// Copyright (c) 2011-present, Facebook, Inc. All rights reserved. // This source code is licensed under both the GPLv2 (found in the // COPYING file in the root directory) and Apache 2.0 License // (found in the LICENSE.Apache file in the root 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. #pragma once #include #include #include #include #include #include #include #include #include #include #include "db/column_family.h" #include "db/compaction/compaction_job.h" #include "db/dbformat.h" #include "db/error_handler.h" #include "db/event_helpers.h" #include "db/external_sst_file_ingestion_job.h" #include "db/flush_job.h" #include "db/flush_scheduler.h" #include "db/internal_stats.h" #include "db/log_writer.h" #include "db/logs_with_prep_tracker.h" #include "db/memtable_list.h" #include "db/pre_release_callback.h" #include "db/range_del_aggregator.h" #include "db/read_callback.h" #include "db/snapshot_checker.h" #include "db/snapshot_impl.h" #include "db/version_edit.h" #include "db/wal_manager.h" #include "db/write_controller.h" #include "db/write_thread.h" #include "logging/event_logger.h" #include "monitoring/instrumented_mutex.h" #include "options/db_options.h" #include "port/port.h" #include "rocksdb/db.h" #include "rocksdb/env.h" #include "rocksdb/memtablerep.h" #include "rocksdb/status.h" #include "rocksdb/trace_reader_writer.h" #include "rocksdb/transaction_log.h" #include "rocksdb/write_buffer_manager.h" #include "table/scoped_arena_iterator.h" #include "trace_replay/block_cache_tracer.h" #include "trace_replay/trace_replay.h" #include "util/autovector.h" #include "util/hash.h" #include "util/repeatable_thread.h" #include "util/stop_watch.h" #include "util/thread_local.h" namespace rocksdb { class Arena; class ArenaWrappedDBIter; class InMemoryStatsHistoryIterator; class MemTable; class PersistentStatsHistoryIterator; class TableCache; class TaskLimiterToken; class Version; class VersionEdit; class VersionSet; class WriteCallback; struct JobContext; struct ExternalSstFileInfo; struct MemTableInfo; // Class to maintain directories for all database paths other than main one. class Directories { public: Status SetDirectories(Env* env, const std::string& dbname, const std::string& wal_dir, const std::vector& data_paths); Directory* GetDataDir(size_t path_id) const { assert(path_id < data_dirs_.size()); Directory* ret_dir = data_dirs_[path_id].get(); if (ret_dir == nullptr) { // Should use db_dir_ return db_dir_.get(); } return ret_dir; } Directory* GetWalDir() { if (wal_dir_) { return wal_dir_.get(); } return db_dir_.get(); } Directory* GetDbDir() { return db_dir_.get(); } private: std::unique_ptr db_dir_; std::vector> data_dirs_; std::unique_ptr wal_dir_; }; // While DB is the public interface of RocksDB, and DBImpl is the actual // class implementing it. It's the entrance of the core RocksdB engine. // All other DB implementations, e.g. TransactionDB, BlobDB, etc, wrap a // DBImpl internally. // Other than functions implementing the DB interface, some public // functions are there for other internal components to call. For // example, TransactionDB directly calls DBImpl::WriteImpl() and // BlobDB directly calls DBImpl::GetImpl(). Some other functions // are for sub-components to call. For example, ColumnFamilyHandleImpl // calls DBImpl::FindObsoleteFiles(). // // Since it's a very large class, the definition of the functions is // divided in several db_impl_*.cc files, besides db_impl.cc. class DBImpl : public DB { public: DBImpl(const DBOptions& options, const std::string& dbname, const bool seq_per_batch = false, const bool batch_per_txn = true); virtual ~DBImpl(); // ---- Implementations of the DB interface ---- using DB::Resume; virtual Status Resume() override; using DB::Put; virtual Status Put(const WriteOptions& options, ColumnFamilyHandle* column_family, const Slice& key, const Slice& value) override; using DB::Merge; virtual Status Merge(const WriteOptions& options, ColumnFamilyHandle* column_family, const Slice& key, const Slice& value) override; using DB::Delete; virtual Status Delete(const WriteOptions& options, ColumnFamilyHandle* column_family, const Slice& key) override; using DB::SingleDelete; virtual Status SingleDelete(const WriteOptions& options, ColumnFamilyHandle* column_family, const Slice& key) override; using DB::Write; virtual Status Write(const WriteOptions& options, WriteBatch* updates) override; using DB::Get; virtual Status Get(const ReadOptions& options, ColumnFamilyHandle* column_family, const Slice& key, PinnableSlice* value) override; using DB::MultiGet; virtual std::vector MultiGet( const ReadOptions& options, const std::vector& column_family, const std::vector& keys, std::vector* values) override; // This MultiGet is a batched version, which may be faster than calling Get // multiple times, especially if the keys have some spatial locality that // enables them to be queried in the same SST files/set of files. The larger // the batch size, the more scope for batching and performance improvement // The values and statuses parameters are arrays with number of elements // equal to keys.size(). This allows the storage for those to be alloacted // by the caller on the stack for small batches virtual void MultiGet(const ReadOptions& options, ColumnFamilyHandle* column_family, const size_t num_keys, const Slice* keys, PinnableSlice* values, Status* statuses, const bool sorted_input = false) override; void MultiGetImpl( const ReadOptions& options, ColumnFamilyHandle* column_family, autovector& key_context, bool sorted_input, ReadCallback* callback = nullptr, bool* is_blob_index = nullptr); virtual Status CreateColumnFamily(const ColumnFamilyOptions& cf_options, const std::string& column_family, ColumnFamilyHandle** handle) override; virtual Status CreateColumnFamilies( const ColumnFamilyOptions& cf_options, const std::vector& column_family_names, std::vector* handles) override; virtual Status CreateColumnFamilies( const std::vector& column_families, std::vector* handles) override; virtual Status DropColumnFamily(ColumnFamilyHandle* column_family) override; virtual Status DropColumnFamilies( const std::vector& column_families) override; // Returns false if key doesn't exist in the database and true if it may. // If value_found is not passed in as null, then return the value if found in // memory. On return, if value was found, then value_found will be set to true // , otherwise false. using DB::KeyMayExist; virtual bool KeyMayExist(const ReadOptions& options, ColumnFamilyHandle* column_family, const Slice& key, std::string* value, bool* value_found = nullptr) override; using DB::NewIterator; virtual Iterator* NewIterator(const ReadOptions& options, ColumnFamilyHandle* column_family) override; virtual Status NewIterators( const ReadOptions& options, const std::vector& column_families, std::vector* iterators) override; virtual const Snapshot* GetSnapshot() override; virtual void ReleaseSnapshot(const Snapshot* snapshot) override; using DB::GetProperty; virtual bool GetProperty(ColumnFamilyHandle* column_family, const Slice& property, std::string* value) override; using DB::GetMapProperty; virtual bool GetMapProperty( ColumnFamilyHandle* column_family, const Slice& property, std::map* value) override; using DB::GetIntProperty; virtual bool GetIntProperty(ColumnFamilyHandle* column_family, const Slice& property, uint64_t* value) override; using DB::GetAggregatedIntProperty; virtual bool GetAggregatedIntProperty(const Slice& property, uint64_t* aggregated_value) override; using DB::GetApproximateSizes; virtual void GetApproximateSizes( ColumnFamilyHandle* column_family, const Range* range, int n, uint64_t* sizes, uint8_t include_flags = INCLUDE_FILES) override; using DB::GetApproximateMemTableStats; virtual void GetApproximateMemTableStats(ColumnFamilyHandle* column_family, const Range& range, uint64_t* const count, uint64_t* const size) override; using DB::CompactRange; virtual Status CompactRange(const CompactRangeOptions& options, ColumnFamilyHandle* column_family, const Slice* begin, const Slice* end) override; using DB::CompactFiles; virtual Status CompactFiles( const CompactionOptions& compact_options, ColumnFamilyHandle* column_family, const std::vector& input_file_names, const int output_level, const int output_path_id = -1, std::vector* const output_file_names = nullptr, CompactionJobInfo* compaction_job_info = nullptr) override; virtual Status PauseBackgroundWork() override; virtual Status ContinueBackgroundWork() override; virtual Status EnableAutoCompaction( const std::vector& column_family_handles) override; using DB::SetOptions; Status SetOptions( ColumnFamilyHandle* column_family, const std::unordered_map& options_map) override; virtual Status SetDBOptions( const std::unordered_map& options_map) override; using DB::NumberLevels; virtual int