost_level, imm_micros, input.get(), compact, true, log_buffer); if (!status.ok()) { break; } // After writing the kv-pairs, we can safely remove the reference // to the string buffer and clean them up compact->CleanupBatchBuffer(); compact->CleanupMergedBuffer(); // Buffer the key that triggers the mismatch in prefix if (ikey.type == kTypeValue && (visible_at_tip || ikey.sequence > latest_snapshot)) { compact->BufferKeyValueSlices(key, value); } else { compact->BufferOtherKeyValueSlices(key, value); } backup_input->Next(); if (!backup_input->Valid()) { // If this is the single last value, we need to merge it. if (compact->key_str_buf_.size() > 0) { CallCompactionFilterV2(compact, compaction_filter_v2); } compact->MergeKeyValueSliceBuffer(&cfd->internal_comparator()); status = ProcessKeyValueCompaction( is_snapshot_supported, visible_at_tip, earliest_snapshot, latest_snapshot, deletion_state, bottommost_level, imm_micros, input.get(), compact, true, log_buffer); compact->CleanupBatchBuffer(); compact->CleanupMergedBuffer(); } } // done processing all prefix batches // finish the last batch if (compact->key_str_buf_.size() > 0) { CallCompactionFilterV2(compact, compaction_filter_v2); } compact->MergeKeyValueSliceBuffer(&cfd->internal_comparator()); status = ProcessKeyValueCompaction( is_snapshot_supported, visible_at_tip, earliest_snapshot, latest_snapshot, deletion_state, bottommost_level, imm_micros, input.get(), compact, true, log_buffer); } // checking for compaction filter v2 if (!compaction_filter_v2) { status = ProcessKeyValueCompaction( is_snapshot_supported, visible_at_tip, earliest_snapshot, latest_snapshot, deletion_state, bottommost_level, imm_micros, input.get(), compact, false, log_buffer); } if (status.ok() && (shutting_down_.Acquire_Load() || cfd->IsDropped())) { status = Status::ShutdownInProgress( "Database shutdown or Column family drop during compaction"); } if (status.ok() && compact->builder != nullptr) { status = FinishCompactionOutputFile(compact, input.get()); } if (status.ok()) { status = input->status(); } input.reset(); if (!options_.disableDataSync) { db_directory_->Fsync(); } InternalStats::CompactionStats stats(1); stats.micros = env_->NowMicros() - start_micros - imm_micros; stats.files_in_leveln = compact->compaction->num_input_files(0); stats.files_in_levelnp1 = compact->compaction->num_input_files(1); MeasureTime(stats_, COMPACTION_TIME, stats.micros); int num_output_files = compact->outputs.size(); if (compact->builder != nullptr) { // An error occurred so ignore the last output. assert(num_output_files > 0); --num_output_files; } stats.files_out_levelnp1 = num_output_files; for (int i = 0; i < compact->compaction->num_input_files(0); i++) { stats.bytes_readn += compact->compaction->input(0, i)->fd.GetFileSize(); } for (int i = 0; i < compact->compaction->num_input_files(1); i++) { stats.bytes_readnp1 += compact->compaction->input(1, i)->fd.GetFileSize(); } for (int i = 0; i < num_output_files; i++) { stats.bytes_written += compact->outputs[i].file_size; } RecordCompactionIOStats(); LogFlush(options_.info_log); mutex_.Lock(); cfd->internal_stats()->AddCompactionStats( compact->compaction->output_level(), stats); // if there were any unused file number (mostly in case of // compaction error), free up the entry from pending_putputs ReleaseCompactionUnusedFileNumbers(compact); if (status.ok()) { status = InstallCompactionResults(compact, log_buffer); InstallSuperVersion(cfd, deletion_state); } Version::LevelSummaryStorage tmp; LogToBuffer( log_buffer, "[%s] compacted to: %s, %.1f MB/sec, level %d, files in(%d, %d) out(%d) " "MB in(%.1f, %.1f) out(%.1f), read-write-amplify(%.1f) " "write-amplify(%.1f) %s\n", cfd->GetName().c_str(), cfd->current()->LevelSummary(&tmp), (stats.bytes_readn + stats.bytes_readnp1 + stats.bytes_written) / (double)stats.micros, compact->compaction->output_level(), stats.files_in_leveln, stats.files_in_levelnp1, stats.files_out_levelnp1, stats.bytes_readn / 1048576.0, stats.bytes_readnp1 / 1048576.0, stats.bytes_written / 1048576.0, (stats.bytes_written + stats.bytes_readnp1 + stats.bytes_readn) / (double)stats.bytes_readn, stats.bytes_written / (double)stats.bytes_readn, status.ToString().c_str()); return status; } namespace { struct IterState { IterState(DBImpl* db, port::Mutex* mu, SuperVersion* super_version) : db(db), mu(mu), super_version(super_version) {} DBImpl* db; port::Mutex* mu; SuperVersion* super_version; }; static void CleanupIteratorState(void* arg1, void* arg2) { IterState* state = reinterpret_cast(arg1); if (state->super_version->Unref()) { DBImpl::DeletionState deletion_state; state->mu->Lock(); state->super_version->Cleanup(); state->db->FindObsoleteFiles(deletion_state, false, true); state->mu->Unlock(); delete state->super_version; if (deletion_state.HaveSomethingToDelete()) { state->db->PurgeObsoleteFiles(deletion_state); } } delete state; } } // namespace Iterator* DBImpl::NewInternalIterator(const ReadOptions& options, ColumnFamilyData* cfd, SuperVersion* super_version, Arena* arena) { Iterator* internal_iter; assert(arena != nullptr); // Need to create internal iterator from the arena. MergeIteratorBuilder merge_iter_builder(&cfd->internal_comparator(), arena); // Collect iterator for mutable mem merge_iter_builder.AddIterator( super_version->mem->NewIterator(options, arena)); // Collect all needed child iterators for immutable memtables super_version->imm->AddIterators(options, &merge_iter_builder); // Collect iterators for files in L0 - Ln super_version->current->AddIterators(options, env_options_, &merge_iter_builder); internal_iter = merge_iter_builder.Finish(); IterState* cleanup = new IterState(this, &mutex_, super_version); internal_iter->RegisterCleanup(CleanupIteratorState, cleanup, nullptr); return internal_iter; } ColumnFamilyHandle* DBImpl::DefaultColumnFamily() const { return default_cf_handle_; } Status DBImpl::Get(const ReadOptions& options, ColumnFamilyHandle* column_family, const Slice& key, std::string* value) { return GetImpl(options, column_family, key, value); } // DeletionState gets created and destructed outside of the lock -- we // use this convinently to: // * malloc one SuperVersion() outside of the lock -- new_superversion // * delete SuperVersion()s outside of the lock -- superversions_to_free // // However, if InstallSuperVersion() gets called twice with the same, // deletion_state, we can't reuse the SuperVersion() that got malloced because // first call already used it. In that rare case, we take a hit and create a // new SuperVersion() inside of the mutex. We do similar thing // for superversion_to_free void DBImpl::InstallSuperVersion(ColumnFamilyData* cfd, DeletionState& deletion_state) { mutex_.AssertHeld(); // if new_superversion == nullptr, it means somebody already used it SuperVersion* new_superversion = (deletion_state.new_superversion != nullptr) ? deletion_state.new_superversion : new SuperVersion(); SuperVersion* old_superversion = cfd->InstallSuperVersion(new_superversion, &mutex_); deletion_state.new_superversion = nullptr; deletion_state.superversions_to_free.push_back(old_superversion); } Status DBImpl::GetImpl(const ReadOptions& options, ColumnFamilyHandle* column_family, const Slice& key, std::string* value, bool* value_found) { StopWatch sw(env_, stats_, DB_GET); PERF_TIMER_GUARD(get_snapshot_time); auto cfh = reinterpret_cast(column_family); auto cfd = cfh->cfd(); SequenceNumber snapshot; if (options.snapshot != nullptr) { snapshot = reinterpret_cast(options.snapshot)->number_; } else { snapshot = versions_->LastSequence(); } // Acquire SuperVersion SuperVersion* sv = GetAndRefSuperVersion(cfd); // Prepare to store a list of merge operations if merge occurs. MergeContext merge_context; Status s; // First look in the memtable, then in the immutable memtable (if any). // s is both in/out. When in, s could either be OK or MergeInProgress. // merge_operands will contain the sequence of merges in the latter case. LookupKey lkey(key, snapshot); PERF_TIMER_STOP(get_snapshot_time); if (sv->mem->Get(lkey, value, &s, merge_context, *cfd->options())) { // Done RecordTick(stats_, MEMTABLE_HIT); } else if (sv->imm->Get(lkey, value, &s, merge_context, *cfd->options())) { // Done RecordTick(stats_, MEMTABLE_HIT); } else { PERF_TIMER_GUARD(get_from_output_files_time); sv->current->Get(options, lkey, value, &s, &merge_context, value_found); RecordTick(stats_, MEMTABLE_MISS); } { PERF_TIMER_GUARD(get_post_process_time); ReturnAndCleanupSuperVersion(cfd, sv); RecordTick(stats_, NUMBER_KEYS_READ); RecordTick(stats_, BYTES_READ, value->size()); } return s; } std::vector DBImpl::MultiGet( const ReadOptions& options, const std::vector& column_family, const std::vector& keys, std::vector* values) { StopWatch sw(env_, stats_, DB_MULTIGET); PERF_TIMER_GUARD(get_snapshot_time); SequenceNumber snapshot; struct MultiGetColumnFamilyData { ColumnFamilyData* cfd; SuperVersion* super_version; }; std::unordered_map multiget_cf_data; // fill up and allocate outside of mutex for (auto cf : column_family) { auto cfh = reinterpret_cast(cf); auto cfd = cfh->cfd(); if (multiget_cf_data.find(cfd->GetID()) == multiget_cf_data.end()) { auto mgcfd = new MultiGetColumnFamilyData(); mgcfd->cfd = cfd; multiget_cf_data.insert({cfd->GetID(), mgcfd}); } } mutex_.Lock(); if (options.snapshot != nullptr) { snapshot = reinterpret_cast(options.snapshot)->number_; } else { snapshot = versions_->LastSequence(); } for (auto mgd_iter : multiget_cf_data) { mgd_iter.second->super_version = mgd_iter.second->cfd->GetSuperVersion()->Ref(); } mutex_.Unlock(); // Contain a list of merge operations if merge occurs. MergeContext merge_context; // Note: this always resizes the values array size_t num_keys = keys.size(); std::vector stat_list(num_keys); values->resize(num_keys); // Keep track of bytes that we read for statistics-recording later uint64_t bytes_read = 0; PERF_TIMER_STOP(get_snapshot_time); // For each of the given keys, apply the entire "get" process as follows: // First look in the memtable, then in the immutable memtable (if any). // s is both in/out. When in, s could either be OK or MergeInProgress. // merge_operands will contain the sequence of merges in the latter case. for (size_t i = 0; i < num_keys; ++i) { merge_context.Clear(); Status& s = stat_list[i]; std::string* value = &(*values)[i]; LookupKey lkey(keys[i], snapshot); auto cfh = reinterpret_cast(column_family[i]); auto mgd_iter = multiget_cf_data.find(cfh->cfd()->GetID()); assert(mgd_iter != multiget_cf_data.end()); auto mgd = mgd_iter->second; auto super_version = mgd->super_version; auto cfd = mgd->cfd; if (super_version->mem->Get(lkey, value, &s, merge_context, *cfd->options())) { // Done } else if (super_version->imm->Get(lkey, value, &s, merge_context, *cfd->options())) { // Done } else { super_version->current->Get(options, lkey, value, &s, &merge_context); } if (s.ok()) { bytes_read += value->size(); } } // Post processing (decrement reference counts and record statistics) PERF_TIMER_GUARD(get_post_process_time); autovector superversions_to_delete; // TODO(icanadi) do we need lock here or just around Cleanup()? mutex_.Lock(); for (auto mgd_iter : multiget_cf_data) { auto mgd = mgd_iter.second; if (mgd->super_version->Unref()) { mgd->super_version->Cleanup(); superversions_to_delete.push_back(mgd->super_version); } } mutex_.Unlock(); for (auto td : superversions_to_delete) { delete td; } for (auto mgd : multiget_cf_data) { delete mgd.second; } RecordTick(stats_, NUMBER_MULTIGET_CALLS); RecordTick(stats_, NUMBER_MULTIGET_KEYS_READ, num_keys); RecordTick(stats_, NUMBER_MULTIGET_BYTES_READ, bytes_read); PERF_TIMER_STOP(get_post_process_time); return stat_list; } Status DBImpl::CreateColumnFamily(const ColumnFamilyOptions& options, const std::string& column_family_name, ColumnFamilyHandle** handle) { *handle = nullptr; MutexLock l(&mutex_); if (versions_->GetColumnFamilySet()->GetColumnFamily(column_family_name) != nullptr) { return Status::InvalidArgument("Column family already exists"); } VersionEdit edit; edit.AddColumnFamily(column_family_name); uint32_t new_id = versions_->GetColumnFamilySet()->GetNextColumnFamilyID(); edit.SetColumnFamily(new_id); edit.SetLogNumber(logfile_number_); edit.SetComparatorName(options.comparator->Name()); // LogAndApply will both write the creation in MANIFEST and create // ColumnFamilyData object Status s = versions_->LogAndApply(nullptr, &edit, &mutex_, db_directory_.get(), false, &options); if (s.ok()) { single_column_family_mode_ = false; auto cfd = versions_->GetColumnFamilySet()->GetColumnFamily(column_family_name); assert(cfd != nullptr); delete cfd->InstallSuperVersion(new SuperVersion(), &mutex_); *handle = new ColumnFamilyHandleImpl(cfd, this, &mutex_); Log(options_.info_log, "Created column family [%s] (ID %u)", column_family_name.c_str(), (unsigned)cfd->GetID()); max_total_in_memory_state_ += cfd->options()->write_buffer_size * cfd->options()->max_write_buffer_number; } else { Log(options_.info_log, "Creating column family [%s] FAILED -- %s", column_family_name.c_str(), s.ToString().c_str()); } return s; } Status DBImpl::DropColumnFamily(ColumnFamilyHandle* column_family) { auto cfh = reinterpret_cast(column_family); auto cfd = cfh->cfd(); if (cfd->GetID() == 0) { return Status::InvalidArgument("Can't drop default column family"); } VersionEdit edit; edit.DropColumnFamily(); edit.SetColumnFamily(cfd->GetID()); Status s; { MutexLock l(&mutex_); if (cfd->IsDropped()) { s = Status::InvalidArgument("Column family already dropped!