isabella232 / fs-minipass

fs read and write streams based on minipass

fs-minipass

Filesystem streams based on minipass.

4 classes are exported:

• ReadStream
• ReadStreamSync
• WriteStream
• WriteStreamSync

When using ReadStreamSync, all of the data is made available immediately upon consuming the stream. Nothing is buffered in memory when the stream is constructed. If the stream is piped to a writer, then it will synchronously read() and emit data into the writer as fast as the writer can consume it. (That is, it will respect backpressure.) If you call stream.read() then it will read the entire file and return the contents.

When using WriteStreamSync, every write is flushed to the file synchronously. If your writes all come in a single tick, then it'll write it all out in a single tick. It's as synchronous as you are.

The async versions work much like their node builtin counterparts, with the exception of introducing significantly less Stream machinery overhead.

USAGE

It's just streams, you pipe them or read() them or write() to them.

const fsm = require('fs-minipass')
const readStream = new fsm.ReadStream('file.txt')
const writeStream = new fsm.WriteStream('output.txt')
writeStream.write('some file header or whatever\n')
readStream.pipe(writeStream)

ReadStream(path, options)

Path string is required, but somewhat irrelevant if an open file descriptor is passed in as an option.

Options:

• fd Pass in a numeric file descriptor, if the file is already open.
• readSize The size of reads to do, defaults to 16MB
• size The size of the file, if known. Prevents zero-byte read() call at the end.
• autoClose Set to false to prevent the file descriptor from being closed when the file is done being read.

WriteStream(path, options)

Path string is required, but somewhat irrelevant if an open file descriptor is passed in as an option.

Options:

• fd Pass in a numeric file descriptor, if the file is already open.
• mode The mode to create the file with. Defaults to 0o666.
• start The position in the file to start reading. If not specified, then the file will start writing at position zero, and be truncated by default.
• autoClose Set to false to prevent the file descriptor from being closed when the stream is ended.
• flags Flags to use when opening the file. Irrelevant if fd is passed in, since file won't be opened in that case. Defaults to 'a' if a pos is specified, or 'w' otherwise.