NumberLevels(ColumnFamilyHandle* column_family) override; using DB::MaxMemCompactionLevel; virtual int MaxMemCompactionLevel(ColumnFamilyHandle* column_family) override; using DB::Level0StopWriteTrigger; virtual int Level0StopWriteTrigger( ColumnFamilyHandle* column_family) override; virtual const std::string& GetName() const override; virtual Env* GetEnv() const override; using DB::GetOptions; virtual Options GetOptions(ColumnFamilyHandle* column_family) const override; using DB::GetDBOptions; virtual DBOptions GetDBOptions() const override; using DB::Flush; virtual Status Flush(const FlushOptions& options, ColumnFamilyHandle* column_family) override; virtual Status Flush( const FlushOptions& options, const std::vector& column_families) override; virtual Status FlushWAL(bool sync) override; bool TEST_WALBufferIsEmpty(bool lock = true); virtual Status SyncWAL() override; virtual Status LockWAL() override; virtual Status UnlockWAL() override; virtual SequenceNumber GetLatestSequenceNumber() const override; virtual bool SetPreserveDeletesSequenceNumber(SequenceNumber seqnum) override; virtual Status GetDbIdentity(std::string& identity) const override; ColumnFamilyHandle* DefaultColumnFamily() const override; ColumnFamilyHandle* PersistentStatsColumnFamily() const; virtual Status Close() override; Status GetStatsHistory( uint64_t start_time, uint64_t end_time, std::unique_ptr* stats_iterator) override; #ifndef ROCKSDB_LITE using DB::ResetStats; virtual Status ResetStats() override; virtual Status DisableFileDeletions() override; virtual Status EnableFileDeletions(bool force) override; virtual int IsFileDeletionsEnabled() const; // All the returned filenames start with "/" virtual Status GetLiveFiles(std::vector&, uint64_t* manifest_file_size, bool flush_memtable = true) override; virtual Status GetSortedWalFiles(VectorLogPtr& files) override; virtual Status GetUpdatesSince( SequenceNumber seq_number, std::unique_ptr* iter, const TransactionLogIterator::ReadOptions& read_options = TransactionLogIterator::ReadOptions()) override; virtual Status DeleteFile(std::string name) override; Status DeleteFilesInRanges(ColumnFamilyHandle* column_family, const RangePtr* ranges, size_t n, bool include_end = true); virtual void GetLiveFilesMetaData( std::vector* metadata) override; // Obtains the meta data of the specified column family of the DB. // Status::NotFound() will be returned if the current DB does not have // any column family match the specified name. // TODO(yhchiang): output parameter is placed in the end in this codebase. virtual void GetColumnFamilyMetaData(ColumnFamilyHandle* column_family, ColumnFamilyMetaData* metadata) override; Status SuggestCompactRange(ColumnFamilyHandle* column_family, const Slice* begin, const Slice* end) override; Status PromoteL0(ColumnFamilyHandle* column_family, int target_level) override; using DB::IngestExternalFile; virtual Status IngestExternalFile( ColumnFamilyHandle* column_family, const std::vector& external_files, const IngestExternalFileOptions& ingestion_options) override; using DB::IngestExternalFiles; virtual Status IngestExternalFiles( const std::vector& args) override; virtual Status VerifyChecksum() override; using DB::StartTrace; virtual Status StartTrace( const TraceOptions& options, std::unique_ptr&& trace_writer) override; using DB::EndTrace; virtual Status EndTrace() override; using DB::StartBlockCacheTrace; Status StartBlockCacheTrace( const TraceOptions& options, std::unique_ptr&& trace_writer) override; using DB::EndBlockCacheTrace; Status EndBlockCacheTrace() override; using DB::GetPropertiesOfAllTables; virtual Status GetPropertiesOfAllTables( ColumnFamilyHandle* column_family, TablePropertiesCollection* props) override; virtual Status GetPropertiesOfTablesInRange( ColumnFamilyHandle* column_family, const Range* range, std::size_t n, TablePropertiesCollection* props) override; #endif // ROCKSDB_LITE // ---- End of implementations of the DB interface ---- // Function that Get and KeyMayExist call with no_io true or false // Note: 'value_found' from KeyMayExist propagates here Status GetImpl(const ReadOptions& options, ColumnFamilyHandle* column_family, const Slice& key, PinnableSlice* value, bool* value_found = nullptr, ReadCallback* callback = nullptr, bool* is_blob_index = nullptr); ArenaWrappedDBIter* NewIteratorImpl(const ReadOptions& options, ColumnFamilyData* cfd, SequenceNumber snapshot, ReadCallback* read_callback, bool allow_blob = false, bool allow_refresh = true); virtual SequenceNumber GetLastPublishedSequence() const { if (last_seq_same_as_publish_seq_) { return versions_->LastSequence(); } else { return versions_->LastPublishedSequence(); } } // REQUIRES: joined the main write queue if two_write_queues is disabled, and // the second write queue otherwise. virtual void SetLastPublishedSequence(SequenceNumber seq); // Returns LastSequence in last_seq_same_as_publish_seq_ // mode and LastAllocatedSequence otherwise. This is useful when visiblility // depends also on data written to the WAL but not to the memtable. SequenceNumber TEST_GetLastVisibleSequence() const; #ifndef ROCKSDB_LITE // Similar to Write() but will call the callback once on the single write // thread to determine whether it is safe to perform the write. virtual Status WriteWithCallback(const WriteOptions& write_options, WriteBatch* my_batch, WriteCallback* callback); // Returns the sequence number that is guaranteed to be smaller than or equal // to the sequence number of any key that could be inserted into the current // memtables. It can then be assumed that any write with a larger(or equal) // sequence number will be present in this memtable or a later memtable. // // If the earliest sequence number could not be determined, // kMaxSequenceNumber will be returned. // // If include_history=true, will also search Memtables in MemTableList // History. SequenceNumber GetEarliestMemTableSequenceNumber(SuperVersion* sv, bool include_history); // For a given key, check to see if there are any records for this key // in the memtables, including memtable history. If cache_only is false, // SST files will also be checked. // // If a key is found, *found_record_for_key will be set to true and // *seq will be set to the stored sequence number for the latest // operation on this key or kMaxSequenceNumber if unknown. // If no key is found, *found_record_for_key will be set to false. // // Note: If cache_only=false, it is possible for *seq to be set to 0 if // the sequence number has been cleared from the record. If the caller is // holding an active db snapshot, we know the missing sequence must be less // than the snapshot's sequence number (sequence numbers are only cleared // when there are no earlier active snapshots). // // If NotFound is returned and found_record_for_key is set to false, then no // record for this key was found. If the caller is holding an active db // snapshot, we know that no key could have existing after this snapshot // (since we do not compact keys that have an earlier snapshot). // // Only records newer than or at `lower_bound_seq` are guaranteed to be // returned. Memtables and files may not be checked if it only contains data // older than `lower_bound_seq`. // // Returns OK or NotFound on success, // other status on unexpected error. // TODO(andrewkr): this API need to be aware of range deletion operations Status GetLatestSequenceForKey(SuperVersion* sv, const Slice& key, bool cache_only, SequenceNumber lower_bound_seq, SequenceNumber* seq, bool* found_record_for_key, bool* is_blob_index = nullptr); Status TraceIteratorSeek(const uint32_t& cf_id, const Slice& key); Status TraceIteratorSeekForPrev(const uint32_t& cf_id, const Slice& key); #endif // ROCKSDB_LITE // Similar to GetSnapshot(), but also lets the db know that this snapshot // will be used for transaction write-conflict checking. The DB can then // make sure not to compact any keys that would prevent a write-conflict from // being detected. const Snapshot* GetSnapshotForWriteConflictBoundary(); // checks if all live files exist on file system and that their file sizes // match to our in-memory records virtual Status CheckConsistency(); // max_file_num_to_ignore allows bottom level compaction to filter out newly // compacted SST files. Setting max_file_num_to_ignore to kMaxUint64 will // disable the filtering Status RunManualCompaction(ColumnFamilyData* cfd, int input_level, int output_level, const CompactRangeOptions& compact_range_options, const Slice* begin, const Slice* end, bool exclusive, bool disallow_trivial_move, uint64_t max_file_num_to_ignore); // Return an internal iterator over the current state of the database. // The keys of this iterator are internal keys (see format.h). // The returned iterator should be deleted when no longer needed. InternalIterator* NewInternalIterator( Arena* arena, RangeDelAggregator* range_del_agg, SequenceNumber