log4js-node/lib/appenders/file.js

97 lines
2.5 KiB
JavaScript

"use strict";
var layouts = require('../layouts')
, async = require('async')
, path = require('path')
, fs = require('fs')
, streams = require('../streams')
, os = require('os')
, eol = os.EOL || '\n'
, openFiles = [];
//close open files on process exit.
process.on('exit', function() {
openFiles.forEach(function (file) {
file.end();
});
});
/**
* File Appender writing the logs to a text file. Supports rolling of logs by size.
*
* @param file file log messages will be written to
* @param layout a function that takes a logevent and returns a string
* (defaults to basicLayout).
* @param logSize - the maximum size (in bytes) for a log file,
* if not provided then logs won't be rotated.
* @param numBackups - the number of log files to keep after logSize
* has been reached (default 5)
*/
function fileAppender (file, layout, logSize, numBackups) {
var bytesWritten = 0;
file = path.normalize(file);
layout = layout || layouts.basicLayout;
numBackups = numBackups === undefined ? 5 : numBackups;
//there has to be at least one backup if logSize has been specified
numBackups = numBackups === 0 ? 1 : numBackups;
function openTheStream(file, fileSize, numFiles) {
var stream;
if (fileSize) {
stream = new streams.RollingFileStream(
file,
fileSize,
numFiles
);
} else {
stream = fs.createWriteStream(
file,
{ encoding: "utf8",
mode: parseInt('0644', 8),
flags: 'a' }
);
}
stream.on("error", function (err) {
console.error("log4js.fileAppender - Writing to file %s, error happened ", file, err);
});
return stream;
}
var logFile = openTheStream(file, logSize, numBackups);
// push file to the stack of open handlers
openFiles.push(logFile);
return function(loggingEvent) {
logFile.write(layout(loggingEvent) + eol, "utf8");
};
}
function configure(config, options) {
var layout;
if (config.layout) {
layout = layouts.layout(config.layout.type, config.layout);
}
if (options && options.cwd && !config.absolute) {
config.filename = path.join(options.cwd, config.filename);
}
return fileAppender(config.filename, layout, config.maxLogSize, config.backups);
}
function shutdown(cb) {
async.each(openFiles, function(file, done) {
if (!file.write(eol, "utf-8")) {
file.once('drain', function() {
file.end(done);
});
} else {
file.end(done);
}
}, cb);
}
exports.appender = fileAppender;
exports.configure = configure;
exports.shutdown = shutdown;