// 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 #include "db/column_family.h" #include "db/compaction/compaction_iterator.h" #include "db/compaction/compaction_job.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/import_column_family_job.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/periodic_task_scheduler.h" #include "db/post_memtable_callback.h" #include "db/pre_release_callback.h" #include "db/range_del_aggregator.h" #include "db/read_callback.h" #include "db/seqno_to_time_mapping.h" #include "db/snapshot_checker.h" #include "db/snapshot_impl.h" #include "db/trim_history_scheduler.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/utilities/replayer.h" #include "rocksdb/write_buffer_manager.h" #include "table/merging_iterator.h" #include "table/scoped_arena_iterator.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_NAMESPACE { 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: IOStatus SetDirectories(FileSystem* fs, const std::string& dbname, const std::string& wal_dir, const std::vector& data_paths); FSDirectory* GetDataDir(size_t path_id) const { assert(path_id < data_dirs_.size()); FSDirectory* ret_dir = data_dirs_[path_id].get(); if (ret_dir == nullptr) { // Should use db_dir_ return db_dir_.get(); } return ret_dir; } FSDirectory* GetWalDir() { if (wal_dir_) { return wal_dir_.get(); } return db_dir_.get(); } FSDirectory* GetDbDir() { return db_dir_.get(); } IOStatus Close(const IOOptions& options, IODebugContext* dbg) { // close all directories for all database paths IOStatus s = IOStatus::OK(); // The default implementation for Close() in Directory/FSDirectory class // "NotSupported" status, the upper level interface should be able to // handle this error so that Close() does not fail after upgrading when // run on FileSystems that have not implemented `Directory::Close()` or // `FSDirectory::Close()` yet if (db_dir_) { IOStatus temp_s = db_dir_->Close(options, dbg); if (!temp_s.ok() && !temp_s.IsNotSupported() && s.ok()) { s = std::move(temp_s); } } // Attempt to close everything even if one fails s.PermitUncheckedError(); if (wal_dir_) { IOStatus temp_s = wal_dir_->Close(options, dbg); if (!temp_s.ok() && !temp_s.IsNotSupported() && s.ok()) { s = std::move(temp_s); } } s.PermitUncheckedError(); for (auto& data_dir_ptr : data_dirs_) { if (data_dir_ptr) { IOStatus temp_s = data_dir_ptr->Close(options, dbg); if (!temp_s.ok() && !temp_s.IsNotSupported() && s.ok()) { s = std::move(temp_s); } } } // Ready for caller s.MustCheck(); return s; } 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, bool read_only = false); // No copying allowed DBImpl(const DBImpl&) = delete; void operator=(const DBImpl&) = delete; virtual ~DBImpl(); // ---- Implementations of the DB interface ---- using DB::Resume; Status Resume() override; using DB::Put; Status Put(const WriteOptions& options, ColumnFamilyHandle* column_family, const Slice& key, const Slice& value) override; Status Put(const WriteOptions& options, ColumnFamilyHandle* column_family, const Slice& key, const Slice& ts, const Slice& value) override; using DB::PutEntity; Status PutEntity(const WriteOptions& options, ColumnFamilyHandle* column_family, const Slice& key, const WideColumns& columns) override; using DB::Merge; Status Merge(const WriteOptions& options, ColumnFamilyHandle* column_family, const Slice& key, const Slice& value) override; Status Merge(const WriteOptions& options, ColumnFamilyHandle* column_family, const Slice& key, const Slice& ts, const Slice& value) override; using DB::Delete; Status Delete(const WriteOptions& options, ColumnFamilyHandle* column_family, const Slice& key) override; Status Delete(const WriteOptions& options, ColumnFamilyHandle* column_family, const Slice& key, const Slice& ts) override; using DB::SingleDelete; Status SingleDelete(const WriteOptions& options, ColumnFamilyHandle* column_family, const Slice& key) override; Status SingleDelete(const WriteOptions& options, ColumnFamilyHandle* column_family, const Slice& key, const Slice& ts) override; using DB::DeleteRange; Status DeleteRange(const WriteOptions& options, ColumnFamilyHandle* column_family, const Slice& begin_key, const Slice& end_key) override; Status DeleteRange(const WriteOptions& options, ColumnFamilyHandle* column_family, const Slice& begin_key, const Slice& end_key, const Slice& ts) 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; virtual Status Get(const ReadOptions& options, ColumnFamilyHandle* column_family, const Slice& key, PinnableSlice* value, std::string* timestamp) override; using DB::GetEntity; Status GetEntity(const ReadOptions& options, ColumnFamilyHandle* column_family, const Slice& key, PinnableWideColumns* columns) override; using DB::GetMergeOperands; Status GetMergeOperands(const ReadOptions& options, ColumnFamilyHandle* column_family, const Slice& key, PinnableSlice* merge_operands, GetMergeOperandsOptions* get_merge_operands_options, int* number_of_operands) override { GetImplOptions get_impl_options; get_impl_options.column_family = column_family; get_impl_options.merge_operands = merge_operands; get_impl_options.get_merge_operands_options = get_merge_operands_options; get_impl_options.number_of_operands = number_of_operands; get_impl_options.get_value = false; return GetImpl(options, key, get_impl_options); } using DB::MultiGet; virtual std::vector MultiGet( const ReadOptions& options, const std::vector& column_family, const std::vector& keys, std::vector* values) override; virtual std::vector MultiGet( const ReadOptions& options, const std::vector& column_family, const std::vector& keys, std::vector* values, std::vector* timestamps) 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; virtual void MultiGet(const ReadOptions& options, ColumnFamilyHandle* column_family, const size_t num_keys, const Slice* keys, PinnableSlice* values, std::string* timestamps, Status* statuses, const bool sorted_input = false) override; virtual void MultiGet(const ReadOptions& options, const size_t num_keys, ColumnFamilyHandle** column_families, const Slice* keys, PinnableSlice* values, Status* statuses, const bool sorted_input = false) override; virtual void MultiGet(const ReadOptions& options, const size_t num_keys, ColumnFamilyHandle** column_families, const Slice* keys, PinnableSlice* values, std::string* timestamps, Status* statuses, const bool sorted_input = false) override; virtual void MultiGetWithCallback( const ReadOptions& options, ColumnFamilyHandle* column_family, ReadCallback* callback, autovector* sorted_keys); 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, std::string* timestamp, 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; // Create a timestamped snapshot. This snapshot can be shared by multiple // readers. If any of them uses it for write conflict checking, then // is_write_conflict_boundary is true. For simplicity, set it to true by // default. std::pair> CreateTimestampedSnapshot( SequenceNumber snapshot_seq, uint64_t ts); std::shared_ptr GetTimestampedSnapshot(uint64_t ts) const; void ReleaseTimestampedSnapshotsOlderThan( uint64_t ts, size_t* remaining_total_ss = nullptr); Status GetTimestampedSnapshots(uint64_t ts_lb, uint64_t ts_ub, std::vector>& timestamped_snapshots) const; 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 Status GetApproximateSizes(const SizeApproximationOptions& options, ColumnFamilyHandle* column_family, const Range* range, int n, uint64_t* sizes) 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; virtual void EnableManualCompaction() override; virtual void DisableManualCompaction() 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; virtual FileSystem* GetFileSystem() 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 WALBufferIsEmpty(bool lock = true); virtual Status SyncWAL() override; virtual Status LockWAL() override; virtual Status UnlockWAL() override; virtual SequenceNumber GetLatestSequenceNumber() const override; // IncreaseFullHistoryTsLow(ColumnFamilyHandle*, std::string) will acquire // and release db_mutex Status IncreaseFullHistoryTsLow(ColumnFamilyHandle* column_family, std::string ts_low) override; // GetFullHistoryTsLow(ColumnFamilyHandle*, std::string*) will acquire and // release db_mutex Status GetFullHistoryTsLow(ColumnFamilyHandle* column_family, std::string* ts_low) override; virtual Status GetDbIdentity(std::string& identity) const override; virtual Status GetDbIdentityFromIdentityFile(std::string* identity) const; virtual Status GetDbSessionId(std::string& session_id) const override; ColumnFamilyHandle* DefaultColumnFamily() const override; ColumnFamilyHandle* PersistentStatsColumnFamily() const; virtual Status Close() override; virtual Status DisableFileDeletions() override; virtual Status EnableFileDeletions(bool force) override; virtual bool IsFileDeletionsEnabled() const; Status GetStatsHistory( uint64_t start_time, uint64_t end_time, std::unique_ptr* stats_iterator) override; using DB::ResetStats; virtual Status ResetStats() override; // 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 GetCurrentWalFile( std::unique_ptr* current_log_file) override; virtual Status GetCreationTimeOfOldestFile( uint64_t* creation_time) 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; virtual Status GetLiveFilesChecksumInfo( FileChecksumList* checksum_list) override; virtual Status GetLiveFilesStorageInfo( const LiveFilesStorageInfoOptions& opts, std::vector* files) override; // Obtains the meta data of the specified column family of the DB. // TODO(yhchiang): output parameter is placed in the end in this codebase. virtual void GetColumnFamilyMetaData(ColumnFamilyHandle* column_family, ColumnFamilyMetaData* metadata) override; void GetAllColumnFamilyMetaData( std::vector* 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; using DB::CreateColumnFamilyWithImport; virtual Status CreateColumnFamilyWithImport( const ColumnFamilyOptions& options, const std::string& column_family_name, const ImportColumnFamilyOptions& import_options, const ExportImportFilesMetaData& metadata, ColumnFamilyHandle** handle) override; using DB::VerifyFileChecksums; Status VerifyFileChecksums(const ReadOptions& read_options) override; using DB::VerifyChecksum; virtual Status VerifyChecksum(const ReadOptions& /*read_options*/) override; // Verify the checksums of files in db. Currently only tables are checked. // // read_options: controls file I/O behavior, e.g. read ahead size while // reading all the live table files. // // use_file_checksum: if false, verify the block checksums of all live table // in db. Otherwise, obtain the file checksums and compare // with the MANIFEST. Currently, file checksums are // recomputed by reading all table files. // // Returns: OK if there is no file whose file or block checksum mismatches. Status VerifyChecksumInternal(const ReadOptions& read_options, bool use_file_checksum); Status VerifyFullFileChecksum(const std::string& file_checksum_expected, const std::string& func_name_expected, const std::string& fpath, const ReadOptions& read_options); using DB::StartTrace; virtual Status StartTrace( const TraceOptions& options, std::unique_ptr&& trace_writer) override; using DB::EndTrace; virtual Status EndTrace() override; using DB::NewDefaultReplayer; virtual Status NewDefaultReplayer( const std::vector& handles, std::unique_ptr&& reader, std::unique_ptr* replayer) override; using DB::StartBlockCacheTrace; Status StartBlockCacheTrace( const TraceOptions& trace_options, std::unique_ptr&& trace_writer) override; Status StartBlockCacheTrace( const BlockCacheTraceOptions& options, std::unique_ptr&& trace_writer) override; using DB::EndBlockCacheTrace; Status EndBlockCacheTrace() override; using DB::StartIOTrace; Status StartIOTrace(const TraceOptions& options, std::unique_ptr&& trace_writer) override; using DB::EndIOTrace; Status EndIOTrace() 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; // ---- End of implementations of the DB interface ---- SystemClock* GetSystemClock() const; struct GetImplOptions { ColumnFamilyHandle* column_family = nullptr; PinnableSlice* value = nullptr; PinnableWideColumns* columns = nullptr; std::string* timestamp = nullptr; bool* value_found = nullptr; ReadCallback* callback = nullptr; bool* is_blob_index = nullptr; // If true return value associated with key via value pointer else return // all merge operands for key via merge_operands pointer bool get_value = true; // Pointer to an array of size // get_merge_operands_options.expected_max_number_of_operands allocated by // user PinnableSlice* merge_operands = nullptr; GetMergeOperandsOptions* get_merge_operands_options = nullptr; int* number_of_operands = nullptr; }; // Function that Get and KeyMayExist call with no_io true or false // Note: 'value_found' from