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<?php
// This file is part of Moodle - http://moodle.org/
//
// Moodle is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// Moodle is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with Moodle. If not, see <http://www.gnu.org/licenses/>.
/**
* Cache definition class
*
* This file is part of Moodle's cache API, affectionately called MUC.
* It contains the components that are requried in order to use caching.
*
* @package core
* @category cache
* @copyright 2012 Sam Hemelryk
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
defined('MOODLE_INTERNAL') || die();
/**
* The cache definition class.
*
* Cache definitions need to be defined in db/caches.php files.
* They can be constructed with the following options.
*
* Required settings:
* + mode
* [int] Sets the mode for the definition. Must be one of cache_store::MODE_*
*
* Optional settings:
* + simplekeys
* [bool] Set to true if your cache will only use simple keys for its items.
* Simple keys consist of digits, underscores and the 26 chars of the english language. a-zA-Z0-9_
* If true the keys won't be hashed before being passed to the cache store for gets/sets/deletes. It will be
* better for performance and possible only becase we know the keys are safe.
* + simpledata
* [bool] If set to true we know that the data is scalar or array of scalar.
* + requireidentifiers
* [array] An array of identifiers that must be provided to the cache when it is created.
* + requiredataguarantee
* [bool] If set to true then only stores that can guarantee data will remain available once set will be used.
* + requiremultipleidentifiers
* [bool] If set to true then only stores that support multiple identifiers will be used.
* + requirelockingread
* [bool] If set to true then a lock will be gained before reading from the cache store. It is recommended not to use
* this setting unless 100% absolutely positively required. Remember 99.9% of caches will NOT need this setting.
* This setting will only be used for application caches presently.
* + requirelockingwrite
* [bool] If set to true then a lock will be gained before writing to the cache store. As above this is not recommended
* unless truly needed. Please think about the order of your code and deal with race conditions there first.
* This setting will only be used for application caches presently.
* + maxsize
* [int] If set this will be used as the maximum number of entries within the cache store for this definition.
* Its important to note that cache stores don't actually have to acknowledge this setting or maintain it as a hard limit.
* + overrideclass
* [string] A class to use as the loader for this cache. This is an advanced setting and will allow the developer of the
* definition to take 100% control of the caching solution.
* Any class used here must inherit the cache_loader interface and must extend default cache loader for the mode they are
* using.
* + overrideclassfile
* [string] Suplements the above setting indicated the file containing the class to be used. This file is included when
* required.
* + datasource
* [string] A class to use as the data loader for this definition.
* Any class used here must inherit the cache_data_loader interface.
* + datasourcefile
* [string] Supplements the above setting indicating the file containing the class to be used. This file is included when
* required.
* + staticacceleration
* The cache loader will keep an array of the items set and retrieved to the cache during the request.
* Consider using this setting when you know that there are going to be many calls to the cache for the same information.
* Requests for data in this array will be ultra fast, but it will cost memory.
* + staticaccelerationsize
* [int] This supplements the above setting by limiting the number of items in the static acceleration array.
* Tweaking this setting lower will allow you to minimise the memory implications above while hopefully still managing to
* offset calls to the cache store.
* + ttl
* [int] A time to live for the data (in seconds). It is strongly recommended that you don't make use of this and
* instead try to create an event driven invalidation system.
* Not all cache stores will support this natively and there are undesired performance impacts if the cache store does not.
* + mappingsonly
* [bool] If set to true only the mapped cache store(s) will be used and the default mode store will not. This is a super
* advanced setting and should not be used unless absolutely required. It allows you to avoid the default stores for one
* reason or another.
* + invalidationevents
* [array] An array of events that should cause this cache to invalidate some or all of the items within it.
* + sharingoptions
* [int] The sharing options that are appropriate for this definition. Should be the sum of the possible options.
* + defaultsharing
* [int] The default sharing option to use. It's highly recommended that you don't set this unless there is a very
* specific reason not to use the system default.
* + canuselocalstore
* [bool] The cache is able to safely run with multiple copies on different webservers without any need for administrator
* intervention to ensure that data stays in sync across nodes. This is usually managed by a revision
* system as seen in modinfo cache or language cache. Requiring purge on upgrade is not sufficient as
* it requires administrator intervention on each node to make it work.
