Struct buffer_redux::policy::MinBuffered
source · pub struct MinBuffered(pub usize);
Expand description
A policy for BufReader
which ensures there is at least the given number of
bytes in the buffer, failing this only if the reader is at EOF.
If the minimum buffer length is greater than the buffer capacity, it will be resized.
Example
use buffer_redux::BufReader;
use buffer_redux::policy::MinBuffered;
use std::io::{BufRead, Cursor};
let data = (1 .. 16).collect::<Vec<u8>>();
// normally you should use `BufReader::new()` or give a capacity of several KiB or more
let mut reader = BufReader::with_capacity(8, Cursor::new(data))
// always at least 4 bytes in the buffer (or until the source is empty)
.set_policy(MinBuffered(4)); // always at least 4 bytes in the buffer
// first buffer fill, same as `std::io::BufReader`
assert_eq!(reader.fill_buf().unwrap(), &[1, 2, 3, 4, 5, 6, 7, 8]);
reader.consume(3);
// enough data in the buffer, another read isn't done yet
assert_eq!(reader.fill_buf().unwrap(), &[4, 5, 6, 7, 8]);
reader.consume(4);
// `std::io::BufReader` would return `&[8]`
assert_eq!(reader.fill_buf().unwrap(), &[8, 9, 10, 11, 12, 13, 14, 15]);
reader.consume(5);
// no data left in the reader
assert_eq!(reader.fill_buf().unwrap(), &[13, 14, 15]);
Tuple Fields§
§0: usize