Function thread_io::write::writer

pub fn writer<W, F, O, E>(
    bufsize: usize, 
    queuelen: usize, 
    writer: W, 
    func: F
) -> Result<O, E> where
    F: FnOnce(&mut Writer) -> Result<O, E>,
    W: Write + Send,
    E: Send + From<Error>, 

Sends writer to a background thread and provides another writer in the main thread, which then submits its data to the background writer.

The writer in the closure (func) fills buffers of a given size (bufsize) and submits them to the background writer through a channel. The queue length of the channel can be configured using the queuelen parameter (must be ≥ 1). As a consequence, errors will not be returned immediately, but after some delay, or after writing is finished and the closure ends.

Also note that the last write() in the background can happen after the closure has ended. Finalizing actions should be done in the finish closure supplied to writer_finish or writer_init_finish.

Example:

use thread_io::write::writer;
use std::io::Write;

let text = b"The quick brown fox jumps over the lazy dog";
let mut buf = vec![0; text.len()];

writer(16, 2, &mut buf[..], |writer| {
    writer.write_all(&text[..])
}).expect("write failed");

assert_eq!(&buf[..], &text[..]);