blob: 509dc0dedd1ec332e5346c51ddf0a1f00f310de9 [file] [log] [blame]
/**
* Expose `debug()` as the module.
*/
module.exports = debug;
/**
* Create a debugger with the given `name`.
*
* @param {String} name
* @return {Type}
* @api public
*/
function debug(name) {
if (!debug.enabled(name)) return function(){};
return function(fmt){
fmt = coerce(fmt);
var curr = new Date;
var ms = curr - (debug[name] || curr);
debug[name] = curr;
fmt = name
+ ' '
+ fmt
+ ' +' + debug.humanize(ms);
// This hackery is required for IE8
// where `console.log` doesn't have 'apply'
window.console
&& console.log
&& Function.prototype.apply.call(console.log, console, arguments);
}
}
/**
* The currently active debug mode names.
*/
debug.names = [];
debug.skips = [];
/**
* Enables a debug mode by name. This can include modes
* separated by a colon and wildcards.
*
* @param {String} name
* @api public
*/
debug.enable = function(name) {
try {
localStorage.debug = name;
} catch(e){}
var split = (name || '').split(/[\s,]+/)
, len = split.length;
for (var i = 0; i < len; i++) {
name = split[i].replace('*', '.*?');
if (name[0] === '-') {
debug.skips.push(new RegExp('^' + name.substr(1) + '$'));
}
else {
debug.names.push(new RegExp('^' + name + '$'));
}
}
};
/**
* Disable debug output.
*
* @api public
*/
debug.disable = function(){
debug.enable('');
};
/**
* Humanize the given `ms`.
*
* @param {Number} m
* @return {String}
* @api private
*/
debug.humanize = function(ms) {
var sec = 1000
, min = 60 * 1000
, hour = 60 * min;
if (ms >= hour) return (ms / hour).toFixed(1) + 'h';
if (ms >= min) return (ms / min).toFixed(1) + 'm';
if (ms >= sec) return (ms / sec | 0) + 's';
return ms + 'ms';
};
/**
* Returns true if the given mode name is enabled, false otherwise.
*
* @param {String} name
* @return {Boolean}
* @api public
*/
debug.enabled = function(name) {
for (var i = 0, len = debug.skips.length; i < len; i++) {
if (debug.skips[i].test(name)) {
return false;
}
}
for (var i = 0, len = debug.names.length; i < len; i++) {
if (debug.names[i].test(name)) {
return true;
}
}
return false;
};
/**
* Coerce `val`.
*/
function coerce(val) {
if (val instanceof Error) return val.stack || val.message;
return val;
}
// persist
try {
if (window.localStorage) debug.enable(localStorage.debug);
} catch(e){}