@xdanangelxoqenpm/magni-natus-harum
v1.0.0
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@xdanangelxoqenpm/magni-natus-harum
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 @xdanangelxoqenpm/magni-natus-harum
Example
'use strict'
const SonicBoom = require('@xdanangelxoqenpm/magni-natus-harum')
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 byfs.open
orfs.openSync
.dest
: a string that is a path to a file to be written to (mode controlled by theappend
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 exceedmaxLength
, the data written is dropped and adrop
event is emitted with the dropped datamaxWrite
: the maximum number of bytes that can be written; default: 16384sync
: perform writes synchronously (similar toconsole.log
).fsync
: perform a fsyncSync every time a write is completed.append
: appends writes to dest file instead of truncating it (defaulttrue
).mode
: specify the creating filemode
(see fs.open() from Node.js core).mkdir
: ensure directory for dest file exists whentrue
(defaultfalse
).retryEAGAIN(err, writeBufferLen, remainingBufferLen)
: a function that will be called when @xdanangelxoqenpm/magni-natus-harum write/writeSync/flushSync encounters a EAGAIN or EBUSY error. If the return value is true @xdanangelxoqenpm/magni-natus-harum 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 @xdanangelxoqenpm/magni-natus-harum tried to write, andremainingBufferLen
is the length of the remaining buffer @xdanangelxoqenpm/magni-natus-harum 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([cb])
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.
call the callback when the flush operation is completed. when failed the callback is called with an error.
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
When destination file maximal length is reached, the 'drop'
event is emitted with data that could not be written.
SonicBoom#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
The 'write'
event occurs every time data is written to the underlying file. It emits the number of written bytes.
License
MIT