LineReader is a byte-delimiter-focused buffered reader for Rust, meant as a
faster, less error-prone alternative to BufRead::read_until.
It provides two main functions:
next_line()Returns Option<io::Result<&[u8]>> - None on end-of-file, an IO error from the
wrapped reader, or an immutable byte slice ending on and including any delimiter.
Line length is limited to the size of the internal buffer - longer lines will be spread across multiple reads.
In contrast with read_until, detecting end-of-file is more natural with the
use of Option; line length is naturally limited to some sensible value without
the use of by_ref().take(limit); copying is minimised by returning borrowed
slices; you'll never forget to call buf.clear().
next_batch()Behaves identically to next_line(), except it returns a slice of all the
complete lines in the buffer.
```rust extern crate linereader; use linereader::LineReader;
let mut file = File::open(myfile).expect("open");
// Defaults to a 64 KiB buffer and b'\n' delimiter; change with one of: // * LineReader::withcapacity(usize); // * LineReader::withdelimiter(u8); // * LineReader::withdelimiterand_capacity(u8, usize) let mut reader = LineReader::new(file);
while let Some(line) = reader.next_line() { let line = line.expect("read error"); // line is a &[u8] owned by reader. } ```
Tests performed using 'DickensCharlesPickwick_Papers.xml', concatinated to itself 480 times. The resulting file is 976 MB and 10.3 million lines long.
| Method | Time | Lines/sec | Bandwidth | |------------------|--------:|------------:|--------------:| | read() | 0.25s | 41429738/s | 3907.62 MB/s | | LR::nextbatch() | 0.27s | 38258946/s | 3608.55 MB/s | | LR::nextline() | 1.51s | 6874006/s | 648.35 MB/s | | readuntil() | 1.94s | 5327387/s | 502.47 MB/s | | readline() | 2.54s | 4081562/s | 384.97 MB/s | | lines() | 3.23s | 3199491/s | 301.77 MB/s |