tkrzw::BabyDBM::Iterator Class Reference

Iterator for each record. More...

#include <tkrzw_dbm_baby.h>

Public Member Functions
	~Iterator ()
	Destructor. More...
	Iterator (const Iterator &rhs)=delete
	Copy and assignment are disabled. More...
Iterator &	operator= (const Iterator &rhs)=delete
Status	First () override
	Initializes the iterator to indicate the first record. More...
Status	Last () override
	Initializes the iterator to indicate the last record. More...
Status	Jump (std::string_view key) override
	Initializes the iterator to indicate a specific record. More...
Status	JumpLower (std::string_view key, bool inclusive=false) override
	Initializes the iterator to indicate the last record whose key is lower than a given key. More...
Status	JumpUpper (std::string_view key, bool inclusive=false) override
	Initializes the iterator to indicate the first record whose key is upper than a given key. More...
Status	Next () override
	Moves the iterator to the next record. More...
Status	Previous () override
	Moves the iterator to the previous record. More...
Status	Process (RecordProcessor *proc, bool writable) override
	Processes the current record with a processor. More...
Public Member Functions inherited from tkrzw::DBM::Iterator
virtual Status	Process (RecordLambdaType rec_lambda, bool writable)
	Processes the current record with a lambda function. More...
virtual Status	Get (std::string *key=nullptr, std::string *value=nullptr)
	Gets the key and the value of the current record of the iterator. More...
virtual std::string	GetKey (std::string_view default_value="")
	Gets the key of the current record, in a simple way. More...
virtual std::string	GetValue (std::string_view default_value="")
	Gets the value of the current record, in a simple way. More...
virtual Status	Set (std::string_view value, std::string *old_key=nullptr, std::string *old_value=nullptr)
	Sets the value of the current record. More...
virtual Status	Remove (std::string *old_key=nullptr, std::string *old_value=nullptr)
	Removes the current record. More...
virtual Status	Step (std::string *key=nullptr, std::string *value=nullptr)
	Gets the current record and moves the iterator to the next record. More...

Friends
class	BabyDBM

Detailed Description

Iterator for each record.

When the database is updated, some iterators may or may not be invalided. Operations with invalidated iterators fails gracefully with NOT_FOUND_ERROR. One iterator cannot be shared by multiple threads.

Constructor & Destructor Documentation

~Iterator()

tkrzw::BabyDBM::Iterator::~Iterator ( )

virtual

Destructor.

Reimplemented from tkrzw::DBM::Iterator.

Iterator()

tkrzw::BabyDBM::Iterator::Iterator ( const Iterator &  rhs )

explicitdelete

Copy and assignment are disabled.

Member Function Documentation

First()

Status tkrzw::BabyDBM::Iterator::First ( )

overridevirtual

Initializes the iterator to indicate the first record.

Returns

The result status.

Even if there's no record, the operation doesn't fail.

Implements tkrzw::DBM::Iterator.

Last()

Status tkrzw::BabyDBM::Iterator::Last ( )

overridevirtual

Initializes the iterator to indicate the last record.

Returns

The result status.

Even if there's no record, the operation doesn't fail.

Implements tkrzw::DBM::Iterator.

Jump()

Status tkrzw::BabyDBM::Iterator::Jump ( std::string_view  key )

overridevirtual

Initializes the iterator to indicate a specific record.

Parameters

key	The key of the record to look for.

Returns

The result status.

This database is ordered so it supports "lower bound" jump. If there's no record with the same key, the iterator refers to the first record whose key is greater than the given key.

Implements tkrzw::DBM::Iterator.

JumpLower()

Status tkrzw::BabyDBM::Iterator::JumpLower ( std::string_view  key, bool  inclusive = false  )

overridevirtual

Initializes the iterator to indicate the last record whose key is lower than a given key.

Parameters

key	The key to compare with.
inclusive	If true, the considtion is inclusive: equal to or lower than the key.

Returns

The result status.

Precondition: The database is opened.

Even if there's no matching record, the operation doesn't fail.

Implements tkrzw::DBM::Iterator.

JumpUpper()

Status tkrzw::BabyDBM::Iterator::JumpUpper ( std::string_view  key, bool  inclusive = false  )

overridevirtual

Initializes the iterator to indicate the first record whose key is upper than a given key.

Parameters

key	The key to compare with.
inclusive	If true, the considtion is inclusive: equal to or upper than the key.

Returns

The result status.

Precondition: The database is opened.

Even if there's no matching record, the operation doesn't fail. If the inclusive parameter is true, this method is the same as Jump(key).

Implements tkrzw::DBM::Iterator.

Next()

Status tkrzw::BabyDBM::Iterator::Next ( )

overridevirtual

Moves the iterator to the next record.

Returns

The result status.

If the current record is missing, the operation fails. Even if there's no next record, the operation doesn't fail.

Implements tkrzw::DBM::Iterator.

Previous()

Status tkrzw::BabyDBM::Iterator::Previous ( )

overridevirtual

Moves the iterator to the previous record.

Returns

The result status.

If the current record is missing, the operation fails. Even if there's no previous previous record, the operation doesn't fail.

Implements tkrzw::DBM::Iterator.

Process()

Status tkrzw::BabyDBM::Iterator::Process ( RecordProcessor *  proc, bool  writable  )

overridevirtual

Processes the current record with a processor.

Parameters

proc	The pointer to the processor object.
writable	True if the processor can edit the record.

Returns

The result status.

If the current record exists, the ProcessFull of the processor is called. Otherwise, this method fails and no method of the processor is called. If the current record is removed, the iterator is moved to the next record.

Implements tkrzw::DBM::Iterator.