filebuffer

Buffering data to file with rotating

Installation

npm install filebuffer --save 

About

This package provides FileBuffer class which lets to save data to file. File buffer may rotate based on file size or age. Originally created for ingesting large amount of data and save into files.

Usage

Writing to buffer

const { FileBuffer } = require('filebuffer');

const fb = new FileBuffer();

fb.write('Data to write'); // write() method will append \n characted at the end

Providing configuration

Some configuration may be added to FileBuffer(config). When no data is supplied in config, the default configuration will be used. Allowed options are described in Options section.

const { FileBuffer } = require('filebuffer');

const fb = new FileBuffer({
  activeBufferMaxAge: 120
});

Using bufferExchange event

When buffer is overloaded or activeBufferMaxAge time elapsed the file buffer will be exchanged. FileBuffer will emit bufferExchange event with name of closed file.

const { FileBuffer } = require('filebuffer');

const fb = new FileBuffer();

fb.on('bufferExchange', e => {
  // e.fileName will store closed file
  console.log(e.fileName);
});

Options

Default configaration:

{
  dataDir: './data/',
  activeBufferFileExtension: 'active',
  inactiveBufferFileExtension: 'stored',
  activeBufferMaxSize: '1M',
  activeBufferMaxAge: 60,
  allowTimeRollover: true
};

dataDir [string]

Specifies the directory where all files should be stored.

activeBufferFileExtension [string]

Specifies the extension of file which is currently active for writing. By default this extension is .active.

inactiveBufferFileExtension [string]

Specifies the extension of file which was closed and stored. By default this extension is .stored.

activeBufferMaxSize [string]

Specifies the maximal size of file. When this size is exceeded file will be closed and rotated (new file will be created). The value should be a string containing size - allowed are {number}k for kilobytes and {number}M for megabytes.

activeBufferMaxAge [number]

Specifies the maximal age of buffer. When buffer size is more than 0B but less than activeBufferMaxSize the file will be rotated after specified in activeBufferMaxAge time. This is time in seconds.

allowTimeRollover [boolean]

Specifies wheather activeBufferMaxAge should work. By defaul this option is enabled.

MIT License

Copyright (c) 2019 lookasc

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.