Transactions

Functions dealing with transactions. More...

Functions
void	_transaction_writing (s4_transaction_t *trans)
s4_lock_t *	_transaction_get_waiting_for (s4_transaction_t *trans)
void	_transaction_set_waiting_for (s4_transaction_t *trans, s4_lock_t *waiting_for)
GList *	_transaction_get_locks (s4_transaction_t *trans)
void	_transaction_add_lock (s4_transaction_t *trans, s4_lock_t *lock)
void	_transaction_set_deadlocked (s4_transaction_t *trans)
s4_transaction_t *	_transaction_dummy_alloc (s4_t *s4)
void	_transaction_dummy_free (s4_transaction_t *trans)
int	_transaction_get_flags (s4_transaction_t *trans)
s4_transaction_t *	s4_begin (s4_t *s4, int flags)
	Starts a new transaction. More...
int	s4_commit (s4_transaction_t *trans)
	Commits a transaction. More...
int	s4_abort (s4_transaction_t *trans)
	Aborts a transaction. More...
s4_t *	_transaction_get_db (s4_transaction_t *trans)
int	s4_add (s4_transaction_t *trans, const char *key_a, const s4_val_t *val_a, const char *key_b, const s4_val_t *val_b, const char *src)
	Adds a relationship to the database. More...
int	s4_del (s4_transaction_t *trans, const char *key_a, const s4_val_t *val_a, const char *key_b, const s4_val_t *val_b, const char *src)
	Deletes a relationship from the database. More...
s4_resultset_t *	s4_query (s4_transaction_t *trans, s4_fetchspec_t *spec, s4_condition_t *cond)
	Queries an S4 database. More...

Detailed Description

Functions dealing with transactions.

Function Documentation

void _transaction_add_lock	(	s4_transaction_t *	trans,
		s4_lock_t *	lock
	)

Referenced by _lock_exclusive(), and _lock_shared().

s4_transaction_t* _transaction_dummy_alloc

(

s4_t *

s4

)

void _transaction_dummy_free

(

s4_transaction_t *

trans

)

s4_t* _transaction_get_db

(

s4_transaction_t *

trans

)

Referenced by _oplist_get_db(), _s4_add(), _s4_del(), _s4_query(), s4_add(), s4_commit(), and s4_del().

int _transaction_get_flags

(

s4_transaction_t *

trans

)

Referenced by _lock_shared().

GList* _transaction_get_locks

(

s4_transaction_t *

trans

)

Referenced by _lock_unlock_all().

s4_lock_t* _transaction_get_waiting_for

(

s4_transaction_t *

trans

)

void _transaction_set_deadlocked

(

s4_transaction_t *

trans

)

Referenced by _s4_add(), _s4_del(), and _s4_query().

void _transaction_set_waiting_for	(	s4_transaction_t *	trans,
		s4_lock_t *	waiting_for
	)

Referenced by _lock_exclusive(), and _lock_shared().

void _transaction_writing

(

s4_transaction_t *

trans

)

int s4_abort

(

s4_transaction_t *

trans

)

Aborts a transaction.

The database will behave like the transaction never happened.

Parameters

trans

The transaction

Returns

0 on error, non-zero on success.

Referenced by CASE(), and xmms_medialib_session_abort().

int s4_add	(	s4_transaction_t *	trans,
		const char *	key_a,
		const s4_val_t *	val_a,
		const char *	key_b,
		const s4_val_t *	val_b,
		const char *	src
	)

Adds a relationship to the database.

It takes both a database handle and a transaction handle, but only one if used. If the transaction handle is NULL it will create a local transaction, otherwise it will use the transaction passed, and thus s4 is not needed.

Parameters

s4	The database to add to.
trans	The transaction to use.
key_a	Key A.
val_a	Value A.
key_b	Key B.
val_b	Value B.
src	Source.

Returns

0 on error, non-zero on success.

Referenced by CASE(), main(), and xmms_medialib_session_property_set().

s4_transaction_t* s4_begin	(	s4_t *	s4,
		int	flags
	)

Starts a new transaction.

Parameters

s4	The database to run the transaction on.
flags	Flags specifying what kind of transaction this should be.

Returns

A new transaction that can be used when calling s4_add, s4_del and s4_query.

Referenced by CASE(), and main().

int s4_commit

(

s4_transaction_t *

trans

)

Commits a transaction.

On success the operations in the transactions will be applied in one atomic step, on error none of the operations in the transaction will be applied.

Parameters

trans

The transaction to commit.

Returns

0 on error (and sets s4_errno), non-zero on success.

Referenced by CASE(), main(), and xmms_medialib_session_commit().

int s4_del	(	s4_transaction_t *	trans,
		const char *	key_a,
		const s4_val_t *	val_a,
		const char *	key_b,
		const s4_val_t *	val_b,
		const char *	src
	)

Deletes a relationship from the database.

It takes both a database handle and a transaction handle, but only one if used. If the transaction handle is NULL it will create a local transaction, otherwise it will use the transaction passed, and thus s4 is not needed.

Parameters

s4	The database to delete from.
trans	The transaction to use.
key_a	Key A.
val_a	Value A.
key_b	Key B.
val_b	Value B.
src	Source.

Returns

0 on error, non-zero on success.

Referenced by CASE(), main(), xmms_medialib_session_property_set(), and xmms_medialib_session_property_unset().

s4_resultset_t* s4_query	(	s4_transaction_t *	trans,
		s4_fetchspec_t *	spec,
		s4_condition_t *	cond
	)

Queries an S4 database.

Parameters

s4	The database to query. If s4 is NULL trans must be non-null.
trans	The transaction to use. If trans is NULL s4 must be non-null.
spec	The fetchspecification to use when querying.
cond	The condition to use when querying.

Returns

A resultset containing the fetched data.

Referenced by CASE(), xmms_medialib_session_property_set(), and xmms_medialib_session_query().