KeyMayExist propagates here // This function is also called by GetMergeOperands // If get_impl_options.get_value = true get value associated with // get_impl_options.key via get_impl_options.value // If get_impl_options.get_value = false get merge operands associated with // get_impl_options.key via get_impl_options.merge_operands Status GetImpl(const ReadOptions& options, const Slice& key, GetImplOptions& get_impl_options); // If `snapshot` == kMaxSequenceNumber, set a recent one inside the file. ArenaWrappedDBIter* NewIteratorImpl(const ReadOptions& options, ColumnFamilyData* cfd, SequenceNumber snapshot, ReadCallback* read_callback, bool expose_blob_index = 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; // 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. // // `key` should NOT have user-defined timestamp appended to user key even if // timestamp is enabled. // // 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 user-defined // timestamp is enabled for this column family and timestamp is not nullptr, // then *timestamp will be set to the stored timestamp for the latest // operation on this key. // 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, std::string* timestamp, bool* found_record_for_key, bool* is_blob_index); Status TraceIteratorSeek(const uint32_t& cf_id, const Slice& key, const Slice& lower_bound, const Slice upper_bound); Status TraceIteratorSeekForPrev(const uint32_t& cf_id, const Slice& key, const Slice& lower_bound, const Slice upper_bound); // 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, const std::string& trim_ts); // 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. // If allow_unprepared_value is true, the returned iterator may defer reading // the value and so will require PrepareValue() to be called before value(); // allow_unprepared_value = false is convenient when this optimization is not // useful, e.g. when reading the whole column family. // // read_options.ignore_range_deletions determines whether range tombstones are // processed in the returned interator internally, i.e., whether range // tombstone covered keys are in this iterator's output. // @param read_options Must outlive the returned iterator. InternalIterator* NewInternalIterator( const ReadOptions& read_options, Arena* arena, SequenceNumber sequence, ColumnFamilyHandle* column_family = nullptr, bool allow_unprepared_value = false); // Note: to support DB iterator refresh, memtable range tombstones in the // underlying merging iterator needs to be refreshed. If db_iter is not // nullptr, db_iter->SetMemtableRangetombstoneIter() is called with the // memtable range tombstone iterator used by the underlying merging iterator. // This range tombstone iterator can be refreshed later by db_iter. // @param read_options Must outlive the returned iterator. InternalIterator* NewInternalIterator(const ReadOptions& read_options, ColumnFamilyData* cfd, SuperVersion* super_version, Arena* arena, SequenceNumber sequence, bool allow_unprepared_value, ArenaWrappedDBIter* db_iter = 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_; } // 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) { mutex_.AssertHeld(); logs_to_free_queue_.push_back(log_writer); } void AddSuperVersionsToFreeQueue(SuperVersion* sv) { superversions_to_free_queue_.push_back(sv); } 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. Push new manifest file name into `new_filenames`. Status NewDB(std::vector* new_filenames); // 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 IOStatus CreateAndNewDirectory( FileSystem* fs, 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); // Print information of all tombstones of all iterators to the std::string // This is only used by ldb. The output might be capped. Tombstones // printed out are not guaranteed to be in any order. Status TablesRangeTombstoneSummary(ColumnFamilyHandle* column_family, int max_entries_to_print, std::string* out_str); VersionSet* GetVersionSet() const { return versions_.get(); } // 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 WaitForCompact(bool waitUnscheduled = false); #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); Status 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); Status TEST_FlushMemTable(ColumnFamilyData* cfd, const FlushOptions& flush_opts); // Flush (multiple) ColumnFamilyData without using ColumnFamilyHandle. This // is because in certain cases, we can flush column families, wait for the // flush to complete, but delete the column family handle before the wait // finishes. For example in CompactRange. Status TEST_AtomicFlushMemTables(const autovector& cfds, const FlushOptions& flush_opts); // Wait for background threads to complete scheduled work. Status TEST_WaitForBackgroundWork(); // 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); // Wait for any background purge Status TEST_WaitForPurge(); // Get the background error status Status TEST_GetBGError(); // Return the maximum overlapping data (in bytes) at next level for any // file at a level >= 1. uint64_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, std::vector>* blob_metadata = nullptr); 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_WaitForPeriodicTaskRun(std::function callback) const; SeqnoToTimeMapping TEST_GetSeqnoToTimeMapping() const; size_t TEST_EstimateInMemoryStatsHistorySize() const; uint64_t TEST_GetCurrentLogNumber() const { InstrumentedMutexLock l(mutex()); assert(!logs_.empty()); return logs_.back().number; } const std::unordered_set& TEST_GetFilesGrabbedForPurge() const { return files_grabbed_for_purge_; } const PeriodicTaskScheduler& TEST_GetPeriodicTaskScheduler() const; #endif // NDEBUG // persist stats to column family "_persistent_stats" void PersistStats(); // dump rocksdb.stats to LOG void DumpStats(); // flush LOG out of application buffer void FlushInfoLog(); // record current sequence number to time mapping void RecordSeqnoToTimeMapping(); // Interface to block and signal the DB in case of stalling writes by // WriteBufferManager. Each DBImpl object contains ptr to WBMStallInterface. // When DB needs to be blocked or signalled by WriteBufferManager, // state_ is changed accordingly. class WBMStallInterface : public StallInterface { public: enum State { BLOCKED = 0, RUNNING, }; WBMStallInterface() : state_cv_(&state_mutex_) { MutexLock lock(&state_mutex_); state_ = State::RUNNING; } void SetState(State state) { MutexLock lock(&state_mutex_); state_ = state; } // Change the state_ to State::BLOCKED and wait until its state is // changed by WriteBufferManager. When stall is cleared, Signal() is // called to change the state and unblock the DB. void Block() override { MutexLock lock(&state_mutex_); while (state_ == State::BLOCKED) { TEST_SYNC_POINT("WBMStallInterface::BlockDB"); state_cv_.Wait(); } } // Called from WriteBufferManager. This function changes the state_ // to State::RUNNING indicating the stall is cleared and DB can proceed. void Signal() override { { MutexLock lock(&state_mutex_); state_ = State::RUNNING; } state_cv_.Signal(); } private: // Conditional variable and mutex to block and // signal the DB during stalling process. port::Mutex state_mutex_; port::CondVar state_cv_; // state represting whether DB is running or blocked because of stall by // WriteBufferManager. State state_; }; static void TEST_ResetDbSessionIdGen(); static std::string GenerateDbSessionId(Env* env); bool seq_per_batch() const { return seq_per_batch_; } protected: const std::string dbname_; // TODO(peterd): unify with VersionSet::db_id_ std::string db_id_; // db_session_id_ is an identifier that gets reset // every time the DB is opened std::string db_session_id_; std::unique_ptr versions_; // Flag to check whether we allocated and own the info log file bool own_info_log_; Status init_logger_creation_s_; const DBOptions initial_db_options_; Env* const env_; std::shared_ptr io_tracer_; const ImmutableDBOptions immutable_db_options_; FileSystemPtr fs_; MutableDBOptions mutable_db_options_; Statistics* stats_; std::unordered_map recovered_transactions_; std::unique_ptr tracer_; InstrumentedMutex trace_mutex_; BlockCacheTracer block_cache_tracer_; // constant false canceled flag, used when the compaction is not manual const std::atomic kManualCompactionCanceledFalse_{false}; // 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. // // `mutex_` can be a hot lock in some workloads, so it deserves dedicated // cachelines. mutable CacheAlignedInstrumentedMutex mutex_; ColumnFamilyHandleImpl* default_cf_handle_; InternalStats* default_cf_internal_stats_; // table_cache_ provides its own synchronization std::shared_ptr table_cache_; ErrorHandler error_handler_; // Unified interface for logging events EventLogger event_logger_; // 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 std::atomic max_total_in_memory_state_; // The options to access storage files const FileOptions file_options_; // Additonal options for compaction and flush FileOptions file_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_; // Each flush or compaction gets its own job id. this counter makes sure // they're unique std::atomic next_job_id_; std::atomic shutting_down_; // RecoveryContext struct stores the context about version edits along // with corresponding column_family_data and column_family_options. class RecoveryContext { public: ~RecoveryContext() { for (auto& edit_list : edit_lists_) { for (auto* edit : edit_list) { delete edit; } } } void UpdateVersionEdits(ColumnFamilyData* cfd, const VersionEdit& edit) { assert(cfd != nullptr); if (map_.find(cfd->GetID()) == map_.end()) { uint32_t size = static_cast(map_.size()); map_.emplace(cfd->GetID(), size); cfds_.emplace_back(cfd); mutable_cf_opts_.emplace_back(cfd->GetLatestMutableCFOptions()); edit_lists_.emplace_back(autovector()); } uint32_t i = map_[cfd->GetID()]; edit_lists_[i].emplace_back(new VersionEdit(edit)); } std::unordered_map map_; // cf_id to index; autovector cfds_; autovector mutable_cf_opts_; autovector> edit_lists_; // files_to_delete_ contains sst files std::unordered_set files_to_delete_; }; // 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); Status CompactRangeInternal(const CompactRangeOptions& options, ColumnFamilyHandle* column_family, const Slice* begin, const Slice* end, const std::string& trim_ts); // 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, FlushReason flush_reason); void NotifyOnFlushCompleted( ColumnFamilyData* cfd, const MutableCFOptions& mutable_cf_options, std::list>* flush_jobs_info); 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); void NotifyOnExternalFileIngested( ColumnFamilyData* cfd, const ExternalSstFileIngestionJob& ingestion_job); virtual Status FlushForGetLiveFiles(); 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, PostMemTableCallback* post_memtable_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. // recovered_seq is set to less than kMaxSequenceNumber if the log's tail is // skipped. // recovery_ctx stores the context about version edits and all those // edits are persisted to new Manifest after successfully syncing the new WAL. virtual Status Recover( const std::vector& column_families, bool read_only = false, bool error_if_wal_file_exists = false, bool error_if_data_exists_in_wals = false, uint64_t* recovered_seq = nullptr, RecoveryContext* recovery_ctx = nullptr); virtual bool OwnTablesAndLogs() const { return true; } // Setup DB identity file, and write DB ID to manifest if necessary. Status SetupDBId(bool read_only, RecoveryContext* recovery_ctx); // Assign db_id_ and write DB ID to manifest if necessary. void SetDBId(std::string&& id, bool read_only, RecoveryContext* recovery_ctx); // REQUIRES: db mutex held when calling this function, but the db mutex can // be released and re-acquired. Db mutex will be held when the function // returns. // After recovery, there may be SST files in db/cf paths that are // not referenced in the MANIFEST (e.g. // 1. It's best effort recovery; // 2. The VersionEdits referencing the SST files are appended to // RecoveryContext, DB crashes when syncing the MANIFEST, the VersionEdits are // still not synced to MANIFEST during recovery.) // It stores the SST files to be deleted in RecoveryContext. In the // meantime, we find out the largest file number present in the paths, and // bump up the version set's next_file_number_ to be 1 + largest_file_number. // recovery_ctx stores the context about version edits and files to be // deleted. All those edits are persisted to new Manifest after successfully // syncing the new WAL. Status DeleteUnreferencedSstFiles(RecoveryContext* recovery_ctx); // SetDbSessionId() should be called in the constuctor DBImpl() // to ensure that db_session_id_ gets updated