mirror of https://github.com/facebook/rocksdb.git
Improve comment in db_impl.h (#5338)
Summary: Add some comments in db_impl.h. Also reordered function order a little bit so that I can add a comment to flag the area of functions implementing DB interface. Pull Request resolved: https://github.com/facebook/rocksdb/pull/5338 Differential Revision: D15498284 Pulled By: siying fbshipit-source-id: 3d7c59c8303577fe44d13c74ae84c7ce05164f77
This commit is contained in:
Siying Dong
Facebook Github Bot
parent
f66026c8c7
commit
6267ed251a
355
db/db_impl.h
355
db/db_impl.h
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@ -75,16 +75,30 @@ struct JobContext;
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struct ExternalSstFileInfo;
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struct MemTableInfo;
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// While DB is the public interface of RocksDB, and DBImpl is the actual
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// class implementing it. It's the entrance of the core RocksdB engine.
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// All other DB implementations, e.g. TransactionDB, BlobDB, etc, wrap a
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// DBImpl internally.
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// Other than functions implementing the DB interface, some public
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// functions are there for other internal components to call. For
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// example, TransactionDB directly calls DBImpl::WriteImpl() and
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// BlobDB directly calls DBImpl::GetImpl(). Some other functions
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// are for sub-components to call. For example, ColumnFamilyHandleImpl
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// calls DBImpl::FindObsoleteFiles().
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//
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// Since it's a very large class, the definition of the functions is
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// divided in several db_impl_*.cc files, besides db_impl.cc.
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class DBImpl : public DB {
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public:
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DBImpl(const DBOptions& options, const std::string& dbname,
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const bool seq_per_batch = false, const bool batch_per_txn = true);
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virtual ~DBImpl();
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// ---- Implementations of the DB interface ----
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using DB::Resume;
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virtual Status Resume() override;
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// Implementations of the DB interface
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using DB::Put;
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virtual Status Put(const WriteOptions& options,
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ColumnFamilyHandle* column_family, const Slice& key,
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@ -110,13 +124,6 @@ class DBImpl : public DB {
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ColumnFamilyHandle* column_family, const Slice& key,
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PinnableSlice* value) override;
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// Function that Get and KeyMayExist call with no_io true or false
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// Note: 'value_found' from KeyMayExist propagates here
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Status GetImpl(const ReadOptions& options, ColumnFamilyHandle* column_family,
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const Slice& key, PinnableSlice* value,
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bool* value_found = nullptr, ReadCallback* callback = nullptr,
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bool* is_blob_index = nullptr);
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using DB::MultiGet;
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virtual std::vector<Status> MultiGet(
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const ReadOptions& options,
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@ -174,12 +181,6 @@ class DBImpl : public DB {
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const ReadOptions& options,
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const std::vector<ColumnFamilyHandle*>& column_families,
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std::vector<Iterator*>* iterators) override;
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ArenaWrappedDBIter* NewIteratorImpl(const ReadOptions& options,
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ColumnFamilyData* cfd,
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SequenceNumber snapshot,
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ReadCallback* read_callback,
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bool allow_blob = false,
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bool allow_refresh = true);
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virtual const Snapshot* GetSnapshot() override;
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virtual void ReleaseSnapshot(const Snapshot* snapshot) override;
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@ -259,23 +260,19 @@ class DBImpl : public DB {
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virtual Status UnlockWAL() override;
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virtual SequenceNumber GetLatestSequenceNumber() const override;
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virtual SequenceNumber GetLastPublishedSequence() const {
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if (last_seq_same_as_publish_seq_) {
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return versions_->LastSequence();
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} else {
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return versions_->LastPublishedSequence();
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}
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}
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// REQUIRES: joined the main write queue if two_write_queues is disabled, and
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// the second write queue otherwise.
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virtual void SetLastPublishedSequence(SequenceNumber seq);
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// Returns LastSequence in last_seq_same_as_publish_seq_
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// mode and LastAllocatedSequence otherwise. This is useful when visiblility
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// depends also on data written to the WAL but not to the memtable.
