backend.c File Reference

Everything related to a backend. More...

#include <kdbassert.h>
#include <kdbinternal.h>

Include dependency graph for backend.c:

Functions
int	elektraBackendSetMountpoint (Backend *backend, KeySet *elektraConfig, Key *errorKey)
	sets mountpoint More...
Backend *	backendOpen (KeySet *elektraConfig, KeySet *modules, KeySet *global, Key *errorKey)
	Builds a backend out of the configuration supplied from: More...
Backend *	backendOpenDefault (KeySet *modules, KeySet *global, const char *file, Key *errorKey)
	Opens a default backend using the plugin named KDB_RESOLVER and KDB_STORAGE. More...
Backend *	backendOpenModules (KeySet *modules, KeySet *global, Key *errorKey)
Backend *	backendOpenVersion (KeySet *global, Key *errorKey)
	Opens the internal version backend. More...
int	backendUpdateSize (Backend *backend, Key *parent, int size)
	Update internal size in backend. More...

Detailed Description

Everything related to a backend.

Copyright

BSD License (see LICENSE.md or https://www.libelektra.org)

Function Documentation

backendOpen()

Backend* backendOpen	(	KeySet *	elektraConfig,
		KeySet *	modules,
		KeySet *	global,
		Key *	errorKey
	)

Builds a backend out of the configuration supplied from:

system/elektra/mountpoints/<name>

The root key must be like the above example. You do not need to rewind the keyset. But every key must be below the root key.

The internal consistency will be checked in this function. If necessary parts are missing, like no plugins, they cant be loaded or similar 0 will be returned.

ksCut() is perfectly suitable for cutting out the configuration like needed.

Note

The given KeySet will be deleted within the function, don't use it afterwards.

Parameters

elektraConfig	the configuration to work with. It is used to build up this backend.
modules	used to load new modules or get references to existing one
global	the global keyset of the KDB instance
errorKey	the key where an error and warnings are added

Returns

a pointer to a freshly allocated backend this could be the requested backend or a so called "missing backend".

Return values

0	if out of memory

backendOpenDefault()

Backend* backendOpenDefault	(	KeySet *	modules,
		KeySet *	global,
		const char *	file,
		Key *	errorKey
	)

Opens a default backend using the plugin named KDB_RESOLVER and KDB_STORAGE.

Parameters

modules	the modules to work with
global	the global keyset of the KDB instance
errorKey	the key to issue warnings and errors to

Returns

the fresh allocated default backend or 0 if it failed

backendOpenModules()

Backend* backendOpenModules	(	KeySet *	modules,
		KeySet *	global,
		Key *	errorKey
	)

Returns

a backend which gives plugin configuration of the module which is currently point to.

Parameters

modules	the modules to work with
global	the global keyset of the KDB instance
errorKey	the key to issue warnings and errors to

backendOpenVersion()

Backend* backendOpenVersion	(	KeySet *	global,
		Key *	errorKey
	)

Opens the internal version backend.

Parameters

global	the global keyset of the KDB instance
errorKey	the key to issue warnings and errors to

Returns

the fresh allocated default backend or 0 if it failed

backendUpdateSize()

int backendUpdateSize	(	Backend *	backend,
		Key *	parent,
		int	size
	)

Update internal size in backend.

Parameters

backend	the backend to update
parent	for parent
size	to update (-1 default, 0 empty, >0 otherwise)

Precondition

parent must be serializable namespace

Return values

-1	if invalid parent (assert)
0	on success

elektraBackendSetMountpoint()

int elektraBackendSetMountpoint	(	Backend *	backend,
		KeySet *	elektraConfig,
		Key *	errorKey
	)

sets mountpoint

Parameters

	backend	where the mountpoint should be set
	elektraConfig	the config where the mountpoint can be found
[out]	errorKey	the name also has the mountpoint set

Precondition

ksCurrent() is root key

Postcondition

ksCurrent() is root key

Return values

-1	if no mountpoint is found or memory allocation problem
0	on success