\n"); } if (s.ok()) { s = versions_->LogAndApply(cfd, &edit, &mutex_); } } if (s.ok()) { assert(cfd->IsDropped()); max_total_in_memory_state_ -= cfd->options()->write_buffer_size * cfd->options()->max_write_buffer_number; Log(options_.info_log, "Dropped column family with id %u\n", cfd->GetID()); } else { Log(options_.info_log, "Dropping column family with id %u FAILED -- %s\n", cfd->GetID(), s.ToString().c_str()); } return s; } bool DBImpl::KeyMayExist(const ReadOptions& options, ColumnFamilyHandle* column_family, const Slice& key, std::string* value, bool* value_found) { if (value_found != nullptr) { // falsify later if key-may-exist but can't fetch value *value_found = true; } ReadOptions roptions = options; roptions.read_tier = kBlockCacheTier; // read from block cache only auto s = GetImpl(roptions, column_family, key, value, value_found); // If block_cache is enabled and the index block of the table didn't // not present in block_cache, the return value will be Status::Incomplete. // In this case, key may still exist in the table. return s.ok() || s.IsIncomplete(); } Iterator* DBImpl::NewIterator(const ReadOptions& options, ColumnFamilyHandle* column_family) { auto cfh = reinterpret_cast(column_family); auto cfd = cfh->cfd(); if (options.tailing) { #ifdef ROCKSDB_LITE // not supported in lite version return nullptr; #else // TODO(ljin): remove tailing iterator auto iter = new ForwardIterator(this, options, cfd); return NewDBIterator(env_, *cfd->options(), cfd->user_comparator(), iter, kMaxSequenceNumber, options.iterate_upper_bound); // return new TailingIterator(env_, this, options, cfd); #endif } else { SequenceNumber latest_snapshot = versions_->LastSequence(); SuperVersion* sv = nullptr; sv = cfd->GetReferencedSuperVersion(&mutex_); auto snapshot = options.snapshot != nullptr ? reinterpret_cast(options.snapshot)->number_ : latest_snapshot; // Try to generate a DB iterator tree in continuous memory area to be // cache friendly. Here is an example of result: // +-------------------------------+ // | | // | ArenaWrappedDBIter | // | + | // | +---> Inner Iterator ------------+ // | | | | // | | +-- -- -- -- -- -- -- --+ | // | +--- | Arena | | // | | | | // | Allocated Memory: | | // | | +-------------------+ | // | | | DBIter | <---+ // | | + | // | | | +-> iter_ ------------+ // | | | | | // | | +-------------------+ | // | | | MergingIterator | <---+ // | | + | // | | | +->child iter1 ------------+ // | | | | | | // | | +->child iter2 ----------+ | // | | | | | | | // | | | +->child iter3 --------+ | | // | | | | | | // | | +-------------------+ | | | // | | | Iterator1 | <--------+ // | | +-------------------+ | | // | | | Iterator2 | <------+ // | | +-------------------+ | // | | | Iterator3 | <----+ // | | +-------------------+ // | | | // +-------+-----------------------+ // // ArenaWrappedDBIter inlines an arena area where all the iterartor in the // the iterator tree is allocated in the order of being accessed when // querying. // Laying out the iterators in the order of being accessed makes it more // likely that any iterator pointer is close to the iterator it points to so // that they are likely to be in the same cache line and/or page. ArenaWrappedDBIter* db_iter = NewArenaWrappedDbIterator( env_, *cfd->options(), cfd->user_comparator(), snapshot, options.iterate_upper_bound); Iterator* internal_iter = NewInternalIterator(options, cfd, sv, db_iter->GetArena()); db_iter->SetIterUnderDBIter(internal_iter); return db_iter; } } Status DBImpl::NewIterators( const ReadOptions& options, const std::vector& column_families, std::vector* iterators) { iterators->clear(); iterators->reserve(column_families.size()); SequenceNumber latest_snapshot = 0; std::vector super_versions; super_versions.reserve(column_families.size()); if (!options.tailing) { mutex_.Lock(); latest_snapshot = versions_->LastSequence(); for (auto cfh : column_families) { auto cfd = reinterpret_cast(cfh)->cfd(); super_versions.push_back(cfd->GetSuperVersion()->Ref()); } mutex_.Unlock(); } if (options.tailing) { #ifdef ROCKSDB_LITE return Status::InvalidArgument( "Tailing interator not supported in RocksDB lite"); #else for (auto cfh : column_families) { auto cfd = reinterpret_cast(cfh)->cfd(); auto iter = new ForwardIterator(this, options, cfd); iterators->push_back( NewDBIterator(env_, *cfd->options(), cfd->user_comparator(), iter, kMaxSequenceNumber)); } #endif } else { for (size_t i = 0; i < column_families.size(); ++i) { auto cfh = reinterpret_cast(column_families[i]); auto cfd = cfh->cfd(); auto snapshot = options.snapshot != nullptr ? reinterpret_cast(options.snapshot)->number_ : latest_snapshot; ArenaWrappedDBIter* db_iter = NewArenaWrappedDbIterator( env_, *cfd->options(), cfd->user_comparator(), snapshot); Iterator* internal_iter = NewInternalIterator( options, cfd, super_versions[i], db_iter->GetArena()); db_iter->SetIterUnderDBIter(internal_iter); iterators->push_back(db_iter); } } return Status::OK(); } bool DBImpl::IsSnapshotSupported() const { for (auto cfd : *versions_->GetColumnFamilySet()) { if (!cfd->mem()->IsSnapshotSupported()) { return false; } } return true; } const Snapshot* DBImpl::GetSnapshot() { MutexLock l(&mutex_); // returns null if the underlying memtable does not support snapshot. if (!IsSnapshotSupported()) return nullptr; return snapshots_.New(versions_->LastSequence()); } void DBImpl::ReleaseSnapshot(const Snapshot* s) { MutexLock l(&mutex_); snapshots_.Delete(reinterpret_cast(s)); } // Convenience methods Status DBImpl::Put(const WriteOptions& o, ColumnFamilyHandle* column_family, const Slice& key, const Slice& val) { return DB::Put(o, column_family, key, val); } Status DBImpl::Merge(const WriteOptions& o, ColumnFamilyHandle* column_family, const Slice& key, const Slice& val) { auto cfh = reinterpret_cast(column_family); if (!cfh->cfd()->options()->merge_operator) { return Status::NotSupported("Provide a merge_operator when opening DB"); } else { return DB::Merge(o, column_family, key, val); } } Status DBImpl::Delete(const WriteOptions& options, ColumnFamilyHandle* column_family, const Slice& key) { return DB::Delete(options, column_family, key); } // REQUIRES: mutex_ is held Status DBImpl::BeginWrite(Writer* w, uint64_t expiration_time) { // the following code block pushes the current writer "w" into the writer // queue "writers_" and wait until one of the following conditions met: // 1. the job of "w" has been done by some other writers. // 2. "w" becomes the first writer in "writers_" // 3. "w" timed-out. mutex_.AssertHeld(); writers_.push_back(w); bool timed_out = false; while (!w->done && w != writers_.front()) { if (expiration_time == 0) { w->cv.Wait(); } else if (w->cv.TimedWait(expiration_time)) { if (w->in_batch_group) { // then it means the front writer is currently doing the // write on behalf of this "timed-out" writer. Then it // should wait until the write completes. expiration_time = 0; } else { timed_out = true; break; } } } if (timed_out) { #ifndef NDEBUG bool found = false; #endif for (auto iter = writers_.begin(); iter != writers_.end(); iter++) { if (*iter == w) { writers_.erase(iter); #ifndef NDEBUG found = true; #endif break; } } #ifndef NDEBUG assert(found); #endif // writers_.front() might still be in cond_wait without a time-out. // As a result, we need to signal it to wake it up. Otherwise no // one else will wake him up, and RocksDB will hang. if (!writers_.empty()) { writers_.front()->cv.Signal(); } return Status::TimedOut(); } return Status::OK(); } // REQUIRES: mutex_ is held void DBImpl::EndWrite(Writer* w, Writer* last_writer, Status status) { // Pop out the current writer and all writers being pushed before the // current writer from the writer queue. mutex_.AssertHeld(); while (!writers_.empty()) { Writer* ready = writers_.front(); writers_.pop_front(); if (ready != w) { ready->status = status; ready->done = true; ready->cv.Signal(); } if (ready == last_writer) break; } // Notify new head of write queue if (!writers_.empty()) { writers_.front()->cv.Signal(); } } Status DBImpl::Write(const WriteOptions& options, WriteBatch* my_batch) { if (my_batch == nullptr) { return Status::Corruption("Batch is nullptr!"); } PERF_TIMER_GUARD(write_pre_and_post_process_time); Writer w(&mutex_); w.batch = my_batch; w.sync = options.sync; w.disableWAL = options.disableWAL; w.in_batch_group = false; w.done = false; w.timeout_hint_us = options.timeout_hint_us; uint64_t expiration_time = 0; if (w.timeout_hint_us == 0) { w.timeout_hint_us = kNoTimeOut; } else { expiration_time = env_->NowMicros() + w.timeout_hint_us; } if (!options.disableWAL) { RecordTick(stats_, WRITE_WITH_WAL); default_cf_internal_stats_->AddDBStats(InternalStats::WRITE_WITH_WAL, 1); } WriteContext context; mutex_.Lock(); Status status = BeginWrite(&w, expiration_time); assert(status.ok() || status.IsTimedOut()); if (status.IsTimedOut()) { mutex_.Unlock(); RecordTick(stats_, WRITE_TIMEDOUT); return Status::TimedOut(); } if (w.done) { // write was done by someone else default_cf_internal_stats_->AddDBStats(InternalStats::WRITE_DONE_BY_OTHER, 1); mutex_.Unlock(); RecordTick(stats_, WRITE_DONE_BY_OTHER); return w.status; } RecordTick(stats_, WRITE_DONE_BY_SELF); default_cf_internal_stats_->AddDBStats(InternalStats::WRITE_DONE_BY_SELF, 1); // Once reaches this point, the current writer "w" will try to do its write // job. It may also pick up some of the remaining writers in the "writers_" // when it finds suitable, and finish them in the same write batch. // This is how a write job could be done by the other writer. assert(!single_column_family_mode_ || versions_->GetColumnFamilySet()->NumberOfColumnFamilies() == 1); uint64_t flush_column_family_if_log_file = 0; uint64_t max_total_wal_size = (options_.max_total_wal_size == 0) ? 4 * max_total_in_memory_state_ : options_.max_total_wal_size; if (UNLIKELY(!single_column_family_mode_) && alive_log_files_.begin()->getting_flushed == false && total_log_size_ > max_total_wal_size) { flush_column_family_if_log_file = alive_log_files_.begin()->number; alive_log_files_.begin()->getting_flushed = true; Log(options_.info_log, "Flushing all column families with data in WAL number %" PRIu64 ". Total log size is %" PRIu64 " while max_total_wal_size is %" PRIu64, flush_column_family_if_log_file, total_log_size_, max_total_wal_size); } if (LIKELY(single_column_family_mode_)) { // fast path status = MakeRoomForWrite(default_cf_handle_->cfd(), &context, expiration_time); } else { // refcounting cfd in iteration bool dead_cfd = false; for (auto cfd : *versions_->GetColumnFamilySet()) { cfd->Ref(); if (flush_column_family_if_log_file != 0 && cfd->GetLogNumber() <= flush_column_family_if_log_file) { // log size excedded limit and we need to do flush // SetNewMemtableAndNewLogFie may temporarily unlock and wait status = SetNewMemtableAndNewLogFile(cfd, &context); cfd->imm()->FlushRequested(); MaybeScheduleFlushOrCompaction(); } else { // May temporarily unlock and wait. status = MakeRoomForWrite(cfd, &context, expiration_time); } if (cfd->Unref()) { dead_cfd = true; } if (!status.ok()) { break; } } if (dead_cfd) { versions_->GetColumnFamilySet()->FreeDeadColumnFamilies(); } } uint64_t last_sequence = versions_->LastSequence(); Writer* last_writer = &w; if (status.ok()) { autovector write_batch_group; BuildBatchGroup(&last_writer, &write_batch_group); // Add to log and apply to memtable. We can release the lock // during this phase since &w is currently responsible for logging // and protects against concurrent loggers and concurrent writes // into memtables { mutex_.Unlock(); WriteBatch* updates = nullptr; if (write_batch_group.size() == 1) { updates = write_batch_group[0]; } else { updates = &tmp_batch_; for (size_t i = 0; i < write_batch_group.size(); ++i) { WriteBatchInternal::Append(updates, write_batch_group[i]); } } const SequenceNumber current_sequence = last_sequence + 1; WriteBatchInternal::SetSequence(updates, current_sequence); int my_batch_count = WriteBatchInternal::Count(updates); last_sequence += my_batch_count; const uint64_t batch_size = WriteBatchInternal::ByteSize(updates); // Record statistics RecordTick(stats_, NUMBER_KEYS_WRITTEN, my_batch_count); RecordTick(stats_, BYTES_WRITTEN, WriteBatchInternal::ByteSize(updates)); if (options.disableWAL) { flush_on_destroy_ = true; } PERF_TIMER_STOP(write_pre_and_post_process_time); uint64_t log_size = 0; if (!options.disableWAL) { PERF_TIMER_GUARD(write_wal_time); Slice log_entry = WriteBatchInternal::Contents(updates); status = log_->AddRecord(log_entry); total_log_size_ += log_entry.size(); alive_log_files_.back().AddSize(log_entry.size()); log_empty_ = false; log_size = log_entry.size(); RecordTick(stats_, WAL_FILE_SYNCED); RecordTick(stats_, WAL_FILE_BYTES, log_size); if (status.ok() && options.sync) { if (options_.use_fsync) { StopWatch(env_, stats_, WAL_FILE_SYNC_MICROS); status = log_->file()->Fsync(); } else { StopWatch(env_, stats_, WAL_FILE_SYNC_MICROS); status = log_->file()->Sync(); } } } if (status.ok()) { PERF_TIMER_GUARD(write_memtable_time); status = WriteBatchInternal::InsertInto( updates, column_family_memtables_.get(), options.ignore_missing_column_families, 0, this, false); // A non-OK status here indicates iteration failure (either in-memory // writebatch corruption (very bad), or the client specified invalid // column family). This will later on trigger bg_error_. // // Note that existing logic was not sound. Any partial failure writing // into the memtable would result in a state that some write ops might // have succeeded in memtable but Status reports error for all writes. SetTickerCount(stats_, SEQUENCE_NUMBER, last_sequence); } PERF_TIMER_START(write_pre_and_post_process_time); if (updates == &tmp_batch_) { tmp_batch_.Clear(); } mutex_.Lock(); // internal stats default_cf_internal_stats_->AddDBStats( InternalStats::BYTES_WRITTEN, batch_size); if (!options.disableWAL) { default_cf_internal_stats_->AddDBStats( InternalStats::WAL_FILE_SYNCED, 1); default_cf_internal_stats_->AddDBStats( InternalStats::WAL_FILE_BYTES, log_size); } if (status.ok()) { versions_->SetLastSequence(last_sequence); } } } if (options_.paranoid_checks && !status.ok() && !status.IsTimedOut() && bg_error_.ok()) { bg_error_ = status; // stop compaction & fail any further writes } EndWrite(&w, last_writer, status); mutex_.Unlock(); if (status.IsTimedOut()) { RecordTick(stats_, WRITE_TIMEDOUT); } return status; } // This function will be called only when the first writer succeeds. // All writers in the to-be-built batch group will be processed. // // REQUIRES: Writer list must be non-empty // REQUIRES: First writer must have a non-nullptr batch void DBImpl::BuildBatchGroup(Writer** last_writer, autovector* write_batch_group) { assert(!writers_.empty()); Writer* first = writers_.front(); assert(first->batch != nullptr); size_t size = WriteBatchInternal::ByteSize(first->batch); write_batch_group->push_back(first->batch); // Allow the group to grow up to a maximum size, but if the // original write is small, limit the growth so we do not slow // down the small write too much. size_t max_size = 1 << 20; if (size <= (128<<10)) { max_size = size + (128<<10); } *last_writer = first; std::deque::iterator iter = writers_.begin(); ++iter; // Advance past "first" for (; iter != writers_.end(); ++iter) { Writer* w = *iter; if (w->sync && !first->sync) { // Do not include a sync write into a batch handled by a non-sync write. break; } if (!w->disableWAL && first->disableWAL) { // Do not include a write that needs WAL into a batch that has // WAL disabled. break; } if (w->timeout_hint_us < first->timeout_hint_us) { // Do not include those writes with shorter timeout. Otherwise, we might // execute a write that should instead be aborted because of timeout. break; } if (w->batch != nullptr) { size += WriteBatchInternal::ByteSize(w->batch); if (size > max_size) { // Do not make batch too big break; } write_batch_group->push_back(w->batch); } w->in_batch_group = true; *last_writer = w; } } // This function computes the amount of time in microseconds by which a write // should be delayed based on the number of level-0 files according to the // following formula: // if n < bottom, return 0; // if n >= top, return 1000; // otherwise, let r = (n - bottom) / // (top - bottom) // and return r^2 * 1000. // The goal of this formula is to gradually increase the rate at which writes // are slowed. We also tried linear delay (r * 1000), but it seemed to do // slightly worse. There is no other particular reason for choosing quadratic. uint64_t DBImpl::SlowdownAmount(int n, double bottom, double top) { uint64_t delay; if (n >= top) { delay = 1000; } else if (n < bottom) { delay = 0; } else { // If we are here, we know that: // level0_start_slowdown <= n < level0_slowdown // since the previous two conditions are false. double how_much = (double) (n - bottom) / (top - bottom); delay = std::max(how_much * how_much * 1000, 100.0); } assert(delay <= 1000); return delay; } // REQUIRES: mutex_ is held // REQUIRES: this thread is currently at the front of the writer queue Status DBImpl::MakeRoomForWrite(ColumnFamilyData* cfd, WriteContext* context, uint64_t expiration_time) { mutex_.AssertHeld(); assert(!writers_.empty()); bool allow_delay = true; bool allow_hard_rate_limit_delay = true; bool allow_soft_rate_limit_delay = true; uint64_t rate_limit_delay_millis = 0; Status s; double score; // Once we schedule background work, we shouldn't schedule it again, since it // might generate a tight feedback loop, constantly scheduling more background // work, even if additional background work is not needed bool schedule_background_work = true; bool has_timeout = (expiration_time > 0); while (true) { if (!bg_error_.ok()) { // Yield previous error s = bg_error_; break; } else if (has_timeout && env_->NowMicros() > expiration_time) { s = Status::TimedOut(); break; } else if (allow_delay && cfd->NeedSlowdownForNumLevel0Files()) { // We are getting close to hitting a hard limit on the number of // L0 files. Rather than delaying a single write by several // seconds when we hit the hard limit, start delaying each // individual write by 0-1ms to reduce latency variance. Also, // this delay hands over some CPU to the compaction thread in // case it is sharing the same core as the writer. uint64_t slowdown = SlowdownAmount(cfd->current()->NumLevelFiles(0), cfd->options()->level0_slowdown_writes_trigger, cfd->options()->level0_stop_writes_trigger); mutex_.Unlock(); uint64_t delayed; { StopWatch sw(env_, stats_, STALL_L0_SLOWDOWN_COUNT, &delayed); env_->SleepForMicroseconds(slowdown); } RecordTick(stats_, STALL_L0_SLOWDOWN_MICROS, delayed); allow_delay = false; // Do not delay a single write more than once mutex_.Lock(); cfd->internal_stats()->AddCFStats( InternalStats::LEVEL0_SLOWDOWN, delayed); delayed_writes_++; } else if (!cfd->mem()->ShouldFlush()) { // There is room in current memtable if (allow_delay) { DelayLoggingAndReset(); } break; } else if (cfd->NeedWaitForNumMemtables()) { // We have filled up the current memtable, but the previous // ones are still being flushed, so we wait. DelayLoggingAndReset(); Log(options_.info_log, "[%s] wait for memtable flush...\n", cfd->GetName().c_str()); if (schedule_background_work) { MaybeScheduleFlushOrCompaction(); schedule_background_work = false; } uint64_t stall; { StopWatch sw(env_, stats_, STALL_MEMTABLE_COMPACTION_COUNT, &stall); if (!has_timeout) { bg_cv_.Wait(); } else { bg_cv_.TimedWait(expiration_time); } } RecordTick(stats_, STALL_MEMTABLE_COMPACTION_MICROS, stall); cfd->internal_stats()->AddCFStats( InternalStats::MEMTABLE_COMPACTION, stall); } else if (cfd->NeedWaitForNumLevel0Files()) { DelayLoggingAndReset(); Log(options_.info_log, "[%s] wait for fewer level0 files...