log4js-node/lib/streams/RollingFileStream.js
2013-05-30 07:56:28 +10:00

96 lines
2.7 KiB
JavaScript

"use strict";
var BaseRollingFileStream = require('./BaseRollingFileStream')
, util = require('util')
, path = require('path')
, fs = require('fs')
, async = require('async');
var debug;
if (process.env.NODE_DEBUG && /\blog4js\b/.test(process.env.NODE_DEBUG)) {
debug = function(message) { console.error('LOG4JS: (RollingFileStream) %s', message); };
} else {
debug = function() { };
}
module.exports = RollingFileStream;
function RollingFileStream (filename, size, backups, options) {
this.size = size;
this.backups = backups || 1;
function throwErrorIfArgumentsAreNotValid() {
if (!filename || !size || size <= 0) {
throw new Error("You must specify a filename and file size");
}
}
throwErrorIfArgumentsAreNotValid();
RollingFileStream.super_.call(this, filename, options);
}
util.inherits(RollingFileStream, BaseRollingFileStream);
RollingFileStream.prototype.shouldRoll = function() {
debug("should roll with current size %d, and max size %d", this.currentSize, this.size);
return this.currentSize >= this.size;
};
RollingFileStream.prototype.roll = function(filename, callback) {
var that = this,
nameMatcher = new RegExp('^' + path.basename(filename));
function justTheseFiles (item) {
return nameMatcher.test(item);
}
function index(filename_) {
return parseInt(filename_.substring((path.basename(filename) + '.').length), 10) || 0;
}
function byIndex(a, b) {
if (index(a) > index(b)) {
return 1;
} else if (index(a) < index(b) ) {
return -1;
} else {
return 0;
}
}
function increaseFileIndex (fileToRename, cb) {
var idx = index(fileToRename);
debug('Index of ' + fileToRename + ' is ' + idx);
if (idx < that.backups) {
//on windows, you can get a EEXIST error if you rename a file to an existing file
//so, we'll try to delete the file we're renaming to first
fs.unlink(filename + '.' + (idx+1), function (err) {
//ignore err: if we could not delete, it's most likely that it doesn't exist
debug('Renaming ' + fileToRename + ' -> ' + filename + '.' + (idx+1));
fs.rename(path.join(path.dirname(filename), fileToRename), filename + '.' + (idx + 1), cb);
});
} else {
cb();
}
}
function renameTheFiles(cb) {
//roll the backups (rename file.n to file.n+1, where n <= numBackups)
debug("Renaming the old files");
fs.readdir(path.dirname(filename), function (err, files) {
async.forEachSeries(
files.filter(justTheseFiles).sort(byIndex).reverse(),
increaseFileIndex,
cb
);
});
}
debug("Rolling, rolling, rolling");
async.series([
this.closeTheStream.bind(this),
renameTheFiles,
this.openTheStream.bind(this)
], callback);
};