Current Path : C:/xampp/htdocs/moodle/cache/stores/redis/ |
Current File : C:/xampp/htdocs/moodle/cache/stores/redis/lib.php |
<?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/>. /** * Redis Cache Store - Main library * * @package cachestore_redis * @copyright 2013 Adam Durana * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later */ defined('MOODLE_INTERNAL') || die(); /** * Redis Cache Store * * To allow separation of definitions in Moodle and faster purging, each cache * is implemented as a Redis hash. That is a trade-off between having functionality of TTL * and being able to manage many caches in a single redis instance. Given the recommendation * not to use TTL if at all possible and the benefits of having many stores in Redis using the * hash configuration, the hash implementation has been used. * * @copyright 2013 Adam Durana * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later */ class cachestore_redis extends cache_store implements cache_is_key_aware, cache_is_lockable, cache_is_configurable, cache_is_searchable { /** * Compressor: none. */ const COMPRESSOR_NONE = 0; /** * Compressor: PHP GZip. */ const COMPRESSOR_PHP_GZIP = 1; /** * Compressor: PHP Zstandard. */ const COMPRESSOR_PHP_ZSTD = 2; /** * Name of this store. * * @var string */ protected $name; /** * The definition hash, used for hash key * * @var string */ protected $hash; /** * Flag for readiness! * * @var boolean */ protected $isready = false; /** * Cache definition for this store. * * @var cache_definition */ protected $definition = null; /** * Connection to Redis for this store. * * @var Redis */ protected $redis; /** * Serializer for this store. * * @var int */ protected $serializer = Redis::SERIALIZER_PHP; /** * Compressor for this store. * * @var int */ protected $compressor = self::COMPRESSOR_NONE; /** * Determines if the requirements for this type of store are met. * * @return bool */ public static function are_requirements_met() { return class_exists('Redis'); } /** * Determines if this type of store supports a given mode. * * @param int $mode * @return bool */ public static function is_supported_mode($mode) { return ($mode === self::MODE_APPLICATION || $mode === self::MODE_SESSION); } /** * Get the features of this type of cache store. * * @param array $configuration * @return int */ public static function get_supported_features(array $configuration = array()) { return self::SUPPORTS_DATA_GUARANTEE + self::DEREFERENCES_OBJECTS + self::IS_SEARCHABLE; } /** * Get the supported modes of this type of cache store. * * @param array $configuration * @return int */ public static function get_supported_modes(array $configuration = array()) { return self::MODE_APPLICATION + self::MODE_SESSION; } /** * Constructs an instance of this type of store. * * @param string $name * @param array $configuration */ public function __construct($name, array $configuration = array()) { $this->name = $name; if (!array_key_exists('server', $configuration) || empty($configuration['server'])) { return; } if (array_key_exists('serializer', $configuration)) { $this->serializer = (int)$configuration['serializer']; } if (array_key_exists('compressor', $configuration)) { $this->compressor = (int)$configuration['compressor']; } $password = !empty($configuration['password']) ? $configuration['password'] : ''; $prefix = !empty($configuration['prefix']) ? $configuration['prefix'] : ''; $this->redis = $this->new_redis($configuration['server'], $prefix, $password); } /** * Create a new Redis instance and * connect to the server. * * @param string $server The server connection string * @param string $prefix The key prefix * @param string $password The server connection password * @return Redis */ protected function new_redis($server, $prefix = '', $password = '') { $redis = new Redis(); // Check if it isn't a Unix socket to set default port. $port = ($server[0] === '/') ? null : 6379; if (strpos($server, ':')) { $serverconf = explode(':', $server); $server = $serverconf[0]; $port = $serverconf[1]; } if ($redis->connect($server, $port)) { if (!empty($password)) { $redis->auth($password); } // If using compressor, serialisation will be done at cachestore level, not php-redis. if ($this->compressor == self::COMPRESSOR_NONE) { $redis->setOption(Redis::OPT_SERIALIZER, $this->serializer); } if (!empty($prefix)) { $redis->setOption(Redis::OPT_PREFIX, $prefix); } // Database setting option... $this->isready = $this->ping($redis); } else { $this->isready = false; } return $redis; } /** * See if we can ping Redis server * * @param Redis $redis * @return bool */ protected function ping(Redis $redis) { try { if ($redis->ping() === false) { return false; } } catch (Exception $e) { return false; } return true; } /** * Get the name of the store. * * @return string */ public function my_name() { return $this->name; } /** * Initialize the store. * * @param cache_definition $definition * @return bool */ public function initialise(cache_definition $definition) { $this->definition = $definition; $this->hash = $definition->generate_definition_hash(); return true; } /** * Determine if the store is initialized. * * @return bool */ public function is_initialised() { return ($this->definition !