Merge branch 'MDL-79165-main' of https://github.com/daledavies/moodle

cache/stores/file/addinstanceform.php

@@ -53,5 +53,11 @@ class cachestore_file_addinstance_form extends cachestore_addinstance_form {
         $form->setDefault('lockwait', 60);
         $form->setType('lockwait', PARAM_INT);
         $form->addHelpButton('lockwait', 'lockwait', 'cachestore_file');
+
+        $serializeroptions = cachestore_file::config_get_serializer_options();
+        $form->addElement('select', 'serializer', get_string('useserializer', 'cachestore_file'), $serializeroptions);
+        $form->setDefault('serializer', cachestore_file::SERIALIZER_PHP);
+        $form->setType('serializer', PARAM_ALPHA);
+        $form->addHelpButton('serializer', 'useserializer', 'cachestore_file');
     }
 }

cache/stores/file/lang/en/cachestore_file.php

@@ -40,6 +40,8 @@ $string['pluginname'] = 'File cache';
 $string['privacy:metadata'] = 'The File cache cachestore plugin stores data briefly as part of its caching functionality but this data is regularly cleared.';
 $string['prescan'] = 'Prescan directory';
 $string['prescan_help'] = 'If enabled the directory is scanned when the cache is first used and requests for files are first checked against the scan data. This can help if you have a slow file system and are finding that file operations are causing you a bottle neck.';
+$string['serializer_igbinary'] = 'The igbinary serializer.';
+$string['serializer_php'] = 'The default PHP serializer.';
 $string['singledirectory'] = 'Single directory store';
 $string['singledirectory_help'] = 'If enabled files (cached items) will be stored in a single directory rather than being broken up into multiple directories.
 
@@ -50,6 +52,9 @@ It is advisable to only turn this on if the following is true:
 * If you know the number of items in the cache is going to be small enough that it won\'t cause issues on the file system you are running with.
 * The data being cached is not expensive to generate. If it is then sticking with the default may still be the better option as it reduces the chance of issues.';
 $string['task_asyncpurge'] = 'Asynchronously purge file store old cache revision directories';
+$string['useserializer'] = 'Use serializer';
+$string['useserializer_help'] = 'Specifies the serializer to use for serializing.
+If available the igbinary serializer can reduce the storage requirements for large caches, this is supported only when the igbinary extension is loaded.';
 
 /**
  * This is is like the file store, but designed for siutations where:

cache/stores/file/lib.php

@@ -39,6 +39,16 @@ class cachestore_file extends store implements
     searchable_cache_interface,
     lockable_cache_interface
 {
+    /**
+     * Value to represent use of the PHP serializer.
+     */
+    public const SERIALIZER_PHP = 'php';
+
+    /**
+     * Value to represent use of the Igbinary serializer.
+     */
+    public const SERIALIZER_IGBINARY = 'igbinary';
+
     /**
      * The name of the store.
      * @var string
@@ -145,6 +155,37 @@ class cachestore_file extends store implements
      */
     protected $locks = [];
 
+    /**
+     * Serializer for this store.
+     *
+     * @var string
+     */
+    protected $serializer = self::SERIALIZER_PHP;
+
+    /**
+     * Determine if igbinary functions are available for use.
+     *
+     * @return boolean
+     */
+    public static function igbinary_available(): bool {
+        return function_exists('igbinary_serialize');
+    }
+
+    /**
+     * Gets an array of options to use as the serialiser.
+     *
+     * @return array
+     */
+    public static function config_get_serializer_options(): array {
+        $options = [
+            self::SERIALIZER_PHP => get_string('serializer_php', 'cachestore_file'),
+        ];
+        if (self::igbinary_available()) {
+            $options[self::SERIALIZER_IGBINARY] = get_string('serializer_igbinary', 'cachestore_file');
+        }
+        return $options;
+    }
+
     /**
      * Constructs the store instance.
      *
@@ -225,6 +266,11 @@ class cachestore_file extends store implements
             // File locking is disabled in config, fall back to default lock factory.
             $this->lockfactory = \core\lock\lock_config::get_lock_factory('cachestore_file');
         }
+
+        // Set the serializer to use based on configuration.
+        if (array_key_exists('serializer', $configuration)) {
+            $this->serializer = (string)$configuration['serializer'];
+        }
     }
 