every time the DB is opened void SetDbSessionId(); Status FailIfCfHasTs(const ColumnFamilyHandle* column_family) const; Status FailIfTsMismatchCf(ColumnFamilyHandle* column_family, const Slice& ts, bool ts_for_read) const; // recovery_ctx stores the context about version edits and // LogAndApplyForRecovery persist all those edits to new Manifest after // successfully syncing new WAL. // LogAndApplyForRecovery should be called only once during recovery and it // should be called when RocksDB writes to a first new MANIFEST since this // recovery. Status LogAndApplyForRecovery(const RecoveryContext& recovery_ctx); void InvokeWalFilterIfNeededOnColumnFamilyToWalNumberMap(); // Return true to proceed with current WAL record whose content is stored in // `batch`. Return false to skip current WAL record. bool InvokeWalFilterIfNeededOnWalRecord(uint64_t wal_number, const std::string& wal_fname, log::Reader::Reporter& reporter, Status& status, bool& stop_replay, WriteBatch& batch); 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; friend class ForwardIterator; 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 WriteCallbackPTest_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) {} LogFileNumberSize() {} 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; } bool IsSyncing() { return getting_synced; } uint64_t GetPreSyncSize() { assert(getting_synced); return pre_sync_size; } void PrepareForSync() { assert(!getting_synced); // Size is expected to be monotonically increasing. assert(writer->file()->GetFlushedSize() >= pre_sync_size); getting_synced = true; pre_sync_size = writer->file()->GetFlushedSize(); } void FinishSync() { assert(getting_synced); getting_synced = false; } 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 private: // true for some prefix of logs_ bool getting_synced = false; // The size of the file before the sync happens. This amount is guaranteed // to be persisted even if appends happen during sync so it can be used for // tracking the synced size in MANIFEST. uint64_t pre_sync_size = 0; }; struct LogContext { explicit LogContext(bool need_sync = false) : need_log_sync(need_sync), need_log_dir_sync(need_sync) {} bool need_log_sync = false; bool need_log_dir_sync = false; log::Writer* writer = nullptr; LogFileNumberSize* log_file_number_size = nullptr; }; // PurgeFileInfo is a structure to hold information of files to be deleted in // purge_files_ 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), flush_reason_(FlushReason::kOthers) {} BGFlushArg(ColumnFamilyData* cfd, uint64_t max_memtable_id, SuperVersionContext* superversion_context, FlushReason flush_reason) : cfd_(cfd), max_memtable_id_(max_memtable_id), superversion_context_(superversion_context), flush_reason_(flush_reason) {} // 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_; FlushReason flush_reason_; }; // Argument passed to flush thread. struct FlushThreadArg { DBImpl* db_; Env::Priority thread_pri_; }; // Information for a manual compaction struct ManualCompactionState { ManualCompactionState(ColumnFamilyData* _cfd, int _input_level, int _output_level, uint32_t _output_path_id, bool _exclusive, bool _disallow_trivial_move, std::atomic* _canceled) : cfd(_cfd), input_level(_input_level), output_level(_output_level), output_path_id(_output_path_id), exclusive(_exclusive), disallow_trivial_move(_disallow_trivial_move), canceled(_canceled ? *_canceled : canceled_internal_storage) {} // When _canceled is not provided by ther user, we assign the reference of // canceled_internal_storage to it to consolidate canceled and // manual_compaction_paused since DisableManualCompaction() might be // called ColumnFamilyData* cfd; int input_level; int output_level; uint32_t output_path_id; Status status; bool done = false; bool in_progress = false; // compaction request being processed? bool incomplete = false; // 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; // nullptr means beginning of key range const InternalKey* end = nullptr; // nullptr means end of key range InternalKey* manual_end = nullptr; // 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 // When the user provides a canceled pointer in CompactRangeOptions, the // above varaibe is the reference of the user-provided // `canceled`, otherwise, it is the reference of canceled_internal_storage std::atomic canceled_internal_storage = false; std::atomic& canceled; // Compaction canceled pointer reference }; 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; Env::Priority compaction_pri_; }; // 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(DBRecoverContext context); 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::unique_ptr::iterator>& v); IOStatus SyncClosedLogs(JobContext* job_context, VersionEdit* synced_wals); // 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, FlushReason flush_reason, 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 // corrupted_log_found is set to true if we recover from a corrupted log file. Status RecoverLogFiles(const std::vector& log_numbers, SequenceNumber* next_sequence, bool read_only, bool* corrupted_log_found, RecoveryContext* recovery_ctx); // 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); // Get the size of a log file and, if truncate is true, truncate the // log file to its actual size, thereby freeing preallocated space. // Return success even if truncate fails Status GetLogSizeAndMaybeTruncate(uint64_t wal_number, bool truncate, LogFileNumberSize* log); // 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, WriteThread& write_thread, const WriteOptions& write_options); // Begin stalling of writes when memory usage increases beyond a certain // threshold. void WriteBufferManagerStallWrites(); Status ThrottleLowPriWritesIfNeeded(const WriteOptions& write_options, WriteBatch* my_batch); // REQUIRES: mutex locked and in write thread. Status ScheduleFlushes(WriteContext* context); void MaybeFlushStatsCF(autovector* cfds); Status TrimMemtableHistory(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 entered_write_thread = false); Status AtomicFlushMemTables( const autovector& column_family_datas, const FlushOptions& options, FlushReason flush_reason, bool entered_write_thread = 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() { mutex_.AssertHeld(); TEST_SYNC_POINT("DBImpl::WaitForPendingWrites:BeforeBlock"); // In case of pipelined write