sequence, ColumnFamilyHandle* column_family = nullptr); LogsWithPrepTracker* logs_with_prep_tracker() { return &logs_with_prep_tracker_; } struct BGJobLimits { int max_flushes; int max_compactions; }; // Returns maximum background flushes and compactions allowed to be scheduled BGJobLimits GetBGJobLimits() const; // Need a static version that can be called during SanitizeOptions(). static BGJobLimits GetBGJobLimits(int max_background_flushes, int max_background_compactions, int max_background_jobs, bool parallelize_compactions); // move logs pending closing from job_context to the DB queue and // schedule a purge void ScheduleBgLogWriterClose(JobContext* job_context); uint64_t MinLogNumberToKeep(); // Returns the lower bound file number for SSTs that won't be deleted, even if // they're obsolete. This lower bound is used internally to prevent newly // created flush/compaction output files from being deleted before they're // installed. This technique avoids the need for tracking the exact numbers of // files pending creation, although it prevents more files than necessary from // being deleted. uint64_t MinObsoleteSstNumberToKeep(); // Returns the list of live files in 'live' and the list // of all files in the filesystem in 'candidate_files'. // If force == false and the last call was less than // db_options_.delete_obsolete_files_period_micros microseconds ago, // it will not fill up the job_context void FindObsoleteFiles(JobContext* job_context, bool force, bool no_full_scan = false); // Diffs the files listed in filenames and those that do not // belong to live files are possibly 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. // If FindObsoleteFiles() was run, we need to also run // PurgeObsoleteFiles(), even if disable_delete_obsolete_files_ is true void PurgeObsoleteFiles(JobContext& background_contet, bool schedule_only = false); // Schedule a background job to actually delete obsolete files. void SchedulePurge(); const SnapshotList& snapshots() const { return snapshots_; } // load list of snapshots to `snap_vector` that is no newer than `max_seq` // in ascending order. // `oldest_write_conflict_snapshot` is filled with the oldest snapshot // which satisfies SnapshotImpl.is_write_conflict_boundary_ = true. void LoadSnapshots(std::vector* snap_vector, SequenceNumber* oldest_write_conflict_snapshot, const SequenceNumber& max_seq) const { InstrumentedMutexLock l(mutex()); snapshots().GetAll(snap_vector, oldest_write_conflict_snapshot, max_seq); } const ImmutableDBOptions& immutable_db_options() const { return immutable_db_options_; } // Cancel all background jobs, including flush, compaction, background // purging, stats dumping threads, etc. If `wait` = true, wait for the // running jobs to abort or finish before returning. Otherwise, only // sends the signals. void CancelAllBackgroundWork(bool wait); // Find Super version and reference it. Based on options, it might return // the thread local cached one. // Call ReturnAndCleanupSuperVersion() when it is no longer needed. SuperVersion* GetAndRefSuperVersion(ColumnFamilyData* cfd); // Similar to the previous function but looks up based on a column family id. // nullptr will be returned if this column family no longer exists. // REQUIRED: this function should only be called on the write thread or if the // mutex is held. SuperVersion* GetAndRefSuperVersion(uint32_t column_family_id); // Un-reference the super version and clean it up if it is the last reference. void CleanupSuperVersion(SuperVersion* sv); // Un-reference the super version and return it to thread local cache if // needed. If it is the last reference of the super version. Clean it up // after un-referencing it. void ReturnAndCleanupSuperVersion(ColumnFamilyData* cfd, SuperVersion* sv); // Similar to the previous function but looks up based on a column family id. // nullptr will be returned if this column family no longer exists. // REQUIRED: this function should only be called on the write thread. void ReturnAndCleanupSuperVersion(uint32_t colun_family_id, SuperVersion* sv); // REQUIRED: this function should only be called on the write thread or if the // mutex is held. Return value only valid until next call to this function or // mutex is released. ColumnFamilyHandle* GetColumnFamilyHandle(uint32_t column_family_id); // Same as above, should called without mutex held and not on write thread. std::unique_ptr GetColumnFamilyHandleUnlocked( uint32_t column_family_id); // Returns the number of currently running flushes. // REQUIREMENT: mutex_ must be held when calling this function. int num_running_flushes() { mutex_.AssertHeld(); return num_running_flushes_; } // Returns the number of currently running compactions. // REQUIREMENT: mutex_ must be held when calling this function. int num_running_compactions() { mutex_.AssertHeld(); return num_running_compactions_; } const WriteController& write_controller() { return write_controller_; } InternalIterator* NewInternalIterator( const ReadOptions&, ColumnFamilyData* cfd, SuperVersion* super_version, Arena* arena, RangeDelAggregator* range_del_agg, SequenceNumber sequence); // hollow transactions shell used for recovery. // these will then be passed to TransactionDB so that // locks can be reacquired before writing can resume. struct RecoveredTransaction { std::string name_; bool unprepared_; struct BatchInfo { uint64_t log_number_; // TODO(lth): For unprepared, the memory usage here can be big for // unprepared transactions. This is only useful for rollbacks, and we // can in theory just keep keyset for that. WriteBatch* batch_; // Number of sub-batches. A new sub-batch is created if txn attempts to // insert a duplicate key,seq to memtable. This is currently used in // WritePreparedTxn/WriteUnpreparedTxn. size_t batch_cnt_; }; // This maps the seq of the first key in the batch to BatchInfo, which // contains WriteBatch and other information relevant to the batch. // // For WriteUnprepared, batches_ can have size greater than 1, but for // other write policies, it must be of size 1. std::map batches_; explicit RecoveredTransaction(const uint64_t log, const std::string& name, WriteBatch* batch, SequenceNumber seq, size_t batch_cnt, bool unprepared) : name_(name), unprepared_(unprepared) { batches_[seq] = {log, batch, batch_cnt}; } ~RecoveredTransaction() { for (auto& it : batches_) { delete it.second.batch_; } } void AddBatch(SequenceNumber seq, uint64_t log_number, WriteBatch* batch, size_t batch_cnt, bool unprepared) { assert(batches_.count(seq) == 0); batches_[seq] = {log_number, batch, batch_cnt}; // Prior state must be unprepared, since the prepare batch must be the // last batch. assert(unprepared_); unprepared_ = unprepared; } }; bool allow_2pc() const { return immutable_db_options_.allow_2pc; } std::unordered_map recovered_transactions() { return recovered_transactions_; } RecoveredTransaction* GetRecoveredTransaction(const std::string& name) { auto it = recovered_transactions_.find(name); if (it == recovered_transactions_.end()) { return nullptr; } else { return it->second; } } void InsertRecoveredTransaction(const uint64_t log, const std::string& name, WriteBatch* batch, SequenceNumber seq, size_t batch_cnt, bool unprepared_batch) { // For WriteUnpreparedTxn, InsertRecoveredTransaction is called multiple // times for every unprepared batch encountered during recovery. // // If the transaction is prepared, then the last call to // InsertRecoveredTransaction will have unprepared_batch = false. auto rtxn = recovered_transactions_.find(name); if (rtxn == recovered_transactions_.end()) { recovered_transactions_[name] = new RecoveredTransaction( log, name, batch, seq, batch_cnt, unprepared_batch); } else { rtxn->second->AddBatch(seq, log, batch, batch_cnt, unprepared_batch); } logs_with_prep_tracker_.MarkLogAsContainingPrepSection(log); } void DeleteRecoveredTransaction(const std::string& name) { auto it = recovered_transactions_.find(name); assert(it != recovered_transactions_.end()); auto* trx = it->second; recovered_transactions_.erase(it); for (const auto& info : trx->batches_) { logs_with_prep_tracker_.MarkLogAsHavingPrepSectionFlushed( info.second.log_number_); } delete trx; } void DeleteAllRecoveredTransactions() { for (auto it = recovered_transactions_.begin(); it != recovered_transactions_.end(); ++it) { delete it->second; } recovered_transactions_.clear(); } void AddToLogsToFreeQueue(log::Writer* log_writer) { logs_to_free_queue_.push_back(log_writer); } void SetSnapshotChecker(SnapshotChecker* snapshot_checker); // Fill JobContext with snapshot information needed by flush and compaction. void GetSnapshotContext(JobContext* job_context, std::vector* snapshot_seqs, SequenceNumber* earliest_write_conflict_snapshot, SnapshotChecker** snapshot_checker); // Not thread-safe. void SetRecoverableStatePreReleaseCallback(PreReleaseCallback* callback); InstrumentedMutex* mutex() const { return &mutex_; } // Initialize a brand new DB. The DB directory is expected to be empty before // calling it. Status NewDB(); // This is to be used only by internal rocksdb classes. static Status Open(const DBOptions& db_options, const std::string& name, const std::vector& column_families, std::vector* handles, DB** dbptr, const bool seq_per_batch, const bool batch_per_txn); static Status CreateAndNewDirectory(Env* env, const std::string& dirname, std::unique_ptr* directory); // find stats map from stats_history_ with smallest timestamp in // the range of [start_time, end_time) bool FindStatsByTime(uint64_t start_time, uint64_t end_time, uint64_t* new_time, std::map* stats_map); #ifndef NDEBUG // Compact any files in the named level that overlap [*begin, *end] Status TEST_CompactRange(int level, const Slice* begin, const Slice* end, ColumnFamilyHandle* column_family = nullptr, bool disallow_trivial_move = false); void TEST_SwitchWAL(); bool TEST_UnableToReleaseOldestLog() { return unable_to_release_oldest_log_; } bool TEST_IsLogGettingFlushed() { return alive_log_files_.begin()->getting_flushed; } Status TEST_SwitchMemtable(ColumnFamilyData* cfd = nullptr); // Force current memtable contents to be flushed. Status TEST_FlushMemTable(bool wait = true, bool allow_write_stall = false, ColumnFamilyHandle* cfh = nullptr); // Wait for memtable compaction Status TEST_WaitForFlushMemTable(ColumnFamilyHandle* column_family = nullptr); // Wait for any compaction // We add a bool parameter to wait for unscheduledCompactions_ == 0, but this // is only for the special test of CancelledCompactions Status TEST_WaitForCompact(bool waitUnscheduled = false); // Return the maximum overlapping data (in bytes) at next level for any // file at a level >= 1. int64_t TEST_MaxNextLevelOverlappingBytes( ColumnFamilyHandle* column_family = nullptr); // Return the current manifest file no. uint64_t TEST_Current_Manifest_FileNo(); // Returns the number that'll be assigned to the next file that's created. uint64_t TEST_Current_Next_FileNo(); // get total level0 file size. Only for testing. uint64_t TEST_GetLevel0TotalSize(); void TEST_GetFilesMetaData(ColumnFamilyHandle* column_family, std::vector>* metadata); void TEST_LockMutex(); void TEST_UnlockMutex(); // REQUIRES: mutex locked void* TEST_BeginWrite(); // REQUIRES: mutex locked // pass the pointer that you got from TEST_BeginWrite() void TEST_EndWrite(void* w); uint64_t TEST_MaxTotalInMemoryState() const { return max_total_in_memory_state_; } size_t TEST_LogsToFreeSize(); uint64_t TEST_LogfileNumber(); uint64_t TEST_total_log_size() const { return total_log_size_; } // Returns column family name to ImmutableCFOptions map. Status TEST_GetAllImmutableCFOptions( std::unordered_map* iopts_map); // Return the lastest MutableCFOptions of a column family Status TEST_GetLatestMutableCFOptions(ColumnFamilyHandle* column_family, MutableCFOptions* mutable_cf_options); Cache* TEST_table_cache() { return table_cache_.get(); } WriteController& TEST_write_controler() { return write_controller_; } uint64_t TEST_FindMinLogContainingOutstandingPrep(); uint64_t TEST_FindMinPrepLogReferencedByMemTable(); size_t TEST_PreparedSectionCompletedSize(); size_t TEST_LogsWithPrepSize(); int TEST_BGCompactionsAllowed() const; int TEST_BGFlushesAllowed() const; size_t TEST_GetWalPreallocateBlockSize(uint64_t write_buffer_size) const; void TEST_WaitForDumpStatsRun(std::function callback) const; void TEST_WaitForPersistStatsRun(std::function callback) const; bool TEST_IsPersistentStatsEnabled() const; size_t TEST_EstimateInMemoryStatsHistorySize() const; #endif // NDEBUG protected: Env* const env_; const std::string dbname_; std::unique_ptr versions_; // Flag to check whether we allocated and own the info log file bool own_info_log_; const DBOptions initial_db_options_; const ImmutableDBOptions immutable_db_options_; MutableDBOptions mutable_db_options_; Statistics* stats_; std::unordered_map recovered_transactions_; std::unique_ptr tracer_; InstrumentedMutex trace_mutex_; BlockCacheTracer block_cache_tracer_; // State below is protected by mutex_ // With two_write_queues enabled, some of the variables that accessed during // WriteToWAL need different synchronization: log_empty_, alive_log_files_, // logs_, logfile_number_. Refer to the definition of each variable below for // more description. mutable InstrumentedMutex mutex_; ColumnFamilyHandleImpl* default_cf_handle_; InternalStats* default_cf_internal_stats_; // only used for dynamically adjusting max_total_wal_size. it is a sum of // [write_buffer_size * max_write_buffer_number] over all column families uint64_t max_total_in_memory_state_; // If true, we have only one (default) column family. We use this to optimize // some code-paths bool single_column_family_mode_; // The options to access storage files const EnvOptions env_options_; // Additonal options for compaction and flush EnvOptions env_options_for_compaction_; std::unique_ptr column_family_memtables_; // Increase the sequence number after writing each batch, whether memtable is // disabled for that or not. Otherwise the sequence number is increased after // writing each key into memtable. This implies that when disable_memtable is // set, the seq is not increased at all. // // Default: false const bool seq_per_batch_; // This determines during recovery whether we expect one writebatch per // recovered transaction, or potentially multiple writebatches per // transaction. For WriteUnprepared, this is set to false, since multiple // batches can exist per transaction. // // Default: true const bool batch_per_txn_; // Except in DB::Open(), WriteOptionsFile can only be called when: // Persist options to options file. // If need_mutex_lock = false, the method will lock DB mutex. // If need_enter_write_thread = false, the method will enter write thread. Status WriteOptionsFile(bool need_mutex_lock, bool need_enter_write_thread); // The following two functions can only be called when: // 1. WriteThread::Writer::EnterUnbatched() is used. // 2. db_mutex is NOT held Status RenameTempFileToOptionsFile(const std::string& file_name); Status DeleteObsoleteOptionsFiles(); void NotifyOnFlushBegin(ColumnFamilyData* cfd, FileMetaData* file_meta, const MutableCFOptions& mutable_cf_options, int job_id, TableProperties prop); void NotifyOnFlushCompleted(ColumnFamilyData* cfd, FileMetaData* file_meta, const MutableCFOptions& mutable_cf_options, int job_id, TableProperties prop); void NotifyOnCompactionBegin(ColumnFamilyData* cfd, Compaction* c, const Status& st, const CompactionJobStats& job_stats, int job_id); void NotifyOnCompactionCompleted(ColumnFamilyData* cfd, Compaction* c, const Status& st, const CompactionJobStats& job_stats, int job_id); void NotifyOnMemTableSealed(ColumnFamilyData* cfd, const MemTableInfo& mem_table_info); #ifndef ROCKSDB_LITE void NotifyOnExternalFileIngested( ColumnFamilyData* cfd, const ExternalSstFileIngestionJob& ingestion_job); #endif // !ROCKSDB_LITE void NewThreadStatusCfInfo(ColumnFamilyData* cfd) const; void EraseThreadStatusCfInfo(ColumnFamilyData* cfd) const; void EraseThreadStatusDbInfo() const; // If disable_memtable is set the application logic must guarantee that the // batch will still be skipped from memtable during the recovery. An excption // to this is seq_per_batch_ mode, in which since each batch already takes one // seq, it is ok for the batch to write to memtable during recovery as long as // it only takes one sequence number: i.e., no duplicate keys. // In WriteCommitted it is guarnateed since disable_memtable is used for // prepare batch which will be written to memtable later during the commit, // and in WritePrepared it is guaranteed since it will be used only for WAL // markers which will never be written to memtable. If the commit marker is // accompanied with CommitTimeWriteBatch that is not written to memtable as // long as it has no duplicate keys, it does not violate the one-seq-per-batch // policy. // batch_cnt is expected to be non-zero in seq_per_batch mode and // indicates the number of sub-patches. A sub-patch is a subset of the write // batch that does not have duplicate keys. Status WriteImpl(const WriteOptions& options, WriteBatch* updates, WriteCallback* callback = nullptr, uint64_t* log_used = nullptr, uint64_t log_ref = 0, bool disable_memtable = false, uint64_t* seq_used = nullptr, size_t batch_cnt = 0, PreReleaseCallback* pre_release_callback = nullptr); Status PipelinedWriteImpl(const WriteOptions& options, WriteBatch* updates, WriteCallback* callback = nullptr, uint64_t* log_used = nullptr, uint64_t log_ref = 0, bool disable_memtable = false, uint64_t* seq_used = nullptr); // Write only to memtables without joining any write queue Status UnorderedWriteMemtable(const