kyototycoon::TimedDB::Cursor Class Reference

Cursor to indicate a record. More...

#include <kttimeddb.h>

List of all members.

Public Member Functions
	Cursor (TimedDB *db)
	Constructor.
virtual	~Cursor ()
	Destructor.
bool	jump ()
	Jump the cursor to the first record for forward scan.
bool	jump (const char *kbuf, size_t ksiz)
	Jump the cursor to a record for forward scan.
bool	jump (const std::string &key)
	Jump the cursor to a record for forward scan.
bool	jump_back ()
	Jump the cursor to the last record for backward scan.
bool	jump_back (const char *kbuf, size_t ksiz)
	Jump the cursor to a record for backward scan.
bool	jump_back (const std::string &key)
	Jump the cursor to a record for backward scan.
bool	step ()
	Step the cursor to the next record.
bool	step_back ()
	Step the cursor to the previous record.
bool	accept (Visitor *visitor, bool writable=true, bool step=false)
	Accept a visitor to the current record.
bool	set_value (const char *vbuf, size_t vsiz, int64_t xt=kc::INT64MAX, bool step=false)
	Set the value of the current record.
bool	set_value_str (const std::string &value, int64_t xt=kc::INT64MAX, bool step=false)
	Set the value of the current record.
bool	remove ()
	Remove the current record.
char *	get_key (size_t *sp, bool step=false)
	Get the key of the current record.
bool	get_key (std::string *key, bool step=false)
	Get the key of the current record.
char *	get_value (size_t *sp, bool step=false)
	Get the value of the current record.
bool	get_value (std::string *value, bool step=false)
	Get the value of the current record.
char *	get (size_t *ksp, const char **vbp, size_t *vsp, int64_t *xtp=NULL, bool step=false)
	Get a pair of the key and the value of the current record.
bool	get (std::string *key, std::string *value, int64_t *xtp=NULL, bool step=false)
	Get a pair of the key and the value of the current record.
char *	seize (size_t *ksp, const char **vbp, size_t *vsp, int64_t *xtp=NULL)
	Get a pair of the key and the value of the current record and remove it atomically.
bool	seize (std::string *key, std::string *value, int64_t *xtp=NULL)
	Get a pair of the key and the value of the current record and remove it atomically.
TimedDB *	db ()
	Get the database object.
kc::BasicDB::Error	error ()
	Get the last happened error.
Friends
class	TimedDB

---

Detailed Description

Cursor to indicate a record.

---

Constructor & Destructor Documentation

kyototycoon::TimedDB::Cursor::Cursor

(

TimedDB *

db

)

[explicit]

Constructor.

Parameters:

db	the container database object.

virtual kyototycoon::TimedDB::Cursor::~Cursor

(

)

[virtual]

Destructor.

---

Member Function Documentation

bool kyototycoon::TimedDB::Cursor::jump

(

)

Jump the cursor to the first record for forward scan.

Returns:

true on success, or false on failure.

bool kyototycoon::TimedDB::Cursor::jump	(	const char *	kbuf,
		size_t	ksiz
	)

Jump the cursor to a record for forward scan.

Parameters:

kbuf	the pointer to the key region.
ksiz	the size of the key region.

Returns:

true on success, or false on failure.

bool kyototycoon::TimedDB::Cursor::jump

(

const std::string &

key

)

Jump the cursor to a record for forward scan.

Note:

Equal to the original Cursor::jump method except that the parameter is std::string.

bool kyototycoon::TimedDB::Cursor::jump_back

(

)

Jump the cursor to the last record for backward scan.

Returns:

true on success, or false on failure.

Note:

This method is dedicated to tree databases. Some database types, especially hash databases, may provide a dummy implementation.

bool kyototycoon::TimedDB::Cursor::jump_back	(	const char *	kbuf,
		size_t	ksiz
	)

Jump the cursor to a record for backward scan.

Parameters:

kbuf	the pointer to the key region.
ksiz	the size of the key region.

Returns:

true on success, or false on failure.

Note:

This method is dedicated to tree databases. Some database types, especially hash databases, will provide a dummy implementation.

bool kyototycoon::TimedDB::Cursor::jump_back

(

const std::string &

key

)

Jump the cursor to a record for backward scan.

Note:

Equal to the original Cursor::jump_back method except that the parameter is std::string.

bool kyototycoon::TimedDB::Cursor::step

(

)

Step the cursor to the next record.

Returns:

true on success, or false on failure.

bool kyototycoon::TimedDB::Cursor::step_back

(

)

Step the cursor to the previous record.

Returns:

true on success, or false on failure.

Note:

This method is dedicated to tree databases. Some database types, especially hash databases, may provide a dummy implementation.

bool kyototycoon::TimedDB::Cursor::accept	(	Visitor *	visitor,
		bool	writable = true,
		bool	step = false
	)

Accept a visitor to the current record.

Parameters:

visitor	a visitor object.
writable	true for writable operation, or false for read-only operation.
step	true to move the cursor to the next record, or false for no move.

Returns:

true on success, or false on failure.

Note:

the operation for each record is performed atomically and other threads accessing the same record are blocked.

bool kyototycoon::TimedDB::Cursor::set_value	(	const char *	vbuf,
		size_t	vsiz,
		int64_t	xt = kc::INT64MAX,
		bool	step = false
	)

Set the value of the current record.