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SequenceNumber TEST_GetLastVisibleSequence() const;
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virtual bool SetPreserveDeletesSequenceNumber(SequenceNumber seqnum) override;
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virtual Status GetDbIdentity(std::string& identity) const override;
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ColumnFamilyHandle* DefaultColumnFamily() const override;
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virtual Status Close() override;
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Status GetStatsHistory(
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uint64_t start_time, uint64_t end_time,
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std::unique_ptr<StatsHistoryIterator>* stats_iterator) override;
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#ifndef ROCKSDB_LITE
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using DB::ResetStats;
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virtual Status ResetStats() override;
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@ -313,12 +310,76 @@ class DBImpl : public DB {
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Status PromoteL0(ColumnFamilyHandle* column_family,
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int target_level) override;
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using DB::IngestExternalFile;
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virtual Status IngestExternalFile(
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ColumnFamilyHandle* column_family,
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const std::vector<std::string>& external_files,
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const IngestExternalFileOptions& ingestion_options) override;
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using DB::IngestExternalFiles;
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virtual Status IngestExternalFiles(
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const std::vector<IngestExternalFileArg>& args) override;
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virtual Status VerifyChecksum() override;
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using DB::StartTrace;
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virtual Status StartTrace(
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const TraceOptions& options,
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std::unique_ptr<TraceWriter>&& trace_writer) override;
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using DB::EndTrace;
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virtual Status EndTrace() override;
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using DB::GetPropertiesOfAllTables;
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virtual Status GetPropertiesOfAllTables(
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ColumnFamilyHandle* column_family,
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TablePropertiesCollection* props) override;
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virtual Status GetPropertiesOfTablesInRange(
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ColumnFamilyHandle* column_family, const Range* range, std::size_t n,
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TablePropertiesCollection* props) override;
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#endif // ROCKSDB_LITE
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// ---- End of implementations of the DB interface ----
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// Function that Get and KeyMayExist call with no_io true or false
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// Note: 'value_found' from KeyMayExist propagates here
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Status GetImpl(const ReadOptions& options, ColumnFamilyHandle* column_family,
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const Slice& key, PinnableSlice* value,
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bool* value_found = nullptr, ReadCallback* callback = nullptr,
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bool* is_blob_index = nullptr);
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ArenaWrappedDBIter* NewIteratorImpl(const ReadOptions& options,
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ColumnFamilyData* cfd,
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SequenceNumber snapshot,
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ReadCallback* read_callback,
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bool allow_blob = false,
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bool allow_refresh = true);
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virtual SequenceNumber GetLastPublishedSequence() const {
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if (last_seq_same_as_publish_seq_) {
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return versions_->LastSequence();
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} else {
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return versions_->LastPublishedSequence();
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}
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}
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// REQUIRES: joined the main write queue if two_write_queues is disabled, and
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// the second write queue otherwise.
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virtual void SetLastPublishedSequence(SequenceNumber seq);
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// Returns LastSequence in last_seq_same_as_publish_seq_
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// mode and LastAllocatedSequence otherwise. This is useful when visiblility
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// depends also on data written to the WAL but not to the memtable.
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SequenceNumber TEST_GetLastVisibleSequence() const;
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#ifndef ROCKSDB_LITE
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// Similar to Write() but will call the callback once on the single write
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// thread to determine whether it is safe to perform the write.