== null); } /** * Determine if the store is ready for use. * * @return bool */ public function is_ready() { return $this->isready; } /** * Get the value associated with a given key. * * @param string $key The key to get the value of. * @return mixed The value of the key, or false if there is no value associated with the key. */ public function get($key) { $value = $this->redis->hGet($this->hash, $key); if ($this->compressor == self::COMPRESSOR_NONE) { return $value; } return $this->uncompress($value); } /** * Get the values associated with a list of keys. * * @param array $keys The keys to get the values of. * @return array An array of the values of the given keys. */ public function get_many($keys) { $values = $this->redis->hMGet($this->hash, $keys); if ($this->compressor == self::COMPRESSOR_NONE) { return $values; } foreach ($values as &$value) { $value = $this->uncompress($value); } return $values; } /** * Set the value of a key. * * @param string $key The key to set the value of. * @param mixed $value The value. * @return bool True if the operation succeeded, false otherwise. */ public function set($key, $value) { if ($this->compressor != self::COMPRESSOR_NONE) { $value = $this->compress($value); } return ($this->redis->hSet($this->hash, $key, $value) !== false); } /** * Set the values of many keys. * * @param array $keyvaluearray An array of key/value pairs. Each item in the array is an associative array * with two keys, 'key' and 'value'. * @return int The number of key/value pairs successfuly set. */ public function set_many(array $keyvaluearray) { $pairs = []; foreach ($keyvaluearray as $pair) { $key = $pair['key']; if ($this->compressor != self::COMPRESSOR_NONE) { $pairs[$key] = $this->compress($pair['value']); } else { $pairs[$key] = $pair['value']; } } if ($this->redis->hMSet($this->hash, $pairs)) { return count($pairs); } return 0; } /** * Delete the given key. * * @param string $key The key to delete. * @return bool True if the delete operation succeeds, false otherwise. */ public function delete($key) { return ($this->redis->hDel($this->hash, $key) > 0); } /** * Delete many keys. * * @param array $keys The keys to delete. * @return int The number of keys successfully deleted. */ public function delete_many(array $keys) { // Redis needs the hash as the first argument, so we have to put it at the start of the array. array_unshift($keys, $this->hash); return call_user_func_array(array($this->redis, 'hDel'), $keys); } /** * Purges all keys from the store. * * @return bool */ public function purge() { return ($this->redis->del($this->hash) !== false); } /** * Cleans up after an instance of the store. */ public function instance_deleted() { $this->purge(); $this->redis->close(); unset($this->redis); } /** * Determines if the store has a given key. * * @see cache_is_key_aware * @param string $key The key to check for. * @return bool True if the key exists, false if it does not. */ public function has($key) { return !empty($this->redis->hExists($this->hash, $key)); } /** * Determines if the store has any of the keys in a list. * * @see cache_is_key_aware * @param array $keys The keys to check for. * @return bool True if any of the keys are found, false none of the keys are found. */ public function has_any(array $keys) { foreach ($keys as $key) { if ($this->has($key)) { return true; } } return false; } /** * Determines if the store has all of the keys in a list. * * @see cache_is_key_aware * @param array $keys The keys to check for. * @return bool True if all of the keys are found, false otherwise. */ public function has_all(array $keys) { foreach ($keys as $key) { if (!$this->has($key)) { return false; } } return true; } /** * Tries to acquire a lock with a given name. * * @see cache_is_lockable * @param string $key Name of the lock to acquire. * @param string $ownerid Information to identify owner of lock if acquired. * @return bool True if the lock was acquired, false if it was not. */ public function acquire_lock($key, $ownerid) { return $this->redis->setnx($key, $ownerid); } /** * Checks a lock with a given name and owner information. * * @see cache_is_lockable * @param string $key Name of the lock to check. * @param string $ownerid Owner information to check existing lock against. * @return mixed True if the lock exists and the owner information matches, null if the lock does not * exist, and false otherwise. */ public function check_lock_state($key, $ownerid) { $result = $this->redis->get($key); if ($result === $ownerid) { return true; } if ($result === false) { return null; } return false; } /** * Finds all of the keys being used by this cache store instance. * * @return array of all keys in the hash as a numbered array. */ public function find_all() { return $this->redis->hKeys($this->hash); } /** * Finds all of the keys whose keys start with the given prefix. * * @param string $prefix * * @return array List of keys that match this prefix. */ public function find_by_prefix($prefix) { $return = []; foreach ($this->find_all() as $key) { if (strpos($key, $prefix) === 0) { $return[] = $key; } } return $return; } /** * Releases a given lock if the owner information matches. * * @see cache_is_lockable * @param string $key Name of the lock to release. * @param string $ownerid Owner information to use. * @return bool True if the lock is released, false if it is not. */ public function release_lock($key, $ownerid) { if ($this->check_lock_state($key, $ownerid)) { return ($this->redis->del($key) !