logger.js | |
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/*
* logger.js: Core logger object used by winston.
*
* (C) 2010 Charlie Robbins
* MIT LICENCE
*
*/
require.paths.unshift(require('path').join(__dirname, '..'));
var util = require('util'),
events = require('events'),
winston = require('winston'),
utils = require('./utils');
function capitalize(str) {
return str && str[0].toUpperCase() + str.slice(1);
} | |
Time constants | var ticksPerMillisecond = 10000; |
function Logger (options) Constructor for the logger object. | var Logger = exports.Logger = function (options) {
events.EventEmitter.call(this);
var self = this;
options = options || {};
|
Set Levels and default logging level | this.setLevels(options.levels);
this.level = options.level || 'info';
this.emitErrs = options.emitErrs || false;
this.transports = {};
this.profilers = {};
if (options.transports) {
options.transports.forEach(function (transport) {
self.transports[transport.name] = transport;
});
}
};
util.inherits(Logger, events.EventEmitter); |
function extend (target) Extends the target object with a 'log' method along with a method for each level in this instance. | Logger.prototype.extend = function (target) {
var self = this;
['log', 'profile'].concat(Object.keys(this.levels)).forEach(function (method) {
target[method] = function () {
return self[method].apply(self, arguments);
};
});
}; |
function log (level, msg, [meta, callback]) Core logging method for Winston. Metadata and callback are is optional. | Logger.prototype.log = function (level, msg) {
var self = this, logged = 0, errs = [],
len = Object.keys(this.transports).length,
meta, callback;
if (arguments.length === 3) {
if (typeof arguments[2] === 'function') {
meta = {};
callback = arguments[2];
}
else if (typeof arguments[2] === 'object') {
meta = arguments[2];
}
}
else if (arguments.length === 4) {
meta = arguments[2];
callback = arguments[3];
}
if (this.transports.length === 0) return callback(new Error('Cannot log with no transports.'));
else if (typeof self.levels[level] === 'undefined') return callback(new Error('Unknown log level: ' + level));
for (var key in this.transports) {
var transport = this.transports[key];
if ((transport.level && self.levels[transport.level] <= self.levels[level])
|| (!transport.level && self.levels[self.level] <= self.levels[level])) {
transport.log(level, msg, meta, function (err) {
if (err) errs.push({ error: err, transport: transport });
if (err && self.emitErrs) return self.emit('error', err, transport);
self.emit('log', transport, level, msg, meta);
if (++logged == len && callback) callback(errs.length > 0 ? errs : null, level, msg, meta);
});
}
};
return this;
}; |
function add (transport, [options]) Adds a transport of the specified type to this instance. | Logger.prototype.add = function (transport, options) {
var name = winston.findTransport(transport);
if (!name && !transport.prototype.log) throw new Error('Unknown transport with no log() method');
else if (this.transports[name]) throw new Error('Transport already attached: ' + name);
var instance = (new (transport)(options));
this.transports[instance.name] = instance;
return this;
}; |
function remove (transport) Removes a transport of the specified type from this instance. | Logger.prototype.remove = function (transport) {
var name = winston.findTransport(transport);
|
If we can't find the name, try to use transport.name | if (!name) name = transport.name;
if (!this.transports[name]) throw new Error('Transport ' + name + ' not attached to this instance');
var transportObject = this.transports[name];
delete this.transports[name];
if (transportObject.close) transportObject.close();
return this;
}; |
function profile (id, [msg, meta, callback]) Tracks the time inbetween subsequent calls to this method with the same [id] parameter. The second call to this method will log the difference in milliseconds along with the message. | Logger.prototype.profile = function (id) {
var now = Date.now(), then, args,
msg, meta, callback;
if (this.profilers[id] && arguments.length !== 1) {
then = this.profilers[id];
delete this.profilers[id];
|
Support variable arguments: msg, meta, callback | args = Array.prototype.slice.call(arguments);
callback = typeof args[args.length - 1] === 'function' ? args.pop() : null;
meta = typeof args[args.length - 1] === 'object' ? args.pop() : {};
msg = args.length === 2 ? args[1] : id;
|
Set the duration property of the metadata | meta.duration = now - then + 'ms';
return this.info(msg, meta, callback);
}
else {
this.profilers[id] = now;
}
};
Logger.prototype.setLevels = function (current) {
return utils.setLevels(this, this.levels, current);
};
|