File Source for Log.php

<?php
/**
* $Header: /repository/pear/Log/Log.php,v 1.64 2006/10/08 23:03:15 jon Exp $
* $Horde: horde/lib/Log.php,v 1.15 2000/06/29 23:39:45 jon Exp $
*
* @version $Revision: 1.64 $
* @package Log
*/
define('PEAR_LOG_EMERG', 0); /** System is unusable */
define('PEAR_LOG_ALERT', 1); /** Immediate action required */
define('PEAR_LOG_CRIT', 2); /** Critical conditions */
define('PEAR_LOG_ERR', 3); /** Error conditions */
define('PEAR_LOG_WARNING', 4); /** Warning conditions */
define('PEAR_LOG_NOTICE', 5); /** Normal but significant */
define('PEAR_LOG_INFO', 6); /** Informational */
define('PEAR_LOG_DEBUG', 7); /** Debug-level messages */
define('PEAR_LOG_ALL', bindec('11111111')); /** All messages */
define('PEAR_LOG_NONE', bindec('00000000')); /** No message */
/* Log types for PHP's native error_log() function. */
define('PEAR_LOG_TYPE_SYSTEM', 0); /** Use PHP's system logger */
define('PEAR_LOG_TYPE_MAIL', 1); /** Use PHP's mail() function */
define('PEAR_LOG_TYPE_DEBUG', 2); /** Use PHP's debugging connection */
define('PEAR_LOG_TYPE_FILE', 3); /** Append to a file */
/**
* 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@php.net>
* @since Horde 1.3
* @package Log
*/
class Log
{
/**
* Indicates whether or not the log can been opened / connected.
*
* @var boolean
* @access private
*/
var $_opened = false;
/**
* Instance-specific unique identification number.
*
* @var integer
* @access private
*/
var $_id = 0;
/**
* The label that uniquely identifies this set of log messages.
*
* @var string
* @access private
*/
var $_ident = '';
/**
* The default priority to use when logging an event.
*
* @var integer
* @access private
*/
var $_priority = PEAR_LOG_INFO;
/**
* The bitmask of allowed log levels.
*
* @var integer
* @access private
*/
var $_mask = PEAR_LOG_ALL;
/**
* Holds all Log_observer objects that wish to be notified of new messages.
*
* @var array
* @access private
*/
var $_listeners = array();
/**
* Maps canonical format keys to position arguments for use in building
* "line format" strings.
*
* @var array
* @access private
*/
var $_formatMap = array('%{timestamp}' => '%1$s',
'%{ident}' => '%2$s',
'%{priority}' => '%3$s',
'%{message}' => '%4$s',
'%{file}' => '%5$s',
'%{line}' => '%6$s',
'%{function}' => '%7$s',
'%\{' => '%%{');
/**
* Attempts to return a concrete Log instance of type $handler.
*
* @param string $handler The type of concrete Log subclass to return.
* Attempt to dynamically include the code for
* this subclass. Currently, valid values are
* 'console', 'syslog', 'sql', 'file', and 'mcal'.
*
* @param string $name 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 string $ident The identity reported to the log system.
*
* @param array $conf A hash containing any additional configuration
* information that a subclass might need.
*
* @param int $level Log messages up to and including this level.
*
* @return object Log The newly created concrete Log instance, or
* null on an error.
* @access public
* @since Log 1.0
*/
function &factory($handler, $name = '', $ident = '', $conf = array(),
$level = PEAR_LOG_DEBUG)
{
$handler = strtolower($handler);
$class = 'Log_' . $handler;
$classfile = 'Log/' . $handler . '.php';
/*
* Attempt to include our version of the named class, but don't treat
* a failure as fatal. The caller may have already included their own
* version of the named class.
*/
if (!class_exists($class)) {
include_once $classfile;
}
/* If the class exists, return a new instance of it. */
if (class_exists($class)) {
$obj = &new $class($name, $ident, $conf, $level);
return $obj;
}
$null = null;
return $null;
}
/**
* Attempts to return a reference to a concrete Log instance of type
* $handler, 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 string $handler The type of concrete Log subclass to return.
* Attempt to dynamically include the code for
* this subclass. Currently, valid values are
* 'console', 'syslog', 'sql', 'file', and 'mcal'.
*
* @param string $name 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 string $ident The identity reported to the log system.
