node-bunyan-lite/lib/bunyan.js
2012-02-03 17:05:13 -08:00

618 lines
17 KiB
JavaScript

/*
* Copyright 2012 (c) Trent Mick. All rights reserved.
*/
var VERSION = "0.2.0";
// Bunyan log format version. This becomes the 'v' field on all log records.
// `0` is until I release a version "1.0.0" of node-bunyan. Thereafter,
// starting with `1`, this will be incremented if there is any backward
// incompatible change to the log record format. Details will be in
// "CHANGES.md" (the change log).
var LOG_VERSION = 0;
var xxx = function xxx(s) { // internal dev/debug logging
var args = ['XX' + 'X: '+s].concat(Array.prototype.slice.call(arguments, 1));
console.error.apply(this, args);
};
var xxx = function xxx() {}; // uncomment to turn of debug logging
var os = require('os');
var fs = require('fs');
var util = require('util');
//---- Internal support stuff
function objCopy(obj) {
var copy = {};
Object.keys(obj).forEach(function (k) {
copy[k] = obj[k];
});
return copy;
}
var format = util.format;
if (!format) {
// If not node 0.6, then use its `util.format`:
// <https://github.com/joyent/node/blob/master/lib/util.js#L22>:
var inspect = util.inspect;
var formatRegExp = /%[sdj%]/g;
format = function format(f) {
if (typeof f !== 'string') {
var objects = [];
for (var i = 0; i < arguments.length; i++) {
objects.push(inspect(arguments[i]));
}
return objects.join(' ');
}
var i = 1;
var args = arguments;
var len = args.length;
var str = String(f).replace(formatRegExp, function(x) {
if (i >= len) return x;
switch (x) {
case '%s': return String(args[i++]);
case '%d': return Number(args[i++]);
case '%j': return JSON.stringify(args[i++]);
case '%%': return '%';
default:
return x;
}
});
for (var x = args[i]; i < len; x = args[++i]) {
if (x === null || typeof x !== 'object') {
str += ' ' + x;
} else {
str += ' ' + inspect(x);
}
}
return str;
};
}
//---- Levels
var TRACE = 1;
var DEBUG = 2;
var INFO = 3;
var WARN = 4;
var ERROR = 5;
var FATAL = 6;
var levelFromName = {
'trace': TRACE,
'debug': DEBUG,
'info': INFO,
'warn': WARN,
'error': ERROR,
'fatal': FATAL
};
var nameFromLevel = [undefined].concat(Object.keys(levelFromName));
function getLevel(nameOrNum) {
return (typeof(nameOrNum) === 'string'
? levelFromName[nameOrNum]
: nameOrNum);
}
//---- Logger class
/**
* Create a Logger instance.
*
* @param options {Object} See documentation for full details. At minimum
* this must include a "service" string key.
* @param _newCloneKeys {Array} Internal var. Should not be used externally.
* Array of new keys for this clone. This is necessary to assist with
* applying necessary serializers to the new keys.
*/
function Logger(options, _newCloneKeys) {
xxx('Logger start:', options)
if (! this instanceof Logger) {
return new Logger(options);
}
var self = this;
if (!options) {
throw new TypeError('options (object) is required');
}
if (options.stream && options.streams) {
throw new TypeError('can only have one of "stream" or "streams"');
}
if (_newCloneKeys && !Array.isArray(_newCloneKeys)) {
throw new TypeError('_newCloneKeys (Array) is an internal var');
}
// These are the default fields for log records (minus the attributes
// removed in this constructor). To allow storing raw log records
// (unrendered), `this.fields` must never be mutated. Create a copy for
// any changes.
this.fields = objCopy(options);
// Extract and setup the configuration options (the remaining ones are
// log record fields).
var lowestLevel = Number.POSITIVE_INFINITY;
var level;
if (options.level) {
level = getLevel(options.level);
if (! (TRACE <= level && level <= FATAL)) {
throw new Error('invalid level: ' + options.level);
}
delete this.fields.level;
} else {
level = INFO;
}
this.streams = [];
if (options.stream) {
this.streams.push({
type: "stream",
stream: options.stream,
closeOnExit: false,
level: level
});
if (level < lowestLevel) {
lowestLevel = level;
}
delete this.fields.stream;
} else if (options.streams) {
options.streams.forEach(function (s) {
s = objCopy(s);
// Implicit 'type' from other args.
