[LIB_REFACTOR] Moving files into separate semantic categories

lib/util/daemon.php

@@ -0,0 +1,176 @@
+<?php
+/**
+ * StatusNet - the distributed open-source microblogging tool
+ * Copyright (C) 2008, 2009, 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') && !defined('LACONICA')) {
+    exit(1);
+}
+
+class Daemon
+{
+    var $daemonize = true;
+    var $_id = 'generic';
+
+    function __construct($daemonize = true)
+    {
+        $this->daemonize = $daemonize;
+    }
+
+    function name()
+    {
+        return null;
+    }
+
+    function get_id()
+    {
+        return $this->_id;
+    }
+
+    function set_id($id)
+    {
+        $this->_id = $id;
+    }
+
+    function background()
+    {
+        /*
+         * This prefers to Starting PHP 5.4 (dotdeb), maybe earlier for some version/distrib
+         * seems MySQL connection using mysqli driver get lost when fork.
+         * Need to unset it so that child process recreate it.
+         *
+         * @todo FIXME cleaner way to do it ?
+         */
+        global $_DB_DATAOBJECT;
+        unset($_DB_DATAOBJECT['CONNECTIONS']);
+
+        $pid = pcntl_fork();
+        if ($pid < 0) { // error
+            common_log(LOG_ERR, "Could not fork.");
+            return false;
+        } else if ($pid > 0) { // parent
+            common_log(LOG_INFO, "Successfully forked.");
+            exit(0);
+        } else { // child
+            return true;
+        }
+    }
+
+    function alreadyRunning()
+    {
+        $pidfilename = $this->pidFilename();
+
+        if (!$pidfilename) {
+            return false;
+        }
+
+        if (!file_exists($pidfilename)) {
+            return false;
+        }
+        $contents = file_get_contents($pidfilename);
+        if (posix_kill(trim($contents), 0)) {
+            return true;
+        } else {
+            return false;
+        }
+    }
+
+    function writePidFile()
+    {
+        $pidfilename = $this->pidFilename();
+
+        if (!$pidfilename) {
+            return false;
+        }
+
+        return file_put_contents($pidfilename, posix_getpid() . "\n");
+    }
+
+    function clearPidFile()
+    {
+        $pidfilename = $this->pidFilename();
+        if (!$pidfilename) {
+            return false;
+        }
+        return unlink($pidfilename);
+    }
+
+    function pidFilename()
+    {
+        $piddir = common_config('daemon', 'piddir');
+        if (!$piddir) {
+            return null;
+        }
+        $name = $this->name();
+        if (!$name) {
+            return null;
+        }
+        return $piddir . '/' . $name . '.pid';
+    }
+
+    function changeUser()
+    {
+        $groupname = common_config('daemon', 'group');
+
+        if ($groupname) {
+            $group_info = posix_getgrnam($groupname);
+            if (!$group_info) {
+                common_log(LOG_WARNING,
+                           'Ignoring unknown group for daemon: ' . $groupname);
+            } else {
+                common_log(LOG_INFO, "Setting group to " . $groupname);
+                posix_setgid($group_info['gid']);
+            }
+        }
+
+        $username = common_config('daemon', 'user');
+
+        if ($username) {
+            $user_info = posix_getpwnam($username);
+            if (!$user_info) {
+                common_log(LOG_WARNING,
+                           'Ignoring unknown user for daemon: ' . $username);
+            } else {
+                common_log(LOG_INFO, "Setting user to " . $username);
+                posix_setuid($user_info['uid']);
+            }
+        }
+    }
+
+    function runOnce()
+    {
+        if ($this->alreadyRunning()) {
+            common_log(LOG_INFO, $this->name() . ' already running. Exiting.');
+            exit(0);
+        }
+
+        if ($this->daemonize) {
+            common_log(LOG_INFO, 'Backgrounding daemon "'.$this->name().'"');
+            $this->background();
+        }
+
+        $this->writePidFile();
+        $this->changeUser();
+        $this->run();
+        $this->clearPidFile();
+    }
+
+    function run()
+    {
+        return true;
+    }
+}