WriteOptions& write_options, WriteBatch* my_batch, WriteCallback* callback, uint64_t log_ref, SequenceNumber seq, const size_t sub_batch_cnt); // Whether the batch requires to be assigned with an order enum AssignOrder : bool { kDontAssignOrder, kDoAssignOrder }; // Whether it requires publishing last sequence or not enum PublishLastSeq : bool { kDontPublishLastSeq, kDoPublishLastSeq }; // Join the write_thread to write the batch only to the WAL. It is the // responsibility of the caller to also write the write batch to the memtable // if it required. // // sub_batch_cnt is expected to be non-zero when assign_order = kDoAssignOrder // indicating the number of sub-batches in my_batch. A sub-patch is a subset // of the write batch that does not have duplicate keys. When seq_per_batch is // not set, each key is a separate sub_batch. Otherwise each duplicate key // marks start of a new sub-batch. Status WriteImplWALOnly( WriteThread* write_thread, const WriteOptions& options, WriteBatch* updates, WriteCallback* callback, uint64_t* log_used, const uint64_t log_ref, uint64_t* seq_used, const size_t sub_batch_cnt, PreReleaseCallback* pre_release_callback, const AssignOrder assign_order, const PublishLastSeq publish_last_seq, const bool disable_memtable); // write cached_recoverable_state_ to memtable if it is not empty // The writer must be the leader in write_thread_ and holding mutex_ Status WriteRecoverableState(); // Actual implementation of Close() Status CloseImpl(); // Recover the descriptor from persistent storage. May do a significant // amount of work to recover recently logged updates. Any changes to // be made to the descriptor are added to *edit. virtual Status Recover( const std::vector& column_families, bool read_only = false, bool error_if_log_file_exist = false, bool error_if_data_exists_in_logs = false); private: friend class DB; friend class ErrorHandler; friend class InternalStats; friend class PessimisticTransaction; friend class TransactionBaseImpl; friend class WriteCommittedTxn; friend class WritePreparedTxn; friend class WritePreparedTxnDB; friend class WriteBatchWithIndex; friend class WriteUnpreparedTxnDB; friend class WriteUnpreparedTxn; #ifndef ROCKSDB_LITE friend class ForwardIterator; #endif friend struct SuperVersion; friend class CompactedDBImpl; friend class DBTest_ConcurrentFlushWAL_Test; friend class DBTest_MixedSlowdownOptionsStop_Test; friend class DBCompactionTest_CompactBottomLevelFilesWithDeletions_Test; friend class DBCompactionTest_CompactionDuringShutdown_Test; friend class StatsHistoryTest_PersistentStatsCreateColumnFamilies_Test; #ifndef NDEBUG friend class DBTest2_ReadCallbackTest_Test; friend class WriteCallbackTest_WriteWithCallbackTest_Test; friend class XFTransactionWriteHandler; friend class DBBlobIndexTest; friend class WriteUnpreparedTransactionTest_RecoveryTest_Test; #endif struct CompactionState; struct PrepickedCompaction; struct PurgeFileInfo; struct WriteContext { SuperVersionContext superversion_context; autovector memtables_to_free_; explicit WriteContext(bool create_superversion = false) : superversion_context(create_superversion) {} ~WriteContext() { superversion_context.Clean(); for (auto& m : memtables_to_free_) { delete m; } } }; struct LogFileNumberSize { explicit LogFileNumberSize(uint64_t _number) : number(_number) {} void AddSize(uint64_t new_size) { size += new_size; } uint64_t number; uint64_t size = 0; bool getting_flushed = false; }; struct LogWriterNumber { // pass ownership of _writer LogWriterNumber(uint64_t _number, log::Writer* _writer) : number(_number), writer(_writer) {} log::Writer* ReleaseWriter() { auto* w = writer; writer = nullptr; return w; } Status ClearWriter() { Status s = writer->WriteBuffer(); delete writer; writer = nullptr; return s; } uint64_t number; // Visual Studio doesn't support deque's member to be noncopyable because // of a std::unique_ptr as a member. log::Writer* writer; // own // true for some prefix of logs_ bool getting_synced = false; }; // PurgeFileInfo is a structure to hold information of files to be deleted in // purge_queue_ struct PurgeFileInfo { std::string fname; std::string dir_to_sync; FileType type; uint64_t number; int job_id; PurgeFileInfo(std::string fn, std::string d, FileType t, uint64_t num, int jid) : fname(fn), dir_to_sync(d), type(t), number(num), job_id(jid) {} }; // Argument required by background flush thread. struct BGFlushArg { BGFlushArg() : cfd_(nullptr), max_memtable_id_(0), superversion_context_(nullptr) {} BGFlushArg(ColumnFamilyData* cfd, uint64_t max_memtable_id, SuperVersionContext* superversion_context) : cfd_(cfd), max_memtable_id_(max_memtable_id), superversion_context_(superversion_context) {} // Column family to flush. ColumnFamilyData* cfd_; // Maximum ID of memtable to flush. In this column family, memtables with // IDs smaller than this value must be flushed before this flush completes. uint64_t max_memtable_id_; // Pointer to a SuperVersionContext object. After flush completes, RocksDB // installs a new superversion for the column family. This operation // requires a SuperVersionContext object (currently embedded in JobContext). SuperVersionContext* superversion_context_; }; // Argument passed to flush thread. struct FlushThreadArg { DBImpl* db_; Env::Priority thread_pri_; }; // Information for a manual compaction struct ManualCompactionState { ColumnFamilyData* cfd; int input_level; int output_level; uint32_t output_path_id; Status status; bool done; bool in_progress; // compaction request being processed? bool incomplete; // only part of requested range compacted bool exclusive; // current behavior of only one manual bool disallow_trivial_move; // Force actual compaction to run const InternalKey* begin; // nullptr means beginning of key range const InternalKey* end; // nullptr means end of key range InternalKey* manual_end; // how far we are compacting InternalKey tmp_storage; // Used to keep track of compaction progress InternalKey tmp_storage1; // Used to keep track of compaction progress }; struct PrepickedCompaction { // background compaction takes ownership of `compaction`. Compaction* compaction; // caller retains ownership of `manual_compaction_state` as it is reused // across background compactions. ManualCompactionState* manual_compaction_state; // nullptr if non-manual // task limiter token is requested during compaction picking. std::unique_ptr task_token; }; struct CompactionArg { // caller retains ownership of `db`. DBImpl* db; // background compaction takes ownership of `prepicked_compaction`. PrepickedCompaction* prepicked_compaction; }; // Initialize the built-in column family for persistent stats. Depending on // whether on-disk persistent stats have been enabled before, it may either // create a new column family and column family handle or just a column family // handle. // Required: DB mutex held Status InitPersistStatsColumnFamily(); // Persistent Stats column family has two format version key which are used // for compatibility check. Write format version if it's created for the // first time, read format version and check compatibility if recovering // from disk. This function requires DB mutex held at entrance but may // release and re-acquire DB mutex in the process. // Required: DB mutex held Status PersistentStatsProcessFormatVersion(); Status ResumeImpl(); void MaybeIgnoreError(Status* s) const; const Status CreateArchivalDirectory(); Status CreateColumnFamilyImpl(const ColumnFamilyOptions& cf_options, const std::string& cf_name, ColumnFamilyHandle** handle); Status DropColumnFamilyImpl(ColumnFamilyHandle* column_family); // Delete any unneeded files and stale in-memory entries. void DeleteObsoleteFiles(); // Delete obsolete files and log status and information of file deletion void DeleteObsoleteFileImpl(int job_id, const std::string& fname, const std::string& path_to_sync, FileType type, uint64_t number); // Background process needs to call // auto x = CaptureCurrentFileNumberInPendingOutputs() // auto file_num = versions_->NewFileNumber(); // // ReleaseFileNumberFromPendingOutputs(x) // This will protect any file with number `file_num` or greater from being // deleted while is running. // ----------- // This function will capture current file number and append it to // pending_outputs_. This will prevent any background process to delete any // file created after this point. std::list::iterator CaptureCurrentFileNumberInPendingOutputs(); // This function should be called with the result of // CaptureCurrentFileNumberInPendingOutputs(). It then marks that any file // created between the calls CaptureCurrentFileNumberInPendingOutputs() and // ReleaseFileNumberFromPendingOutputs() can now be deleted (if it's not live // and blocked by any other pending_outputs_ calls) void ReleaseFileNumberFromPendingOutputs(std::list::iterator v); Status SyncClosedLogs(JobContext* job_context); // Flush