type = s.type;
if (!s.type) {
if (s.stream) {
s.type = "stream";
} else if (s.path) {
s.type = "file"
}
}
if (s.level) {
s.level = getLevel(s.level);
} else {
s.level = level;
}
if (s.level < lowestLevel) {
lowestLevel = s.level;
}
switch (s.type) {
case "stream":
if (!s.closeOnExit) {
s.closeOnExit = false;
}
break;
case "file":
if (!s.stream) {
s.stream = fs.createWriteStream(s.path,
{flags: 'a', encoding: 'utf8'});
if (!s.closeOnExit) {
s.closeOnExit = true;
}
} else {
if (!s.closeOnExit) {
s.closeOnExit = false;
}
}
break;
default:
throw new TypeError('unknown stream type "' + s.type + '"');
}
self.streams.push(s);
});
delete this.fields.streams;
} else {
this.streams.push({
type: "stream",
stream: process.stdout,
closeOnExit: false,
level: level
});
if (level < lowestLevel) {
lowestLevel = level;
}
}
this.level = lowestLevel;
delete this.fields.serializers;
if (!options.serializers) {
this.serializers = null;
} else {
this.serializers = {};
Object.keys(options.serializers).forEach(function (field) {
var serializer = options.serializers[field];
if (typeof(serializer) !== "function") {
throw new TypeError(format(
'invalid serializer for "%s" field: must be a function', field));
} else {
self.serializers[field] = serializer;
}
});
}
xxx("Logger: ", self)
// Apply serializers to initial fields.
if (this.serializers) {
if (_newCloneKeys && _newCloneKeys.length > 0) {
// Note that this includes *config* vars send to `log.clone()` in
// addition to log record *fields*, so the impl. needs to handle that.
this._applySerializers(this.fields, _newCloneKeys);
} else {
this._applySerializers(this.fields);
}
}
// Automatic fields.
if (!this.fields.hostname) {
this.fields.hostname = os.hostname();
}
//XXX Turn this on or ditch it.
//process.on('exit', function () {
// self.streams.forEach(function (s) {
// if (s.closeOnExit) {
// xxx("closing stream s:", s);
// s.stream.end();
// }
// });
//});
}
/**
* Clone this logger to a new one, additionally adding the given config
* options.
*
* This can be useful when passing a logger to a sub-component, e.g. a
* "wuzzle" component of your service:
*
* var wuzzleLog = log.clone({component: "wuzzle"})
* var wuzzle = new Wuzzle({..., log: wuzzleLog})
*
* Then log records from the wuzzle code will have the same structure as
* the app log, *plus the component="wuzzle" field*.
*
* @param options {Object} Optional. Set of options to apply to the clone.
* Supports the same set of options as the constructor.
*/
Logger.prototype.clone = function (options) {
var cloneOptions = objCopy(this.fields);
cloneOptions.streams = this.streams;
if (options) {
var newCloneKeys = Object.keys(options);
newCloneKeys.forEach(function(k) {
cloneOptions[k] = options[k];
});
}
return new Logger(cloneOptions, newCloneKeys);
}
/**
* Apply registered serializers to the appropriate keys in the given fields.
*
* Pre-condition: This is only called if there is at least one serializer.
*
* @param fields (Object) The log record fields.
* @param keys (Array) Optional array of keys to which to limit processing.
*/
Logger.prototype._applySerializers = function (fields, keys) {
var self = this;
// Mapping of keys to potentially serialize.
var applyKeys = fields;
if (keys) {
applyKeys = {};
for (var i=0; i < keys.length; i++) {
applyKeys[keys[i]] = true;
}
}
xxx('_applySerializers: applyKeys', applyKeys);
// Check each serializer against these (presuming number of serializers
// is typically less than number of fields).
Object.keys(this.serializers).forEach(function (name) {
if (applyKeys[name]) {
xxx('_applySerializers; apply to "%s" key', name)
try {
fields[name] = self.serializers[name](fields[name]);
} catch (err) {
process.stderr.write(format('bunyan: ERROR: This should never happen. '
+ 'This is a bug in <https://github.com/trentm/node-bunyan> or '
+ 'in this application. Exception from "%s" Logger serializer: %s',
name, err.stack || err));
fields[name] = format('(Error in Bunyan log "%s" serializer '
+ 'broke field. See stderr for details.)', name);
}
}
});
}
/**
* A log record is a 4-tuple:
* [<default fields object>,
* <log record fields object>,
* <level integer>,
* <msg args array>]
* For Perf reasons, we only render this down to a single object when
* it is emitted.