== false); } return false; } /** * Creates a configuration array from given 'add instance' form data. * * @see cache_is_configurable * @param stdClass $data * @return array */ public static function config_get_configuration_array($data) { return array( 'server' => $data->server, 'prefix' => $data->prefix, 'password' => $data->password, 'serializer' => $data->serializer, 'compressor' => $data->compressor, ); } /** * Sets form data from a configuration array. * * @see cache_is_configurable * @param moodleform $editform * @param array $config */ public static function config_set_edit_form_data(moodleform $editform, array $config) { $data = array(); $data['server'] = $config['server']; $data['prefix'] = !empty($config['prefix']) ? $config['prefix'] : ''; $data['password'] = !empty($config['password']) ? $config['password'] : ''; if (!empty($config['serializer'])) { $data['serializer'] = $config['serializer']; } if (!empty($config['compressor'])) { $data['compressor'] = $config['compressor']; } $editform->set_data($data); } /** * Creates an instance of the store for testing. * * @param cache_definition $definition * @return mixed An instance of the store, or false if an instance cannot be created. */ public static function initialise_test_instance(cache_definition $definition) { if (!self::are_requirements_met()) { return false; } $config = get_config('cachestore_redis'); if (empty($config->test_server)) { return false; } $configuration = array('server' => $config->test_server); if (!empty($config->test_serializer)) { $configuration['serializer'] = $config->test_serializer; } if (!empty($config->test_password)) { $configuration['password'] = $config->test_password; } $cache = new cachestore_redis('Redis test', $configuration); $cache->initialise($definition); return $cache; } /** * Return configuration to use when unit testing. * * @return array */ public static function unit_test_configuration() { global $DB; if (!self::are_requirements_met() || !self::ready_to_be_used_for_testing()) { throw new moodle_exception('TEST_CACHESTORE_REDIS_TESTSERVERS not configured, unable to create test configuration'); } return ['server' => TEST_CACHESTORE_REDIS_TESTSERVERS, 'prefix' => $DB->get_prefix(), ]; } /** * Returns true if this cache store instance is both suitable for testing, and ready for testing. * * When TEST_CACHESTORE_REDIS_TESTSERVERS is set, then we are ready to be use d for testing. * * @return bool */ public static function ready_to_be_used_for_testing() { return defined('TEST_CACHESTORE_REDIS_TESTSERVERS'); } /** * Gets an array of options to use as the serialiser. * @return array */ public static function config_get_serializer_options() { $options = array( Redis::SERIALIZER_PHP => get_string('serializer_php', 'cachestore_redis') ); if (defined('Redis::SERIALIZER_IGBINARY')) { $options[Redis::SERIALIZER_IGBINARY] = get_string('serializer_igbinary', 'cachestore_redis'); } return $options; } /** * Gets an array of options to use as the compressor. * * @return array */ public static function config_get_compressor_options() { $arr = [ self::COMPRESSOR_NONE => get_string('compressor_none', 'cachestore_redis'), self::COMPRESSOR_PHP_GZIP => get_string('compressor_php_gzip', 'cachestore_redis'), ]; // Check if the Zstandard PHP extension is installed. if (extension_loaded('zstd')) { $arr[self::COMPRESSOR_PHP_ZSTD] = get_string('compressor_php_zstd', 'cachestore_redis'); } return $arr; } /** * Compress the given value, serializing it first. * * @param mixed $value * @return string */ private function compress($value) { $value = $this->serialize($value); switch ($this->compressor) { case self::COMPRESSOR_NONE: return $value; case self::COMPRESSOR_PHP_GZIP: return gzencode($value); case self::COMPRESSOR_PHP_ZSTD: return zstd_compress($value); default: debugging("Invalid compressor: {$this->compressor}"); return $value; } } /** * Uncompresses (deflates) the data, unserialising it afterwards. * * @param string $value * @return mixed */ private function uncompress($value) { if ($value === false) { return false; } switch ($this->compressor) { case self::COMPRESSOR_NONE: break; case self::COMPRESSOR_PHP_GZIP: $value = gzdecode($value); break; case self::COMPRESSOR_PHP_ZSTD: $value = zstd_uncompress($value); break; default: debugging("Invalid compressor: {$this->compressor}"); } return $this->unserialize($value); } /** * Serializes the data according to the configured serializer. * * @param mixed $value * @return string */ private function serialize($value) { switch ($this->serializer) { case Redis::SERIALIZER_NONE: return $value; case Redis::SERIALIZER_PHP: return serialize($value); case defined('Redis::SERIALIZER_IGBINARY') && Redis::SERIALIZER_IGBINARY: return igbinary_serialize($value); default: debugging("Invalid serializer: {$this->serializer}"); return $value; } } /** * Unserializes the data according to the configured serializer * * @param string $value * @return mixed */ private function unserialize($value) { switch ($this->serializer) { case Redis::SERIALIZER_NONE: return $value; case Redis::SERIALIZER_PHP: return unserialize($value); case defined('Redis::SERIALIZER_IGBINARY') && Redis::SERIALIZER_IGBINARY: return igbinary_unserialize($value); default: debugging("Invalid serializer: {$this->serializer}"); return $value; } } }