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use crate::cmp::{max, min};
use crate::io::prelude::*;
use crate::io::{
copy, empty, repeat, sink, BufWriter, Empty, Repeat, Result, SeekFrom, Sink, DEFAULT_BUF_SIZE,
};
#[test]
fn copy_copies() {
let mut r = repeat(0).take(4);
let mut w = sink();
assert_eq!(copy(&mut r, &mut w).unwrap(), 4);
let mut r = repeat(0).take(1 << 17);
assert_eq!(copy(&mut r as &mut dyn Read, &mut w as &mut dyn Write).unwrap(), 1 << 17);
}
struct ShortReader {
cap: usize,
read_size: usize,
observed_buffer: usize,
}
impl Read for ShortReader {
fn read(&mut self, buf: &mut [u8]) -> Result<usize> {
let bytes = min(self.cap, self.read_size);
self.cap -= bytes;
self.observed_buffer = max(self.observed_buffer, buf.len());
Ok(bytes)
}
}
struct WriteObserver {
observed_buffer: usize,
}
impl Write for WriteObserver {
fn write(&mut self, buf: &[u8]) -> Result<usize> {
self.observed_buffer = max(self.observed_buffer, buf.len());
Ok(buf.len())
}
fn flush(&mut self) -> Result<()> {
Ok(())
}
}
#[test]
fn copy_specializes_bufwriter() {
let cap = 117 * 1024;
let buf_sz = 16 * 1024;
let mut r = ShortReader { cap, observed_buffer: 0, read_size: 1337 };
let mut w = BufWriter::with_capacity(buf_sz, WriteObserver { observed_buffer: 0 });
assert_eq!(
copy(&mut r, &mut w).unwrap(),
cap as u64,
"expected the whole capacity to be copied"
);
assert_eq!(r.observed_buffer, buf_sz, "expected a large buffer to be provided to the reader");
assert!(w.get_mut().observed_buffer > DEFAULT_BUF_SIZE, "expected coalesced writes");
}
#[test]
fn sink_sinks() {
let mut s = sink();
assert_eq!(s.write(&[]).unwrap(), 0);
assert_eq!(s.write(&[0]).unwrap(), 1);
assert_eq!(s.write(&[0; 1024]).unwrap(), 1024);
assert_eq!(s.by_ref().write(&[0; 1024]).unwrap(), 1024);
}
#[test]
fn empty_reads() {
let mut e = empty();
assert_eq!(e.read(&mut []).unwrap(), 0);
assert_eq!(e.read(&mut [0]).unwrap(), 0);
assert_eq!(e.read(&mut [0; 1024]).unwrap(), 0);
assert_eq!(e.by_ref().read(&mut [0; 1024]).unwrap(), 0);
}
#[test]
fn empty_seeks() {
let mut e = empty();
assert!(matches!(e.seek(SeekFrom::Start(0)), Ok(0)));
assert!(matches!(e.seek(SeekFrom::Start(1)), Ok(0)));
assert!(matches!(e.seek(SeekFrom::Start(u64::MAX)), Ok(0)));
assert!(matches!(e.seek(SeekFrom::End(i64::MIN)), Ok(0)));
assert!(matches!(e.seek(SeekFrom::End(-1)), Ok(0)));
assert!(matches!(e.seek(SeekFrom::End(0)), Ok(0)));
assert!(matches!(e.seek(SeekFrom::End(1)), Ok(0)));
assert!(matches!(e.seek(SeekFrom::End(i64::MAX)), Ok(0)));
assert!(matches!(e.seek(SeekFrom::Current(i64::MIN)), Ok(0)));
assert!(matches!(e.seek(SeekFrom::Current(-1)), Ok(0)));
assert!(matches!(e.seek(SeekFrom::Current(0)), Ok(0)));
assert!(matches!(e.seek(SeekFrom::Current(1)), Ok(0)));
assert!(matches!(e.seek(SeekFrom::Current(i64::MAX)), Ok(0)));
}
#[test]
fn repeat_repeats() {
let mut r = repeat(4);
let mut b = [0; 1024];
assert_eq!(r.read(&mut b).unwrap(), 1024);
assert!(b.iter().all(|b| *b == 4));
}
#[test]
fn take_some_bytes() {
assert_eq!(repeat(4).take(100).bytes().count(), 100);
assert_eq!(repeat(4).take(100).bytes().next().unwrap().unwrap(), 4);
assert_eq!(repeat(1).take(10).chain(repeat(2).take(10)).bytes().count(), 20);
}
#[allow(dead_code)]
fn const_utils() {
const _: Empty = empty();
const _: Repeat = repeat(b'c');
const _: Sink = sink();
}
|