*
* For examples take a look at lib/db/caches.php
*
* @package core
* @category cache
* @copyright 2012 Sam Hemelryk
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
class cache_definition {
/** The cache can be shared with everyone */
const SHARING_ALL = 1;
/** The cache can be shared with other sites using the same siteid. */
const SHARING_SITEID = 2;
/** The cache can be shared with other sites of the same version. */
const SHARING_VERSION = 4;
/** The cache can be shared with other sites using the same key */
const SHARING_INPUT = 8;
/**
* The default sharing options available.
* All + SiteID + Version + Input.
*/
const SHARING_DEFAULTOPTIONS = 15;
/**
* The default sharing option that gets used if none have been selected.
* SiteID. It is the most restrictive.
*/
const SHARING_DEFAULT = 2;
/**
* The identifier for the definition
* @var string
*/
protected $id;
/**
* The mode for the defintion. One of cache_store::MODE_*
* @var int
*/
protected $mode;
/**
* The component this definition is associated with.
* @var string
*/
protected $component;
/**
* The area this definition is associated with.
* @var string
*/
protected $area;
/**
* If set to true we know the keys are simple. a-zA-Z0-9_
* @var bool
*/
protected $simplekeys = false;
/**
* Set to true if we know the data is scalar or array of scalar.
* @var bool
*/
protected $simpledata = false;
/**
* An array of identifiers that must be provided when the definition is used to create a cache.
* @var array
*/
protected $requireidentifiers = array();
/**
* If set to true then only stores that guarantee data may be used with this definition.
* @var bool
*/
protected $requiredataguarantee = false;
/**
* If set to true then only stores that support multple identifiers may be used with this definition.
* @var bool
*/
protected $requiremultipleidentifiers = false;
/**
* If set to true then we know that this definition requires the locking functionality.
* This gets set during construction based upon the settings requirelockingread and requirelockingwrite.
* @var bool
*/
protected $requirelocking = false;
/**
* Set to true if this definition requires read locking.
* @var bool
*/
protected $requirelockingread = false;
/**
* Gets set to true if this definition requires write locking.
* @var bool
*/
protected $requirelockingwrite = false;
/**
* Gets set to true if this definition requires searchable stores.
* @since Moodle 2.4.4
* @var bool
*/
protected $requiresearchable = false;
/**
* Sets the maximum number of items that can exist in the cache.
* Please note this isn't a hard limit, and doesn't need to be enforced by the caches. They can choose to do so optionally.
* @var int
*/
protected $maxsize = null;
/**
* The class to use as the cache loader for this definition.
* @var string
*/
protected $overrideclass = null;
/**
* The file in which the override class exists. This will be included if required.
* @var string Absolute path
*/
protected $overrideclassfile = null;
/**
* The data source class to use with this definition.
* @var string
*/
protected $datasource = null;
/**
* The file in which the data source class exists. This will be included if required.
* @var string
*/
protected $datasourcefile = null;
/**
* Set to true if the cache should hold onto items passing through it to speed up subsequent requests.
* @var bool
*/
protected $staticacceleration = false;
/**
* The maximum number of items that static acceleration cache should hold onto.
* @var int
*/
protected $staticaccelerationsize = false;
/**
* The TTL for data in this cache. Please don't use this, instead use event driven invalidation.
* @var int
*/
protected $ttl = 0;
/**
* Set to true if this cache should only use mapped cache stores and not the default mode cache store.
* @var bool
*/
protected $mappingsonly = false;
/**
* An array of events that should cause this cache to invalidate.
* @var array
*/
protected $invalidationevents = array();
/**
* An array of identifiers provided to this cache when it was initialised.
* @var array
*/
protected $identifiers = null;
/**
* Key prefix for use with single key cache stores
* @var string
*/
protected $keyprefixsingle = null;
/**
* Key prefix to use with cache stores that support multi keys.
* @var array
*/
protected $keyprefixmulti = null;
/**
* A hash identifier of this definition.
* @var string
*/
protected $definitionhash = null;
/**
* The selected sharing mode for this definition.
