aboutsummaryrefslogtreecommitdiff
path: root/engine/classes/ElggCache.php
diff options
context:
space:
mode:
Diffstat (limited to 'engine/classes/ElggCache.php')
-rw-r--r--engine/classes/ElggCache.php243
1 files changed, 243 insertions, 0 deletions
diff --git a/engine/classes/ElggCache.php b/engine/classes/ElggCache.php
new file mode 100644
index 000000000..4317f4be9
--- /dev/null
+++ b/engine/classes/ElggCache.php
@@ -0,0 +1,243 @@
+<?php
+/**
+ * ElggCache The elgg cache superclass.
+ * This defines the interface for a cache (wherever that cache is stored).
+ *
+ * @package Elgg.Core
+ * @subpackage Cache
+ */
+abstract class ElggCache implements ArrayAccess {
+ /**
+ * Variables for the cache object.
+ *
+ * @var array
+ */
+ private $variables;
+
+ /**
+ * Set the constructor.
+ */
+ function __construct() {
+ $this->variables = array();
+ }
+
+ /**
+ * Set a cache variable.
+ *
+ * @param string $variable Name
+ * @param string $value Value
+ *
+ * @return void
+ *
+ * @deprecated 1.8 Use ElggCache:setVariable()
+ */
+ public function set_variable($variable, $value) {
+ elgg_deprecated_notice('ElggCache::set_variable() is deprecated by ElggCache::setVariable()', 1.8);
+ $this->setVariable($variable, $value);
+ }
+
+ /**
+ * Set a cache variable.
+ *
+ * @param string $variable Name
+ * @param string $value Value
+ *
+ * @return void
+ */
+ public function setVariable($variable, $value) {
+ if (!is_array($this->variables)) {
+ $this->variables = array();
+ }
+
+ $this->variables[$variable] = $value;
+ }
+
+ /**
+ * Get variables for this cache.
+ *
+ * @param string $variable Name
+ *
+ * @return mixed The value or null;
+ *
+ * @deprecated 1.8 Use ElggCache::getVariable()
+ */
+ public function get_variable($variable) {
+ elgg_deprecated_notice('ElggCache::get_variable() is deprecated by ElggCache::getVariable()', 1.8);
+ return $this->getVariable($variable);
+ }
+
+ /**
+ * Get variables for this cache.
+ *
+ * @param string $variable Name
+ *
+ * @return mixed The variable or null;
+ */
+ public function getVariable($variable) {
+ if (isset($this->variables[$variable])) {
+ return $this->variables[$variable];
+ }
+
+ return null;
+ }
+
+ /**
+ * Class member get overloading, returning key using $this->load defaults.
+ *
+ * @param string $key Name
+ *
+ * @return mixed
+ */
+ function __get($key) {
+ return $this->load($key);
+ }
+
+ /**
+ * Class member set overloading, setting a key using $this->save defaults.
+ *
+ * @param string $key Name
+ * @param mixed $value Value
+ *
+ * @return mixed
+ */
+ function __set($key, $value) {
+ return $this->save($key, $value);
+ }
+
+ /**
+ * Supporting isset, using $this->load() with default values.
+ *
+ * @param string $key The name of the attribute or metadata.
+ *
+ * @return bool
+ */
+ function __isset($key) {
+ return (bool)$this->load($key);
+ }
+
+ /**
+ * Supporting unsetting of magic attributes.
+ *
+ * @param string $key The name of the attribute or metadata.
+ *
+ * @return bool
+ */
+ function __unset($key) {
+ return $this->delete($key);
+ }
+
+ /**
+ * Save data in a cache.
+ *
+ * @param string $key Name
+ * @param string $data Value
+ *
+ * @return bool
+ */
+ abstract public function save($key, $data);
+
+ /**
+ * Load data from the cache using a given key.
+ *
+ * @todo $offset is a horrible variable name because it creates confusion
+ * with the ArrayAccess methods
+ *
+ * @param string $key Name
+ * @param int $offset Offset
+ * @param int $limit Limit
+ *
+ * @return mixed The stored data or false.
+ */
+ abstract public function load($key, $offset = 0, $limit = null);
+
+ /**
+ * Invalidate a key
+ *
+ * @param string $key Name
+ *
+ * @return bool
+ */
+ abstract public function delete($key);
+
+ /**
+ * Clear out all the contents of the cache.
+ *
+ * @return bool
+ */
+ abstract public function clear();
+
+ /**
+ * Add a key only if it doesn't already exist.
+ * Implemented simply here, if you extend this class and your caching engine
+ * provides a better way then override this accordingly.
+ *
+ * @param string $key Name
+ * @param string $data Value
+ *
+ * @return bool
+ */
+ public function add($key, $data) {
+ if (!isset($this[$key])) {
+ return $this->save($key, $data);
+ }
+
+ return false;
+ }
+
+ // ARRAY ACCESS INTERFACE //////////////////////////////////////////////////////////
+
+ /**
+ * Assigns a value for the specified key
+ *
+ * @see ArrayAccess::offsetSet()
+ *
+ * @param mixed $key The key (offset) to assign the value to.
+ * @param mixed $value The value to set.
+ *
+ * @return void
+ */
+ function offsetSet($key, $value) {
+ $this->save($key, $value);
+ }
+
+ /**
+ * Get the value for specified key
+ *
+ * @see ArrayAccess::offsetGet()
+ *
+ * @param mixed $key The key (offset) to retrieve.
+ *
+ * @return mixed
+ */
+ function offsetGet($key) {
+ return $this->load($key);
+ }
+
+ /**
+ * Unsets a key.
+ *
+ * @see ArrayAccess::offsetUnset()
+ *
+ * @param mixed $key The key (offset) to unset.
+ *
+ * @return void
+ */
+ function offsetUnset($key) {
+ if (isset($this->$key)) {
+ unset($this->$key);
+ }
+ }
+
+ /**
+ * Does key exist
+ *
+ * @see ArrayAccess::offsetExists()
+ *
+ * @param mixed $key A key (offset) to check for.
+ *
+ * @return bool
+ */
+ function offsetExists($key) {
+ return isset($this->$key);
+ }
+}