*
* @param array $conf A hash containing any additional configuration
* information that a subclass might need.
*
* @param int $level Log messages up to and including this level.
*
* @return object Log The newly created concrete Log instance, or
* null on an error.
* @access public
* @since Log 1.0
*/
function &singleton($handler, $name = '', $ident = '', $conf = array(),
$level = PEAR_LOG_DEBUG)
{
static $instances;
if (!isset($instances)) $instances = array();
$signature = serialize(array($handler, $name, $ident, $conf, $level));
if (!isset($instances[$signature])) {
$instances[$signature] = &Log::factory($handler, $name, $ident,
$conf, $level);
}
return $instances[$signature];
}
/**
* Abstract implementation of the open() method.
* @since Log 1.0
*/
function open()
{
return false;
}
/**
* Abstract implementation of the close() method.
* @since Log 1.0
*/
function close()
{
return false;
}
/**
* Abstract implementation of the flush() method.
* @since Log 1.8.2
*/
function flush()
{
return false;
}
/**
* Abstract implementation of the log() method.
* @since Log 1.0
*/
function log($message, $priority = null)
{
return false;
}
/**
* A convenience function for logging a emergency event. It will log a
* message at the PEAR_LOG_EMERG log level.
*
* @param mixed $message String or object containing the message
* to log.
*
* @return boolean True if the message was successfully logged.
*
* @access public
* @since Log 1.7.0
*/
function emerg($message)
{
return $this->log($message, PEAR_LOG_EMERG);
}
/**
* A convenience function for logging an alert event. It will log a
* message at the PEAR_LOG_ALERT log level.
*
* @param mixed $message String or object containing the message
* to log.
*
* @return boolean True if the message was successfully logged.
*
* @access public
* @since Log 1.7.0
*/
function alert($message)
{
return $this->log($message, PEAR_LOG_ALERT);
}
/**
* A convenience function for logging a critical event. It will log a
* message at the PEAR_LOG_CRIT log level.
*
* @param mixed $message String or object containing the message
* to log.
*
* @return boolean True if the message was successfully logged.
*
* @access public
* @since Log 1.7.0
*/
function crit($message)
{
return $this->log($message, PEAR_LOG_CRIT);
}
/**
* A convenience function for logging a error event. It will log a
* message at the PEAR_LOG_ERR log level.
*
* @param mixed $message String or object containing the message
* to log.
*
* @return boolean True if the message was successfully logged.
*
* @access public
* @since Log 1.7.0
*/
function err($message)
{
return $this->log($message, PEAR_LOG_ERR);
}
/**
* A convenience function for logging a warning event. It will log a
* message at the PEAR_LOG_WARNING log level.
*
* @param mixed $message String or object containing the message
* to log.
*
* @return boolean True if the message was successfully logged.
*
* @access public
* @since Log 1.7.0
*/
function warning($message)
{
return $this->log($message, PEAR_LOG_WARNING);
}
/**
* A convenience function for logging a notice event. It will log a
* message at the PEAR_LOG_NOTICE log level.
*
* @param mixed $message String or object containing the message
* to log.
*
* @return boolean True if the message was successfully logged.
*
* @access public
* @since Log 1.7.0
*/
function notice($message)
{
return $this->log($message, PEAR_LOG_NOTICE);
}
/**
* A convenience function for logging a information event. It will log a
* message at the PEAR_LOG_INFO log level.
*
* @param mixed $message String or object containing the message
* to log.
*
* @return boolean True if the message was successfully logged.
*
* @access public
* @since Log 1.7.0
*/
function info($message)
{
return $this->log($message, PEAR_LOG_INFO);
}
/**
* A convenience function for logging a debug event. It will log a
* message at the PEAR_LOG_DEBUG log level.
*
* @param mixed $message String or object containing the message
* to log.
*
* @return boolean True if the message was successfully logged.
*
* @access public
* @since Log 1.7.0
*/
function debug($message)
{
return $this->log($message, PEAR_LOG_DEBUG);
}
/**
* Returns the string representation of the message data.
*
* If $message is an object, _extractMessage() will attempt to extract
* the message text using a known method (such as a PEAR_Error object's
* getMessage() method). If a known method, cannot be found, the
* serialized representation of the object will be returned.
*
* If the message data is already a string, it will be returned unchanged.
*
* @param mixed $message The original message data. This may be a
* string or any object.
*
* @return string The string representation of the message.
