TYPO3\CMS\Core\Cache\Backend\ApcuBackend Class Reference

Inheritance diagram for TYPO3\CMS\Core\Cache\Backend\ApcuBackend:

Public Member Functions
	__construct ($context, array $options=[])
	setCache (\TYPO3\CMS\Core\Cache\Frontend\FrontendInterface $cache)
	set ($entryIdentifier, $data, array $tags=[], $lifetime=null)
	get ($entryIdentifier)
	has ($entryIdentifier)
	remove ($entryIdentifier)
	findIdentifiersByTag ($tag)
	flush ()
	flushByTag ($tag)
	collectGarbage ()
Public Member Functions inherited from TYPO3\CMS\Core\Cache\Backend\AbstractBackend
	__construct ($context, array $options=[])
	setCache (\TYPO3\CMS\Core\Cache\Frontend\FrontendInterface $cache)
	setDefaultLifetime ($defaultLifetime)

Protected Member Functions
	setIdentifierPrefix ($identifierPrefix)
	getIdentifierPrefix ()
	getCurrentUserData ()
	getPathSite ()
	findTagsByIdentifier ($identifier)
	addIdentifierToTags ($entryIdentifier, array $tags)
	removeIdentifierFromAllTags ($entryIdentifier)
Protected Member Functions inherited from TYPO3\CMS\Core\Cache\Backend\AbstractBackend
	calculateExpiryTime ($lifetime=null)

Protected Attributes
	$identifierPrefix
Protected Attributes inherited from TYPO3\CMS\Core\Cache\Backend\AbstractBackend
	$cache
	$cacheIdentifier
	$context
	$defaultLifetime = 3600

Additional Inherited Members
Public Attributes inherited from TYPO3\CMS\Core\Cache\Backend\AbstractBackend
const	DATETIME_EXPIRYTIME_UNLIMITED = '9999-12-31T23:59:59+0000'
const	UNLIMITED_LIFETIME = 0

Detailed Description

A caching backend which stores cache entries by using APCu.

This backend uses the following types of keys:

• tag_xxx xxx is tag name, value is array of associated identifiers identifier. This is "forward" tag index. It is mainly used for obtaining content by tag (get identifier by tag -> get content by identifier)
• ident_xxx xxx is identifier, value is array of associated tags. This is "reverse" tag index. It provides quick access for all tags associated with this identifier and used when removing the identifier

Each key is prepended with a prefix. By default prefix consists from two parts separated by underscore character and ends in yet another underscore character:

• "TYPO3"
• MD5 of path to TYPO3 and user running TYPO3 This prefix makes sure that keys from the different installations do not conflict.

Definition at line 41 of file ApcuBackend.php.

Constructor & Destructor Documentation

__construct()

TYPO3\CMS\Core\Cache\Backend\ApcuBackend::__construct	(		$context,
		array	$options = []
	)

Constructs this backend

Parameters

string	$context	FLOW3's application context
array	$options	Configuration options - unused here

Exceptions

Cache

Definition at line 77 of file ApcuBackend.php.

References TYPO3\CMS\Core\Cache\Backend\AbstractBackend\$context.

Member Function Documentation

addIdentifierToTags()

TYPO3\CMS\Core\Cache\Backend\ApcuBackend::addIdentifierToTags (   $entryIdentifier, array  $tags  )

protected

Associates the identifier with the given tags

Parameters

string	$entryIdentifier
array	$tags

Returns

void

Definition at line 267 of file ApcuBackend.php.

References TYPO3\CMS\Core\Cache\Backend\ApcuBackend\findIdentifiersByTag(), TYPO3\CMS\Core\Cache\Backend\ApcuBackend\findTagsByIdentifier(), and TYPO3\CMS\Core\Cache\Backend\ApcuBackend\getIdentifierPrefix().

Referenced by TYPO3\CMS\Core\Cache\Backend\ApcuBackend\set().

collectGarbage()

TYPO3\CMS\Core\Cache\Backend\ApcuBackend::collectGarbage

(

)

Does nothing, as APCu does GC itself

Returns

void

Implements TYPO3\CMS\Core\Cache\Backend\BackendInterface.

Definition at line 329 of file ApcuBackend.php.

findIdentifiersByTag()

TYPO3\CMS\Core\Cache\Backend\ApcuBackend::findIdentifiersByTag

(

$tag

)

Finds and returns all cache entry identifiers which are tagged by the specified tag.

Parameters

string

$tag

The tag to search for

Returns

array An array with identifiers of all matching entries. An empty array if no entries matched

Implements TYPO3\CMS\Core\Cache\Backend\TaggableBackendInterface.

Definition at line 205 of file ApcuBackend.php.

References TYPO3\CMS\Core\Cache\Backend\ApcuBackend\getIdentifierPrefix().

