#buffer #pattern #bufread #traits #reading #found #needle

until_needle

An extension to the BufRead trait that allows reading until a specified pattern (needle) is found

1 unstable release

0.1.0 Sep 29, 2024

#1 in #bufread

MIT license

16KB
329 lines

until_needle

until_needle is a Rust crate that extends the BufRead trait to allow reading from a buffer until a specified "needle" (search pattern) is found. This is useful for reading a stream or buffer until a certain pattern is encountered, and is similar in concept to read_until but more flexible with custom patterns.

Features

  • Provides the UntilNeedleRead trait to extend BufRead functionality.
  • Reads data from a buffer until a specified "needle" is found or the end of the stream is reached.
  • Stores data before the needle and the needle itself separately for further processing.

Example

use until_needle::io::UntilNeedleRead;
use std::io::{BufRead, Cursor};

fn main() {
    let data = b"hello world!!";
    let mut cursor = Cursor::new(data);
    let mut before = Vec::new();
    let mut matched = Vec::new();

    let bytes_read = cursor.read_until_needle(b"world", &mut before, &mut matched).unwrap();
    assert_eq!(bytes_read, b"hello world".len());
    assert_eq!(before, b"hello ");
    assert_eq!(matched, b"world");
}

This code reads the data until the pattern "world" is found, storing the data before the needle in the before buffer and the needle itself in the matched buffer. The until_needle crate also supports regular expressions (regex) as the needle.

Dependencies

~2.2–3.5MB
~58K SLoC