the in-memory write buffer to storage. Switches to a new // log-file/memtable and writes a new descriptor iff successful. Then // installs a new super version for the column family. Status FlushMemTableToOutputFile( ColumnFamilyData* cfd, const MutableCFOptions& mutable_cf_options, bool* madeProgress, JobContext* job_context, SuperVersionContext* superversion_context, std::vector& snapshot_seqs, SequenceNumber earliest_write_conflict_snapshot, SnapshotChecker* snapshot_checker, LogBuffer* log_buffer, Env::Priority thread_pri); // Flush the memtables of (multiple) column families to multiple files on // persistent storage. Status FlushMemTablesToOutputFiles( const autovector& bg_flush_args, bool* made_progress, JobContext* job_context, LogBuffer* log_buffer, Env::Priority thread_pri); Status AtomicFlushMemTablesToOutputFiles( const autovector& bg_flush_args, bool* made_progress, JobContext* job_context, LogBuffer* log_buffer, Env::Priority thread_pri); // REQUIRES: log_numbers are sorted in ascending order Status RecoverLogFiles(const std::vector& log_numbers, SequenceNumber* next_sequence, bool read_only); // The following two methods are used to flush a memtable to // storage. The first one is used at database RecoveryTime (when the // database is opened) and is heavyweight because it holds the mutex // for the entire period. The second method WriteLevel0Table supports // concurrent flush memtables to storage. Status WriteLevel0TableForRecovery(int job_id, ColumnFamilyData* cfd, MemTable* mem, VersionEdit* edit); // Restore alive_log_files_ and total_log_size_ after recovery. // It needs to run only when there's no flush during recovery // (e.g. avoid_flush_during_recovery=true). May also trigger flush // in case total_log_size > max_total_wal_size. Status RestoreAliveLogFiles(const std::vector& log_numbers); // num_bytes: for slowdown case, delay time is calculated based on // `num_bytes` going through. Status DelayWrite(uint64_t num_bytes, const WriteOptions& write_options); Status ThrottleLowPriWritesIfNeeded(const WriteOptions& write_options, WriteBatch* my_batch); Status ScheduleFlushes(WriteContext* context); Status SwitchMemtable(ColumnFamilyData* cfd, WriteContext* context); void SelectColumnFamiliesForAtomicFlush(autovector* cfds); // Force current memtable contents to be flushed. Status FlushMemTable(ColumnFamilyData* cfd, const FlushOptions& options, FlushReason flush_reason, bool writes_stopped = false); Status AtomicFlushMemTables( const autovector& column_family_datas, const FlushOptions& options, FlushReason flush_reason, bool writes_stopped = false); // Wait until flushing this column family won't stall writes Status WaitUntilFlushWouldNotStallWrites(ColumnFamilyData* cfd, bool* flush_needed); // Wait for memtable flushed. // If flush_memtable_id is non-null, wait until the memtable with the ID // gets flush. Otherwise, wait until the column family don't have any // memtable pending flush. // resuming_from_bg_err indicates whether the caller is attempting to resume // from background error. Status WaitForFlushMemTable(ColumnFamilyData* cfd, const uint64_t* flush_memtable_id = nullptr, bool resuming_from_bg_err = false) { return WaitForFlushMemTables({cfd}, {flush_memtable_id}, resuming_from_bg_err); } // Wait for memtables to be flushed for multiple column families. Status WaitForFlushMemTables( const autovector& cfds, const autovector& flush_memtable_ids, bool resuming_from_bg_err); inline void WaitForPendingWrites() { if (!immutable_db_options_.unordered_write) { // Then the writes are finished before the next write group starts return; } // Wait for the ones who already wrote to the WAL to finish their // memtable write. if (pending_memtable_writes_.load() != 0) { std::unique_lock guard(switch_mutex_); switch_cv_.wait(guard, [&] { return pending_memtable_writes_.load() == 0; }); } } // REQUIRES: mutex locked and in write thread. void AssignAtomicFlushSeq(const autovector& cfds); // REQUIRES: mutex locked Status SwitchWAL(WriteContext* write_context); // REQUIRES: mutex locked Status HandleWriteBufferFull(WriteContext* write_context); // REQUIRES: mutex locked Status PreprocessWrite(const WriteOptions& write_options, bool* need_log_sync, WriteContext* write_context); WriteBatch* MergeBatch(const WriteThread::WriteGroup& write_group, WriteBatch* tmp_batch, size_t* write_with_wal, WriteBatch** to_be_cached_state); Status WriteToWAL(const WriteBatch& merged_batch, log::Writer* log_writer, uint64_t* log_used, uint64_t* log_size); Status WriteToWAL(const WriteThread::WriteGroup& write_group, log::Writer* log_writer, uint64_t* log_used, bool need_log_sync, bool need_log_dir_sync, SequenceNumber sequence); Status ConcurrentWriteToWAL(const WriteThread::WriteGroup& write_group, uint64_t* log_used, SequenceNumber* last_sequence, size_t seq_inc); // Used by WriteImpl to update bg_error_ if paranoid check is enabled. void WriteStatusCheck(const Status& status); // Used by WriteImpl to update bg_error_ in case of memtable insert error. void MemTableInsertStatusCheck(const Status& memtable_insert_status); #ifndef ROCKSDB_LITE Status CompactFilesImpl(const CompactionOptions& compact_options, ColumnFamilyData* cfd, Version* version, const std::vector& input_file_names, std::vector* const output_file_names, const int output_level, int output_path_id, JobContext* job_context, LogBuffer* log_buffer, CompactionJobInfo* compaction_job_info); // Wait for current IngestExternalFile() calls to finish. // REQUIRES: mutex_ held void WaitForIngestFile(); #else // IngestExternalFile is not supported in ROCKSDB_LITE so this function // will be no-op void WaitForIngestFile() {} #endif // ROCKSDB_LITE ColumnFamilyData* GetColumnFamilyDataByName(const std::string& cf_name); void MaybeScheduleFlushOrCompaction(); // A flush request specifies the column families to flush as well as the // largest memtable id to persist for each column family. Once all the // memtables whose IDs are smaller than or equal to this per-column-family // specified value, this flush request is considered to have completed its // work of flushing this column family. After completing the work for all // column families in this request, this flush is considered complete. typedef std::vector> FlushRequest; void GenerateFlushRequest(const autovector& cfds, FlushRequest* req); void SchedulePendingFlush(const FlushRequest& req, FlushReason flush_reason); void SchedulePendingCompaction(ColumnFamilyData* cfd); void SchedulePendingPurge(std::string fname, std::string dir_to_sync, FileType type, uint64_t number, int job_id); static void BGWorkCompaction(void* arg); // Runs a pre-chosen universal compaction involving bottom level in a // separate, bottom-pri thread pool. static void BGWorkBottomCompaction(void* arg); static void BGWorkFlush(void* arg); static void BGWorkPurge(void* arg); static void UnscheduleCompactionCallback(void* arg); static void UnscheduleFlushCallback(void* arg); void BackgroundCallCompaction(PrepickedCompaction* prepicked_compaction, Env::Priority thread_pri); void BackgroundCallFlush(Env::Priority thread_pri); void BackgroundCallPurge(); Status BackgroundCompaction(bool* madeProgress, JobContext* job_context, LogBuffer* log_buffer, PrepickedCompaction* prepicked_compaction, Env::Priority thread_pri); Status BackgroundFlush(bool* madeProgress, JobContext* job_context, LogBuffer* log_buffer, FlushReason* reason, Env::Priority thread_pri); bool EnoughRoomForCompaction(ColumnFamilyData* cfd, const std::vector& inputs, bool* sfm_bookkeeping, LogBuffer* log_buffer); // Request compaction tasks token from compaction thread limiter. // It always succeeds if force = true or limiter is disable. bool RequestCompactionToken(ColumnFamilyData* cfd, bool force, std::unique_ptr* token, LogBuffer* log_buffer); // Schedule background tasks void StartTimedTasks(); void PrintStatistics(); size_t EstimateInMemoryStatsHistorySize() const; // persist stats to column family "_persistent_stats" void PersistStats(); // dump rocksdb.stats to LOG void DumpStats(); // Return the minimum empty level that could hold the total data in the // input level. Return the input level, if such level could not be found. int FindMinimumEmptyLevelFitting(ColumnFamilyData* cfd, const MutableCFOptions& mutable_cf_options, int level); // Move the files in the input level to the target level. // If target_level < 0, automatically calculate the minimum level that could // hold the data set. Status ReFitLevel(ColumnFamilyData* cfd, int level, int target_level = -1); // helper functions for adding and removing from flush & compaction queues void AddToCompactionQueue(ColumnFamilyData* cfd); ColumnFamilyData* PopFirstFromCompactionQueue(); FlushRequest PopFirstFromFlushQueue(); // Pick the first unthrottled compaction with task token from