Referenced by TYPO3\CMS\Core\Cache\Backend\ApcuBackend\addIdentifierToTags(), TYPO3\CMS\Core\Cache\Backend\ApcuBackend\flushByTag(), and TYPO3\CMS\Core\Cache\Backend\ApcuBackend\removeIdentifierFromAllTags().

findTagsByIdentifier()

TYPO3\CMS\Core\Cache\Backend\ApcuBackend::findTagsByIdentifier (   $identifier )

protected

Finds all tags for the given identifier. This function uses reverse tag index to search for tags.

Parameters

string

$identifier

Identifier to find tags by

Returns

array Array with tags

Definition at line 223 of file ApcuBackend.php.

References TYPO3\CMS\Core\Cache\Backend\ApcuBackend\getIdentifierPrefix().

Referenced by TYPO3\CMS\Core\Cache\Backend\ApcuBackend\addIdentifierToTags(), and TYPO3\CMS\Core\Cache\Backend\ApcuBackend\removeIdentifierFromAllTags().

flush()

TYPO3\CMS\Core\Cache\Backend\ApcuBackend::flush

(

)

Removes all cache entries of this cache.

Returns

void

Exceptions

Cache

Implements TYPO3\CMS\Core\Cache\Backend\BackendInterface.

Definition at line 237 of file ApcuBackend.php.

References TYPO3\CMS\Core\Cache\Backend\ApcuBackend\flushByTag().

flushByTag()

TYPO3\CMS\Core\Cache\Backend\ApcuBackend::flushByTag

(

$tag

)

Removes all cache entries of this cache which are tagged by the specified tag.

Parameters

string

$tag

The tag the entries must have

Returns

void

Implements TYPO3\CMS\Core\Cache\Backend\TaggableBackendInterface.

Definition at line 252 of file ApcuBackend.php.

References TYPO3\CMS\Core\Cache\Backend\ApcuBackend\findIdentifiersByTag().

Referenced by TYPO3\CMS\Core\Cache\Backend\ApcuBackend\flush().

get()

TYPO3\CMS\Core\Cache\Backend\ApcuBackend::get

(

$entryIdentifier

)

Loads data from the cache.

Parameters

string

$entryIdentifier

An identifier which describes the cache entry to load

Returns

mixed The cache entry's content as a string or FALSE if the cache entry could not be loaded

Implements TYPO3\CMS\Core\Cache\Backend\BackendInterface.

Definition at line 161 of file ApcuBackend.php.

References TYPO3\CMS\Core\Cache\Backend\ApcuBackend\getIdentifierPrefix().

getCurrentUserData()

TYPO3\CMS\Core\Cache\Backend\ApcuBackend::getCurrentUserData ( )

protected

Returns the current user data with posix_getpwuid or a default structure when posix_getpwuid is not available.

Returns

array

Definition at line 108 of file ApcuBackend.php.

Referenced by TYPO3\CMS\Core\Cache\Backend\ApcuBackend\setCache().

getIdentifierPrefix()

TYPO3\CMS\Core\Cache\Backend\ApcuBackend::getIdentifierPrefix ( )

protected

Retrieves the cache identifier prefix.

Returns

string

Definition at line 65 of file ApcuBackend.php.

References TYPO3\CMS\Core\Cache\Backend\ApcuBackend\$identifierPrefix.

Referenced by TYPO3\CMS\Core\Cache\Backend\ApcuBackend\addIdentifierToTags(), TYPO3\CMS\Core\Cache\Backend\ApcuBackend\findIdentifiersByTag(), TYPO3\CMS\Core\Cache\Backend\ApcuBackend\findTagsByIdentifier(), TYPO3\CMS\Core\Cache\Backend\ApcuBackend\get(), TYPO3\CMS\Core\Cache\Backend\ApcuBackend\has(), TYPO3\CMS\Core\Cache\Backend\ApcuBackend\remove(), TYPO3\CMS\Core\Cache\Backend\ApcuBackend\removeIdentifierFromAllTags(), and TYPO3\CMS\Core\Cache\Backend\ApcuBackend\set().

getPathSite()

TYPO3\CMS\Core\Cache\Backend\ApcuBackend::getPathSite ( )

protected

Returns the PATH_site constant.

Returns

string

Definition at line 118 of file ApcuBackend.php.

Referenced by TYPO3\CMS\Core\Cache\Backend\ApcuBackend\setCache().

has()

TYPO3\CMS\Core\Cache\Backend\ApcuBackend::has

(

$entryIdentifier

)

Checks if a cache entry with the specified identifier exists.

Parameters

string

$entryIdentifier

An identifier specifying the cache entry

Returns

bool TRUE if such an entry exists, FALSE if not

Implements TYPO3\CMS\Core\Cache\Backend\BackendInterface.