* @var int
*/
protected $sharingoptions;
/**
* Whether this cache supports local storages.
* @var bool
*/
protected $canuselocalstore = false;
/**
* The selected sharing option.
* @var int One of self::SHARING_*
*/
protected $selectedsharingoption = self::SHARING_DEFAULT;
/**
* The user input key to use if the SHARING_INPUT option has been selected.
* @var string Must be ALPHANUMEXT
*/
protected $userinputsharingkey = '';
/**
* Creates a cache definition given a definition from the cache configuration or from a caches.php file.
*
* @param string $id
* @param array $definition
* @param string $unused Used to be datasourceaggregate but that was removed and this is now unused.
* @return cache_definition
* @throws coding_exception
*/
public static function load($id, array $definition, $unused = null) {
global $CFG;
if (!array_key_exists('mode', $definition)) {
throw new coding_exception('You must provide a mode when creating a cache definition');
}
if (!array_key_exists('component', $definition)) {
throw new coding_exception('You must provide a component when creating a cache definition');
}
if (!array_key_exists('area', $definition)) {
throw new coding_exception('You must provide an area when creating a cache definition');
}
$mode = (int)$definition['mode'];
$component = (string)$definition['component'];
$area = (string)$definition['area'];
// Set the defaults.
$simplekeys = false;
$simpledata = false;
$requireidentifiers = array();
$requiredataguarantee = false;
$requiremultipleidentifiers = false;
$requirelockingread = false;
$requirelockingwrite = false;
$requiresearchable = ($mode === cache_store::MODE_SESSION) ? true : false;
$maxsize = null;
$overrideclass = null;
$overrideclassfile = null;
$datasource = null;
$datasourcefile = null;
$staticacceleration = false;
$staticaccelerationsize = false;
$ttl = 0;
$mappingsonly = false;
$invalidationevents = array();
$sharingoptions = self::SHARING_DEFAULT;
$selectedsharingoption = self::SHARING_DEFAULT;
$userinputsharingkey = '';
$canuselocalstore = false;
if (array_key_exists('simplekeys', $definition)) {
$simplekeys = (bool)$definition['simplekeys'];
}
if (array_key_exists('simpledata', $definition)) {
$simpledata = (bool)$definition['simpledata'];
}
if (array_key_exists('requireidentifiers', $definition)) {
$requireidentifiers = (array)$definition['requireidentifiers'];
}
if (array_key_exists('requiredataguarantee', $definition)) {
$requiredataguarantee = (bool)$definition['requiredataguarantee'];
}
if (array_key_exists('requiremultipleidentifiers', $definition)) {
$requiremultipleidentifiers = (bool)$definition['requiremultipleidentifiers'];
}
if (array_key_exists('requirelockingread', $definition)) {
$requirelockingread = (bool)$definition['requirelockingread'];
}
if (array_key_exists('requirelockingwrite', $definition)) {
$requirelockingwrite = (bool)$definition['requirelockingwrite'];
}
$requirelocking = $requirelockingwrite || $requirelockingread;
if (array_key_exists('requiresearchable', $definition)) {
$requiresearchable = (bool)$definition['requiresearchable'];
}
if (array_key_exists('maxsize', $definition)) {
$maxsize = (int)$definition['maxsize'];
}
if (array_key_exists('overrideclass', $definition)) {
$overrideclass = $definition['overrideclass'];
}
if (array_key_exists('overrideclassfile', $definition)) {
$overrideclassfile = $definition['overrideclassfile'];
}
if (array_key_exists('datasource', $definition)) {
$datasource = $definition['datasource'];
}
if (array_key_exists('datasourcefile', $definition)) {
$datasourcefile = $definition['datasourcefile'];
}
if (array_key_exists('persistent', $definition)) {
// Ahhh this is the legacy persistent option.
$staticacceleration = (bool)$definition['persistent'];
}
if (array_key_exists('staticacceleration', $definition)) {
$staticacceleration = (bool)$definition['staticacceleration'];
}
if (array_key_exists('persistentmaxsize', $definition)) {
// Ahhh this is the legacy persistentmaxsize option.
