From b6e5b1d294030f5dd9d386b15d8cef7fcbea3768 Mon Sep 17 00:00:00 2001
From: Brion Vibber <brion@pobox.com>
Date: Wed, 24 Nov 2010 10:13:03 -0800
Subject: [PATCH] Add LogFilter plugin: quickie way to filter out/in log output
 based on priority or keyword matches. Should be helpful for folks who can't
 easily adjust their syslog filtering.

---
 plugins/LogFilter/LogFilterPlugin.php | 94 +++++++++++++++++++++++++++
 1 file changed, 94 insertions(+)
 create mode 100644 plugins/LogFilter/LogFilterPlugin.php

diff --git a/plugins/LogFilter/LogFilterPlugin.php b/plugins/LogFilter/LogFilterPlugin.php
new file mode 100644
index 0000000000..e2153e959c
--- /dev/null
+++ b/plugins/LogFilter/LogFilterPlugin.php
@@ -0,0 +1,94 @@
+<?php
+/*
+ * StatusNet - the distributed open-source microblogging tool
+ * Copyright (C) 2010, StatusNet, Inc.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+if (!defined('STATUSNET')) {
+    exit(1);
+}
+
+/**
+ * Example to disable all debug messages and those containing 'About to push':
+ * addPlugin('LogFilter', array(
+ *    'priority' => array(LOG_DEBUG => false),
+ *    'regex' => array('/About to push/' => false)
+ * ));
+ *
+ * @todo add an admin panel
+ *
+ * @package LogFilterPlugin
+ * @maintainer Brion Vibber <brion@status.net>
+ */
+class LogFilterPlugin extends Plugin
+{
+    public $default = true;     // Set to false to require opting things in
+    public $priority = array(); // override by priority: array(LOG_ERR => true, LOG_DEBUG => false)
+    public $regex = array();    // override by regex match of message: array('/twitter/i' => false)
+
+    function onPluginVersion(&$versions)
+    {
+        $versions[] = array('name' => 'LogFilter',
+                            'version' => STATUSNET_VERSION,
+                            'author' => 'Brion Vibber',
+                            'homepage' => 'http://status.net/wiki/Plugin:LogFilter',
+                            'rawdescription' =>
+                            _m('Provides server-side setting to filter log output by type or keyword.'));
+
+        return true;
+    }
+
+    /**
+     * Hook for the StartLog event in common_log().
+     * If a message doesn't pass our filters, we'll abort it.
+     *
+     * @param string $priority
+     * @param string $msg
+     * @param string $filename
+     * @return boolean hook result code
+     */
+    function onStartLog(&$priority, &$msg, &$filename)
+    {
+        if ($this->filter($priority, $msg)) {
+            // Let it through
+            return true;
+        } else {
+            // Abort -- this line will go to /dev/null :)
+            return false;
+        }
+    }
+
+    /**
+     * Do the filtering...
+     *
+     * @param string $priority
+     * @param string $msg
+     * @return boolean true to let the log message be processed
+     */
+    function filter($priority, $msg)
+    {
+        $state = $this->default;
+        if (array_key_exists($priority, $this->priority)) {
+            $state = $this->priority[$priority];
+        }
+        foreach ($this->regex as $regex => $override) {
+            if (preg_match($regex, $msg)) {
+                $state = $override;
+            }
+        }
+        return $state;
+    }
+}