RedisCache.php

<?php

use Redis;
use Exception;

/**
 * Redis cache - Port from Phalcon Cache
 * Cut intergate from backend and front cache
 * I don't test or try run it. This pass on php linter.
 * When I want to use it, I will check later.
 * Welcome any fix.
 *
 * Port by Nimit Suwannagate <[email protected]>
 */
class RedisCache
{

    protected $_redis = null;
    protected $_options = null;
    protected $_prefix = "";

    /**
     * RedisLoggerAdapter constructor
     *
     * @param   array options
     */
    public function __construct($options = null)
    {
        if ($options != "array") {
            $options = [];
        }

        $this->_options = $options;

        if (!isset($this->_options["host"])) {
            $this->_options["host"] = "127.0.0.1";
        }

        if (!isset($this->_options["port"])) {
            $this->_options["port"] = 6379;
        }

        if (!isset($this->_options["index"])) {
            $this->_options["index"] = 0;
        }

        if (!isset($this->_options["persistent"])) {
            $this->_options["persistent"] = false;
        }

        if (!isset($this->_options["statsKey"]) || empty($this->_options["statsKey"])) {
            $this->_options["statsKey"] = "_RDC";
        }

        if (!empty($this->_options["prefix"])) {
            $this->_prefix = $this->_options["prefix"];
        }

    }

    /**
     * Create internal connection to redis
     */
    public function _connect()
    {
        $this->_options = $this->_options;
        $redis = new Redis();

        if (!empty($this->_options["host"]) && !empty($this->_options["port"]) && !empty($this->_options["persistent"])){
            throw new Exception("Unexpected inconsistency in options");
        }

        if ($this->_options["persistent"]) {
            $success = $redis->pconnect($this->_options["host"], $this->_options["port"]);
        } else {
            $success = $redis->connect($this->_options["host"], $this->_options["port"]);
        }

        if (!$success) {
            throw new Exception("Could not connect to the Redisd server ".$this->_options["host"].":".$this->_options["port"]);
        }

        if (!empty($this->_options["auth"])){
            $success = $redis->auth($this->_options["auth"]);

            if (!$success) {
                throw new Exception("Failed to authenticate with the Redisd server");
            }
        }

        if (!empty($this->_options["index"])){
            $success = $redis->select($this->_options["index"]);

            if (!$success) {
                throw new Exception("Redisd server selected database failed");
            }
        }

        $this->_redis = $redis;
    }

    protected function _prepareKey($keyName)
    {
        if (!isset($this->_options["statsKey"])) {
            throw new Exception("Unexpected inconsistency in options");
        }
        return $this->options["statsKey"] . $this->_prefix . $keyName;
    }

    /**
     * Returns a cached content
     *
     * @param int|string keyName
     * @param   long lifetime
     * @return  mixed
     */
    public function get($keyName, $lifetime = null)
    {
        /**
         * Check if a connection is created or make a new one
         */
        if (!is_object($this->_redis)) {
            $this->_connect();
        }

        $lastKey = $this->_prepareKey($keyName);

        $cachedContent = $this->_redis->get($lastKey);
        
        if (! $cachedContent) {
            return null;
        }

        return json_decode($cachedContent, true);
    }

    /**
     * Stores cached content into the file backend and stops the frontend
     *
     * @param int|string keyName
     * @param string content
     * @param long lifetime
     */
    public function save($keyName, $content, $lifetime = null)
    {
        if (!isset($this->_options["statsKey"])) {
            throw new Exception("Unexpected inconsistency in options");
        }

        $lastKey = $this->_prepareKey($keyName);

        /**
         * Check if a connection is created or make a new one
         */
        if (!is_object($this->_redis)) {
            $this->_connect();
        }

        $success = $this->_redis->set($lastKey, json_encode($content));

        if (!$success) {
            throw new Exception("Failed storing the data in redis");
        }

        if ($lifetime) {
            $this->_redis->settimeout($lastKey, $lifetime);
        }

        // add last key for list purge
        $this->_redis->sAdd($this->_options["statsKey"], $lastKey);

        return true;
    }

    /**
     * Deletes a value from the cache by its key
     *
     * @param int|string keyName
     * @return boolean
     */
    public function delete($keyName)
    {
        /**
         * Check if a connection is created or make a new one
         */
        if (!is_object($this->_redis)) {
            $this->_connect();
        }

        if (!isset($this->_options["statsKey"])) {
            throw new Exception("Unexpected inconsistency in options");
        }

        $lastKey = $this->_prepareKey($keyName);

        $this->_redis->sRem($this->_options["statsKey"], $lastKey);

        /**
        * Delete the key from redis
        */
        return $this->_redis->delete($lastKey);
    }

    /**
     * Query the existing cached keys
     *
     * @return array
     */
    public function queryKeys($prefix = null)
    {
        /**
         * Check if a connection is created or make a new one
         */
        if (!is_object($this->_redis)) {
            $this->_connect();
        }

        if (!isset($this->_options["statsKey"])) {
            throw new Exception("Unexpected inconsistency in options");
        }

        /**
        * Get the key from redis
        */
        $keys = $this->_redis->sMembers($this->_options["statsKey"]);
        if (is_array($keys)) {
            foreach ($keys as $key => $value) {
                if ($prefix && !strpos($value, $prefix) === 0) {
                    unset($keys[$key]);
                }
            }
        }

        return $keys;
    }

    /**
     * Checks if cache exists and it isn't expired
     *
     * @param string keyName
     * @return boolean
     */
    public function exists($keyName)
    {
        $lastKey = $this->_prepareKey($keyName);

        if ($lastKey) {
            /**
             * Check if a connection is created or make a new one
             */
            if (!is_object($this->_redis)) {
                $this->_connect();
            }

            if (!$this->_redis->get($lastKey)) {
                return false;
            }
            return true;
        }

        return false;
    }

    /**
     * Increment of given $keyName by $value
     *
     * @param  string keyName
     * @param  long value
     * @return long
     */
    public function increment($keyName, $value = null)
    {
        /**
         * Check if a connection is created or make a new one
         */
        if (!is_object($this->_redis)) {
            $this->_connect();
        }

        $lastKey = $this->_prepareKey($keyName);

        if (!$value) {
            $value = 1;
        }

        return $this->_redis->incrBy($lastKey, $value);
    }

    /**
     * Decrement of $keyName by given $value
     *
     * @param  string keyName
     * @param  long value
     * @return long
     */
    public function decrement($keyName, $value = null)
    {
        /**
         * Check if a connection is created or make a new one
         */
        if (!is_object($this->_redis)) {
            $this->_connect();
        }

        $lastKey = $this->_prepareKey($keyName);

        if (!$value) {
            $value = 1;
        }

        return $this->_redis->decrBy($lastKey, $value);
    }

    /**
     * Immediately invalidates all existing items.
     */
    public function flush()
    {
        /**
         * Check if a connection is created or make a new one
         */
        if (!is_object($this->_redis)) {
            $this->_connect();
        }

        if (!isset($this->_options["statsKey"])) {
            throw new Exception("Unexpected inconsistency in options");
        }

        $keys = $this->_redis->sMembers($this->_options["statsKey"]);
        if (is_array($keys)) {
            foreach ($keys as $key) {
                $this->_redis->sRem($this->_options["statsKey"], $key);
                $this->_redis->delete($key);
            }
        }

        return true;
    }

}