Split :: Represents splitted keysets

used internally for kdbSet() More...

Functions
Split *	elektraSplitNew (void)
void	elektraSplitDel (Split *keysets)
void	elektraSplitResize (Split *split)
ssize_t	elektraSplitAppend (Split *split, Backend *backend, Key *parentKey, int syncbits)
ssize_t	elektraSplitSearchBackend (Split *split, Backend *backend, Key *parent)
int	elektraSplitSearchRoot (Split *split, Key *parentKey)
int	elektraSplitBuildup (Split *split, KDB *kdb, Key *parentKey)
int	elektraSplitDivide (Split *split, KDB *handle, KeySet *ks)
int	elektraSplitAppoint (Split *split, KDB *handle, KeySet *ks)
int	elektraSplitGet (Split *split, KDB *handle)
int	elektraSplitMerge (Split *split, KeySet *dest)
int	elektraSplitSync (Split *split)
int	elektraSplitPrepare (Split *split)

---

Detailed Description

used internally for kdbSet()

Splits up a keyset into multiple keysets where each of them will passed to the correct kdbSet().

---

Function Documentation

ssize_t elektraSplitAppend	(	Split *	split,
		Backend *	backend,
		Key *	parentKey,
		int	syncbits
	)

Increases the size of split and appends a new empty keyset.

Initializes the element with the given parameters at size-1 to be used.

Will automatically resize split if needed.

Parameters:

	split	the split object to work with
	backend	the backend which should be appended
	parentKey	the parentKey which should be appended
	syncbits	the initial syncstate which should be appended

Return values:

-1

if no split is found

Returns:

the size of split - 1

int elektraSplitAppoint	(	Split *	split,
		KDB *	handle,
		KeySet *	ks
	)

Appoints all keys from ks to yet unsynced splits.

Precondition:

elektraSplitBuildup() need to be executed before.

Parameters:

	split	the split object to work with
	handle	to determine to which backend a key belongs
	ks	the keyset to appoint to split

Returns:

1 on success

-1 if no backend was found for a key

int elektraSplitBuildup	(	Split *	split,
		KDB *	kdb,
		Key *	parentKey
	)

Walks through the trie and adds all backends below parentKey.

Sets syncbits to 2 if it is a default or root backend (which needs splitting).

Precondition:

split needs to be empty, directly after creation with elektraSplitNew().

there needs to be a valid defaultBackend but its ok not to have a trie inside KDB.

parentKey must be a valid key! (could be implemented more generally, but that would require splitting up of keysets of the same backend)

Parameters:

	split	the split object to work with
	kdb	the handle to get information about backends
	parentKey	the information below which key the backends are from interest

Returns:

always 1

void elektraSplitDel

(

Split *

keysets

)

Delete a split object.

Will free all allocated resources of a splitted keyset.

Parameters:

keysets

the split object to work with

int elektraSplitDivide	(	Split *	split,
		KDB *	handle,
		KeySet *	ks
	)

Splits up the keysets and search for a sync bit.

It does not check if there were removed keys, see elektraSplitRemove() for the next step.

It does not create new backends, this has to be done by buildup before.

Precondition:

elektraSplitBuildup() need to be executed before.

Parameters:

	split	the split object to work with
	handle	to get information where the individual keys belong
	ks	the keyset to divide

Returns:

0 if there were no sync bits

1 if there were sync bits

-1 if no backend was found for a key

int elektraSplitGet	(	Split *	split,
		KDB *	handle
	)

Does some work after getting of backends is finished.

Precondition:

elektraSplitAppoint() needs to be executed before.

• check if keys are in correct backend
• remove syncbits
• update usersize and systemsize

Parameters:

	split	the split object to work with
	handle	the handle to preprocess the keys

Returns:

1 on success

-1 if no backend was found for a key

int elektraSplitMerge	(	Split *	split,
		KeySet *	dest
	)

Merges together all parts of split into dest.

Parameters:

	split	the split object to work with
	dest	the destination keyset where all keysets are appended.

Returns:

1 on success

Split* elektraSplitNew

(

void

)

Allocates a new split object.

Initially the size is APPROXIMATE_NR_OF_BACKENDS.

Returns:

a fresh allocated split object

See also:

elektraSplitDel()

int elektraSplitPrepare

(

Split *

split

)

Prepares for kdbSet() mainloop afterwards.

All splits which do not need sync are removed and a deep copy of the remaining keysets is done.

Parameters:

split

the split object to work with

Return values:

0

on success

void elektraSplitResize

(

Split *

split

)

Doubles the size of how many parts of keysets can be appended.

Parameters:

split

the split object to work with

ssize_t elektraSplitSearchBackend	(	Split *	split,
		Backend *	backend,
		Key *	parent
	)

Determines if the backend is already inserted or not.

Warning:

If no parent Key is given, the default/root backends won't be searched.

Parameters:

	split	the split object to work with
	backend	the backend to search for
	parent	the key to check for domains in default/root backends.

Returns:

pos of backend if it already exist

-1 if it does not exist

int elektraSplitSearchRoot	(	Split *	split,
		Key *	parentKey
	)

Returns:

1 if one of the backends in split has all keys below parentKey

0 if parentKey == 0 or there are keys below or same than parentKey which do not fit in any of splitted keysets

Parameters:

	split	the split object to work with
	parentKey	the key which relation is searched for

int elektraSplitSync

(

Split *

split

)

Add sync bits everywhere keys were removed.

Only this function can really decide if sync is needed or not.

Precondition:

split needs to be processed with elektraSplitDivide() before.

Returns:

0 if kdbSet() is not needed

1 if kdbSet() is needed

Precondition:

user/system was splitted before.

Parameters:

split

the split object to work with