\n", cfd->GetName().c_str()); uint64_t stall; { StopWatch sw(env_, stats_, STALL_L0_NUM_FILES_COUNT, &stall); if (!has_timeout) { bg_cv_.Wait(); } else { bg_cv_.TimedWait(expiration_time); } } RecordTick(stats_, STALL_L0_NUM_FILES_MICROS, stall); cfd->internal_stats()->AddCFStats( InternalStats::LEVEL0_NUM_FILES, stall); } else if (allow_hard_rate_limit_delay && cfd->ExceedsHardRateLimit()) { // Delay a write when the compaction score for any level is too large. const int max_level = cfd->current()->MaxCompactionScoreLevel(); score = cfd->current()->MaxCompactionScore(); mutex_.Unlock(); uint64_t delayed; { StopWatch sw(env_, stats_, HARD_RATE_LIMIT_DELAY_COUNT, &delayed); env_->SleepForMicroseconds(1000); } // Make sure the following value doesn't round to zero. uint64_t rate_limit = std::max((delayed / 1000), (uint64_t) 1); rate_limit_delay_millis += rate_limit; RecordTick(stats_, RATE_LIMIT_DELAY_MILLIS, rate_limit); if (cfd->options()->rate_limit_delay_max_milliseconds > 0 && rate_limit_delay_millis >= (unsigned)cfd->options()->rate_limit_delay_max_milliseconds) { allow_hard_rate_limit_delay = false; } mutex_.Lock(); cfd->internal_stats()->RecordLevelNSlowdown(max_level, delayed, false); } else if (allow_soft_rate_limit_delay && cfd->ExceedsSoftRateLimit()) { const int max_level = cfd->current()->MaxCompactionScoreLevel(); score = cfd->current()->MaxCompactionScore(); // Delay a write when the compaction score for any level is too large. // TODO: add statistics uint64_t slowdown = SlowdownAmount(score, cfd->options()->soft_rate_limit, cfd->options()->hard_rate_limit); uint64_t elapsed = 0; mutex_.Unlock(); { StopWatch sw(env_, stats_, SOFT_RATE_LIMIT_DELAY_COUNT, &elapsed); env_->SleepForMicroseconds(slowdown); rate_limit_delay_millis += slowdown; } allow_soft_rate_limit_delay = false; mutex_.Lock(); cfd->internal_stats()->RecordLevelNSlowdown(max_level, elapsed, true); } else { s = SetNewMemtableAndNewLogFile(cfd, context); if (!s.ok()) { break; } MaybeScheduleFlushOrCompaction(); } } return s; } // REQUIRES: mutex_ is held // REQUIRES: this thread is currently at the front of the writer queue Status DBImpl::SetNewMemtableAndNewLogFile(ColumnFamilyData* cfd, WriteContext* context) { mutex_.AssertHeld(); unique_ptr lfile; log::Writer* new_log = nullptr; MemTable* new_mem = nullptr; // Attempt to switch to a new memtable and trigger flush of old. // Do this without holding the dbmutex lock. assert(versions_->PrevLogNumber() == 0); bool creating_new_log = !log_empty_; uint64_t new_log_number = creating_new_log ? versions_->NewFileNumber() : logfile_number_; SuperVersion* new_superversion = nullptr; mutex_.Unlock(); Status s; { DelayLoggingAndReset(); if (creating_new_log) { s = env_->NewWritableFile(LogFileName(options_.wal_dir, new_log_number), &lfile, env_->OptimizeForLogWrite(env_options_)); if (s.ok()) { // Our final size should be less than write_buffer_size // (compression, etc) but err on the side of caution. lfile->SetPreallocationBlockSize(1.1 * cfd->options()->write_buffer_size); new_log = new log::Writer(std::move(lfile)); } } if (s.ok()) { new_mem = new MemTable(cfd->internal_comparator(), *cfd->options()); new_superversion = new SuperVersion(); } } mutex_.Lock(); if (!s.ok()) { // how do we fail if we're not creating new log? assert(creating_new_log); // Avoid chewing through file number space in a tight loop. versions_->ReuseLogFileNumber(new_log_number); assert(!new_mem); assert(!new_log); return s; } if (creating_new_log) { logfile_number_ = new_log_number; assert(new_log != nullptr); context->logs_to_free_.push_back(log_.release()); log_.reset(new_log); log_empty_ = true; alive_log_files_.push_back(LogFileNumberSize(logfile_number_)); for (auto cfd : *versions_->GetColumnFamilySet()) { // all this is just optimization to delete logs that // are no longer needed -- if CF is empty, that means it // doesn't need that particular log to stay alive, so we just // advance the log number. no need to persist this in the manifest if (cfd->mem()->GetFirstSequenceNumber() == 0 && cfd->imm()->size() == 0) { cfd->SetLogNumber(logfile_number_); } } } cfd->mem()->SetNextLogNumber(logfile_number_); cfd->imm()->Add(cfd->mem()); new_mem->Ref(); cfd->SetMemtable(new_mem); Log(options_.info_log, "[%s] New memtable created with log file: #%" PRIu64 "\n", cfd->GetName().c_str(), logfile_number_); context->superversions_to_free_.push_back( cfd->InstallSuperVersion(new_superversion, &mutex_)); return s; } #ifndef ROCKSDB_LITE Status DBImpl::GetPropertiesOfAllTables(ColumnFamilyHandle* column_family, TablePropertiesCollection* props) { auto cfh = reinterpret_cast(column_family); auto cfd = cfh->cfd(); // Increment the ref count mutex_.Lock(); auto version = cfd->current(); version->Ref(); mutex_.Unlock(); auto s = version->GetPropertiesOfAllTables(props); // Decrement the ref count mutex_.Lock(); version->Unref(); mutex_.Unlock(); return s; } #endif // ROCKSDB_LITE const std::string& DBImpl::GetName() const { return dbname_; } Env* DBImpl::GetEnv() const { return env_; } const Options& DBImpl::GetOptions(ColumnFamilyHandle* column_family) const { auto cfh = reinterpret_cast(column_family); return *cfh->cfd()->options(); } bool DBImpl::GetProperty(ColumnFamilyHandle* column_family, const Slice& property, std::string* value) { bool is_int_property = false; bool need_out_of_mutex = false; DBPropertyType property_type = GetPropertyType(property, &is_int_property, &need_out_of_mutex); value->clear(); if (is_int_property) { uint64_t int_value; bool ret_value = GetIntPropertyInternal(column_family, property_type, need_out_of_mutex, &int_value); if (ret_value) { *value = std::to_string(int_value); } return ret_value; } else { auto cfh = reinterpret_cast(column_family); auto cfd = cfh->cfd(); MutexLock l(&mutex_); return cfd->internal_stats()->GetStringProperty(property_type, property, value); } } bool DBImpl::GetIntProperty(ColumnFamilyHandle* column_family, const Slice& property, uint64_t* value) { bool is_int_property = false; bool need_out_of_mutex = false; DBPropertyType property_type = GetPropertyType(property, &is_int_property, &need_out_of_mutex); if (!is_int_property) { return false; } return GetIntPropertyInternal(column_family, property_type, need_out_of_mutex, value); } bool DBImpl::GetIntPropertyInternal(ColumnFamilyHandle* column_family, DBPropertyType property_type, bool need_out_of_mutex, uint64_t* value) { auto cfh = reinterpret_cast(column_family); auto cfd = cfh->cfd(); if (!need_out_of_mutex) { MutexLock l(&mutex_); return cfd->internal_stats()->GetIntProperty(property_type, value, this); } else { SuperVersion* sv = GetAndRefSuperVersion(cfd); bool ret = cfd->internal_stats()->GetIntPropertyOutOfMutex( property_type, sv->current, value); ReturnAndCleanupSuperVersion(cfd, sv); return ret; } } SuperVersion* DBImpl::GetAndRefSuperVersion(ColumnFamilyData* cfd) { // TODO(ljin): consider using GetReferencedSuperVersion() directly if (LIKELY(options_.allow_thread_local)) { return cfd->GetThreadLocalSuperVersion(&mutex_); } else { MutexLock l(&mutex_); return cfd->GetSuperVersion()->Ref(); } } void DBImpl::ReturnAndCleanupSuperVersion(ColumnFamilyData* cfd, SuperVersion* sv) { bool unref_sv = true; if (LIKELY(options_.allow_thread_local)) { unref_sv = !cfd->ReturnThreadLocalSuperVersion(sv); } if (unref_sv) { // Release SuperVersion if (sv->Unref()) { { MutexLock l(&mutex_); sv->Cleanup(); } delete sv; RecordTick(stats_, NUMBER_SUPERVERSION_CLEANUPS); } RecordTick(stats_, NUMBER_SUPERVERSION_RELEASES); } } void DBImpl::GetApproximateSizes(ColumnFamilyHandle* column_family, const Range* range, int n, uint64_t* sizes) { // TODO(opt): better implementation Version* v; auto cfh = reinterpret_cast(column_family); auto cfd = cfh->cfd(); { MutexLock l(&mutex_); v = cfd->current(); v->Ref(); } for (int i = 0; i < n; i++) { // Convert user_key into a corresponding internal key. InternalKey k1(range[i].start, kMaxSequenceNumber, kValueTypeForSeek); InternalKey k2(range[i].limit, kMaxSequenceNumber, kValueTypeForSeek); uint64_t start = versions_->ApproximateOffsetOf(v, k1); uint64_t limit = versions_->ApproximateOffsetOf(v, k2); sizes[i] = (limit >= start ? limit - start : 0); } { MutexLock l(&mutex_); v->Unref(); } } inline void DBImpl::DelayLoggingAndReset() { if (delayed_writes_ > 0) { Log(options_.info_log, "delayed %d write...