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virtual Status WriteWithCallback(const WriteOptions& write_options,
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WriteBatch* my_batch,
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WriteCallback* callback);
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// Returns the sequence number that is guaranteed to be smaller than or equal
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// to the sequence number of any key that could be inserted into the current
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// memtables. It can then be assumed that any write with a larger(or equal)
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@ -360,25 +421,6 @@ class DBImpl : public DB {
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bool* found_record_for_key,
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bool* is_blob_index = nullptr);
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using DB::IngestExternalFile;
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virtual Status IngestExternalFile(
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ColumnFamilyHandle* column_family,
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const std::vector<std::string>& external_files,
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const IngestExternalFileOptions& ingestion_options) override;
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using DB::IngestExternalFiles;
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virtual Status IngestExternalFiles(
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const std::vector<IngestExternalFileArg>& args) override;
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virtual Status VerifyChecksum() override;
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using DB::StartTrace;
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virtual Status StartTrace(
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const TraceOptions& options,
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std::unique_ptr<TraceWriter>&& trace_writer) override;
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using DB::EndTrace;
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virtual Status EndTrace() override;
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Status TraceIteratorSeek(const uint32_t& cf_id, const Slice& key);
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Status TraceIteratorSeekForPrev(const uint32_t& cf_id, const Slice& key);
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#endif // ROCKSDB_LITE
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@ -393,8 +435,6 @@ class DBImpl : public DB {
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// match to our in-memory records
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virtual Status CheckConsistency();
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virtual Status GetDbIdentity(std::string& identity) const override;
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// max_file_num_to_ignore allows bottom level compaction to filter out newly
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// compacted SST files. Setting max_file_num_to_ignore to kMaxUint64 will
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// disable the filtering
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@ -416,102 +456,6 @@ class DBImpl : public DB {
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return &logs_with_prep_tracker_;
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}
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#ifndef NDEBUG
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// Extra methods (for testing) that are not in the public DB interface
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// Implemented in db_impl_debug.cc
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// Compact any files in the named level that overlap [*begin, *end]
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Status TEST_CompactRange(int level, const Slice* begin, const Slice* end,
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ColumnFamilyHandle* column_family = nullptr,
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bool disallow_trivial_move = false);
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void TEST_SwitchWAL();
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bool TEST_UnableToReleaseOldestLog() { return unable_to_release_oldest_log_; }
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bool TEST_IsLogGettingFlushed() {
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return alive_log_files_.begin()->getting_flushed;
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}
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Status TEST_SwitchMemtable(ColumnFamilyData* cfd = nullptr);
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// Force current memtable contents to be flushed.
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Status TEST_FlushMemTable(bool wait = true, bool allow_write_stall = false,
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ColumnFamilyHandle* cfh = nullptr);
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// Wait for memtable compaction
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Status TEST_WaitForFlushMemTable(ColumnFamilyHandle* column_family = nullptr);
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// Wait for any compaction
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// We add a bool parameter to wait for unscheduledCompactions_ == 0, but this
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// is only for the special test of CancelledCompactions
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Status TEST_WaitForCompact(bool waitUnscheduled = false);
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// Return the maximum overlapping data (in bytes) at next level for any
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// file at a level >= 1.
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int64_t TEST_MaxNextLevelOverlappingBytes(
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ColumnFamilyHandle* column_family = nullptr);
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// Return the current manifest file no.
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uint64_t TEST_Current_Manifest_FileNo();
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// Returns the number that'll be assigned to the next file that's created.
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uint64_t TEST_Current_Next_FileNo();
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// get total level0 file size. Only for testing.
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uint64_t TEST_GetLevel0TotalSize();
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void TEST_GetFilesMetaData(ColumnFamilyHandle* column_family,
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std::vector<std::vector<FileMetaData>>* metadata);
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void TEST_LockMutex();
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void TEST_UnlockMutex();
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// REQUIRES: mutex locked
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void* TEST_BeginWrite();
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// REQUIRES: mutex locked
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// pass the pointer that you got from TEST_BeginWrite()
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void TEST_EndWrite(void* w);
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uint64_t TEST_MaxTotalInMemoryState() const {
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return max_total_in_memory_state_;
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}
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size_t TEST_LogsToFreeSize();
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uint64_t TEST_LogfileNumber();
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uint64_t TEST_total_log_size() const { return total_log_size_; }
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// Returns column family name to ImmutableCFOptions map.
