SDBM library

Collaboration diagram for SDBM library:

Data Structures
struct	apr_sdbm_datum_t

Macros
#define	APR_SDBM_DIRFEXT   ".dir"
#define	APR_SDBM_PAGFEXT   ".pag"
#define	APR_SDBM_INSERT   0
#define	APR_SDBM_REPLACE   1
#define	APR_SDBM_INSERTDUP   2

Typedefs
typedef struct apr_sdbm_t	apr_sdbm_t

Functions
apr_status_t	apr_sdbm_open (apr_sdbm_t **db, const char *name, apr_int32_t mode, apr_fileperms_t perms, apr_pool_t *p)
apr_status_t	apr_sdbm_close (apr_sdbm_t *db)
apr_status_t	apr_sdbm_lock (apr_sdbm_t *db, int type)
apr_status_t	apr_sdbm_unlock (apr_sdbm_t *db)
apr_status_t	apr_sdbm_fetch (apr_sdbm_t *db, apr_sdbm_datum_t *value, apr_sdbm_datum_t key)
apr_status_t	apr_sdbm_store (apr_sdbm_t *db, apr_sdbm_datum_t key, apr_sdbm_datum_t value, int opt)
apr_status_t	apr_sdbm_delete (apr_sdbm_t *db, const apr_sdbm_datum_t key)
apr_status_t	apr_sdbm_firstkey (apr_sdbm_t *db, apr_sdbm_datum_t *key)
apr_status_t	apr_sdbm_nextkey (apr_sdbm_t *db, apr_sdbm_datum_t *key)
int	apr_sdbm_rdonly (apr_sdbm_t *db)

Detailed Description

Macro Definition Documentation

#define APR_SDBM_DIRFEXT   ".dir"

SDBM Directory file extension

#define APR_SDBM_INSERT   0

Insert

#define APR_SDBM_INSERTDUP   2

Insert with duplicates

#define APR_SDBM_PAGFEXT   ".pag"

SDBM page file extension

#define APR_SDBM_REPLACE   1

Replace

Typedef Documentation

typedef struct apr_sdbm_t apr_sdbm_t

Structure for referencing an sdbm

Function Documentation

apr_status_t apr_sdbm_close

(

apr_sdbm_t *

db

)

Close an sdbm file previously opened by apr_sdbm_open

Parameters

db	The database to close

apr_status_t apr_sdbm_delete	(	apr_sdbm_t *	db,
		const apr_sdbm_datum_t	key
	)

Delete an sdbm record value by key

Parameters

db	The database
key	The key datum of the record to delete

Remarks

It is not an error to delete a non-existent record.

apr_status_t apr_sdbm_fetch	(	apr_sdbm_t *	db,
		apr_sdbm_datum_t *	value,
		apr_sdbm_datum_t	key
	)

Fetch an sdbm record value by key

Parameters

db	The database
value	The value datum retrieved for this record
key	The key datum to find this record

apr_status_t apr_sdbm_firstkey	(	apr_sdbm_t *	db,
		apr_sdbm_datum_t *	key
	)

Retrieve the first record key from a dbm

Parameters

db	The database
key	The key datum of the first record

Remarks

The keys returned are not ordered. To traverse the list of keys for an sdbm opened with APR_SHARELOCK, the caller must use apr_sdbm_lock prior to retrieving the first record, and hold the lock until after the last call to apr_sdbm_nextkey.

apr_status_t apr_sdbm_lock	(	apr_sdbm_t *	db,
		int	type
	)

Lock an sdbm database for concurency of multiple operations

Parameters

db	The database to lock
type	The lock type APR_FLOCK_SHARED APR_FLOCK_EXCLUSIVE

Remarks

Calls to apr_sdbm_lock may be nested. All apr_sdbm functions perform implicit locking. Since an APR_FLOCK_SHARED lock cannot be portably promoted to an APR_FLOCK_EXCLUSIVE lock, apr_sdbm_store and apr_sdbm_delete calls will fail if an APR_FLOCK_SHARED lock is held. The apr_sdbm_lock call requires the database to be opened with the APR_SHARELOCK mode value.

apr_status_t apr_sdbm_nextkey	(	apr_sdbm_t *	db,
		apr_sdbm_datum_t *	key
	)

Retrieve the next record key from an sdbm

Parameters

db	The database
key	The key datum of the next record

apr_status_t apr_sdbm_open	(	apr_sdbm_t **	db,
		const char *	name,
		apr_int32_t	mode,
		apr_fileperms_t	perms,
		apr_pool_t *	p
	)

Open an sdbm database by file name

Parameters

db	The newly opened database
name	The sdbm file to open
mode	The flag values (APR_READ and APR_BINARY flags are implicit) APR_WRITE open for read-write access APR_CREATE create the sdbm if it does not exist APR_TRUNCATE empty the contents of the sdbm APR_EXCL fail for APR_CREATE if the file exists APR_DELONCLOSE delete the sdbm when closed APR_SHARELOCK support locking across process/machines
perms	Permissions to apply to if created
p	The pool to use when creating the sdbm

Remarks

The sdbm name is not a true file name, as sdbm appends suffixes for seperate data and index files.

int apr_sdbm_rdonly

(

apr_sdbm_t *

db

)

Returns true if the sdbm database opened for read-only access

Parameters

db	The database to test

apr_status_t apr_sdbm_store	(	apr_sdbm_t *	db,
		apr_sdbm_datum_t	key,
		apr_sdbm_datum_t	value,
		int	opt
	)

Store an sdbm record value by key

Parameters

db	The database
key	The key datum to store this record by
value	The value datum to store in this record
opt	The method used to store the record APR_SDBM_INSERT return an error if the record exists APR_SDBM_REPLACE overwrite any existing record for key

apr_status_t apr_sdbm_unlock

(

apr_sdbm_t *

db

)

Release an sdbm lock previously aquired by apr_sdbm_lock

Parameters

db	The database to unlock