is enabled, wait for all pending memtable // writers. if (immutable_db_options_.enable_pipelined_write) { // Memtable writers may call DB::Get in case max_successive_merges > 0, // which may lock mutex. Unlocking mutex here to avoid deadlock. mutex_.Unlock(); write_thread_.WaitForMemTableWriters(); mutex_.Lock(); } 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; }); } } // TaskType is used to identify tasks in thread-pool, currently only // differentiate manual compaction, which could be unscheduled from the // thread-pool. enum class TaskType : uint8_t { kDefault = 0, kManualCompaction = 1, kCount = 2, }; // Task tag is used to identity tasks in thread-pool, which is // dbImpl obj address + type inline void* GetTaskTag(TaskType type) { return GetTaskTag(static_cast(type)); } inline void* GetTaskTag(uint8_t type) { return static_cast(static_cast(this)) + type; } // REQUIRES: mutex locked and in write thread. void AssignAtomicFlushSeq(const autovector& cfds); // REQUIRES: mutex locked and in write thread. Status SwitchWAL(WriteContext* write_context); // REQUIRES: mutex locked and in write thread. Status HandleWriteBufferManagerFlush(WriteContext* write_context); // REQUIRES: mutex locked Status PreprocessWrite(const WriteOptions& write_options, LogContext* log_context, WriteContext* write_context); // Merge write batches in the write group into merged_batch. // Returns OK if merge is successful. // Returns Corruption if corruption in write batch is detected. Status MergeBatch(const WriteThread::WriteGroup& write_group, WriteBatch* tmp_batch, WriteBatch** merged_batch, size_t* write_with_wal, WriteBatch** to_be_cached_state); // rate_limiter_priority is used to charge `DBOptions::rate_limiter` // for automatic WAL flush (`Options::manual_wal_flush` == false) // associated with this WriteToWAL IOStatus WriteToWAL(const WriteBatch& merged_batch, log::Writer* log_writer, uint64_t* log_used, uint64_t* log_size, Env::IOPriority rate_limiter_priority, LogFileNumberSize& log_file_number_size); IOStatus 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, LogFileNumberSize& log_file_number_size); IOStatus 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. // Caller must hold mutex_. void WriteStatusCheckOnLocked(const Status& status); // Used by WriteImpl to update bg_error_ if paranoid check is enabled. void WriteStatusCheck(const Status& status); // Used by WriteImpl to update bg_error_ when IO error happens, e.g., write // WAL, sync WAL fails, if paranoid check is enabled. void IOStatusCheck(const IOStatus& status); // Used by WriteImpl to update bg_error_ in case of memtable insert error. void MemTableInsertStatusCheck(const Status& memtable_insert_status); 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); ColumnFamilyData* GetColumnFamilyDataByName(const std::string& cf_name); void MaybeScheduleFlushOrCompaction(); struct FlushRequest { FlushReason flush_reason; // A map from column family to flush to 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. std::unordered_map cfd_to_max_mem_id_to_persist; }; void GenerateFlushRequest(const autovector& cfds, FlushReason flush_reason, FlushRequest* req); void SchedulePendingFlush(const FlushRequest& req); 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 Status StartPeriodicTaskScheduler(); Status RegisterRecordSeqnoTimeWorker(); void PrintStatistics(); size_t EstimateInMemoryStatsHistorySize() const; // 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, VersionEdit* edit); Status ApplyWALToManifest(VersionEdit* edit); // WALs with log number up to up_to are not synced successfully. void MarkLogsNotSynced(uint64_t up_to); SnapshotImpl* GetSnapshotImpl(bool is_write_conflict_boundary, bool lock = true); // If snapshot_seq != kMaxSequenceNumber, then this function can only be // called from the write thread that publishes sequence numbers to readers. // For 1) write-committed, or 2) write-prepared + one-write-queue, this will // be the write thread performing memtable writes. For write-prepared with // two write queues, this will be the write thread writing commit marker to // the WAL. // If snapshot_seq == kMaxSequenceNumber, this function is called by a caller // ensuring no writes to the database. std::pair> CreateTimestampedSnapshotImpl(SequenceNumber snapshot_seq, uint64_t ts, bool lock = true); uint64_t GetMaxTotalWalSize() const; FSDirectory* GetDataDir(ColumnFamilyData* cfd, size_t path_id) const; Status MaybeReleaseTimestampedSnapshotsAndCheck(); Status CloseHelper(); void WaitForBackgroundWork(); // 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); 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::unique_ptr::iterator>& pending_output_elem, uint64_t* next_file_number); 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; } IOStatus 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); // Utility function to do some debug validation and sort the given vector // of MultiGet keys void PrepareMultiGetKeys( const size_t num_keys, bool sorted, autovector* key_ptrs); // A structure to hold the information required to process MultiGet of keys // belonging to one column family. For a multi column family MultiGet, there // will be a container of these objects. struct MultiGetColumnFamilyData { ColumnFamilyHandle* cf; ColumnFamilyData* cfd; // For the batched MultiGet which relies on sorted keys, start specifies // the index of first key belonging to this column family in the sorted // list. size_t start; // For the batched MultiGet case, num_keys specifies the number of keys // belonging to this column family in the sorted list size_t num_keys; // SuperVersion for the column family obtained in a manner that ensures a // consistent view across all column families in the DB SuperVersion* super_version; MultiGetColumnFamilyData(ColumnFamilyHandle* column_family, SuperVersion* sv) : cf(column_family), cfd(static_cast(cf)->cfd()), start(0), num_keys(0), super_version(sv) {} MultiGetColumnFamilyData(ColumnFamilyHandle* column_family, size_t first, size_t count, SuperVersion* sv) : cf(column_family), cfd(static_cast(cf)->cfd()), start(first), num_keys(count), super_version(sv) {} MultiGetColumnFamilyData() = default; }; // A common function to obtain a consistent snapshot, which can be implicit // if the user doesn't specify a snapshot in read_options, across // multiple column families for