init

composer.json

+{
+    "name": "ethereal/simpleCache",
+    "type": "project",
+    "require": {
+        "php": ">=5.3.9",
+    },
+    "require-dev": {
+        "php": ">=5.3.9",
+        "phpunit/phpunit": "~4.8",
+    },
+    "minimum-stability": "dev",
+    "autoload": {
+        "psr-4": {
+            "Ethereal\\": "lib"
+        }
+    }
+}

lib/Cache.php

+<?php
+
+namespace Ethereal;
+
+use Predis\Client;
+
+class Cache extends Predis\Client
+{
+    protected $namespace = '';
+  
+    public function set($key, $val, $exp = null)
+    {
+        if (!is_string($key)) {
+            throw new \Exception("Key must be a string");
+        }
+        $key = "{$this->namespace}{$key}";
+        if (!is_string($val)) {
+            $val = json_encode($val);
+        }
+        if ($exp && is_numeric($exp)) {
+            return parent::set($key, $val, "EX {$exp}");
+        }
+        return parent::set($key, $val);
+    }
+  
+    public function get($key)
+    {
+        if (!is_string($key)) {
+            throw new \Exception("Key must be a string");
+        }
+        $key = "{$this->namespace}{$key}";
+        $value = parent::get($key);
+        if (is_null($value)) {
+            return null;
+        }
+        if ($decode = json_decode($value)) {
+            return $decode;
+        }
+        return $value;
+    }
+    
+    public function setNamespace($namespace)
+    {
+        $this->namespace = "{$namespace}";
+    }
+}