\n", delayed_writes_ ); delayed_writes_ = 0; } } #ifndef ROCKSDB_LITE Status DBImpl::GetUpdatesSince( SequenceNumber seq, unique_ptr* iter, const TransactionLogIterator::ReadOptions& read_options) { RecordTick(stats_, GET_UPDATES_SINCE_CALLS); if (seq > versions_->LastSequence()) { return Status::NotFound("Requested sequence not yet written in the db"); } // Get all sorted Wal Files. // Do binary search and open files and find the seq number. std::unique_ptr wal_files(new VectorLogPtr); Status s = GetSortedWalFiles(*wal_files); if (!s.ok()) { return s; } s = RetainProbableWalFiles(*wal_files, seq); if (!s.ok()) { return s; } iter->reset(new TransactionLogIteratorImpl(options_.wal_dir, &options_, read_options, env_options_, seq, std::move(wal_files), this)); return (*iter)->status(); } Status DBImpl::DeleteFile(std::string name) { uint64_t number; FileType type; WalFileType log_type; if (!ParseFileName(name, &number, &type, &log_type) || (type != kTableFile && type != kLogFile)) { Log(options_.info_log, "DeleteFile %s failed.\n", name.c_str()); return Status::InvalidArgument("Invalid file name"); } Status status; if (type == kLogFile) { // Only allow deleting archived log files if (log_type != kArchivedLogFile) { Log(options_.info_log, "DeleteFile %s failed - not archived log.\n", name.c_str()); return Status::NotSupported("Delete only supported for archived logs"); } status = env_->DeleteFile(options_.wal_dir + "/" + name.c_str()); if (!status.ok()) { Log(options_.info_log, "DeleteFile %s failed -- %s.\n", name.c_str(), status.ToString().c_str()); } return status; } int level; FileMetaData* metadata; ColumnFamilyData* cfd; VersionEdit edit; DeletionState deletion_state(true); { MutexLock l(&mutex_); status = versions_->GetMetadataForFile(number, &level, &metadata, &cfd); if (!status.ok()) { Log(options_.info_log, "DeleteFile %s failed. File not found\n", name.c_str()); return Status::InvalidArgument("File not found"); } assert((level > 0) && (level < cfd->NumberLevels())); // If the file is being compacted no need to delete. if (metadata->being_compacted) { Log(options_.info_log, "DeleteFile %s Skipped. File about to be compacted\n", name.c_str()); return Status::OK(); } // Only the files in the last level can be deleted externally. // This is to make sure that any deletion tombstones are not // lost. Check that the level passed is the last level. for (int i = level + 1; i < cfd->NumberLevels(); i++) { if (cfd->current()->NumLevelFiles(i) != 0) { Log(options_.info_log, "DeleteFile %s FAILED. File not in last level\n", name.c_str()); return Status::InvalidArgument("File not in last level"); } } edit.DeleteFile(level, number); status = versions_->LogAndApply(cfd, &edit, &mutex_, db_directory_.get()); if (status.ok()) { InstallSuperVersion(cfd, deletion_state); } FindObsoleteFiles(deletion_state, false); } // lock released here LogFlush(options_.info_log); // remove files outside the db-lock if (deletion_state.HaveSomethingToDelete()) { PurgeObsoleteFiles(deletion_state); } { MutexLock l(&mutex_); // schedule flush if file deletion means we freed the space for flushes to // continue MaybeScheduleFlushOrCompaction(); } return status; } void DBImpl::GetLiveFilesMetaData(std::vector* metadata) { MutexLock l(&mutex_); versions_->GetLiveFilesMetaData(metadata); } #endif // ROCKSDB_LITE Status DBImpl::CheckConsistency() { mutex_.AssertHeld(); std::vector metadata; versions_->GetLiveFilesMetaData(&metadata); std::string corruption_messages; for (const auto& md : metadata) { std::string file_path = md.db_path + "/" + md.name; uint64_t fsize = 0; Status s = env_->GetFileSize(file_path, &fsize); if (!s.ok()) { corruption_messages += "Can't access " + md.name + ": " + s.ToString() + "\n"; } else if (fsize != md.size) { corruption_messages += "Sst file size mismatch: " + file_path + ". Size recorded in manifest " + std::to_string(md.size) + ", actual size " + std::to_string(fsize) + "\n"; } } if (corruption_messages.size() == 0) { return Status::OK(); } else { return Status::Corruption(corruption_messages); } } Status DBImpl::GetDbIdentity(std::string& identity) { std::string idfilename = IdentityFileName(dbname_); unique_ptr idfile; const EnvOptions soptions; Status s = env_->NewSequentialFile(idfilename, &idfile, soptions); if (!s.ok()) { return s; } uint64_t file_size; s = env_->GetFileSize(idfilename, &file_size); if (!s.ok()) { return s; } char buffer[file_size]; Slice id; s = idfile->Read(file_size, &id, buffer); if (!s.ok()) { return s; } identity.assign(id.ToString()); // If last character is '\n' remove it from identity if (identity.size() > 0 && identity.back() == '\n') { identity.pop_back(); } return s; } // Default implementations of convenience methods that subclasses of DB // can call if they wish Status DB::Put(const WriteOptions& opt, ColumnFamilyHandle* column_family, const Slice& key, const Slice& value) { // Pre-allocate size of write batch conservatively. // 8 bytes are taken by header, 4 bytes for count, 1 byte for type, // and we allocate 11 extra bytes for key length, as well as value length. WriteBatch batch(key.size() + value.size() + 24); batch.Put(column_family, key, value); return Write(opt, &batch); } Status DB::Delete(const WriteOptions& opt, ColumnFamilyHandle* column_family, const Slice& key) { WriteBatch batch; batch.Delete(column_family, key); return Write(opt, &batch); } Status DB::Merge(const WriteOptions& opt, ColumnFamilyHandle* column_family, const Slice& key, const Slice& value) { WriteBatch batch; batch.Merge(column_family, key, value); return Write(opt, &batch); } // Default implementation -- returns not supported status Status DB::CreateColumnFamily(const ColumnFamilyOptions& options, const std::string& column_family_name, ColumnFamilyHandle** handle) { return Status::NotSupported(""); } Status DB::DropColumnFamily(ColumnFamilyHandle* column_family) { return Status::NotSupported(""); } DB::~DB() { } Status DB::Open(const Options& options, const std::string& dbname, DB** dbptr) { DBOptions db_options(options); ColumnFamilyOptions cf_options(options); std::vector column_families; column_families.push_back( ColumnFamilyDescriptor(kDefaultColumnFamilyName, cf_options)); std::vector handles; Status s = DB::Open(db_options, dbname, column_families, &handles, dbptr); if (s.ok()) { assert(handles.size() == 1); // i can delete the handle since DBImpl is always holding a reference to // default column family delete handles[0]; } return s; } Status DB::Open(const DBOptions& db_options, const std::string& dbname, const std::vector& column_families, std::vector* handles, DB** dbptr) { Status s = SanitizeDBOptionsByCFOptions(&db_options, column_families); if (!s.ok()) { return s; } if (db_options.db_paths.size() > 1) { for (auto& cfd : column_families) { if (cfd.options.compaction_style != kCompactionStyleUniversal) { return Status::NotSupported( "More than one DB paths are only supported in " "universal compaction style. "); } } if (db_options.db_paths.size() > 4) { return Status::NotSupported( "More than four DB paths are not supported yet. "); } } *dbptr = nullptr; handles->clear(); size_t max_write_buffer_size = 0; for (auto cf : column_families) { max_write_buffer_size = std::max(max_write_buffer_size, cf.options.write_buffer_size); } DBImpl* impl = new DBImpl(db_options, dbname); s = impl->env_->CreateDirIfMissing(impl->options_.wal_dir); if (s.ok()) { for (auto db_path : impl->options_.db_paths) { s = impl->env_->CreateDirIfMissing(db_path.path); if (!s.ok()) { break; } } } if (!s.ok()) { delete impl; return s; } s = impl->CreateArchivalDirectory(); if (!s.ok()) { delete impl; return s; } impl->mutex_.Lock(); // Handles create_if_missing, error_if_exists s = impl->Recover(column_families); if (s.ok()) { uint64_t new_log_number = impl->versions_->NewFileNumber(); unique_ptr lfile; EnvOptions soptions(db_options); s = impl->options_.env->NewWritableFile( LogFileName(impl->options_.wal_dir, new_log_number), &lfile, impl->options_.env->OptimizeForLogWrite(soptions)); if (s.ok()) { lfile->SetPreallocationBlockSize(1.1 * max_write_buffer_size); impl->logfile_number_ = new_log_number; impl->log_.reset(new log::Writer(std::move(lfile))); // set column family handles for (auto cf : column_families) { auto cfd = impl->versions_->GetColumnFamilySet()->GetColumnFamily(cf.name); if (cfd != nullptr) { handles->push_back( new ColumnFamilyHandleImpl(cfd, impl, &impl->mutex_)); } else { if (db_options.create_missing_column_families) { // missing column family, create it ColumnFamilyHandle* handle; impl->mutex_.Unlock(); s = impl->CreateColumnFamily(cf.options, cf.name, &handle); impl->mutex_.Lock(); if (s.ok()) { handles->push_back(handle); } else { break; } } else { s = Status::InvalidArgument("Column family not found: ", cf.name); break; } } } } if (s.ok()) { for (auto cfd : *impl->versions_->GetColumnFamilySet()) { delete cfd->InstallSuperVersion(new SuperVersion(), &impl->mutex_); } impl->alive_log_files_.push_back( DBImpl::LogFileNumberSize(impl->logfile_number_)); impl->DeleteObsoleteFiles(); impl->MaybeScheduleFlushOrCompaction(); s = impl->db_directory_->Fsync(); } } if (s.ok()) { for (auto cfd : *impl->versions_->GetColumnFamilySet()) { if (cfd->options()->compaction_style == kCompactionStyleUniversal || cfd->options()->compaction_style == kCompactionStyleFIFO) { Version* current = cfd->current(); for (int i = 1; i < current->NumberLevels(); ++i) { int num_files = current->NumLevelFiles(i); if (num_files > 0) { s = Status::InvalidArgument( "Not all files are at level 0. Cannot " "open with universal or FIFO compaction style."); break; } } } if (cfd->options()->merge_operator != nullptr && !cfd->mem()->IsMergeOperatorSupported()) { s = Status::InvalidArgument( "The memtable of column family %s does not support merge operator " "its options.merge_operator is non-null", cfd->GetName().c_str()); } if (!s.ok()) { break; } } } impl->mutex_.Unlock(); if (s.ok()) { impl->opened_successfully_ = true; *dbptr = impl; } else { for (auto h : *handles) { delete h; } handles->clear(); delete impl; } return s; } Status DB::ListColumnFamilies(const DBOptions& db_options, const std::string& name, std::vector* column_families) { return VersionSet::ListColumnFamilies(column_families, name, db_options.env); } Snapshot::~Snapshot() { } Status DestroyDB(const std::string& dbname, const Options& options) { const InternalKeyComparator comparator(options.comparator); const Options& soptions(SanitizeOptions(dbname, &comparator, options)); Env* env = soptions.env; std::vector filenames; std::vector archiveFiles; std::string archivedir = ArchivalDirectory(dbname); // Ignore error in case directory does not exist env->GetChildren(dbname, &filenames); if (dbname != soptions.wal_dir) { std::vector logfilenames; env->GetChildren(soptions.wal_dir, &logfilenames); filenames.insert(filenames.end(), logfilenames.begin(), logfilenames.end()); archivedir = ArchivalDirectory(soptions.wal_dir); } if (filenames.empty()) { return Status::OK(); } FileLock* lock; const std::string lockname = LockFileName(dbname); Status result = env->LockFile(lockname, &lock); if (result.ok()) { uint64_t number; FileType type; InfoLogPrefix info_log_prefix(!options.db_log_dir.empty(), dbname); for (size_t i = 0; i < filenames.size(); i++) { if (ParseFileName(filenames[i], &number, info_log_prefix.prefix, &type) && type != kDBLockFile) { // Lock file will be deleted at end Status del; if (type == kMetaDatabase) { del = DestroyDB(dbname + "/" + filenames[i], options); } else if (type == kLogFile) { del = env->DeleteFile(soptions.wal_dir + "/" + filenames[i]); } else { del = env->DeleteFile(dbname + "/" + filenames[i]); } if (result.ok() && !del.ok()) { result = del; } } } for (auto& db_path : options.db_paths) { env->GetChildren(db_path.path, &filenames); uint64_t number; FileType type; for (size_t i = 0; i < filenames.size(); i++) { if (ParseFileName(filenames[i], &number, &type) && type == kTableFile) { // Lock file will be deleted at end Status del = env->DeleteFile(db_path.path + "/" + filenames[i]); if (result.ok() && !del.ok()) { result = del; } } } } env->GetChildren(archivedir, &archiveFiles); // Delete archival files. for (size_t i = 0; i < archiveFiles.size(); ++i) { if (ParseFileName(archiveFiles[i], &number, &type) && type == kLogFile) { Status del = env->DeleteFile(archivedir + "/" + archiveFiles[i]); if (result.ok() && !del.ok()) { result = del; } } } // ignore case where no archival directory is present. env->DeleteDir(archivedir); env->UnlockFile(lock); // Ignore error since state is already gone env->DeleteFile(lockname); env->DeleteDir(dbname); // Ignore error in case dir contains other files env->DeleteDir(soptions.wal_dir); } return result; } // // A global method that can dump out the build version void DumpLeveldbBuildVersion(Logger * log) { #if !defined(IOS_CROSS_COMPILE) // if we compile with Xcode, we don't run build_detect_vesion, so we don't generate util/build_version.cc Log(log, "Git sha %s", rocksdb_build_git_sha); Log(log, "Compile time %s %s", rocksdb_build_compile_time, rocksdb_build_compile_date); #endif } } // namespace rocksdb