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MDL-36768 cache: replaced cache_store interface with abstract class

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1 parent bd18885 commit 75cde6b9ac7757d91cd3941cec75bb1c0f4aa708 Sam Hemelryk committed Nov 23, 2012
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2 cache/classes/config.php
@@ -182,7 +182,7 @@ public function load() {
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
26 cache/classes/dummystore.php
@@ -37,7 +37,7 @@
* @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.
@@ -136,30 +136,6 @@ public static function is_supported_mode($mode) {
}
/**
- * 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 $key
* @return string|false
View
221 cache/classes/interfaces.php
@@ -231,227 +231,6 @@ public function release_lock($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
*
* This is a feature that cache stores can implement if they wish to support locking themselves rather
View
21 cache/classes/loaders.php
@@ -638,19 +638,22 @@ public function set_many(array $keyvaluearray) {
public function has($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
197 cache/classes/store.php
@@ -29,21 +29,204 @@
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
* @category cache
* @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 @@ public function supports_multiple_identifiers() {
public function supports_native_ttl() {
return $this::supports_data_guarantee() & self::SUPPORTS_NATIVE_TTL;
}
-}
+}
View
2 cache/locallib.php
@@ -137,7 +137,7 @@ public function add_store_instance($name, $plugin, array $configuration = array(
}
}
$reflection = new ReflectionClass($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()) {
View
2 cache/stores/file/lib.php
@@ -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
2 cache/stores/memcache/lib.php
@@ -37,7 +37,7 @@
* @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
2 cache/stores/memcached/lib.php
@@ -43,7 +43,7 @@
* @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
2 cache/stores/mongodb/lib.php
@@ -37,7 +37,7 @@
* @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
2 cache/stores/session/lib.php
@@ -351,7 +351,7 @@ public function my_name() {
* @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
4 cache/stores/static/lib.php
@@ -34,7 +34,7 @@
* @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 @@ public function my_name() {
* @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.

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