--- /dev/null
+<?php
+// $Horde: horde/lib/Log.php,v 1.15 2000/06/29 23:39:45 jon Exp $
+
+/**
+ * The Log:: class implements both an abstraction for various logging
+ * mechanisms and the Subject end of a Subject-Observer pattern.
+ *
+ * @author Chuck Hagenbuch <chuck@horde.org>
+ * @author Jon Parise <jon@csh.rit.edu>
+ * @version $Revision$
+ * @since Horde 1.3
+ */
+class Log {
+
+ // {{{ properties
+
+ /** Boolean indicating whether or not the log connection is
+ currently open. */
+ var $opened = false;
+
+ /** String holding the identifier that will be stored along with
+ each logged message. */
+ var $ident = '';
+
+ /** Array holding all Log_observer objects that wish to be notified
+ of any messages that we handle. */
+ var $listeners = array();
+
+ // }}}
+
+ // {{{ factory()
+ /**
+ * Attempts to return a concrete Log instance of $log_type.
+ *
+ * @param $log_type The type of concrete Log subclass to return.
+ * Attempt to dynamically include the code for this
+ * subclass. Currently, valid values are 'syslog',
+ * 'sql', 'file', and 'mcal'.
+ *
+ * @param $log_name (optional) The name of the actually log file,
+ * table, or other specific store to use. Defaults
+ * to an empty string, with which the subclass will
+ * attempt to do something intelligent.
+ *
+ * @param $ident (optional) The indentity reported to the log system.
+ *
+ * @param $conf (optional) A hash containing any additional
+ * configuration information that a subclass might need.
+ *
+ * @return The newly created concrete Log instance, or an
+ * false on an error.
+ */
+ function factory ($log_type, $log_name = '', $ident = '', $conf = array()) {
+ $log_type = strtolower($log_type);
+ $classfile = dirname(__FILE__) . '/Log/' . $log_type . '.php';
+ if (@is_readable($classfile)) {
+ include_once $classfile;
+ $class = 'Log_' . $log_type;
+ return new $class($log_name, $ident, $conf);
+ } else {
+ return false;
+ }
+ }
+ // }}}
+
+ // {{{ singleton()
+ /**
+ * Attempts to return a reference to a concrete Log instance of
+ * $log_type, only creating a new instance if no log instance with
+ * the same parameters currently exists.
+ *
+ * You should use this if there are multiple places you might
+ * create a logger, you don't want to create multiple loggers, and
+ * you don't want to check for the existance of one each time. The
+ * singleton pattern does all the checking work for you.
+ *
+ * <b>You MUST call this method with the $var = &Log::singleton()
+ * syntax. Without the ampersand (&) in front of the method name,
+ * you will not get a reference, you will get a copy.</b>
+ *
+ * @param $log_type The type of concrete Log subclass to return.
+ * Attempt to dynamically include the code for
+ * this subclass. Currently, valid values are
+ * 'syslog', 'sql', 'file', and 'mcal'.
+ *
+ * @param $log_name (optional) The name of the actually log file,
+ * table, or other specific store to use. Defaults
+ * to an empty string, with which the subclass will
+ * attempt to do something intelligent.
+ *
+ * @param $ident (optional) The identity reported to the log system.
+ *
+ * @param $conf (optional) A hash containing any additional
+ * configuration information that a subclass might need.
+ *
+ * @return The concrete Log reference, or false on an error.
+ */
+ function &singleton ($log_type, $log_name = '', $ident = '', $conf = array()) {
+ static $instances;
+ if (!isset($instances)) $instances = array();
+
+ $signature = md5($log_type . '][' . $log_name . '][' . $ident . '][' . implode('][', $conf));
+ if (!isset($instances[$signature])) {
+ $instances[$signature] = Log::factory($log_type, $log_name, $ident, $conf);
+ }
+ return $instances[$signature];
+ }
+ // }}}
+
+ // {{{ priorityToString()
+ /**
+ * Returns the string representation of a LOG_* integer constant.
+ *
+ * @param $priority The LOG_* integer constant.
+ *
+ * @return The string representation of $priority.
+ */
+ function priorityToString ($priority) {
+ $priorities = array(
+ LOG_EMERG => 'emergency',
+ LOG_ALERT => 'alert',
+ LOG_CRIT => 'critical',
+ LOG_ERR => 'error',
+ LOG_WARNING => 'warning',
+ LOG_NOTICE => 'notice',
+ LOG_INFO => 'info',
+ LOG_DEBUG => 'debug'
+ );
+ return $priorities[$priority];
+ }
+ // }}}
+
+ // {{{ attach()
+ /**
+ * Adds a Log_observer instance to the list of observers that are
+ * be notified when a message is logged.
+ *
+ * @param $logObserver The Log_observer instance to be added to
+ * the $listeners array.
+ */
+ function attach (&$logObserver) {
+ if (!is_object($logObserver))
+ return false;
+
+ $logObserver->_listenerID = uniqid(rand());
+
+ $this->listeners[$logObserver->_listenerID] = &$logObserver;
+ }
+ // }}}
+
+ // {{{ detach()
+ /**
+ * Removes a Log_observer instance from the list of observers.
+ *
+ * @param $logObserver The Log_observer instance to be removed
+ * from the $listeners array.
+ */
+ function detach ($logObserver) {
+ if (isset($this->listeners[$logObserver->_listenerID]))
+ unset($this->listeners[$logObserver->_listenerID]);
+ }
+ // }}}
+
+ // {{{ notifyAll()
+ /**
+ * Sends any Log_observer objects listening to this Log the message
+ * that was just logged.
+ *
+ * @param $messageOb The data structure holding all relevant log
+ * information - the message, the priority, what
+ * log this is, etc.
+ */
+ function notifyAll ($messageOb) {
+ reset($this->listeners);
+ foreach ($this->listeners as $listener) {
+ if ($messageOb['priority'] <= $listener->priority)
+ $listener->notify($messageOb);
+ }
+ }
+ // }}}
+
+ // {{{ isComposite()
+ /**
+ * @return a Boolean: true if this is a composite class, false
+ * otherwise. The composite subclass overrides this to return
+ * true.
+ */
+ function isComposite () {
+ return false;
+ }
+ // }}}
+}
+
+?>
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