class-php-redis.php

<?php
/**
 * Use redis cache
 * 
 * @package codetot-optimization
 * @author codetot
 * @since 0.0.1
 */

class Sample_Redis_Cache {
	/**
	 * Singleton instance
	 *
	 * @var Sample_Redis_Cache
	 */
	protected static $instance;

	/**
	 * Get singleton instance.
	 *
	 * @return Sample_Redis_Cache
	 */
	public final static function instance()
	{
		if (is_null(self::$instance)) {
			self::$instance = new self();
		}
		return self::$instance;
	}

    public function __construct()
    {  
		$this->redis_status= false;
		
		//init redis
		if (defined('REDIS_CONFIG')) {
			$config = REDIS_CONFIG;  
			$this->redis = new Redis();  
			$this->redis_status = $this->redis->pconnect($config['host'], $config['port']);  
			$this->redis->select($config['database']);
		}     
    }	 

    function get_status() {
        return $this->redis_status;
    }
	/**
	 * Get
	 *
	 * @param    string  $key
	 *
	 * @return array|string|null
	 */
    public function get($key) {
        if ($this->get_status()) { 
            return $this->redis->get($key);
        } else { 
            return false;
        }
    }

	/**
	 * Incr
	 *
	 * @param    string  $key
	 * @param    array|string|null  $value
	 *
	 * @return void
	 */

	public function inc($key, $value = 1) {
		if ($this->get_status()) {
		    $this->redis->incr($key, $value);
		}
	    }

	/**
	 * Decrement
	 *
	 * @param    string  $key
	 * @param    array|string|null  $value
	 *
	 * @return void
	 */

	public function dec($key, $value = 1) {
		if ($this->get_status()) {
		    $this->redis->decr($key, $value);
		}
	    }

	/**
	 * Set
	 *
	 * @param    string  $key
	 * @param    array|string|null  $value
	 *
	 * @return void
	 */
	public function set($key, $value, $time = 0) {
		if ($this->get_status()) {
			$result = $this->redis->set($key, $value);
			if ($time>0) {
				$this->redis->expire($key, $time);
			}
			return $result;
		} else {
		    return false;
		}
	} 

	/**
	 * Delete
	 *
	 * @param    string  $key
	 *
	 * @return void
	 */
    public function del($key) { 
	if ($this->get_status()) {
		$this->redis->del($key);
	}  
    }	

	/**
	 * Flush by key
	 *
	 * @return void
	 */
	public function delete_by_key($key) {
		if ($this->get_status()) {
			$keys = $this->redis->keys($key.'*');
			foreach ($keys as $key) {
				$this->redis->del($key);
			} 
		}
	}

	/**
	 * Flush 
	 *
	 * @return void
	 */
	public function flush() {
		$this->redis->flushAll();
	}
}

Sample_Redis_Cache::instance();

config.php

<?php

define('REDIS_CONFIG', [
    'host' => 'redis', // or localhost
    'port' => 6379,
    'database' => 0, // change for each site
    'maxttl' => 86400 * 7,
    'timeout' => 1.0,
    'read_timeout' => 1.0,
    'split_alloptions' => true,
    'debug' => false, 
]);