Definition at line 175 of file ApcuBackend.php.

References TYPO3\CMS\Core\Cache\Backend\ApcuBackend\getIdentifierPrefix().

remove()

TYPO3\CMS\Core\Cache\Backend\ApcuBackend::remove

(

$entryIdentifier

)

Removes all cache entries matching the specified identifier. Usually this only affects one entry but if - for what reason ever - old entries for the identifier still exist, they are removed as well.

Parameters

string

$entryIdentifier

Specifies the cache entry to remove

Returns

bool TRUE if (at least) an entry could be removed or FALSE if no entry was found

Implements TYPO3\CMS\Core\Cache\Backend\BackendInterface.

Definition at line 191 of file ApcuBackend.php.

References TYPO3\CMS\Core\Cache\Backend\ApcuBackend\getIdentifierPrefix(), and TYPO3\CMS\Core\Cache\Backend\ApcuBackend\removeIdentifierFromAllTags().

removeIdentifierFromAllTags()

TYPO3\CMS\Core\Cache\Backend\ApcuBackend::removeIdentifierFromAllTags (   $entryIdentifier )

protected

Removes association of the identifier with the given tags

Parameters

string

$entryIdentifier

Returns

void

Definition at line 299 of file ApcuBackend.php.

References TYPO3\CMS\Core\Cache\Backend\ApcuBackend\findIdentifiersByTag(), TYPO3\CMS\Core\Cache\Backend\ApcuBackend\findTagsByIdentifier(), and TYPO3\CMS\Core\Cache\Backend\ApcuBackend\getIdentifierPrefix().

Referenced by TYPO3\CMS\Core\Cache\Backend\ApcuBackend\remove(), and TYPO3\CMS\Core\Cache\Backend\ApcuBackend\set().

set()

TYPO3\CMS\Core\Cache\Backend\ApcuBackend::set	(		$entryIdentifier,
			$data,
		array	$tags = [],
			$lifetime = null
	)

Saves data in the cache.

Parameters

string	$entryIdentifier	An identifier for this specific cache entry
string	$data	The data to be stored
array	$tags	Tags to associate with this cache entry
int	$lifetime	Lifetime of this cache entry in seconds. If NULL is specified, the default lifetime is used. "0" means unlimited liftime.

Returns

void

Exceptions

Cache

Implements TYPO3\CMS\Core\Cache\Backend\BackendInterface.

Definition at line 135 of file ApcuBackend.php.

References TYPO3\CMS\Core\Cache\Backend\AbstractBackend\$cacheIdentifier, TYPO3\CMS\Core\Cache\Backend\AbstractBackend\$defaultLifetime, TYPO3\CMS\Core\Cache\Backend\ApcuBackend\addIdentifierToTags(), TYPO3\CMS\Core\Cache\Backend\ApcuBackend\getIdentifierPrefix(), and TYPO3\CMS\Core\Cache\Backend\ApcuBackend\removeIdentifierFromAllTags().

setCache()

TYPO3\CMS\Core\Cache\Backend\ApcuBackend::setCache

(

\TYPO3\CMS\Core\Cache\Frontend\FrontendInterface

$cache

)

Initializes the identifier prefix when setting the cache.

Parameters

\TYPO3\CMS\Core\Cache\Frontend\FrontendInterface

$cache

Returns

void

Implements TYPO3\CMS\Core\Cache\Backend\BackendInterface.

Definition at line 94 of file ApcuBackend.php.

References TYPO3\CMS\Core\Cache\Backend\ApcuBackend\getCurrentUserData(), TYPO3\CMS\Core\Cache\Backend\ApcuBackend\getPathSite(), TYPO3\CMS\Core\Cache\Backend\ApcuBackend\setIdentifierPrefix(), and TYPO3\CMS\Core\Utility\GeneralUtility\shortMD5().

setIdentifierPrefix()

TYPO3\CMS\Core\Cache\Backend\ApcuBackend::setIdentifierPrefix (   $identifierPrefix )

protected

Set the cache identifier prefix.

Parameters

string

$identifierPrefix

Definition at line 55 of file ApcuBackend.php.

References TYPO3\CMS\Core\Cache\Backend\ApcuBackend\$identifierPrefix.

Referenced by TYPO3\CMS\Core\Cache\Backend\ApcuBackend\setCache().

Member Data Documentation

$identifierPrefix

TYPO3\CMS\Core\Cache\Backend\ApcuBackend::$identifierPrefix

protected

Definition at line 48 of file ApcuBackend.php.

Referenced by TYPO3\CMS\Core\Cache\Backend\ApcuBackend\getIdentifierPrefix(), and TYPO3\CMS\Core\Cache\Backend\ApcuBackend\setIdentifierPrefix().