sonic-boom

Extremely fast utf8-only stream implementation to write to files and file descriptors.

This implementation is partial, but support backpressure and .pipe() in is here. However, it is 2-3x faster than Node Core fs.createWriteStream():

benchSonic*1000: 1916.904ms
benchSonicSync*1000: 8605.265ms
benchSonic4k*1000: 1965.231ms
benchSonicSync4k*1000: 1588.224ms
benchCore*1000: 5851.959ms
benchConsole*1000: 7605.713ms

Note that sync mode without buffering is slower than a Node Core WritableStream, however this mode matches the expected behavior of console.log().

Note that if this is used to log to a windows terminal (cmd.exe or powershell), it is needed to run chcp 65001 in the terminal to correctly display utf-8 characters, see chcp for more details.

Install

npm i sonic-boom

Example

'use strict'

const SonicBoom = require('sonic-boom')
const sonic = new SonicBoom({ fd: process.stdout.fd }) // or { dest: '/path/to/destination' }

for (let i = 0; i < 10; i++) {
  sonic.write('hello sonic\n')
}

API

SonicBoom(opts)

Creates a new instance of SonicBoom.

The options are:

fd: a file descriptor, something that is returned by fs.open or fs.openSync.
dest: a string that is a path to a file to be written to (mode controlled by the append option).
minLength: the minimum length of the internal buffer that is required to be full before flushing.
maxLength: the maximum length of the internal buffer. If a write operation would cause the buffer to exceed maxLength, the data written is dropped and a drop event is emitted with the dropped data
maxWrite: the maximum number of bytes that can be written; default: 16384
sync: perform writes synchronously (similar to console.log).
fsync: perform a fsyncSync every time a write is completed.
append: appends writes to dest file instead of truncating it (default true).
mode: specify the creating file mode (see fs.open() from Node.js core).
mkdir: ensure directory for dest file exists when true (default false).
retryEAGAIN(err, writeBufferLen, remainingBufferLen): a function that will be called when sonic-boom write/writeSync/flushSync encounters a EAGAIN or EBUSY error. If the return value is true sonic-boom will retry the operation, otherwise it will bubble the error. err is the error that caused this function to be called, writeBufferLen is the length of the buffer sonic-boom tried to write, and remainingBufferLen is the length of the remaining buffer sonic-boom didn't try to write.

For sync:false a SonicBoom instance will emit the 'ready' event when a file descriptor is available. For sync:true this is not relevant because the 'ready' event will be fired when the SonicBoom instance is created, before it can be subscribed to.

SonicBoom#write(string)

Writes the string to the file. It will return false to signal the producer to slow down.

SonicBoom#flush()

Writes the current buffer to the file if a write was not in progress. Do nothing if minLength is zero or if it is already writing.

SonicBoom#reopen([file])

Reopen the file in place, useful for log rotation.

Example:

const stream = new SonicBoom('./my.log')
process.on('SIGUSR2', function () {
  stream.reopen()
})

SonicBoom#flushSync()

Flushes the buffered data synchronously. This is a costly operation.

SonicBoom#end()

Closes the stream, the data will be flushed down asynchronously

SonicBoom#destroy()

Closes the stream immediately, the data is not flushed.

Events

SonicBoom#close

See Stream#close. The 'close' event when the instance has been closed.

SonicBoom#drain

See Stream#drain. The 'drain' event is emitted when source can resume sending data.

SonicBoom#drop <any>

When destination file maximal length is reached, the 'drop' event is emitted with data that could not be written.

SonicBoom#error <Error>

The 'error' event is emitted when the destination file can not be opened, or written.

SonicBoom#finish

See Stream#finish. The 'finish' event after calling end() method and when all data was written.

SonicBoom#ready

The 'ready' event occurs when the created instance is ready to process input.

SonicBoom#write <number>

The 'write' event occurs every time data is written to the underlying file. It emits the number of written bytes.