Methods to do various tests on Keys. More...

Collaboration diagram for Methods for Making Tests:

Functions
int	keyCmp (const Key k1, const Key k2)
	Compare the name of two keys. More...

int	keyNeedSync (const Key *key)
	Test if a key needs to be synced to backend storage. More...

int	keyIsBelow (const Key key, const Key check)
	Check if the key check is below the key key or not. More...

int	keyIsDirectlyBelow (const Key key, const Key check)
	Check whether the key `check` is directly below the key `key`. More...

int	keyIsBinary (const Key *key)
	Check if a key is binary type. More...

int	keyIsString (const Key *key)
	Check if a key is string type. More...

Detailed Description

Methods to do various tests on Keys.

To use them:

#include <kdb.h>

Function Documentation

◆ keyCmp()

int keyCmp	(	const Key *	k1,
		const Key *	k2
	)

Compare the name of two keys.

Returns: a number less than, equal to or greater than zero if k1 is found, respectively, to be less than, to match, or be greater than k2.

The comparison is based on a strcmp of the keynames, and iff they match a strcmp of the owner will be used to distuingish. If even this matches the keys are found to be exactly the same and 0 is returned. These two keys can't be used in the same KeySet.

keyCmp() defines the sorting order for a KeySet.

The following 3 points are the rules for null values:

A null pointer will be found to be smaller than every other key. If both are null pointers, 0 is returned.
A null name will be found to be smaller than every other name. If both are null names, 0 is returned.

If the name is equal then:

No owner will be found to be smaller then every other owner. If both don't have an owner, 0 is returned.

Note: the owner will only be used if the names are equal.

Given any Keys k1 and k2 constructed with keyNew(), following equation hold true:

        succeed_if (keyCmp (0, 0) == 0, "all null pointers same");
        succeed_if (keyCmp (k1, 0) == 1, "null pointer is smaller");
        succeed_if (keyCmp (0, k2) == -1, "null pointer is smaller");

Here are some more examples:

Key *k1 = keyNew("user:/a", KEY_END);
Key *k2 = keyNew("user:/b", KEY_END);
// keyCmp(k1,k2) < 0
// keyCmp(k2,k1) > 0

Do not strcmp the keyName() yourself because the result differs from simple ascii comparison.

Parameters

k1	the first key object to compare with
k2	the second key object to compare with

See also: ksAppendKey(), ksAppend() will compare keys when appending; ksLookup() will compare keys during searching

◆ keyIsBelow()

int keyIsBelow	(	const Key *	key,
		const Key *	check
	)

Check if the key check is below the key key or not.

Example:

key user:/sw/app
check user:/sw/app/key

returns true because check is below key

Example:

key user:/sw/app
check user:/sw/app/folder/key

returns also true because check is indirect below key

Obviously, there is no key above a namespace (e.g. user, system, /):

key *
check user

Parameters

key	the key object to work with
check	the key to find the relative position of

Return values

1	if check is below key
0	if it is not below or if it is the same key
-1	if key or check is null

See also: keySetName(), keyGetName(), keyIsDirectlyBelow()

◆ keyIsBinary()

int keyIsBinary ( const Key * key )

Check if a key is binary type.

The function checks if the key is a binary. Opposed to string values binary values can have '\0' inside the value and may not be terminated by a null character. Their disadvantage is that you need to pass their size.

Make sure to use this function and don't test the binary type another way to ensure compatibility and to write less error prone programs.

Return values

1	if it is binary
0	if it is not
-1	on NULL pointer

See also: keyGetBinary(), keySetBinary()

Parameters

key	the key to check

◆ keyIsDirectlyBelow()

int keyIsDirectlyBelow	(	const Key *	key,
		const Key *	check
	)

Check whether the key check is directly below the key key.

Example:
key user:/sw/app
check user:/sw/app/key

returns true because check is below key

Example:
key user:/sw/app
check user:/sw/app/folder/key

does not return true, because there is only an indirect relation

Parameters

key	the key object to work with
check	the key to find the relative position of

Return values

1	if check is below key
0	if it is not below or if it is the same key
-1	on null pointer

See also: keyIsBelow(), keySetName(), keyGetName()

◆ keyIsString()

int keyIsString ( const Key * key )

Check if a key is string type.

String values are null terminated and are not allowed to have any '\0' characters inside the string.

Make sure to use this function and don't test the string type another way to ensure compatibility and to write less error prone programs.

Return values

1	if it is string
0	if it is not
-1	on NULL pointer

See also: keyGetString(), keySetString()

Parameters

key	the key to check

◆ keyNeedSync()

int keyNeedSync ( const Key * key )

Test if a key needs to be synced to backend storage.

If any key modification took place the key will be flagged so that kdbSet() knows which keys were modified and which not.

After keyNew() the flag will normally be set, but after kdbGet() and kdbSet() the flag will be removed. When you modify the key the flag will be set again.

In your application you can make use of that flag to know if you changed something in a key after a kdbGet() or kdbSet().

Note: Note that the sync status will be updated on any change, including metadata.

Deprecated:: The handling of synchronization is done internally and does not need to be checked by neither application nor plugins.

See also: after keyNew(), keyDup() keys need sync

Parameters

key	the key object to work with

Return values

1	if `key` was changed in memory, 0 otherwise
-1	on NULL pointer

Functions

Detailed Description

Function Documentation

◆ keyCmp()

◆ keyIsBelow()

◆ keyIsBinary()

◆ keyIsDirectlyBelow()

◆ keyIsString()

◆ keyNeedSync()