Parameters:

vbuf	the pointer to the value region.
vsiz	the size of the value region.
xt	the expiration time from now in seconds. If it is negative, the absolute value is treated as the epoch time.
step	true to move the cursor to the next record, or false for no move.

Returns:

true on success, or false on failure.

bool kyototycoon::TimedDB::Cursor::set_value_str	(	const std::string &	value,
		int64_t	xt = kc::INT64MAX,
		bool	step = false
	)

Set the value of the current record.

Note:

Equal to the original Cursor::set_value method except that the parameter is std::string.

bool kyototycoon::TimedDB::Cursor::remove

(

)

Remove the current record.

Returns:

true on success, or false on failure.

Note:

If no record corresponds to the key, false is returned. The cursor is moved to the next record implicitly.

char* kyototycoon::TimedDB::Cursor::get_key	(	size_t *	sp,
		bool	step = false
	)

Get the key of the current record.

Parameters:

sp	the pointer to the variable into which the size of the region of the return value is assigned.
step	true to move the cursor to the next record, or false for no move.

Returns:

the pointer to the key region of the current record, or NULL on failure.

Note:

If the cursor is invalidated, NULL is returned. Because an additional zero code is appended at the end of the region of the return value, the return value can be treated as a C-style string. Because the region of the return value is allocated with the the new[] operator, it should be released with the delete[] operator when it is no longer in use.

bool kyototycoon::TimedDB::Cursor::get_key	(	std::string *	key,
		bool	step = false
	)

Get the key of the current record.

Note:

Equal to the original Cursor::get_key method except that a parameter is a string to contain the result and the return value is bool for success.

char* kyototycoon::TimedDB::Cursor::get_value	(	size_t *	sp,
		bool	step = false
	)

Get the value of the current record.

Parameters:

sp	the pointer to the variable into which the size of the region of the return value is assigned.
step	true to move the cursor to the next record, or false for no move.

Returns:

the pointer to the value region of the current record, or NULL on failure.

Note:

If the cursor is invalidated, NULL is returned. Because an additional zero code is appended at the end of the region of the return value, the return value can be treated as a C-style string. Because the region of the return value is allocated with the the new[] operator, it should be released with the delete[] operator when it is no longer in use.

bool kyototycoon::TimedDB::Cursor::get_value	(	std::string *	value,
		bool	step = false
	)

Get the value of the current record.

Note:

Equal to the original Cursor::get_value method except that a parameter is a string to contain the result and the return value is bool for success.

char* kyototycoon::TimedDB::Cursor::get	(	size_t *	ksp,
		const char **	vbp,
		size_t *	vsp,
		int64_t *	xtp = NULL,
		bool	step = false
	)

Get a pair of the key and the value of the current record.

Parameters:

ksp	the pointer to the variable into which the size of the region of the return value is assigned.
vbp	the pointer to the variable into which the pointer to the value region is assigned.
vsp	the pointer to the variable into which the size of the value region is assigned.
xtp	the pointer to the variable into which the absolute expiration time is assigned. If it is NULL, it is ignored.
step	true to move the cursor to the next record, or false for no move.

Returns:

the pointer to the pair of the key region, or NULL on failure.

Note:

If the cursor is invalidated, NULL is returned. Because an additional zero code is appended at the end of each region of the key and the value, each region can be treated as a C-style string. The return value should be deleted explicitly by the caller with the detele[] operator.

bool kyototycoon::TimedDB::Cursor::get	(	std::string *	key,
		std::string *	value,
		int64_t *	xtp = NULL,
		bool	step = false
	)

Get a pair of the key and the value of the current record.

Note:

Equal to the original Cursor::get method except that parameters are strings to contain the result and the return value is bool for success.

char* kyototycoon::TimedDB::Cursor::seize	(	size_t *	ksp,
		const char **	vbp,
		size_t *	vsp,
		int64_t *	xtp = NULL
	)

Get a pair of the key and the value of the current record and remove it atomically.

Parameters:

ksp	the pointer to the variable into which the size of the region of the return value is assigned.
vbp	the pointer to the variable into which the pointer to the value region is assigned.
vsp	the pointer to the variable into which the size of the value region is assigned.
xtp	the pointer to the variable into which the absolute expiration time is assigned. If it is NULL, it is ignored.

Returns:

the pointer to the pair of the key region, or NULL on failure.

Note:

If the cursor is invalidated, NULL is returned. Because an additional zero code is appended at the end of each region of the key and the value, each region can be treated as a C-style string. The return value should be deleted explicitly by the caller with the detele[] operator.

bool kyototycoon::TimedDB::Cursor::seize	(	std::string *	key,
		std::string *	value,
		int64_t *	xtp = NULL
	)

Get a pair of the key and the value of the current record and remove it atomically.

Note:

Equal to the original Cursor::seize method except that parameters are strings to contain the result and the return value is bool for success.

TimedDB* kyototycoon::TimedDB::Cursor::db

(

)

Get the database object.

Returns:

the database object.

kc::BasicDB::Error kyototycoon::TimedDB::Cursor::error

(

)

Get the last happened error.

Returns:

the last happened error.