$staticaccelerationsize = (int)$definition['persistentmaxsize'];
}
if (array_key_exists('staticaccelerationsize', $definition)) {
$staticaccelerationsize = (int)$definition['staticaccelerationsize'];
}
if (array_key_exists('ttl', $definition)) {
$ttl = (int)$definition['ttl'];
}
if (array_key_exists('mappingsonly', $definition)) {
$mappingsonly = (bool)$definition['mappingsonly'];
}
if (array_key_exists('invalidationevents', $definition)) {
$invalidationevents = (array)$definition['invalidationevents'];
}
if (array_key_exists('sharingoptions', $definition)) {
$sharingoptions = (int)$definition['sharingoptions'];
}
if (array_key_exists('selectedsharingoption', $definition)) {
$selectedsharingoption = (int)$definition['selectedsharingoption'];
} else if (array_key_exists('defaultsharing', $definition)) {
$selectedsharingoption = (int)$definition['defaultsharing'];
} else if ($sharingoptions ^ $selectedsharingoption) {
if ($sharingoptions & self::SHARING_SITEID) {
$selectedsharingoption = self::SHARING_SITEID;
} else if ($sharingoptions & self::SHARING_VERSION) {
$selectedsharingoption = self::SHARING_VERSION;
} else {
$selectedsharingoption = self::SHARING_ALL;
}
}
if (array_key_exists('canuselocalstore', $definition)) {
$canuselocalstore = (bool)$definition['canuselocalstore'];
}
if (array_key_exists('userinputsharingkey', $definition) && !empty($definition['userinputsharingkey'])) {
$userinputsharingkey = (string)$definition['userinputsharingkey'];
}
if (!is_null($overrideclass)) {
if (!is_null($overrideclassfile)) {
if (strpos($overrideclassfile, $CFG->dirroot) !== 0) {
$overrideclassfile = $CFG->dirroot.'/'.$overrideclassfile;
}
if (strpos($overrideclassfile, '../') !== false) {
throw new coding_exception('No path craziness allowed within override class file path.');
}
if (!file_exists($overrideclassfile)) {
throw new coding_exception('The override class file does not exist.');
}
require_once($overrideclassfile);
}
if (!class_exists($overrideclass)) {
throw new coding_exception('The override class does not exist.');
}
// Make sure that the provided class extends the default class for the mode.
if (get_parent_class($overrideclass) !== cache_helper::get_class_for_mode($mode)) {
throw new coding_exception('The override class does not immediately extend the relevant cache class.');
}
}
if (!is_null($datasource)) {
if (!is_null($datasourcefile)) {
if (strpos($datasourcefile, $CFG->dirroot) !== 0) {
$datasourcefile = $CFG->dirroot.'/'.$datasourcefile;
}
if (strpos($datasourcefile, '../') !== false) {
throw new coding_exception('No path craziness allowed within data source file path.');
}
if (!file_exists($datasourcefile)) {
throw new coding_exception('The data source class file does not exist.');
}
require_once($datasourcefile);
}
if (!class_exists($datasource)) {
throw new coding_exception('The data source class does not exist.');
}
if (!array_key_exists('cache_data_source', class_implements($datasource))) {
throw new coding_exception('Cache data source classes must implement the cache_data_source interface');
}
}
$cachedefinition = new cache_definition();
$cachedefinition->id = $id;
$cachedefinition->mode = $mode;
$cachedefinition->component = $component;
$cachedefinition->area = $area;
$cachedefinition->simplekeys = $simplekeys;
$cachedefinition->simpledata = $simpledata;
$cachedefinition->requireidentifiers = $requireidentifiers;
$cachedefinition->requiredataguarantee = $requiredataguarantee;
$cachedefinition->requiremultipleidentifiers = $requiremultipleidentifiers;
$cachedefinition->requirelocking = $requirelocking;
$cachedefinition->requirelockingread = $requirelockingread;
$cachedefinition->requirelockingwrite = $requirelockingwrite;
$cachedefinition->requiresearchable = $requiresearchable;
$cachedefinition->maxsize = $maxsize;
$cachedefinition->overrideclass = $overrideclass;
$cachedefinition->overrideclassfile = $overrideclassfile;
$cachedefinition->datasource = $datasource;
$cachedefinition->datasourcefile = $datasourcefile;
$cachedefinition->staticacceleration = $staticacceleration;
$cachedefinition->staticaccelerationsize = $staticaccelerationsize;
$cachedefinition->ttl = $ttl;
$cachedefinition->mappingsonly = $mappingsonly;
$cachedefinition->invalidationevents = $invalidationevents;
$cachedefinition->sharingoptions = $sharingoptions;
$cachedefinition->selectedsharingoption = $selectedsharingoption;
$cachedefinition->userinputsharingkey = $userinputsharingkey;
$cachedefinition->canuselocalstore = $canuselocalstore;
return $cachedefinition;
}
/**
* Creates an ah-hoc cache definition given the required params.
*
* Please note that when using an adhoc definition you cannot set any of the optional params.
* This is because we cannot guarantee consistent access and we don't want to mislead people into thinking that.
*
* @param int $mode One of cache_store::MODE_*
* @param string $component The component this definition relates to.
* @param string $area The area this definition relates to.
* @param array $options An array of options, available options are:
* - simplekeys : Set to true if the keys you will use are a-zA-Z0-9_
* - simpledata : Set to true if the type of the data you are going to store is scalar, or an array of scalar vars
* - overrideclass : The class to use as the loader.
* - staticacceleration : If set to true the cache will hold onto data passing through it.
* - staticaccelerationsize : Set it to an int to limit the size of the staticacceleration cache.
* @return cache_application|cache_session|cache_request
*/
public static function load_adhoc($mode, $component, $area, array $options = array()) {
$id = 'adhoc/'.$component.'_'.$area;
$definition = array(
'mode' => $mode,
'component' => $component,
'area' => $area,
);
if (!empty($options['simplekeys'])) {
$definition['simplekeys'] = $options['simplekeys'];
}
if (!empty($options['simpledata'])) {
$definition['simpledata'] = $options['simpledata'];
}
if (!empty($options['persistent'])) {
// Ahhh this is the legacy persistent option.
$definition['staticacceleration'] = (bool)$options['persistent'];
}
if (!empty($options['staticacceleration'])) {
$definition['staticacceleration'] = (bool)$options['staticacceleration'];
}
if (!empty($options['staticaccelerationsize'])) {
$definition['staticaccelerationsize'] = (int)$options['staticaccelerationsize'];
}
if (!empty($options['overrideclass'])) {
$definition['overrideclass'] = $options['overrideclass'];
}
if (!empty($options['sharingoptions'])) {
$definition['sharingoptions'] = $options['sharingoptions'];
}
return self::load($id, $definition, null);
}
/**
* Returns the cache loader class that should be used for this definition.
* @return string
*/
public function get_cache_class() {
if (!is_null($this->overrideclass)) {
return $this->overrideclass;
}
return cache_helper::get_class_for_mode($this->mode);
}
/**
* Returns the id of this definition.
* @return string
*/
public function get_id() {
return $this->id;
}
/**
* Returns the name for this definition
* @return string
*/
public function get_name() {
$identifier = 'cachedef_'.clean_param($this->area, PARAM_STRINGID);
$component = $this->component;
if ($component === 'core') {
$component = 'cache';
}
return new lang_string($identifier, $component);
}
/**
* Returns the mode of this definition
* @return int One more cache_store::MODE_
*/
public function get_mode() {
return $this->mode;
}
/**
* Returns the area this definition is associated with.
* @return string
*/
public function get_area() {
return $this->area;
}
/**
* Returns the component this definition is associated with.
* @return string
*/
public function get_component() {
return $this->component;
}
/**
* Returns true if this definition is using simple keys.
*
* Simple keys contain only a-zA-Z0-9_
*
* @return bool
*/
public function uses_simple_keys() {
return $this->simplekeys;
}
/**
* Returns the identifiers that are being used for this definition.
* @return array
*/
public function get_identifiers() {
if (!isset($this->identifiers)) {
return array();
}
return $this->identifiers;
}
/**
* Returns the ttl in seconds for this definition if there is one, or null if not.
* @return int|null
*/
public function get_ttl() {
return $this->ttl;
}
/**
* Returns the maximum number of items allowed in this cache.
* @return int
*/
public function get_maxsize() {
return $this->maxsize;
}
/**
* Returns true if this definition should only be used with mappings.
* @return bool
*/
public function is_for_mappings_only() {
return $this->mappingsonly;
}
/**
* Returns true if the data is known to be scalar or array of scalar.
* @return bool
*/
public function uses_simple_data() {
return $this->simpledata;
}
/**
* Returns true if this definition requires a data guarantee from the cache stores being used.
* @return bool
*/
public function require_data_guarantee() {
return $this->requiredataguarantee;
}
/**
* Returns true if this definition requires that the cache stores support multiple identifiers
* @return bool
*/
public function require_multiple_identifiers() {
return $this->requiremultipleidentifiers;
}
/**
* Returns true if this definition requires locking functionality. Either read or write locking.
* @return bool
*/
public function require_locking() {
return $this->requirelocking;
}
/**
* Returns true if this definition requires read locking.
* @return bool
*/
public function require_locking_read() {
return $this->requirelockingread;
}
/**
* Returns true if this definition requires write locking.
* @return bool
*/
public function require_locking_write() {
return $this->requirelockingwrite;
}
/**
* Returns true if this definition allows local storage to be used for caching.
* @since Moodle 3.1.0
* @return bool
*/
public function can_use_localstore() {
return $this->canuselocalstore;
}
/**
* Returns true if this definition requires a searchable cache.
* @since Moodle 2.4.4
* @return bool
*/
public function require_searchable() {
return $this->requiresearchable;
}
/**
* Returns true if this definition has an associated data source.
* @return bool
*/
public function has_data_source() {
return !is_null($this->datasource);
}
/**
* Returns an instance of the data source class used for this definition.
*
* @return cache_data_source
* @throws coding_exception
*/
public function get_data_source() {
if (!$this->has_data_source()) {
throw new coding_exception('This cache does not use a data source.');
}
return forward_static_call(array($this->datasource, 'get_instance_for_cache'), $this);
}
/**
* Sets the identifiers for this definition, or updates them if they have already been set.
*
* @param array $identifiers
* @return bool false if no identifiers where changed, true otherwise.
* @throws coding_exception
*/
public function set_identifiers(array $identifiers = array()) {
if ($this->identifiers !== null) {
throw new coding_exception("You can only set identifiers on initial definition creation." .
" Define a new cache to set different identifiers.");
}
if (!empty($identifiers) && !empty($this->invalidationevents)) {
throw new coding_exception("You cannot use event invalidation and identifiers at the same time.");
}
foreach ($this->requireidentifiers as $identifier) {
if (!isset($identifiers[$identifier])) {
throw new coding_exception('Identifier required for cache has not been provided: '.$identifier);
}
}
$this->identifiers = array();
foreach ($identifiers as $name => $value) {
$this->identifiers[$name] = (string)$value;
}
// Reset the key prefix's they need updating now.
$this->keyprefixsingle = null;
$this->keyprefixmulti = null;
return true;
}
/**
* Returns the requirements of this definition as a binary flag.
* @return int
*/
public function get_requirements_bin() {
$requires = 0;
if ($this->require_data_guarantee()) {
$requires += cache_store::SUPPORTS_DATA_GUARANTEE;
}
if ($this->require_multiple_identifiers()) {
$requires += cache_store::SUPPORTS_MULTIPLE_IDENTIFIERS;
}
if ($this->require_searchable()) {
$requires += cache_store::IS_SEARCHABLE;
}
return $requires;
}
/**
* Please call {@link cache_definition::use_static_acceleration()} instead.
*
* @see cache_definition::use_static_acceleration()
* @deprecated since 2.6
*/
public function should_be_persistent() {
throw new coding_exception('cache_definition::should_be_persistent() can not be used anymore.' .
' Please use cache_definition::use_static_acceleration() instead.');
}
/**
* Returns true if we should hold onto the data flowing through the cache.
*
* If set to true data flowing through the cache will be stored in a static variable
* to make subsequent requests for the data much faster.
*
* @return bool
*/
public function use_static_acceleration() {
if ($this->mode === cache_store::MODE_REQUEST) {
// Request caches should never use static acceleration - it just doesn't make sense.
return false;
}
return $this->staticacceleration;
}
/**
* Please call {@link cache_definition::get_static_acceleration_size()} instead.
*
* @see cache_definition::get_static_acceleration_size()
* @deprecated since 2.6
*/
public function get_persistent_max_size() {
throw new coding_exception('cache_definition::get_persistent_max_size() can not be used anymore.' .
' Please use cache_definition::get_static_acceleration_size() instead.');
}
/**
* Returns the max size for the static acceleration array.
* @return int
*/
public function get_static_acceleration_size() {
return $this->staticaccelerationsize;
}
/**
* Generates a hash of this definition and returns it.
* @return string
*/
public function generate_definition_hash() {
if ($this->definitionhash === null) {
$this->definitionhash = md5("{$this->mode} {$this->component} {$this->area}");
}
return $this->definitionhash;
}
/**
* Generates a single key prefix for this definition
*
* @return string
*/
public function generate_single_key_prefix() {
if ($this->keyprefixsingle === null) {
$this->keyprefixsingle = $this->mode.'/'.$this->component.'/'.$this->area;
$this->keyprefixsingle .= '/'.$this->get_cache_identifier();
$identifiers = $this->get_identifiers();
if ($identifiers) {
foreach ($identifiers as $key => $value) {
$this->keyprefixsingle .= '/'.$key.'='.$value;
}
}
$this->keyprefixsingle = md5($this->keyprefixsingle);
}
return $this->keyprefixsingle;
}
/**
* Generates a multi key prefix for this definition
*
* @return array
*/
public function generate_multi_key_parts() {
if ($this->keyprefixmulti === null) {
$this->keyprefixmulti = array(
'mode' => $this->mode,
'component' => $this->component,
'area' => $this->area,
'siteidentifier' => $this->get_cache_identifier()
);
if (isset($this->identifiers) && !empty($this->identifiers)) {
$identifiers = array();
foreach ($this->identifiers as $key => $value) {
$identifiers[] = htmlentities($key, ENT_QUOTES, 'UTF-8').'='.htmlentities($value, ENT_QUOTES, 'UTF-8');
}
$this->keyprefixmulti['identifiers'] = join('&', $identifiers);
}
}
return $this->keyprefixmulti;
}
/**
* Check if this definition should invalidate on the given event.
*
* @param string $event
* @return bool True if the definition should invalidate on the event. False otherwise.
*/
public function invalidates_on_event($event) {
return (in_array($event, $this->invalidationevents));
}
/**
* Check if the definition has any invalidation events.
*
* @return bool True if it does, false otherwise
*/
public function has_invalidation_events() {
return !empty($this->invalidationevents);
}
/**
* Returns all of the invalidation events for this definition.
*
* @return array
*/
public function get_invalidation_events() {
return $this->invalidationevents;
}
/**
* Returns a cache identification string.
*
* @return string A string to be used as part of keys.
*/
protected function get_cache_identifier() {
$identifiers = array();
if ($this->selectedsharingoption & self::SHARING_ALL) {
// Nothing to do here.
} else {
if ($this->selectedsharingoption & self::SHARING_SITEID) {
$identifiers[] = cache_helper::get_site_identifier();
}
if ($this->selectedsharingoption & self::SHARING_VERSION) {
$identifiers[] = cache_helper::get_site_version();
}
if ($this->selectedsharingoption & self::SHARING_INPUT && !empty($this->userinputsharingkey)) {
$identifiers[] = $this->userinputsharingkey;
}
}
return join('/', $identifiers);
}
/**
* Returns true if this definition requires identifiers.
*
* @param bool
*/
public function has_required_identifiers() {
return (count($this->requireidentifiers) > 0);
}
/**
* Returns the possible sharing options that can be used with this defintion.
*
* @return int
*/
public function get_sharing_options() {
return $this->sharingoptions;
}
/**
* Returns the user entered sharing key for this definition.
*
* @return string
*/
public function get_user_input_sharing_key() {
return $this->userinputsharingkey;
}
/**
* Returns the user selected sharing option for this definition.
*
* @return int
*/
public function get_selected_sharing_option() {
return $this->selectedsharingoption;
}
}