*/
Logger.prototype._mkRecord = function (fields, level, msgArgs) {
var recFields = (fields ? objCopy(fields) : null);
return [this.fields, recFields, level, msgArgs];
}
/**
* Emit a log record.
*
* @param rec {log record}
*/
Logger.prototype._emit = function (rec) {
var obj = objCopy(rec[0]);
var recFields = rec[1];
if (recFields) {
if (this.serializers) {
this._applySerializers(recFields);
}
Object.keys(recFields).forEach(function (k) {
obj[k] = recFields[k];
});
}
var level = obj.level = rec[2];
xxx("Record:", rec)
obj.msg = format.apply(this, rec[3]);
if (!obj.time) {
obj.time = (new Date());
}
obj.v = LOG_VERSION;
xxx('_emit: stringify this:', obj);
var str = JSON.stringify(obj) + '\n';
this.streams.forEach(function(s) {
if (s.level <= level) {
xxx('writing log rec "%s" to "%s" stream (%d <= %d)', obj.msg, s.type,
s.level, level);
s.stream.write(str);
}
});
}
/**
* Log a record at TRACE level.
*
* Usages:
* log.trace() -> boolean is-trace-enabled
* log.trace(<string> msg, ...)
* log.trace(<object> fields, <string> msg, ...)
*
* @params fields {Object} Optional set of additional fields to log.
* @params msg {String} Log message. This can be followed by additional
* arguments that are handled like
* [util.format](http://nodejs.org/docs/latest/api/all.html#util.format).
*/
Logger.prototype.trace = function () {
var fields = null, msgArgs = null;
if (arguments.length === 0) { // `log.trace()`
return (this.level <= TRACE);
} else if (this.level > TRACE) {
return;
} else if (typeof arguments[0] === 'string') { // `log.trace(msg, ...)`
fields = null;
msgArgs = Array.prototype.slice.call(arguments);
} else { // `log.trace(fields, msg, ...)`
fields = arguments[0];
msgArgs = Array.prototype.slice.call(arguments, 1);
}
var rec = this._mkRecord(fields, TRACE, msgArgs);
this._emit(rec);
}
/**
* Log a record at DEBUG level.
*
* Usages:
* log.debug() -> boolean is-debug-enabled
* log.debug(<string> msg, ...)
* log.debug(<object> fields, <string> msg, ...)
*
* @params fields {Object} Optional set of additional fields to log.
* @params msg {String} Log message. This can be followed by additional
* arguments that are handled like
* [util.format](http://nodejs.org/docs/latest/api/all.html#util.format).
*/
Logger.prototype.debug = function () {
var fields = null, msgArgs = null;
if (arguments.length === 0) { // `log.debug()`
return (this.level <= DEBUG);
} else if (this.level > DEBUG) {
return;
} else if (typeof arguments[0] === 'string') { // `log.debug(msg, ...)`
fields = null;
msgArgs = Array.prototype.slice.call(arguments);
} else { // `log.debug(fields, msg, ...)`
fields = arguments[0];
msgArgs = Array.prototype.slice.call(arguments, 1);
}
var rec = this._mkRecord(fields, DEBUG, msgArgs);
this._emit(rec);
}
/**
* Log a record at INFO level.
*
* Usages:
* log.info() -> boolean is-info-enabled
* log.info(<string> msg, ...)
* log.info(<object> fields, <string> msg, ...)
*
* @params fields {Object} Optional set of additional fields to log.
* @params msg {String} Log message. This can be followed by additional
* arguments that are handled like
* [util.format](http://nodejs.org/docs/latest/api/all.html#util.format).
*/
Logger.prototype.info = function () {
var fields = null, msgArgs = null;
if (arguments.length === 0) { // `log.info()`
return (this.level <= INFO);
} else if (this.level > INFO) {
return;
} else if (typeof arguments[0] === 'string') { // `log.info(msg, ...)`
fields = null;
msgArgs = Array.prototype.slice.call(arguments);
} else { // `log.info(fields, msg, ...)`
fields = arguments[0];
msgArgs = Array.prototype.slice.call(arguments, 1);
}
var rec = this._mkRecord(fields, INFO, msgArgs);
this._emit(rec);
}
/**
* Log a record at WARN level.
