tkrzw::MemIndex Class Reference

On-memory secondary index implementation with BabyDBM. More...

#include <tkrzw_index.h>

Classes
class	Iterator
	Iterator for each record. More...

Public Member Functions
	MemIndex (KeyComparator key_comparator=PairLexicalKeyComparator)
	Constructor. More...
	MemIndex (const MemIndex &rhs)=delete
	Copy and assignment are disabled. More...
MemIndex &	operator= (const MemIndex &rhs)=delete
bool	Check (std::string_view key, std::string_view value)
	Checks whether a record exists in the index. More...
std::vector< std::string >	GetValues (std::string_view key, size_t max=0)
	Gets all values of records of a key. More...
void	Add (std::string_view key, std::string_view value)
	Adds a record. More...
void	Remove (std::string_view key, std::string_view value)
	Removes a record. More...
size_t	Count ()
	Gets the number of records. More...
void	Clear ()
	Removes all records. More...
std::unique_ptr< Iterator >	MakeIterator ()
	Makes an iterator for each record. More...

Detailed Description

On-memory secondary index implementation with BabyDBM.

All operations are thread-safe; Multiple threads can access the same index concurrently.

Constructor & Destructor Documentation

MemIndex() [1/2]

tkrzw::MemIndex::MemIndex ( KeyComparator  key_comparator = PairLexicalKeyComparator )

explicit

Constructor.

Parameters

key_comparator

The comparator of record keys.

Compatible key comparators are PairLexicalKeyComparator, PairLexicalCaseKeyComparator, PairDecimalKeyComparator, PairHexadecimalKeyComparator, PairRealNumberKeyComparator, and PairFloatBigEndianKeyComparator.

MemIndex() [2/2]

tkrzw::MemIndex::MemIndex ( const MemIndex &  rhs )

explicitdelete

Copy and assignment are disabled.

Member Function Documentation

Check()

bool tkrzw::MemIndex::Check	(	std::string_view	key,
		std::string_view	value
	)

Checks whether a record exists in the index.

Parameters

key	The key of the record.
value	The value of the record.

GetValues()

std::vector< std::string > tkrzw::MemIndex::GetValues	(	std::string_view	key,
		size_t	max = 0
	)

Gets all values of records of a key.

Parameters

key	The key to look for.
max	The maximum number of values to get. 0 means unlimited.

Returns

All values of the key.

Add()

void tkrzw::MemIndex::Add	(	std::string_view	key,
		std::string_view	value
	)

Adds a record.

Parameters

key	The key of the record. This can be an arbitrary expression to search the index.
value	The value of the record. This should be a primary value of another database.

Remove()

void tkrzw::MemIndex::Remove	(	std::string_view	key,
		std::string_view	value
	)

Removes a record.

Parameters

key	The key of the record.
value	The value of the record.

Count()

size_t tkrzw::MemIndex::Count

(

)

Gets the number of records.

Returns

The number of records.

Clear()

void tkrzw::MemIndex::Clear

(

)

Removes all records.

MakeIterator()

std::unique_ptr< MemIndex::Iterator > tkrzw::MemIndex::MakeIterator

(

)

Makes an iterator for each record.

Returns

The iterator for each record.