queue. ColumnFamilyData* PickCompactionFromQueue( std::unique_ptr* token, LogBuffer* log_buffer); // helper function to call after some of the logs_ were synced void MarkLogsSynced(uint64_t up_to, bool synced_dir, const Status& status); SnapshotImpl* GetSnapshotImpl(bool is_write_conflict_boundary, bool lock = true); uint64_t GetMaxTotalWalSize() const; Directory* GetDataDir(ColumnFamilyData* cfd, size_t path_id) const; Status CloseHelper(); void WaitForBackgroundWork(); // No copying allowed DBImpl(const DBImpl&); void operator=(const DBImpl&); // Background threads call this function, which is just a wrapper around // the InstallSuperVersion() function. Background threads carry // sv_context which can have new_superversion already // allocated. // All ColumnFamily state changes go through this function. Here we analyze // the new state and we schedule background work if we detect that the new // state needs flush or compaction. void InstallSuperVersionAndScheduleWork( ColumnFamilyData* cfd, SuperVersionContext* sv_context, const MutableCFOptions& mutable_cf_options); bool GetIntPropertyInternal(ColumnFamilyData* cfd, const DBPropertyInfo& property_info, bool is_locked, uint64_t* value); bool GetPropertyHandleOptionsStatistics(std::string* value); bool HasPendingManualCompaction(); bool HasExclusiveManualCompaction(); void AddManualCompaction(ManualCompactionState* m); void RemoveManualCompaction(ManualCompactionState* m); bool ShouldntRunManualCompaction(ManualCompactionState* m); bool HaveManualCompaction(ColumnFamilyData* cfd); bool MCOverlap(ManualCompactionState* m, ManualCompactionState* m1); #ifndef ROCKSDB_LITE void BuildCompactionJobInfo(const ColumnFamilyData* cfd, Compaction* c, const Status& st, const CompactionJobStats& compaction_job_stats, const int job_id, const Version* current, CompactionJobInfo* compaction_job_info) const; // Reserve the next 'num' file numbers for to-be-ingested external SST files, // and return the current file_number in 'next_file_number'. // Write a version edit to the MANIFEST. Status ReserveFileNumbersBeforeIngestion( ColumnFamilyData* cfd, uint64_t num, std::list::iterator* pending_output_elem, uint64_t* next_file_number); #endif //! ROCKSDB_LITE bool ShouldPurge(uint64_t file_number) const; void MarkAsGrabbedForPurge(uint64_t file_number); size_t GetWalPreallocateBlockSize(uint64_t write_buffer_size) const; Env::WriteLifeTimeHint CalculateWALWriteHint() { return Env::WLTH_SHORT; } Status CreateWAL(uint64_t log_file_num, uint64_t recycle_log_number, size_t preallocate_block_size, log::Writer** new_log); // Validate self-consistency of DB options static Status ValidateOptions(const DBOptions& db_options); // Validate self-consistency of DB options and its consistency with cf options static Status ValidateOptions( const DBOptions& db_options, const std::vector& column_families); // table_cache_ provides its own synchronization std::shared_ptr table_cache_; // Lock over the persistent DB state. Non-nullptr iff successfully acquired. FileLock* db_lock_; // In addition to mutex_, log_write_mutex_ protected writes to stats_history_ InstrumentedMutex stats_history_mutex_; // In addition to mutex_, log_write_mutex_ protected writes to logs_ and // logfile_number_. With two_write_queues it also protects alive_log_files_, // and log_empty_. Refer to the definition of each variable below for more // details. // Note: to avoid dealock, if needed to acquire both log_write_mutex_ and // mutex_, the order should be first mutex_ and then log_write_mutex_. InstrumentedMutex log_write_mutex_; std::atomic shutting_down_; // This condition variable is signaled on these conditions: // * whenever bg_compaction_scheduled_ goes down to 0 // * if AnyManualCompaction, whenever a compaction finishes, even if it hasn't // made any progress // * whenever a compaction made any progress // * whenever bg_flush_scheduled_ or bg_purge_scheduled_ value decreases // (i.e. whenever a flush is done, even if it didn't make any progress) // * whenever there is an error in background purge, flush or compaction // * whenever num_running_ingest_file_ goes to 0. // * whenever pending_purge_obsolete_files_ goes to 0. // * whenever disable_delete_obsolete_files_ goes to 0. // * whenever SetOptions successfully updates options. // * whenever a column family is dropped. InstrumentedCondVar bg_cv_; // Writes are protected by locking both mutex_ and log_write_mutex_, and reads // must be under either mutex_ or log_write_mutex_. Since after ::Open, // logfile_number_ is currently updated only in write_thread_, it can be read // from the same write_thread_ without any locks. uint64_t logfile_number_; std::deque log_recycle_files_; // a list of log files that we can recycle bool log_dir_synced_; // Without two_write_queues, read and writes to log_empty_ are protected by // mutex_. Since it is currently updated/read only in write_thread_, it can be // accessed from the same write_thread_ without any locks. With // two_write_queues writes, where it can be updated in different threads, // read and writes are protected by log_write_mutex_ instead. This is to avoid // expesnive mutex_ lock during WAL write, which update log_empty_. bool log_empty_; ColumnFamilyHandleImpl* persist_stats_cf_handle_; bool persistent_stats_cfd_exists_ = true; // Without two_write_queues, read and writes to alive_log_files_ are // protected by mutex_. However since back() is never popped, and push_back() // is done only from write_thread_, the same thread can access the item // reffered by back() without mutex_. With two_write_queues_, writes // are protected by locking both mutex_ and log_write_mutex_, and reads must // be under either mutex_ or log_write_mutex_. std::deque alive_log_files_; // Log files that aren't fully synced, and the current log file. // Synchronization: // - push_back() is done from write_thread_ with locked mutex_ and // log_write_mutex_ // - pop_front() is done from any thread with locked mutex_ and // log_write_mutex_ // - reads are done with either locked mutex_ or log_write_mutex_ // - back() and items with getting_synced=true are not popped, // - The same thread that sets getting_synced=true will reset it. // - it follows that the object referred by back() can be safely read from // the write_thread_ without using mutex // - it follows that the items with getting_synced=true can be safely read // from the same thread that has set getting_synced=true std::deque logs_; // Signaled when getting_synced becomes false for some of the logs_. InstrumentedCondVar log_sync_cv_; // This is the app-level state that is written to the WAL but will be used // only during recovery. Using this feature enables not writing the state to // memtable on normal writes and hence improving the throughput. Each new // write of the state will replace the previous state entirely even if the // keys in the two consecuitive states do not overlap. // It is protected by log_write_mutex_ when two_write_queues_ is enabled. // Otherwise only the heaad of write_thread_ can access it. WriteBatch cached_recoverable_state_; std::atomic cached_recoverable_state_empty_ = {true}; std::atomic total_log_size_; // If this is non-empty, we need to delete these log files in background // threads. Protected by db mutex. autovector logs_to_free_; bool is_snapshot_supported_; std::map> stats_history_; std::map stats_slice_; bool stats_slice_initialized_ = false; Directories directories_; WriteBufferManager* write_buffer_manager_; WriteThread write_thread_; WriteBatch tmp_batch_; // The write thread when the writers have no memtable write. This will be used // in 2PC to batch the prepares separately from the serial commit. WriteThread nonmem_write_thread_; WriteController write_controller_; std::unique_ptr low_pri_write_rate_limiter_; // Size of the last batch group. In slowdown mode, next write needs to // sleep if it uses up the quota. // Note: This is to protect memtable and compaction. If the batch only writes // to the WAL its size need not to be included in this. uint64_t last_batch_group_size_; FlushScheduler flush_scheduler_; SnapshotList snapshots_; // For each background job, pending_outputs_ keeps the current file number at // the time that background job started. // FindObsoleteFiles()/PurgeObsoleteFiles() never deletes any file that has // number bigger than any of the file number in pending_outputs_. Since file // numbers grow monotonically, this also means that pending_outputs_ is always // sorted. After a background job is done executing, its file number is // deleted from pending_outputs_, which allows PurgeObsoleteFiles() to clean // it up. // State is protected with db mutex. std::list pending_outputs_; // flush_queue_ and compaction_queue_ hold column families that we need to // flush and compact, respectively. // A column family is inserted into flush_queue_ when it satisfies condition // cfd->imm()->IsFlushPending() // A column family is inserted into compaction_queue_ when it satisfied // condition cfd->NeedsCompaction() // Column families in this list are all Ref()-erenced // TODO(icanadi) Provide some kind of ReferencedColumnFamily class that will // do RAII on ColumnFamilyData // Column families are in this queue when they need to be flushed or // compacted. Consumers of these queues are flush and compaction threads. When // column family is put on this queue, we increase unscheduled_flushes_ and // unscheduled_compactions_. When these variables are bigger than zero, that // means we need to schedule background threads for flush and compaction. // Once the background threads are scheduled, we decrease unscheduled_flushes_ // and unscheduled_compactions_. That way we keep track of number of // compaction and flush threads we need to schedule. This scheduling is done // in MaybeScheduleFlushOrCompaction() // invariant(column family present in flush_queue_ <==> // ColumnFamilyData::pending_flush_ == true) std::deque flush_queue_; // invariant(column family present in compaction_queue_ <==> // ColumnFamilyData::pending_compaction_ == true) std::deque compaction_queue_; // A queue to store filenames of the files to be purged std::deque purge_queue_; // A vector to store the file numbers that have been assigned to certain // JobContext. Current implementation tracks ssts only. std::vector files_grabbed_for_purge_; // A queue to store log writers to close std::deque logs_to_free_queue_; int unscheduled_flushes_; int unscheduled_compactions_; // count how many background compactions are running or have been scheduled in // the BOTTOM pool int bg_bottom_compaction_scheduled_; // count how many background compactions are running or have been scheduled int bg_compaction_scheduled_; // stores the number of compactions are currently running int num_running_compactions_; // number of background memtable flush jobs, submitted to the HIGH pool int bg_flush_scheduled_; // stores the number of flushes are currently running int num_running_flushes_; // number of background obsolete file purge jobs, submitted to the HIGH pool int bg_purge_scheduled_; std::deque manual_compaction_dequeue_; // shall we disable deletion of obsolete files // if 0 the deletion is enabled. // if non-zero, files will not be getting deleted // This enables two different threads to call // EnableFileDeletions() and DisableFileDeletions() // without any synchronization int disable_delete_obsolete_files_; // Number of times FindObsoleteFiles has found deletable files and the // corresponding call to PurgeObsoleteFiles has not yet finished. int pending_purge_obsolete_files_; // last time when DeleteObsoleteFiles with full scan was executed. Originally // initialized with startup time. uint64_t delete_obsolete_files_last_run_; // last time stats were dumped to LOG std::atomic last_stats_dump_time_microsec_; // The thread that wants to switch memtable, can wait on this cv until the // pending writes to memtable finishes. std::condition_variable switch_cv_; // The mutex used by switch_cv_. mutex_ should be acquired beforehand. std::mutex switch_mutex_; // Number of threads intending to write to memtable std::atomic pending_memtable_writes_ = {}; // Each flush or compaction gets its own job id. this counter makes sure // they're unique std::atomic next_job_id_; // A flag indicating whether the current rocksdb database has any // data that is not yet persisted into either WAL or SST file. // Used when disableWAL is true. std::atomic has_unpersisted_data_; // if an attempt was made to flush all column families that // the oldest log depends on but uncommitted data in the oldest // log prevents the log from being released. // We must attempt to free the dependent memtables again // at a later time after the transaction in the oldest // log is fully commited. bool unable_to_release_oldest_log_; static const int KEEP_LOG_FILE_NUM = 1000; // MSVC version 1800 still does not have constexpr for ::max() static const uint64_t kNoTimeOut = port::kMaxUint64; std::string db_absolute_path_; // Number of running IngestExternalFile() calls. // REQUIRES: mutex held int num_running_ingest_file_; #ifndef ROCKSDB_LITE WalManager wal_manager_; #endif // ROCKSDB_LITE // Unified interface for logging events EventLogger event_logger_; // A value of > 0 temporarily disables scheduling of background work int bg_work_paused_; // A value of > 0 temporarily disables scheduling of background compaction int bg_compaction_paused_; // Guard against multiple concurrent refitting bool refitting_level_; // Indicate DB was opened successfully bool opened_successfully_; // The min threshold to triggere bottommost compaction for removing // garbages, among all column families. SequenceNumber bottommost_files_mark_threshold_ = kMaxSequenceNumber; LogsWithPrepTracker logs_with_prep_tracker_; // Callback for compaction to check if a key is visible to a snapshot. // REQUIRES: mutex held std::unique_ptr snapshot_checker_; // Callback for when the cached_recoverable_state_ is written to memtable // Only to be set during initialization std::unique_ptr recoverable_state_pre_release_callback_; // handle for scheduling stats dumping at fixed intervals // REQUIRES: mutex locked std::unique_ptr thread_dump_stats_; // handle for scheduling stats snapshoting at fixed intervals // REQUIRES: mutex locked std::unique_ptr thread_persist_stats_; // When set, we use a separate queue for writes that dont write to memtable. // In 2PC these are the writes at Prepare phase. const bool two_write_queues_; const bool manual_wal_flush_; // LastSequence also indicates last published sequence visibile to the // readers. Otherwise LastPublishedSequence should be used. const bool last_seq_same_as_publish_seq_; // It indicates that a customized gc algorithm must be used for // flush/compaction and if it is not provided vis SnapshotChecker, we should // disable gc to be safe. const bool use_custom_gc_; // Flag to indicate that the DB instance shutdown has been initiated. This // different from shutting_down_ atomic in that it is set at the beginning // of shutdown sequence, specifically in order to prevent any background // error recovery from going on in parallel. The latter, shutting_down_, // is set a little later during the shutdown after scheduling memtable // flushes std::atomic shutdown_initiated_; // Flag to indicate whether sst_file_manager object was allocated in // DB::Open() or passed to us bool own_sfm_; // Clients must periodically call SetPreserveDeletesSequenceNumber() // to advance this seqnum. Default value is 0 which means ALL deletes are // preserved. Note that this has no effect if DBOptions.preserve_deletes // is set to false. std::atomic preserve_deletes_seqnum_; const bool preserve_deletes_; // Flag to check whether Close() has been called on this DB bool closed_; ErrorHandler error_handler_; // Conditional variable to coordinate installation of atomic flush results. // With atomic flush, each bg thread installs the result of flushing multiple // column families, and different threads can flush different column // families. It's difficult to rely on one thread to perform batch // installation for all threads. This is different from the non-atomic flush // case. // atomic_flush_install_cv_ makes sure that threads install atomic flush // results sequentially. Flush results of memtables with lower IDs get // installed to MANIFEST first. InstrumentedCondVar atomic_flush_install_cv_; }; extern Options SanitizeOptions(const std::string& db, const Options& src); extern DBOptions SanitizeOptions(const std::string& db, const DBOptions& src); extern CompressionType GetCompressionFlush( const ImmutableCFOptions& ioptions, const MutableCFOptions& mutable_cf_options); // Return the earliest log file to keep after the memtable flush is // finalized. // `cfd_to_flush` is the column family whose memtable (specified in // `memtables_to_flush`) will be flushed and thus will not depend on any WAL // file. // The function is only applicable to 2pc mode. extern uint64_t PrecomputeMinLogNumberToKeep( VersionSet* vset, const ColumnFamilyData& cfd_to_flush, autovector edit_list, const autovector& memtables_to_flush, LogsWithPrepTracker* prep_tracker); // `cfd_to_flush` is the column family whose memtable will be flushed and thus // will not depend on any WAL file. nullptr means no memtable is being flushed. // The function is only applicable to 2pc mode. extern uint64_t FindMinPrepLogReferencedByMemTable( VersionSet* vset, const ColumnFamilyData* cfd_to_flush, const autovector& memtables_to_flush); // Fix user-supplied options to be reasonable template static void ClipToRange(T* ptr, V minvalue, V maxvalue) { if (static_cast(*ptr) > maxvalue) *ptr = maxvalue; if (static_cast(*ptr) < minvalue) *ptr = minvalue; } } // namespace rocksdb