     /**
@@ -549,7 +595,7 @@ class cachestore_file extends store implements
      * @return string
      */
     protected function prep_data_before_save($data) {
-        return serialize($data);
+        return $this->serialize($data);
     }
 
     /**
@@ -560,8 +606,8 @@ class cachestore_file extends store implements
      * @return mixed
      */
     protected function prep_data_after_read($data, $path) {
-        $result = @unserialize($data);
-        if ($result === false && $data != serialize(false)) {
+        $result = @$this->unserialize($data);
+        if ($result === false && $data != @$this->serialize(false)) {
             debugging('Failed to unserialise data from cache file: ' . $path . '. Data: ' . $data, DEBUG_DEVELOPER);
             return false;
         }
@@ -720,6 +766,9 @@ class cachestore_file extends store implements
         if (isset($data->lockwait)) {
             $config['lockwait'] = $data->lockwait;
         }
+        if (isset($data->serializer)) {
+            $config['serializer'] = $data->serializer;
+        }
 
         return $config;
     }
@@ -750,6 +799,9 @@ class cachestore_file extends store implements
         if (isset($config['lockwait'])) {
             $data['lockwait'] = (int)$config['lockwait'];
         }
+        if (isset($config['serializer'])) {
+            $data['serializer'] = (string)$config['serializer'];
+        }
         $editform->set_data($data);
     }
 
@@ -1037,4 +1089,42 @@ class cachestore_file extends store implements
         }
         return $unlocked;
     }
+
+    /**
+     * Serializes the data according to the configured serializer.
+     *
+     * @param mixed $value
+     * @return string
+     */
+    protected function serialize($value): string {
+        switch ($this->serializer) {
+            case self::SERIALIZER_PHP:
+                return serialize($value);
+            case self::SERIALIZER_IGBINARY:
+                if (self::igbinary_available()) {
+                    return igbinary_serialize($value);
+                }
+        }
+        debugging("Unknown or unavailable serializer {$this->serializer}");
+        return serialize($value);
+    }
+
+    /**
+     * Unserializes the data according to the configured serializer.
+     *
+     * @param mixed $value
+     * @return mixed
+     */
+    protected function unserialize($value) {
+        switch ($this->serializer) {
+            case self::SERIALIZER_PHP:
+                return unserialize($value);
+            case self::SERIALIZER_IGBINARY:
+                if (self::igbinary_available()) {
+                    return igbinary_unserialize($value);
+                }
+        }
+        debugging("Unknown or unavailable serializer: {$this->serializer}");
+        return unserialize($value);
+    }
 }

cache/stores/file/tests/store_test.php

@@ -44,6 +44,45 @@ class store_test extends \cachestore_tests {
         return 'cachestore_file';
     }
 
+    /**
+     * Provider for set/get tests with all combinations of serializer.
+     *
+     * @return array
+     */
+    public static function getset_serialization_test_provider(): array {
+        $data = [
+            [
+                'PHP serializer',
+                \cachestore_file::SERIALIZER_PHP,
+            ],
+        ];
+        if (function_exists('igbinary_serialize')) {
+            $data[] = [
+                'Igbinary serializer',
+                \cachestore_file::SERIALIZER_IGBINARY,
+            ];
+        }
+
+        return $data;
+    }
+
+    /**
+     * Test get and set function correctly with all combinations of serializer.
+     *
+     * @dataProvider getset_serialization_test_provider
+     * @param string $name
+     * @param string $serializer
+     */
+    public function test_getset_serialization(string $name, string $serializer): void {
+        $definition = definition::load_adhoc(store::MODE_APPLICATION, 'cachestore_file', 'phpunit_test');
+        $store = new \cachestore_file('Test', ['serializer' => $serializer]);
+        $store->initialise($definition);
+        $originalvalue = 'value12345';
+        $store->set('key', $originalvalue);
+        $unserializedvalue = $store->get('key');
+        self::assertSame($originalvalue, $unserializedvalue, "Invalid serialisation/unserialisation for: {$name}");
+    }
+
     /**
      * Testing cachestore_file::get with prescan enabled and with
      * deleting the cache between the prescan and the call to get.