backends/file.js

// Copyright (c) 2015 Uber Technologies, Inc.
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.

var inherits = require('util').inherits;
var EventEmitter = require('events').EventEmitter;

var LoggerStream = require('./logger-stream.js');
var File = require('../lib/mkdir-file.js');

function FileBackend(opts) {
    if (!(this instanceof FileBackend)) {
        return new FileBackend(opts);
    }
    if (!opts.fileName) {
        throw new Error('FileBackend: opts.fileName is required');
    }
    EventEmitter.call(this);
    this.fileName = opts.fileName;
}

inherits(FileBackend, EventEmitter);

FileBackend.prototype.createStream = function createStream(meta, opts) {
    var logger = new File({
        filename: this.fileName
    });

    return LoggerStream(logger, {
        highWaterMark: opts.highWaterMark
    });
};

module.exports = FileBackend;