litejs/lib/log.js

"use strict";


var enableRe
, currentLevel = 2
, namespaces = log.namespaces = {}
, filters = []
, slice = filters.slice
, lastLog = {}
, formatFns = {}

log.levels = {
	"error": 0,
	"warn":  1,
	"info":  2,
	"debug": 3
}

module.exports = log

log.debug = debug
log.level = level
// expose nop for testing purpose
log.nop = function nop() {}
log.format = format

log.rawStream = null
log.prettyStream = process.stdout



function log(name, enable) {
	var binded = namespaces[name] || (namespaces[name] = function log() {
		if (log.enabled === true) log.debug.apply(log, arguments)
	})
	binded.enabled = typeof enable === "boolean" ? enable : !!(enableRe && enableRe.test(name))
	setLevels(name)
	return binded
}

function level(newLevel) {
	if (newLevel >= 0 && newLevel < Object.keys(log.levels).length) {
		currentLevel = newLevel | 0
	}
	Object.keys(namespaces).forEach(setLevels)
	return currentLevel
}

function setLevels(name) {
	var level
	, levels = log.levels
	, binded = namespaces[name]
	for (level in levels) {
		binded[level] = (
			binded.enabled || levels[level] <= currentLevel ?
			_log.bind(binded, name, level) :
			log.nop
		)
	}
}

function _log(name, level, msg) {
	var len, undef, out, tmp
	, now = Date.now()
	, argi = arguments.length
	, args = argi > 3 ? slice.call(arguments, 3) : null

	if (msg instanceof Error) {
		msg = msg.stack || msg.message
	}

	if (log.rawStream) {
		log.rawStream.write([now, name, level, msg, args])
	}

	if (log.prettyStream) {
		tmp = now - (lastLog[name] || now)
		out = new Date(now).toISOString() + " " + name + " +" + (
			tmp > 36e4 ? (tmp / 36e4).toFixed(1) + "h" :
			tmp > 6e4  ? (tmp / 6e4).toFixed(1) + "m" :
			tmp > 1e3  ? (tmp / 1e3 | 0) + "s" :
			tmp + "ms"
		).replace(".0", "")
		if (args === null) {
			out += " " + msg
		} else {
			out += " " + format(msg, args)
		}

		log.prettyStream.write(out + "\n")
	}

	lastLog[name] = now
}

function debug(filter) {
	enableRe = filter && RegExp(
		"^(" +
		filter
		.replace(/[.+?^${}()|[\]\\]/g, "\\$&")
		.replace(/\*/g, ".*?")
		.replace(/[\s,]+/g, "|") +
		")$"
	)
	Object.keys(namespaces).forEach(log)
}

function format(msg, args) {
	var tmp
	, out = ""
	, i = 0
	, last = 0
	, replaced = 0
	, msgi = msg.length - 1
	, argi = args.length

	for (; i < msgi && replaced < argi; ) {
		if (msg.charCodeAt(i++) === 37) {    //  37 = %
			tmp = msg.charCodeAt(i)
			if (tmp === 115) {           // 115 = s
				out += msg.slice(last, i - 1) + args[replaced++]
				last = ++i
			}
		}
	}
	if (last <= msgi) {
		out += msg.slice(last)
	}

	if (replaced < argi) {
		for (; replaced < argi; ) {
			out += " " + args[replaced++]
		}
	}
	return out
}