new NCache class

1 files changed, 106 insertions, 0 deletions

diff --git a/lib.php b/lib.php
index 28b72cf..600f97d 100644
--- a/lib.php
+++ b/lib.php
@@ -1,6 +1,112 @@
 <?php
 // definition
 
+class NCache
+{
+    function __construct() { }
+
+    /**
+     * Factory.
+     *
+     * @param string $path where cache file store is located, relative to app path.
+     * @param integer $timeout in seconds
+     *
+     * @return NCache
+    */
+    function build($path, $timeout = 3600)
+    {
+        $path = __DIR__ . '/' . $path;
+
+        if (!is_dir($path))
+            return null;
+
+        if ($timeout < 60)
+            $timeout = 60;
+
+        $i           = new self;
+        $i->_path    = $path;
+        $i->_timeout = $timeout;
+
+        return $i;
+    }
+
+    /**
+     * Get value for $key.
+     *
+     * @param mixed $key
+     *
+     * @return mixed
+    */
+    function get($key = null)
+    {
+        if (is_null($key))
+            return false;
+
+        $filename = $this->_get_filename($key);
+
+        if ($this->_is_valid_file($filename, $this->_timeout)) {
+            return unserialize(file_get_contents($filename));
+        }
+
+        return null;
+    }
+
+    /**
+     * Save $value under $key.
+     *
+     * @param mixed $key
+     * @param mixed $value
+    */
+    function set($key, $value)
+    {
+        if (is_null($key))
+            return false;
+
+        $filename = $this->_get_filename($key);
+        file_put_contents($filename, serialize($value));
+
+        return true;
+    }
+
+    /**
+     * Get cache file from key.
+     *
+     * @param mixed $key
+     *
+     * @return string
+    */
+    private function _get_filename($key)
+    {
+        $key  = hash('sha1', serialize($key));
+
+        return $this->_path . '/' . $key . '.cache';
+    }
+
+    /**
+     * Check that the cache file exists and has not expired.
+     *
+     * @param string $filename
+     *
+     * @return boolean
+    */
+    private function _is_valid_file($filename, $timeout)
+    {
+        if (!file_exists($filename)) {
+            //error_log(sprintf('Could not find %s', $filename), 0);
+            return false;
+        }
+
+        if (filemtime($filename) + $timeout < time()) {
+            //error_log(sprintf('%s timestamp expired (timeout was %ds.).', $filename, $timeout));
+            unlink($filename);
+            return false;
+        }
+
+        //error_log(sprintf('Found %s', $filename));
+        return true;
+    }
+}
+
 class l10n
 {
     public static $t;