Opens the session with the Key database. More...

#include <kdb.hpp>

Public Member Functions
	KDB ()
	Opens the session with the Key database.
	KDB (Key &errorKey)
	Opens the session with the Key database.
	~KDB () throw ()

void	open (Key &errorKey)
	Opens the session with the Key database.
void	close (Key &errorKey) throw ()

int	get (KeySet &returned, std::string const &keyname)
	Retrieve keys in an atomic and universal way, all other kdbGet() Functions rely on that one.
int	get (KeySet &returned, Key &parentKey)
	Retrieve keys in an atomic and universal way, all other kdbGet() Functions rely on that one.
int	set (KeySet &returned, std::string const &keyname)

int	set (KeySet &returned, Key &parentKey)

Detailed Description

Opens the session with the Key database.

Constructs a class KDB.

Exceptions

KDBException if database could not be opened

The first step is to open the default backend. With it system/elektra/mountpoints will be loaded and all needed libraries and mountpoints will be determined. These libraries for backends will be loaded and with it the KDB datastructure will be initialized.You must always call this method before retrieving or committing any keys to the database. In the end of the program, after using the key database, you must not forget to kdbClose(). You can use the atexit () handler for it.The pointer to the KDB structure returned will be initialized like described above, and it must be passed along on any kdb*() method your application calls.Get a KDB handle for every thread using elektra. Don't share the handle across threads, and also not the pointer accessing it:

thread1
{
        KDB * h;
        h = kdbOpen(0);
        // fetch keys and work with them
        kdbClose(h, 0);
}
thread2
{
        KDB * h;
        h = kdbOpen(0);
        // fetch keys and work with them
        kdbClose(h, 0);
}

You don't need to use the kdbOpen() if you only want to manipulate plain in-memory Key or KeySet objects without any affairs with the backend key database or when your application loads plugins directly.

Parameters

errorKey the key which holds errors and warnings which were issued must be given

See Also: kdbClose() to end all affairs to the Key database.

Returns: a KDB pointer on success; NULL on failure

Access to the key database.

Invariant: the object holds an valid connection to the key database or is empty

Constructor & Destructor Documentation

kdb::KDB::KDB ( )

inline

Opens the session with the Key database.

Constructs a class KDB.

Exceptions

KDBException if database could not be opened

The first step is to open the default backend. With it system/elektra/mountpoints will be loaded and all needed libraries and mountpoints will be determined. These libraries for backends will be loaded and with it the KDB datastructure will be initialized.You must always call this method before retrieving or committing any keys to the database. In the end of the program, after using the key database, you must not forget to kdbClose(). You can use the atexit () handler for it.The pointer to the KDB structure returned will be initialized like described above, and it must be passed along on any kdb*() method your application calls.Get a KDB handle for every thread using elektra. Don't share the handle across threads, and also not the pointer accessing it:

thread1
{
        KDB * h;
        h = kdbOpen(0);
        // fetch keys and work with them
        kdbClose(h, 0);
}
thread2
{
        KDB * h;
        h = kdbOpen(0);
        // fetch keys and work with them
        kdbClose(h, 0);
}

You don't need to use the kdbOpen() if you only want to manipulate plain in-memory Key or KeySet objects without any affairs with the backend key database or when your application loads plugins directly.

Parameters

errorKey the key which holds errors and warnings which were issued must be given

See Also: kdbClose() to end all affairs to the Key database.

Returns: a KDB pointer on success; NULL on failure

kdb::KDB::KDB ( Key & errorKey )

inline

Opens the session with the Key database.

Constructs a class KDB.

Parameters

errorKey is useful if you want to get the warnings in the successful case, when no exception is thrown.

Exceptions

KDBException if database could not be opened

The first step is to open the default backend. With it system/elektra/mountpoints will be loaded and all needed libraries and mountpoints will be determined. These libraries for backends will be loaded and with it the KDB datastructure will be initialized.You must always call this method before retrieving or committing any keys to the database. In the end of the program, after using the key database, you must not forget to kdbClose(). You can use the atexit () handler for it.The pointer to the KDB structure returned will be initialized like described above, and it must be passed along on any kdb*() method your application calls.Get a KDB handle for every thread using elektra. Don't share the handle across threads, and also not the pointer accessing it:

thread1
{
        KDB * h;
        h = kdbOpen(0);
        // fetch keys and work with them
        kdbClose(h, 0);
}
thread2
{
        KDB * h;
        h = kdbOpen(0);
        // fetch keys and work with them
        kdbClose(h, 0);
}

You don't need to use the kdbOpen() if you only want to manipulate plain in-memory Key or KeySet objects without any affairs with the backend key database or when your application loads plugins directly.

Parameters

errorKey the key which holds errors and warnings which were issued must be given

See Also: kdbClose() to end all affairs to the Key database.

Returns: a KDB pointer on success; NULL on failure

kdb::KDB::~KDB ( ) throw ()

inline

The destructor closes the database.

Closes the session with the Key database.You should call this method when you finished your affairs with the key database. You can manipulate Key and KeySet objects also after kdbClose(). You must not use any kdb* call afterwards. You can implement kdbClose() in the atexit() handler.This is the counterpart of kdbOpen().The handle parameter will be finalized and all resources associated to it will be freed. After a kdbClose(), this handle can't be used anymore, unless it gets initialized again with another call to kdbOpen().