MultiGet. It will attempt to get an implicit // snapshot without acquiring the db_mutes, but will give up after a few // tries and acquire the mutex if a memtable flush happens. The template // allows both the batched and non-batched MultiGet to call this with // either an std::unordered_map or autovector of column families. // // If callback is non-null, the callback is refreshed with the snapshot // sequence number // // A return value of true indicates that the SuperVersions were obtained // from the ColumnFamilyData, whereas false indicates they are thread // local template bool MultiCFSnapshot( const ReadOptions& read_options, ReadCallback* callback, std::function& iter_deref_func, T* cf_list, SequenceNumber* snapshot); // The actual implementation of the batching MultiGet. The caller is expected // to have acquired the SuperVersion and pass in a snapshot sequence number // in order to construct the LookupKeys. The start_key and num_keys specify // the range of keys in the sorted_keys vector for a single column family. Status MultiGetImpl( const ReadOptions& read_options, size_t start_key, size_t num_keys, autovector* sorted_keys, SuperVersion* sv, SequenceNumber snap_seqnum, ReadCallback* callback); Status DisableFileDeletionsWithLock(); Status IncreaseFullHistoryTsLowImpl(ColumnFamilyData* cfd, std::string ts_low); bool ShouldReferenceSuperVersion(const MergeContext& merge_context); // 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_; // If zero, manual compactions are allowed to proceed. If non-zero, manual // compactions may still be running, but will quickly fail with // `Status::Incomplete`. The value indicates how many threads have paused // manual compactions. It is accessed in read mode outside the DB mutex in // compaction code paths. std::atomic manual_compaction_paused_; // 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_; // Log files that we can recycle. Must be protected by db mutex_. std::deque log_recycle_files_; // Protected by log_write_mutex_. 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 // expensive mutex_ lock during WAL write, which update log_empty_. bool log_empty_; ColumnFamilyHandleImpl* persist_stats_cf_handle_; bool persistent_stats_cfd_exists_ = true; // alive_log_files_ is protected by mutex_ and log_write_mutex_ with details // as follows: // 1. read by FindObsoleteFiles() which can be called in either application // thread or RocksDB bg threads, both mutex_ and log_write_mutex_ are // held. // 2. pop_front() by FindObsoleteFiles(), both mutex_ and log_write_mutex_ // are held. // 3. push_back() by DBImpl::Open() and DBImpl::RestoreAliveLogFiles() // (actually called by Open()), only mutex_ is held because at this point, // the DB::Open() call has not returned success to application, and the // only other thread(s) that can conflict are bg threads calling // FindObsoleteFiles() which ensure that both mutex_ and log_write_mutex_ // are held when accessing alive_log_files_. // 4. read by DBImpl::Open() is protected by mutex_. // 5. push_back() by SwitchMemtable(). Both mutex_ and log_write_mutex_ are // held. This is done by the write group leader. Note that in the case of // two-write-queues, another WAL-only write thread can be writing to the // WAL concurrently. See 9. // 6. read by SwitchWAL() with both mutex_ and log_write_mutex_ held. This is // done by write group leader. // 7. read by ConcurrentWriteToWAL() by the write group leader in the case of // two-write-queues. Only log_write_mutex_ is held to protect concurrent // pop_front() by FindObsoleteFiles(). // 8. read by PreprocessWrite() by the write group leader. log_write_mutex_ // is held to protect the data structure from concurrent pop_front() by // FindObsoleteFiles(). // 9. read by ConcurrentWriteToWAL() by a WAL-only write thread in the case // of two-write-queues. Only log_write_mutex_ is held. This suffices to // protect the data structure from concurrent push_back() by current // write group leader as well as pop_front() by FindObsoleteFiles(). std::deque alive_log_files_; // Log files that aren't fully synced, and the current log file. // Synchronization: // 1. read by FindObsoleteFiles() which can be called either in application // thread or RocksDB bg threads. log_write_mutex_ is always held, while // some reads are performed without mutex_. // 2. pop_front() by FindObsoleteFiles() with only log_write_mutex_ held. // 3. read by DBImpl::Open() with both mutex_ and log_write_mutex_. // 4. emplace_back() by DBImpl::Open() with both mutex_ and log_write_mutex. // Note that at this point, DB::Open() has not returned success to // application, thus the only other thread(s) that can conflict are bg // threads calling FindObsoleteFiles(). See 1. // 5. iteration and clear() from CloseHelper() always hold log_write_mutex // and mutex_. // 6. back() called by APIs FlushWAL() and LockWAL() are protected by only // log_write_mutex_. These two can be called by application threads after // DB::Open() returns success to applications. // 7. read by SyncWAL(), another API, protected by only log_write_mutex_. // 8. read by MarkLogsNotSynced() and MarkLogsSynced() are protected by // log_write_mutex_. // 9. erase() by MarkLogsSynced() protected by log_write_mutex_. // 10. read by SyncClosedLogs() protected by only log_write_mutex_. This can // happen in bg flush threads after DB::Open() returns success to // applications. // 11. reads, e.g. front(), iteration, and back() called by PreprocessWrite() // holds only the log_write_mutex_. This is done by the write group // leader. A bg thread calling FindObsoleteFiles() or MarkLogsSynced() // can happen concurrently. This is fine because log_write_mutex_ is used // by all parties. See 2, 5, 9. // 12. reads, empty(), back() called by SwitchMemtable() hold both mutex_ and // log_write_mutex_. This happens in the write group leader. // 13. emplace_back() by SwitchMemtable() hold both mutex_ and // log_write_mutex_. This happens in the write group leader. Can conflict // with bg threads calling FindObsoleteFiles(), MarkLogsSynced(), // SyncClosedLogs(), etc. as well as application threads calling // FlushWAL(), SyncWAL(), LockWAL(). This is fine because all parties // require at least log_write_mutex_. // 14. iteration called in WriteToWAL(write_group) protected by // log_write_mutex_. This is done by write group leader when // two-write-queues is disabled and write needs to sync logs. // 15. back() called in ConcurrentWriteToWAL() protected by log_write_mutex_. // This can be done by the write group leader if two-write-queues is // enabled. It can also be done by another WAL-only write thread. // // Other observations: // - 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. Note that calling back() without // mutex may be unsafe because different implementations of deque::back() may // access other member variables of deque, causing undefined behaviors. // Generally, do not access stl containers without proper synchronization. // - 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 consecutive 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 log_write_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_; // 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_; TrimHistoryScheduler trim_history_scheduler_; SnapshotList snapshots_; TimestampedSnapshotList timestamped_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 map to store file numbers and filenames of the files to be purged std::unordered_map purge_files_; // A vector to store the file numbers that have been assigned to certain // JobContext. Current implementation tracks table and blob files only. std::unordered_set files_grabbed_for_purge_; // A queue to store log writers to close. Protected by db mutex_. std::deque logs_to_free_queue_; std::deque superversions_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_ = {}; // 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_; // Number of running IngestExternalFile() or CreateColumnFamilyWithImport() // calls. // REQUIRES: mutex held int num_running_ingest_file_; WalManager wal_manager_; // 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_; // Scheduler to run DumpStats(), PersistStats(), and FlushInfoLog(). // Currently, internally it has a global timer instance for running the tasks. PeriodicTaskScheduler periodic_task_scheduler_; // It contains the implementations for each periodic task. std::map periodic_task_functions_; // When set, we use a separate queue for writes that don't 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_; // Flag to check whether Close() has been called on this DB bool closed_; // save the closing status, for re-calling the close() Status closing_status_; // mutex for DB::Close() InstrumentedMutex closing_mutex_; // 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_; bool wal_in_db_path_; std::atomic max_total_wal_size_; BlobFileCompletionCallback blob_callback_; // Pointer to WriteBufferManager stalling interface. std::unique_ptr wbm_stall_; // seqno_time_mapping_ stores the sequence number to time mapping, it's not // thread safe, both read and write need db mutex hold. SeqnoToTimeMapping seqno_time_mapping_; // stop write token that is acquired when LockWal() is called. Destructed // when UnlockWal() is called. std::unique_ptr lock_wal_write_token_; }; class GetWithTimestampReadCallback : public ReadCallback { public: explicit GetWithTimestampReadCallback(SequenceNumber seq) : ReadCallback(seq) {} bool IsVisibleFullCheck(SequenceNumber seq) override { return seq <= max_visible_seq_; } }; extern Options SanitizeOptions(const std::string& db, const Options& src, bool read_only = false, Status* logger_creation_s = nullptr); extern DBOptions SanitizeOptions(const std::string& db, const DBOptions& src, bool read_only = false, Status* logger_creation_s = nullptr); 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 PrecomputeMinLogNumberToKeep2PC( VersionSet* vset, const ColumnFamilyData& cfd_to_flush, const autovector& edit_list, const autovector& memtables_to_flush, LogsWithPrepTracker* prep_tracker); // For atomic flush. extern uint64_t PrecomputeMinLogNumberToKeep2PC( VersionSet* vset, const autovector& cfds_to_flush, const autovector>& edit_lists, const autovector*>& memtables_to_flush, LogsWithPrepTracker* prep_tracker); // In non-2PC mode, WALs with log number < the returned number can be // deleted after the cfd_to_flush column family is flushed successfully. extern uint64_t PrecomputeMinLogNumberToKeepNon2PC( VersionSet* vset, const ColumnFamilyData& cfd_to_flush, const autovector& edit_list); // For atomic flush. extern uint64_t PrecomputeMinLogNumberToKeepNon2PC( VersionSet* vset, const autovector& cfds_to_flush, const autovector>& edit_lists); // `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 autovector& memtables_to_flush); // For atomic flush. extern uint64_t FindMinPrepLogReferencedByMemTable( VersionSet* vset, 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; } inline Status DBImpl::FailIfCfHasTs( const ColumnFamilyHandle* column_family) const { column_family = column_family ? column_family : DefaultColumnFamily(); assert(column_family); const Comparator* const ucmp = column_family->GetComparator(); assert(ucmp); if (ucmp->timestamp_size() > 0) { std::ostringstream oss; oss << "cannot call this method on column family " << column_family->GetName() << " that enables timestamp"; return Status::InvalidArgument(oss.str()); } return Status::OK(); } inline Status DBImpl::FailIfTsMismatchCf(ColumnFamilyHandle* column_family, const Slice& ts, bool ts_for_read) const { if (!column_family) { return Status::InvalidArgument("column family handle cannot be null"); } assert(column_family); const Comparator* const ucmp = column_family->GetComparator(); assert(ucmp); if (0 == ucmp->timestamp_size()) { std::stringstream oss; oss << "cannot call this method on column family " << column_family->GetName() << " that does not enable timestamp"; return Status::InvalidArgument(oss.str()); } const size_t ts_sz = ts.size(); if (ts_sz != ucmp->timestamp_size()) { std::stringstream oss; oss << "Timestamp sizes mismatch: expect " << ucmp->timestamp_size() << ", " << ts_sz << " given"; return Status::InvalidArgument(oss.str()); } if (ts_for_read) { auto cfh = static_cast_with_check(column_family); auto cfd = cfh->cfd(); std::string current_ts_low = cfd->GetFullHistoryTsLow(); if (!current_ts_low.empty() && ucmp->CompareTimestamp(ts, current_ts_low) < 0) { std::stringstream oss; oss << "Read timestamp: " << ts.ToString(true) << " is smaller than full_history_ts_low: " << Slice(current_ts_low).ToString(true) << std::endl; return Status::InvalidArgument(oss.str()); } } return Status::OK(); } } // namespace ROCKSDB_NAMESPACE