类 oceanbase::ObLsmImpl 继承关系图:

Public 成员函数
	ObLsmImpl (const ObLsmOptions &options, const string &path)

RC	put (const string_view &key, const string_view &value) override
	Inserts or updates a key-value entry in the LSM-Tree. 更多...

RC	get (const string_view &key, string *value) override
	Retrieves the value associated with a specified key. 更多...

RC	remove (const string_view &key) override
	Delete a key-value entry in the LSM-Tree. 更多...

ObLsmTransaction *	begin_transaction () override

ObLsmIterator *	new_iterator (ObLsmReadOptions options) override
	Creates a new iterator for traversing the LSM-Tree database. 更多...

SSTablesPtr	get_sstables ()

RC	recover ()

RC	batch_put (const std::vector< pair< string, string > > &kvs) override

void	dump_sstables () override
	Dumps all SSTables for debugging purposes. 更多...

Public 成员函数继承自 oceanbase::ObLsm
	ObLsm (const ObLsm &)=delete

ObLsm &	operator= (const ObLsm &)=delete

virtual RC	put (const string_view &key, const string_view &value)=0
	Inserts or updates a key-value entry in the LSM-Tree. 更多...

virtual RC	get (const string_view &key, string *value)=0
	Retrieves the value associated with a specified key. 更多...

virtual RC	remove (const string_view &key)=0
	Delete a key-value entry in the LSM-Tree. 更多...

virtual ObLsmTransaction *	begin_transaction ()=0

virtual ObLsmIterator *	new_iterator (ObLsmReadOptions options)=0
	Creates a new iterator for traversing the LSM-Tree database. 更多...

virtual RC	batch_put (const vector< pair< string, string > > &kvs)=0
	Inserts a batch of key-value entries into the LSM-Tree. 更多...

virtual void	dump_sstables ()=0
	Dumps all SSTables for debugging purposes. 更多...

Private 成员函数
RC	recover_from_wal ()

RC	recover_from_manifest_records (const std::vector< ObManifestCompaction > &records)

RC	load_manifest_snapshot (const ObManifestSnapshot &snapshot)

RC	load_manifest_sstable (const std::vector< std::vector< uint64_t > > &sstables)

RC	write_manifest_snapshot ()

RC	try_freeze_memtable ()
	Attempts to freeze the current active MemTable. 更多...

vector< shared_ptr< ObSSTable > >	do_compaction (ObCompaction *compaction)
	Performs compaction on the SSTables selected by the compaction strategy. 更多...

void	try_major_compaction ()
	Initiates a major compaction process. 更多...

void	background_compaction (std::shared_ptr< ObLsmBgCompactCtx > ctx)
	Handles background compaction tasks. 更多...

void	build_sstable (shared_ptr< ObMemTable > imem)
	Builds an SSTable from the given MemTable. 更多...

string	get_sstable_path (uint64_t sstable_id)
	Retrieves the file path for a given SSTable. 更多...

string	get_wal_path (uint64_t memtable_id)
	Retrieves the file path for a given Memtable id. 更多...

Private 属性
ObLsmOptions	options_

string	path_

mutex	mu_

std::shared_ptr< WAL >	wal_

std::vector< std::shared_ptr< WAL > >	frozen_wals_

shared_ptr< ObMemTable >	mem_table_

vector< shared_ptr< ObMemTable > >	imem_tables_

SSTablesPtr	sstables_

common::ThreadPoolExecutor	executor_

ObManifest	manifest_

atomic< uint64_t >	seq_ {0}

atomic< uint64_t >	sstable_id_ {0}

atomic< uint64_t >	memtable_id_ {0}

condition_variable	cv_

const ObDefaultComparator	default_comparator_

const ObInternalKeyComparator	internal_key_comparator_

atomic< bool >	compacting_ = false

std::unique_ptr< ObLRUCache< uint64_t, shared_ptr< ObBlock > > >	block_cache_

额外继承的成员函数
静态 Public 成员函数继承自 oceanbase::ObLsm
static RC	open (const ObLsmOptions &options, const string &path, ObLsm **dbptr)
	Opens an LSM-Tree database at the specified path. 更多...

成员函数说明

◆ background_compaction()

void oceanbase::ObLsmImpl::background_compaction ( std::shared_ptr< ObLsmBgCompactCtx > ctx )

private

Handles background compaction tasks.

参数

ctx	Save the data that will be used during the compaction process.

◆ begin_transaction()

ObLsmTransaction * oceanbase::ObLsmImpl::begin_transaction ( )

overridevirtual

实现了 oceanbase::ObLsm.

◆ build_sstable()

void oceanbase::ObLsmImpl::build_sstable ( shared_ptr< ObMemTable > imem )

private

Builds an SSTable from the given MemTable.

Converts the data in an immutable MemTable (imem) into a new SSTable and writes it to persistent storage. This step is usually part of the compaction pipeline.

参数

imem	A shared pointer to the immutable MemTable (`ObMemTable`) to be converted into an SSTable.

注解: The caller must ensure that imem is immutable and ready for conversion.