*
* @access private
*/
function _extractMessage($message)
{
/*
* If we've been given an object, attempt to extract the message using
* a known method. If we can't find such a method, default to the
* "human-readable" version of the object.
*
* We also use the human-readable format for arrays.
*/
if (is_object($message)) {
if (method_exists($message, 'getmessage')) {
$message = $message->getMessage();
} else if (method_exists($message, 'tostring')) {
$message = $message->toString();
} else if (method_exists($message, '__tostring')) {
if (version_compare(PHP_VERSION, '5.0.0', 'ge')) {
$message = (string)$message;
} else {
$message = $message->__toString();
}
} else {
$message = print_r($message, true);
}
} else if (is_array($message)) {
if (isset($message['message'])) {
$message = $message['message'];
} else {
$message = print_r($message, true);
}
}
/* Otherwise, we assume the message is a string. */
return $message;
}
/**
* Using debug_backtrace(), returns the file, line, and enclosing function
* name of the source code context from which log() was invoked.
*
* @param int $depth The initial number of frames we should step
* back into the trace.
*
* @return array Array containing three strings: the filename, the line,
* and the function name from which log() was called.
*
* @access private
* @since Log 1.9.4
*/
function _getBacktraceVars($depth)
{
/* Start by generating a backtrace from the current call (here). */
$backtrace = debug_backtrace();
/*
* If we were ultimately invoked by the composite handler, we need to
* increase our depth one additional level to compensate.
*/
if (strcasecmp(@$backtrace[$depth+1]['class'], 'Log_composite') == 0) {
$depth++;
}
/*
* We're interested in the frame which invoked the log() function, so
* we need to walk back some number of frames into the backtrace. The
* $depth parameter tells us where to start looking. We go one step
* further back to find the name of the encapsulating function from
* which log() was called.
*/
$file = @$backtrace[$depth]['file'];
$line = @$backtrace[$depth]['line'];
$func = @$backtrace[$depth + 1]['function'];
/*
* However, if log() was called from one of our "shortcut" functions,
* we're going to need to go back an additional step.
*/
if (in_array($func, array('emerg', 'alert', 'crit', 'err', 'warning',
'notice', 'info', 'debug'))) {
$file = @$backtrace[$depth + 1]['file'];
$line = @$backtrace[$depth + 1]['line'];
$func = @$backtrace[$depth + 2]['function'];
}
/*
* If we couldn't extract a function name (perhaps because we were
* executed from the "main" context), provide a default value.
*/
if (is_null($func)) {
$func = '(none)';
}
/* Return a 3-tuple containing (file, line, function). */
return array($file, $line, $func);
}
/**
* Produces a formatted log line based on a format string and a set of
* variables representing the current log record and state.
*
* @return string Formatted log string.
*
* @access private
* @since Log 1.9.4
*/
function _format($format, $timestamp, $priority, $message)
{
/*
* If the format string references any of the backtrace-driven
* variables (%5, %6, %7), generate the backtrace and fetch them.
*/
if (strpos($format, '%5') || strpos($format, '%6') || strpos($format, '%7')) {
list($file, $line, $func) = $this->_getBacktraceVars(2);
}
/*
* Build the formatted string. We use the sprintf() function's
* "argument swapping" capability to dynamically select and position
* the variables which will ultimately appear in the log string.
*/
return sprintf($format,
$timestamp,
$this->_ident,
$this->priorityToString($priority),
$message,
isset($file) ? $file : '',
isset($line) ? $line : '',
isset($func) ? $func : '');
}
/**
* Returns the string representation of a PEAR_LOG_* integer constant.
*
* @param int $priority A PEAR_LOG_* integer constant.
*
* @return string The string representation of $level.
*
* @since Log 1.0
*/
function priorityToString($priority)
{
$levels = array(
PEAR_LOG_EMERG => 'emergency',
PEAR_LOG_ALERT => 'alert',
PEAR_LOG_CRIT => 'critical',
PEAR_LOG_ERR => 'error',
PEAR_LOG_WARNING => 'warning',
PEAR_LOG_NOTICE => 'notice',
PEAR_LOG_INFO => 'info',
PEAR_LOG_DEBUG => 'debug'
);
return $levels[$priority];
}
/**
* Returns the the PEAR_LOG_* integer constant for the given string
* representation of a priority name. This function performs a

Source for file Log.php