backends/disk.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 path = require('path');
var inherits = require('util').inherits;
var EventEmitter = require('events').EventEmitter;

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

function DiskBackend(opts) {
    if (!(this instanceof DiskBackend)) {
        return new DiskBackend(opts);
    }

    if (!opts.folder) {
        throw new Error('DiskBackend: opts.folder is required');
    }

    EventEmitter.call(this);

    this.folder = opts.folder;
    this.json = opts.json || false;
}

inherits(DiskBackend, EventEmitter);

DiskBackend.prototype.createStream =
    function createStream(meta, opts) {
        var fileName = meta.team + '-' + meta.project + '.log';
        var logger = new DailyRotateFile({
            filename: path.join(this.folder, fileName),
            datePattern: '-yyyyMMdd',
            json: this.json
        });

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

module.exports = DiskBackend;