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Status TEST_GetAllImmutableCFOptions(
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std::unordered_map<std::string, const ImmutableCFOptions*>* iopts_map);
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// Return the lastest MutableCFOptions of a column family
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Status TEST_GetLatestMutableCFOptions(ColumnFamilyHandle* column_family,
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MutableCFOptions* mutable_cf_options);
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Cache* TEST_table_cache() { return table_cache_.get(); }
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WriteController& TEST_write_controler() { return write_controller_; }
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uint64_t TEST_FindMinLogContainingOutstandingPrep();
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uint64_t TEST_FindMinPrepLogReferencedByMemTable();
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size_t TEST_PreparedSectionCompletedSize();
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size_t TEST_LogsWithPrepSize();
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int TEST_BGCompactionsAllowed() const;
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int TEST_BGFlushesAllowed() const;
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size_t TEST_GetWalPreallocateBlockSize(uint64_t write_buffer_size) const;
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void TEST_WaitForDumpStatsRun(std::function<void()> callback) const;
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void TEST_WaitForPersistStatsRun(std::function<void()> callback) const;
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bool TEST_IsPersistentStatsEnabled() const;
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size_t TEST_EstiamteStatsHistorySize() const;
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#endif // NDEBUG
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struct BGJobLimits {
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int max_flushes;
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int max_compactions;
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@ -555,12 +499,15 @@ class DBImpl : public DB {
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void PurgeObsoleteFiles(JobContext& background_contet,
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bool schedule_only = false);
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// Schedule a background job to actually delete obsolete files.
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void SchedulePurge();
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ColumnFamilyHandle* DefaultColumnFamily() const override;
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const SnapshotList& snapshots() const { return snapshots_; }
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// load list of snapshots to `snap_vector` that is no newer than `max_seq`
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// in ascending order.
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// `oldest_write_conflict_snapshot` is filled with the oldest snapshot
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// which satisfies SnapshotImpl.is_write_conflict_boundary_ = true.
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void LoadSnapshots(std::vector<SequenceNumber>* snap_vector,
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SequenceNumber* oldest_write_conflict_snapshot,
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const SequenceNumber& max_seq) const {
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@ -572,6 +519,10 @@ class DBImpl : public DB {
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return immutable_db_options_;
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}
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// Cancel all background jobs, including flush, compaction, background
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// purging, stats dumping threads, etc. If `wait` = true, wait for the
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// running jobs to abort or finish before returning. Otherwise, only
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// sends the signals.
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void CancelAllBackgroundWork(bool wait);
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// Find Super version and reference it. Based on options, it might return
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@ -748,6 +699,8 @@ class DBImpl : public DB {
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InstrumentedMutex* mutex() const { return &mutex_; }
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// Initialize a brand new DB. The DB directory is expected to be empty before
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// calling it.
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Status NewDB();
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// This is to be used only by internal rocksdb classes.
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@ -756,21 +709,109 @@ class DBImpl : public DB {
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std::vector<ColumnFamilyHandle*>* handles, DB** dbptr,
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const bool seq_per_batch, const bool batch_per_txn);
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virtual Status Close() override;
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static Status CreateAndNewDirectory(Env* env, const std::string& dirname,
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std::unique_ptr<Directory>* directory);
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Status GetStatsHistory(
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uint64_t start_time, uint64_t end_time,
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std::unique_ptr<StatsHistoryIterator>* stats_iterator) override;
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// find stats map from stats_history_ with smallest timestamp in
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// the range of [start_time, end_time)
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bool FindStatsByTime(uint64_t start_time, uint64_t end_time,
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uint64_t* new_time,
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std::map<std::string, uint64_t>* stats_map);
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#ifndef NDEBUG
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// Compact any files in the named level that overlap [*begin, *end]
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Status TEST_CompactRange(int level, const Slice* begin, const Slice* end,
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ColumnFamilyHandle* column_family = nullptr,
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bool disallow_trivial_move = false);
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void TEST_SwitchWAL();
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bool TEST_UnableToReleaseOldestLog() { return unable_to_release_oldest_log_; }
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bool TEST_IsLogGettingFlushed() {
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return alive_log_files_.begin()->getting_flushed;
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}
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Status TEST_SwitchMemtable(ColumnFamilyData* cfd = nullptr);
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// Force current memtable contents to be flushed.