◆ do_compaction()

vector< shared_ptr< ObSSTable > > oceanbase::ObLsmImpl::do_compaction ( ObCompaction * compaction )

private

Performs compaction on the SSTables selected by the compaction strategy.

This function takes a compaction plan (represented by ObCompaction) and merges the inputs into a new set of SSTables. It creates iterators for the SSTables being compacted, merges their data, and writes the merged data into new SSTable files.

参数

picked A pointer to the compaction plan that specifies the input SSTables to merge. If picked is nullptr, no compaction is performed and an empty result is returned.

返回: vector<shared_ptr<ObSSTable>> A vector of shared pointers to the newly created SSTables resulting from the compaction process.

The function retrieves the inputs (SSTables) from the picked compaction plan.
For each SSTable, it creates a new iterator to sequentially scan its data.
It merges the iterators using a merging iterator (ObLsmIterator).
It writes the merged key-value pairs into new SSTable files using ObSSTableBuilder.
If the size of the new SSTable exceeds a predefined size (options_.table_size), the builder finalizes the current SSTable and starts a new one.

警告: Ensure that the picked object is properly populated with valid inputs.

◆ dump_sstables()

void oceanbase::ObLsmImpl::dump_sstables ( )

overridevirtual

Dumps all SSTables for debugging purposes.

This method outputs the structure and contents of all SSTables in the LSM-Tree for debugging or inspection purposes.

实现了 oceanbase::ObLsm.

◆ get()

RC oceanbase::ObLsmImpl::get	(	const string_view &	key,
		string *	value
	)

overridevirtual

Retrieves the value associated with a specified key.

This method looks up the value corresponding to the given key in the LSM-Tree. If the key exists, the value is stored in the output parameter *value.

参数

key	The key to look up.
value	Pointer to a string where the retrieved value will be stored.

返回: An RC value indicating success or failure of the operation.

实现了 oceanbase::ObLsm.

◆ get_sstable_path()

string oceanbase::ObLsmImpl::get_sstable_path ( uint64_t sstable_id )

private

Retrieves the file path for a given SSTable.

参数

sstable_id The unique identifier of the SSTable whose path needs to be retrieved.

返回: A string representing the full file path of the SSTable.

◆ get_wal_path()

string oceanbase::ObLsmImpl::get_wal_path ( uint64_t memtable_id )

private

Retrieves the file path for a given Memtable id.

参数

memtable_id The unique identifier of the memtable whose path needs to be retrieved.

返回: A string representing the full file path of the wal.

◆ new_iterator()

ObLsmIterator * oceanbase::ObLsmImpl::new_iterator ( ObLsmReadOptions options )

overridevirtual

Creates a new iterator for traversing the LSM-Tree database.

This method returns a heap-allocated iterator over the contents of the database. The iterator is initially invalid, and the caller must use one of the seek/seek_to_first/seek_to_last methods on the iterator before accessing any elements.

参数

options Read options to configure the behavior of the iterator.

返回: A pointer to the newly created iterator.

注解: The caller is responsible for deleting the iterator when it is no longer needed.

实现了 oceanbase::ObLsm.

◆ put()

RC oceanbase::ObLsmImpl::put	(	const string_view &	key,
		const string_view &	value
	)

overridevirtual

Inserts or updates a key-value entry in the LSM-Tree.

This method adds a new entry

参数

key	The key to insert or update.
value	The value associated with the key.

返回: An RC value indicating success or failure of the operation.

实现了 oceanbase::ObLsm.

◆ remove()

RC oceanbase::ObLsmImpl::remove ( const string_view & key )

overridevirtual

Delete a key-value entry in the LSM-Tree.

This method remove a entry

参数

key	The key to remove.

返回: An RC value indicating success or failure of the operation.

实现了 oceanbase::ObLsm.

◆ try_freeze_memtable()

RC oceanbase::ObLsmImpl::try_freeze_memtable ( )

private

Attempts to freeze the current active MemTable.

This method performs operations to freeze the active MemTable when certain conditions are met, such as size thresholds or timing requirements. A frozen MemTable becomes immutable and is ready for compaction.

返回: RC Status code indicating the success or failure of the freeze operation.

◆ try_major_compaction()

void oceanbase::ObLsmImpl::try_major_compaction ( )

private

Initiates a major compaction process.

Major compaction involves merging all levels of SSTables into a single, consolidated SSTable, which reduces storage fragmentation and improves read performance. This process typically runs periodically or when triggered by specific conditions.

注解: This function should be called with care, as major compaction is a resource-intensive operation and may affect system performance during execution.

该类的文档由以下文件生成:

src/oblsm/ob_lsm_impl.h
src/oblsm/ob_lsm_impl.cpp

Public 成员函数

Private 成员函数

Private 属性

额外继承的成员函数

成员函数说明

◆ background_compaction()

◆ begin_transaction()

◆ build_sstable()

◆ do_compaction()

◆ dump_sstables()

◆ get()

◆ get_sstable_path()

◆ get_wal_path()

◆ new_iterator()

◆ put()

◆ remove()

◆ try_freeze_memtable()

◆ try_major_compaction()