*
* Usages:
* log.warn() -> boolean is-warn-enabled
* log.warn(<string> msg, ...)
* log.warn(<object> fields, <string> msg, ...)
*
* @params fields {Object} Optional set of additional fields to log.
* @params msg {String} Log message. This can be followed by additional
* arguments that are handled like
* [util.format](http://nodejs.org/docs/latest/api/all.html#util.format).
*/
Logger.prototype.warn = function () {
var fields = null, msgArgs = null;
if (arguments.length === 0) { // `log.warn()`
return (this.level <= WARN);
} else if (this.level > WARN) {
return;
} else if (typeof arguments[0] === 'string') { // `log.warn(msg, ...)`
fields = null;
msgArgs = Array.prototype.slice.call(arguments);
} else { // `log.warn(fields, msg, ...)`
fields = arguments[0];
msgArgs = Array.prototype.slice.call(arguments, 1);
}
var rec = this._mkRecord(fields, WARN, msgArgs);
this._emit(rec);
}
/**
* Log a record at ERROR level.
*
* Usages:
* log.error() -> boolean is-error-enabled
* log.error(<string> msg, ...)
* log.error(<object> fields, <string> msg, ...)
*
* @params fields {Object} Optional set of additional fields to log.
* @params msg {String} Log message. This can be followed by additional
* arguments that are handled like
* [util.format](http://nodejs.org/docs/latest/api/all.html#util.format).
*/
Logger.prototype.error = function () {
var fields = null, msgArgs = null;
if (arguments.length === 0) { // `log.error()`
return (this.level <= ERROR);
} else if (this.level > ERROR) {
return;
} else if (typeof arguments[0] === 'string') { // `log.error(msg, ...)`
fields = null;
msgArgs = Array.prototype.slice.call(arguments);
} else { // `log.error(fields, msg, ...)`
fields = arguments[0];
msgArgs = Array.prototype.slice.call(arguments, 1);
}
var rec = this._mkRecord(fields, ERROR, msgArgs);
this._emit(rec);
}
/**
* Log a record at FATAL level.
*
* Usages:
* log.fatal() -> boolean is-fatal-enabled
* log.fatal(<string> msg, ...)
* log.fatal(<object> fields, <string> msg, ...)
*
* @params fields {Object} Optional set of additional fields to log.
* @params msg {String} Log message. This can be followed by additional
* arguments that are handled like
* [util.format](http://nodejs.org/docs/latest/api/all.html#util.format).
*/
Logger.prototype.fatal = function () {
var fields = null, msgArgs = null;
if (arguments.length === 0) { // `log.fatal()`
return (this.level <= FATAL);
} else if (this.level > FATAL) {
return;
} else if (typeof arguments[0] === 'string') { // `log.fatal(msg, ...)`
fields = null;
msgArgs = Array.prototype.slice.call(arguments);
} else { // `log.fatal(fields, msg, ...)`
fields = arguments[0];
msgArgs = Array.prototype.slice.call(arguments, 1);
}
var rec = this._mkRecord(fields, FATAL, msgArgs);
this._emit(rec);
}
//---- Standard serializers
// A serializer is a function that serializes a JavaScript object to a
// JSON representation for logging. There is a standard set of presumed
// interesting objects in node.js-land.
Logger.stdSerializers = {};
// Serialize an HTTP request.
Logger.stdSerializers.req = function req(req) {
return {
method: req.method,
url: req.url,
headers: req.headers,
remoteAddress: req.connection.remoteAddress,
remotePort: req.connection.remotePort
};
// Trailers: Skipping for speed. If you need trailers in your app, then
// make a custom serializers.
//if (Object.keys(trailers).length > 0) {
// obj.trailers = req.trailers;
//}
};
// Serialize an HTTP response.
Logger.stdSerializers.res = function res(res) {
return {
statusCode: res.statusCode,
header: res._header
}
};
//---- Exports
module.exports = Logger;
module.exports.VERSION = VERSION;
module.exports.LOG_VERSION = LOG_VERSION;