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Status TEST_FlushMemTable(bool wait = true, bool allow_write_stall = false,
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ColumnFamilyHandle* cfh = nullptr);
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// Wait for memtable compaction
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Status TEST_WaitForFlushMemTable(ColumnFamilyHandle* column_family = nullptr);
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// Wait for any compaction
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// We add a bool parameter to wait for unscheduledCompactions_ == 0, but this
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// is only for the special test of CancelledCompactions
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Status TEST_WaitForCompact(bool waitUnscheduled = false);
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// Return the maximum overlapping data (in bytes) at next level for any
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// file at a level >= 1.
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int64_t TEST_MaxNextLevelOverlappingBytes(
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ColumnFamilyHandle* column_family = nullptr);
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// Return the current manifest file no.
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uint64_t TEST_Current_Manifest_FileNo();
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// Returns the number that'll be assigned to the next file that's created.
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uint64_t TEST_Current_Next_FileNo();
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// get total level0 file size. Only for testing.
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uint64_t TEST_GetLevel0TotalSize();
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void TEST_GetFilesMetaData(ColumnFamilyHandle* column_family,
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std::vector<std::vector<FileMetaData>>* metadata);
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void TEST_LockMutex();
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void TEST_UnlockMutex();
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// REQUIRES: mutex locked
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void* TEST_BeginWrite();
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// REQUIRES: mutex locked
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// pass the pointer that you got from TEST_BeginWrite()
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void TEST_EndWrite(void* w);
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uint64_t TEST_MaxTotalInMemoryState() const {
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return max_total_in_memory_state_;
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}
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size_t TEST_LogsToFreeSize();
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uint64_t TEST_LogfileNumber();
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uint64_t TEST_total_log_size() const { return total_log_size_; }
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// Returns column family name to ImmutableCFOptions map.
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Status TEST_GetAllImmutableCFOptions(
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std::unordered_map<std::string, const ImmutableCFOptions*>* iopts_map);
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// Return the lastest MutableCFOptions of a column family
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Status TEST_GetLatestMutableCFOptions(ColumnFamilyHandle* column_family,
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MutableCFOptions* mutable_cf_options);
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Cache* TEST_table_cache() { return table_cache_.get(); }
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WriteController& TEST_write_controler() { return write_controller_; }
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uint64_t TEST_FindMinLogContainingOutstandingPrep();
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uint64_t TEST_FindMinPrepLogReferencedByMemTable();
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size_t TEST_PreparedSectionCompletedSize();
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size_t TEST_LogsWithPrepSize();
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int TEST_BGCompactionsAllowed() const;
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int TEST_BGFlushesAllowed() const;
|
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size_t TEST_GetWalPreallocateBlockSize(uint64_t write_buffer_size) const;
|
||||
void TEST_WaitForDumpStatsRun(std::function<void()> callback) const;
|
||||
void TEST_WaitForPersistStatsRun(std::function<void()> callback) const;
|
||||
bool TEST_IsPersistentStatsEnabled() const;
|
||||
size_t TEST_EstiamteStatsHistorySize() const;
|
||||
|
||||
#endif // NDEBUG
|
||||
|
||||
protected:
|
||||
Env* const env_;
|
||||
const std::string dbname_;
|
||||
|
|
@ -1700,16 +1741,6 @@ class DBImpl : public DB {
|
|||
ColumnFamilyData* cfd, SuperVersionContext* sv_context,
|
||||
const MutableCFOptions& mutable_cf_options);
|
||||
|
||||
#ifndef ROCKSDB_LITE
|
||||
using DB::GetPropertiesOfAllTables;
|
||||
virtual Status GetPropertiesOfAllTables(
|
||||
ColumnFamilyHandle* column_family,
|
||||
TablePropertiesCollection* props) override;
|
||||
virtual Status GetPropertiesOfTablesInRange(
|
||||
ColumnFamilyHandle* column_family, const Range* range, std::size_t n,
|
||||
TablePropertiesCollection* props) override;
|
||||
|
||||
#endif // ROCKSDB_LITE
|
||||
|
||||
bool GetIntPropertyInternal(ColumnFamilyData* cfd,
|
||||
const DBPropertyInfo& property_info,
|
||||
|
|
|
|||
Loading…
Reference in New Issue