first commit

lib/Debug/ErrorHook/RemoveDupsWrapper.php

@@ -0,0 +1,87 @@
+<?php
+/**
+ * Wrapper which denies duplicated notifications to be
+ * processed again and again. It is needed to lower the
+ * traffic to mail server in case the site is down. 
+ * 
+ * This class stores meta-informations in filesystem.
+ * It takes care about garbage collecting.
+ */
+
+class Debug_ErrorHook_RemoveDupsWrapper implements Debug_ErrorHook_INotifier
+{
+	const DEFAULT_PERIOD = 300;
+	const ERROR_FILE_SUFFIX = ".error";
+	const GC_PROBABILITY = 0.01;
+	
+	private $_notifier;
+	private $_tmpPath;
+	private $_period;
+	private $_gcExecuted = false;
+	
+	public function __construct(Debug_ErrorHook_INotifier $notifier, $tmpPath = null, $period = null)
+	{
+		$this->_tmpPath = $tmpPath? $tmpPath : $this->_getDefaultTmpPath();
+		$this->_period = $period? $period : self::DEFAULT_PERIOD;
+		$this->_notifier = $notifier;
+		if (!@is_dir($this->_tmpPath)) {
+			if (!@mkdir($this->_tmpPath, 0777, true)) {
+				$error = error_get_last();
+				throw new Exception("Cannot create '{$this->_tmpPath}': {$error['message']}");
+			}
+		}
+	}
+	
+    public function notify($errno, $errstr, $errfile, $errline, $trace)
+    {
+    	$hash = md5(join(":", array($errno, $errfile, $errline)));
+    	if ($this->_isExpired($hash)) {
+    		$this->_notifier->notify($errno, $errstr, $errfile, $errline, $trace);
+    	}
+    	// Touch always, even if we did not send anything. Else same errors will 
+    	// be mailed again and again after $period (e.g. once per 5 minutes).
+        $this->_touch($hash, $errfile, $errline);
+    }
+    
+    protected function _getDefaultTmpPath()
+    {
+    	return sys_get_temp_dir() . "/" . get_class($this);
+    }
+    
+    protected function _getGcProbability()
+    {
+    	return self::GC_PROBABILITY;
+    }
+    
+    private function _getLockFname($hash)
+    {
+    	return $this->_tmpPath . '/' . $hash . self::ERROR_FILE_SUFFIX;
+    }
+    
+    private function _isExpired($hash)
+    {
+    	$file = $this->_getLockFname($hash);
+    	return !file_exists($file) || filemtime($file) < time() - $this->_period;
+    }
+    
+    private function _touch($hash, $errfile, $errline)
+    {
+        $file = $this->_getLockFname($hash);
+    	file_put_contents($file, "$errfile:$errline");
+    	@chmod($file, 0666);
+    	$this->_gc();
+    }
+    
+    private function _gc()
+    {
+    	if ($this->_gcExecuted || mt_rand(0, 10000) >= $this->_getGcProbability() * 10000) {
+    		return;
+    	}
+    	foreach (glob("{$this->_tmpPath}/*" . self::ERROR_FILE_SUFFIX) as $file) {
+    		if (filemtime($file) <= time() - $this->_period * 2) {
+    			@unlink($file);
+    		}
+    	}
+    	$this->_gcExecuted = true;
+    }
+}