See Also: kdbOpen()

Parameters

handle	contains internal information of opened key database
errorKey	the key which holds error information

Returns: 0 on success; -1 on NULL pointer

Member Function Documentation

void kdb::KDB::close ( Key & errorKey ) throw ()

inline

Open the database.

The return value does not matter because its only a null pointer check.

Parameters

errorKey is useful if you want to get the warnings

Closes the session with the Key database.You should call this method when you finished your affairs with the key database. You can manipulate Key and KeySet objects also after kdbClose(). You must not use any kdb* call afterwards. You can implement kdbClose() in the atexit() handler.This is the counterpart of kdbOpen().The handle parameter will be finalized and all resources associated to it will be freed. After a kdbClose(), this handle can't be used anymore, unless it gets initialized again with another call to kdbOpen().

See Also: kdbOpen()

Parameters

handle	contains internal information of opened key database
errorKey	the key which holds error information

Returns: 0 on success; -1 on NULL pointer

int kdb::KDB::get	(	KeySet &	returned,
		std::string const &	keyname
	)

inline

Retrieve keys in an atomic and universal way, all other kdbGet() Functions rely on that one.

Get all keys below keyname inside returned.

The returned KeySet must be initialized. The returned KeySet may already contain some keys. The new retrieved keys will be appended using ksAppendKey().It will fully retrieve all keys under the parentKey folder, with all subfolders and their children.

#include <kdb.hpp>
#include <keyio.hpp>
using namespace kdb;
int main()
{
        KeySet config;
        KDB kdb;
        kdb.get(config, "/sw/MyApp");
        Key k = config.lookup("/sw/MyApp/mykey");
        if (k)
        {
                std::cout << k << " is " << k.get<int>() << std::endl;
        }
        else
        {
                std::cerr << "No key found" << std::endl;
                return 1;
        }
}

Parameters

returned	the keyset where the keys will be in
keyname	the root keyname which should be used to get keys below it

Return values

0	if no key was updated
1	if user or system keys were updated
2	if user and system keys were updated

Exceptions

KDBException if there were problems with the database

See Also: KDB::get (KeySet & returned, Key & parentKey)

int kdb::KDB::get	(	KeySet &	returned,
		Key &	parentKey
	)

inline

Retrieve keys in an atomic and universal way, all other kdbGet() Functions rely on that one.

Get all keys below parentKey inside returned.

The returned KeySet must be initialized. The returned KeySet may already contain some keys. The new retrieved keys will be appended using ksAppendKey().It will fully retrieve all keys under the parentKey folder, with all subfolders and their children.

Parameters

returned	the keyset where the keys will be in
parentKey	the parentKey of returned

Return values

0	if no key was updated
1	if user or system keys were updated
2	if user and system keys were updated

Exceptions

KDBException if there were problems with the database

void kdb::KDB::open ( Key & errorKey )

inline

Opens the session with the Key database.

Open the database

Parameters

errorKey is useful if you want to get the warnings in the successful case, when no exception is thrown.

The first step is to open the default backend. With it system/elektra/mountpoints will be loaded and all needed libraries and mountpoints will be determined. These libraries for backends will be loaded and with it the KDB datastructure will be initialized.You must always call this method before retrieving or committing any keys to the database. In the end of the program, after using the key database, you must not forget to kdbClose(). You can use the atexit () handler for it.The pointer to the KDB structure returned will be initialized like described above, and it must be passed along on any kdb*() method your application calls.Get a KDB handle for every thread using elektra. Don't share the handle across threads, and also not the pointer accessing it:

thread1
{
        KDB * h;
        h = kdbOpen(0);
        // fetch keys and work with them
        kdbClose(h, 0);
}
thread2
{
        KDB * h;
        h = kdbOpen(0);
        // fetch keys and work with them
        kdbClose(h, 0);
}

You don't need to use the kdbOpen() if you only want to manipulate plain in-memory Key or KeySet objects without any affairs with the backend key database or when your application loads plugins directly.

Parameters

errorKey the key which holds errors and warnings which were issued must be given

See Also: kdbClose() to end all affairs to the Key database.

Returns: a KDB pointer on success; NULL on failure

int kdb::KDB::set	(	KeySet &	returned,
		std::string const &	keyname
	)

inline

Set all keys below keyname.

If the keyname of the parentKey is invalid (e.g. empty) all keys will be set.

Set keys in an atomic and universal way.All other kdbSet Functions rely on that one.

Return values

0	if no key was updated
1	if user or system keys were updated
2	if user and system keys were updated

Parameters

returned	the keyset where the keys will be in
keyname	the keyname below the names should be set

Exceptions

KDBException if there were problems with the database

int kdb::KDB::set	(	KeySet &	returned,
		Key &	parentKey
	)

inline

Set all keys below parentKey.

If the keyname of the parentKey is invalid (e.g. empty) all keys will be set.

Set keys in an atomic and universal way.All other kdbSet Functions rely on that one.

Return values

0	if no key was updated
1	if user or system keys were updated
2	if user and system keys were updated

Parameters

returned	the keyset where the keys are passed to the user
parentKey	the parentKey of returned

Exceptions

KDBException if there were problems with the database

The documentation for this class was generated from the following file:

kdb.hpp

Public Member Functions

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation