MDL-36768 cache: replaced cache_store interface with abstract class

This commit is contained in:
Sam Hemelryk 2012-11-23 14:22:44 +13:00
parent bd188851f2
commit 75cde6b9ac
12 changed files with 212 additions and 271 deletions

View File

@ -182,7 +182,7 @@ class cache_config {
if (!class_exists($class)) {
continue;
}
if (!array_key_exists('cache_store', class_implements($class))) {
if (!array_key_exists('cache_store', class_parents($class))) {
continue;
}
if (!array_key_exists('configuration', $store) || !is_array($store['configuration'])) {

View File

@ -37,7 +37,7 @@ defined('MOODLE_INTERNAL') || die();
* @copyright 2012 Sam Hemelryk
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
class cachestore_dummy implements cache_store {
class cachestore_dummy extends cache_store {
/**
* The name of this store.
@ -135,30 +135,6 @@ class cachestore_dummy implements cache_store {
return true;
}
/**
* Returns true if this store supports data guarantee.
* @return bool
*/
public function supports_data_guarantee() {
return false;
}
/**
* Returns true if this store supports multiple identifiers.
* @return bool
*/
public function supports_multiple_identifiers() {
return false;
}
/**
* Returns true if this store supports a native ttl.
* @return bool
*/
public function supports_native_ttl() {
return true;
}
/**
* Returns the data for the given key
* @param string $key

View File

@ -230,227 +230,6 @@ interface cache_loader_with_locking {
public function release_lock($key);
}
/**
* Cache store.
*
* This interface outlines the requirements for a cache store plugin.
* It must be implemented by all such plugins and provides a reference to interacting with cache stores.
*
* Must be implemented by all cache store plugins.
*
* @package core
* @category cache
* @copyright 2012 Sam Hemelryk
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
interface cache_store {
/**#@+
* Constants for features a cache store can support
*/
/**
* Supports multi-part keys
*/
const SUPPORTS_MULTIPLE_IDENTIFIERS = 1;
/**
* Ensures data remains in the cache once set.
*/
const SUPPORTS_DATA_GUARANTEE = 2;
/**
* Supports a native ttl system.
*/
const SUPPORTS_NATIVE_TTL = 4;
/**#@-*/
/**#@+
* Constants for the modes of a cache store
*/
/**
* Application caches. These are shared caches.
*/
const MODE_APPLICATION = 1;
/**
* Session caches. Just access to the PHP session.
*/
const MODE_SESSION = 2;
/**
* Request caches. Static caches really.
*/
const MODE_REQUEST = 4;
/**#@-*/
/**
* Static method to check if the store requirements are met.
*
* @return bool True if the stores software/hardware requirements have been met and it can be used. False otherwise.
*/
public static function are_requirements_met();
/**
* Static method to check if a store is usable with the given mode.
*
* @param int $mode One of cache_store::MODE_*
*/
public static function is_supported_mode($mode);
/**
* Returns the supported features as a binary flag.
*
* @param array $configuration The configuration of a store to consider specifically.
* @return int The supported features.
*/
public static function get_supported_features(array $configuration = array());
/**
* Returns the supported modes as a binary flag.
*
* @param array $configuration The configuration of a store to consider specifically.
* @return int The supported modes.
*/
public static function get_supported_modes(array $configuration = array());
/**
* Returns true if this cache store instance supports multiple identifiers.
*
* @return bool
*/
public function supports_multiple_identifiers();
/**
* Returns true if this cache store instance promotes data guarantee.
*
* @return bool
*/
public function supports_data_guarantee();
/**
* Returns true if this cache store instance supports ttl natively.
*
* @return bool
*/
public function supports_native_ttl();
/**
* Used to control the ability to add an instance of this store through the admin interfaces.
*
* @return bool True if the user can add an instance, false otherwise.
*/
public static function can_add_instance();
/**
* Constructs an instance of the cache store.
*
* This method should not create connections or perform and processing, it should be used
*
* @param string $name The name of the cache store
* @param array $configuration The configuration for this store instance.
*/
public function __construct($name, array $configuration = array());
/**
* Returns the name of this store instance.
* @return string
*/
public function my_name();
/**
* Initialises a new instance of the cache store given the definition the instance is to be used for.
*
* This function should prepare any given connections etc.
*
* @param cache_definition $definition
*/
public function initialise(cache_definition $definition);
/**
* Returns true if this cache store instance has been initialised.
* @return bool
*/
public function is_initialised();
/**
* Returns true if this cache store instance is ready to use.
* @return bool
*/
public function is_ready();
/**
* Retrieves an item from the cache store given its key.
*
* @param string $key The key to retrieve
* @return mixed The data that was associated with the key, or false if the key did not exist.
*/
public function get($key);
/**
* Retrieves several items from the cache store in a single transaction.
*
* If not all of the items are available in the cache then the data value for those that are missing will be set to false.
*
* @param array $keys The array of keys to retrieve
* @return array An array of items from the cache. There will be an item for each key, those that were not in the store will
* be set to false.
*/
public function get_many($keys);
/**
* Sets an item in the cache given its key and data value.
*
* @param string $key The key to use.
* @param mixed $data The data to set.
* @return bool True if the operation was a success false otherwise.
*/
public function set($key, $data);
/**
* Sets many items in the cache in a single transaction.
*
* @param array $keyvaluearray An array of key value pairs. Each item in the array will be an associative array with two
* keys, 'key' and 'value'.
* @return int The number of items successfully set. It is up to the developer to check this matches the number of items
* sent ... if they care that is.
*/
public function set_many(array $keyvaluearray);
/**
* Deletes an item from the cache store.
*
* @param string $key The key to delete.
* @return bool Returns true if the operation was a success, false otherwise.
*/
public function delete($key);
/**
* Deletes several keys from the cache in a single action.
*
* @param array $keys The keys to delete
* @return int The number of items successfully deleted.
*/
public function delete_many(array $keys);
/**
* Purges the cache deleting all items within it.
*
* @return boolean True on success. False otherwise.
*/
public function purge();
/**
* Performs any necessary clean up when the store instance is being deleted.
*/
public function cleanup();
/**
* Generates an instance of the cache store that can be used for testing.
*
* Returns an instance of the cache store, or false if one cannot be created.
*
* @param cache_definition $definition
* @return cache_store|false
*/
public static function initialise_test_instance(cache_definition $definition);
}
/**
* Cache store feature: locking
*

View File

@ -638,19 +638,22 @@ class cache implements cache_loader {
public function has($key, $tryloadifpossible = false) {
$parsedkey = $this->parse_key($key);
if ($this->is_in_persist_cache($parsedkey)) {
// Hoorah, that was easy. It exists in the persist cache so we definitely have it.
return true;
}
if (($this->has_a_ttl() && !$this->store_supports_native_ttl()) || !$this->store_supports_key_awareness()) {
if ($this->store_supports_key_awareness() && !$this->store->has($parsedkey)) {
return false;
}
if ($this->has_a_ttl() && !$this->store_supports_native_ttl()) {
// The data has a TTL and the store doesn't support it natively.
// We must fetch the data and expect a ttl wrapper.
$data = $this->store->get($parsedkey);
if (!$this->store_supports_native_ttl()) {
$has = ($data instanceof cache_ttl_wrapper && !$data->has_expired());
} else {
$has = ($data !== false);
}
$has = ($data instanceof cache_ttl_wrapper && !$data->has_expired());
} else if (!$this->store_supports_key_awareness()) {
// The store doesn't support key awareness, get the data and check it manually... puke.
// Either no TTL is set of the store supports its handling natively.
$data = $this->store->get($parsedkey);
$has = ($data !== false);
} else {
// The store supports key awareness, this is easy!
// Either no TTL is set of the store supports its handling natively.
$has = $this->store->has($parsedkey);
}
if (!$has && $tryloadifpossible) {

View File

@ -29,13 +29,63 @@
defined('MOODLE_INTERNAL') || die();
/**
* Abstract cache store base class.
* Cache store interface.
*
* This class implements the cache_store interface that all caches store plugins are required in implement.
* It then implements basic methods that likely won't need to be overridden by plugins.
* It will also be used to implement any API changes that come about in the future.
* This interface defines the static methods that must be implemented by every cache store plugin.
* To ensure plugins implement this class the abstract cache_store class implements this interface.
*
* While it is not required that you extend this class it is highly recommended.
* @package core
* @category cache
* @copyright 2012 Sam Hemelryk
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
interface cache_store_interface {
/**
* Static method to check if the store requirements are met.
*
* @return bool True if the stores software/hardware requirements have been met and it can be used. False otherwise.
*/
public static function are_requirements_met();
/**
* Static method to check if a store is usable with the given mode.
*
* @param int $mode One of cache_store::MODE_*
*/
public static function is_supported_mode($mode);
/**
* Returns the supported features as a binary flag.
*
* @param array $configuration The configuration of a store to consider specifically.
* @return int The supported features.
*/
public static function get_supported_features(array $configuration = array());
/**
* Returns the supported modes as a binary flag.
*
* @param array $configuration The configuration of a store to consider specifically.
* @return int The supported modes.
*/
public static function get_supported_modes(array $configuration = array());
/**
* Generates an instance of the cache store that can be used for testing.
*
* Returns an instance of the cache store, or false if one cannot be created.
*
* @param cache_definition $definition
* @return cache_store|false
*/
public static function initialise_test_instance(cache_definition $definition);
}
/**
* Abstract cache store class.
*
* All cache store plugins must extend this base class.
* It lays down the foundation for what is required of a cache store plugin.
*
* @since 2.4
* @package core
@ -43,7 +93,140 @@ defined('MOODLE_INTERNAL') || die();
* @copyright 2012 Sam Hemelryk
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
abstract class cache_store_base implements cache_store {
abstract class cache_store implements cache_store_interface {
// Constants for features a cache store can support
/**
* Supports multi-part keys
*/
const SUPPORTS_MULTIPLE_IDENTIFIERS = 1;
/**
* Ensures data remains in the cache once set.
*/
const SUPPORTS_DATA_GUARANTEE = 2;
/**
* Supports a native ttl system.
*/
const SUPPORTS_NATIVE_TTL = 4;
// Constants for the modes of a cache store
/**
* Application caches. These are shared caches.
*/
const MODE_APPLICATION = 1;
/**
* Session caches. Just access to the PHP session.
*/
const MODE_SESSION = 2;
/**
* Request caches. Static caches really.
*/
const MODE_REQUEST = 4;
/**
* Constructs an instance of the cache store.
*
* This method should not create connections or perform and processing, it should be used
*
* @param string $name The name of the cache store
* @param array $configuration The configuration for this store instance.
*/
abstract public function __construct($name, array $configuration = array());
/**
* Returns the name of this store instance.
* @return string
*/
abstract public function my_name();
/**
* Initialises a new instance of the cache store given the definition the instance is to be used for.
*
* This function should prepare any given connections etc.
*
* @param cache_definition $definition
*/
abstract public function initialise(cache_definition $definition);
/**
* Returns true if this cache store instance has been initialised.
* @return bool
*/
abstract public function is_initialised();
/**
* Returns true if this cache store instance is ready to use.
* @return bool
*/
abstract public function is_ready();
/**
* Retrieves an item from the cache store given its key.
*
* @param string $key The key to retrieve
* @return mixed The data that was associated with the key, or false if the key did not exist.
*/
abstract public function get($key);
/**
* Retrieves several items from the cache store in a single transaction.
*
* If not all of the items are available in the cache then the data value for those that are missing will be set to false.
*
* @param array $keys The array of keys to retrieve
* @return array An array of items from the cache. There will be an item for each key, those that were not in the store will
* be set to false.
*/
abstract public function get_many($keys);
/**
* Sets an item in the cache given its key and data value.
*
* @param string $key The key to use.
* @param mixed $data The data to set.
* @return bool True if the operation was a success false otherwise.
*/
abstract public function set($key, $data);
/**
* Sets many items in the cache in a single transaction.
*
* @param array $keyvaluearray An array of key value pairs. Each item in the array will be an associative array with two
* keys, 'key' and 'value'.
* @return int The number of items successfully set. It is up to the developer to check this matches the number of items
* sent ... if they care that is.
*/
abstract public function set_many(array $keyvaluearray);
/**
* Deletes an item from the cache store.
*
* @param string $key The key to delete.
* @return bool Returns true if the operation was a success, false otherwise.
*/
abstract public function delete($key);
/**
* Deletes several keys from the cache in a single action.
*
* @param array $keys The keys to delete
* @return int The number of items successfully deleted.
*/
abstract public function delete_many(array $keys);
/**
* Purges the cache deleting all items within it.
*
* @return boolean True on success. False otherwise.
*/
abstract public function purge();
/**
* Performs any necessary clean up when the store instance is being deleted.
*/
abstract public function cleanup();
/**
* Returns true if the user can add an instance of the store plugin.
@ -80,4 +263,4 @@ abstract class cache_store_base implements cache_store {
public function supports_native_ttl() {
return $this::supports_data_guarantee() & self::SUPPORTS_NATIVE_TTL;
}
}
}

2
cache/locallib.php vendored
View File

@ -137,7 +137,7 @@ class cache_config_writer extends cache_config {
}
}
$reflection = new ReflectionClass($class);
if (!$reflection->implementsInterface('cache_store')) {
if (!$reflection->isSubclassOf('cache_store')) {
throw new cache_exception('Invalid cache plugin specified. The plugin does not extend the required class.');
}
if (!$class::are_requirements_met()) {

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@ -37,7 +37,7 @@
* @copyright 2012 Sam Hemelryk
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
class cachestore_file extends cache_store_base implements cache_is_key_aware {
class cachestore_file extends cache_store implements cache_is_key_aware {
/**
* The name of the store.

View File

@ -37,7 +37,7 @@ defined('MOODLE_INTERNAL') || die();
* @copyright 2012 Sam Hemelryk
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
class cachestore_memcache extends cache_store_base {
class cachestore_memcache extends cache_store {
/**
* The name of the store

View File

@ -43,7 +43,7 @@ defined('MOODLE_INTERNAL') || die();
* @copyright 2012 Sam Hemelryk
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
class cachestore_memcached extends cache_store_base {
class cachestore_memcached extends cache_store {
/**
* The name of the store

View File

@ -37,7 +37,7 @@ defined('MOODLE_INTERNAL') || die();
* @copyright 2012 Sam Hemelryk
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
class cachestore_mongodb extends cache_store_base {
class cachestore_mongodb extends cache_store {
/**
* The name of the store

View File

@ -351,7 +351,7 @@ class cachestore_session extends session_data_store implements cache_is_key_awar
* @copyright 2012 Sam Hemelryk
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
abstract class session_data_store extends cache_store_base {
abstract class session_data_store extends cache_store {
/**
* Used for the actual storage.

View File

@ -34,7 +34,7 @@ defined('MOODLE_INTERNAL') || die();
* @copyright 2012 Sam Hemelryk
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
class cachestore_static extends static_data_store implements cache_store, cache_is_key_aware {
class cachestore_static extends static_data_store implements cache_is_key_aware {
/**
* The name of the store
@ -351,7 +351,7 @@ class cachestore_static extends static_data_store implements cache_store, cache_
* @copyright 2012 Sam Hemelryk
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
abstract class static_data_store extends cache_store_base {
abstract class static_data_store extends cache_store {
/**
* An array for storage.