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use prelude::v1::*;
use io;
use io::ErrorKind;
use io::Read;
use slice::from_raw_parts_mut;
pub unsafe fn read_to_end_uninitialized(r: &mut Read, buf: &mut Vec<u8>) -> io::Result<usize> {
let start_len = buf.len();
buf.reserve(16);
loop {
if buf.len() == buf.capacity() {
buf.reserve(1);
}
let buf_slice = from_raw_parts_mut(buf.as_mut_ptr().offset(buf.len() as isize),
buf.capacity() - buf.len());
match r.read(buf_slice) {
Ok(0) => { return Ok(buf.len() - start_len); }
Ok(n) => { let len = buf.len() + n; buf.set_len(len); },
Err(ref e) if e.kind() == ErrorKind::Interrupted => { }
Err(e) => { return Err(e); }
}
}
}
#[cfg(test)]
pub mod test {
use prelude::v1::*;
use path::{Path, PathBuf};
use env;
use rand::{self, Rng};
use fs;
pub struct TempDir(PathBuf);
impl TempDir {
pub fn join(&self, path: &str) -> PathBuf {
let TempDir(ref p) = *self;
p.join(path)
}
pub fn path<'a>(&'a self) -> &'a Path {
let TempDir(ref p) = *self;
p
}
}
impl Drop for TempDir {
fn drop(&mut self) {
let TempDir(ref p) = *self;
fs::remove_dir_all(p).unwrap();
}
}
pub fn tmpdir() -> TempDir {
let p = env::temp_dir();
let mut r = rand::thread_rng();
let ret = p.join(&format!("rust-{}", r.next_u32()));
fs::create_dir(&ret).unwrap();
TempDir(ret)
}
}
#[cfg(test)]
mod tests {
use prelude::v1::*;
use io::prelude::*;
use super::*;
use io;
use io::{ErrorKind, Take, Repeat, repeat};
use slice::from_raw_parts;
struct ErrorRepeat {
lr: Take<Repeat>
}
fn error_repeat(byte: u8, limit: u64) -> ErrorRepeat {
ErrorRepeat { lr: repeat(byte).take(limit) }
}
impl Read for ErrorRepeat {
fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
let ret = self.lr.read(buf);
if let Ok(0) = ret {
return Err(io::Error::new(ErrorKind::Other, ""))
}
ret
}
}
fn init_vec_data() -> Vec<u8> {
let mut vec = vec![10u8; 200];
unsafe { vec.set_len(0); }
vec
}
fn assert_all_eq(buf: &[u8], value: u8) {
for n in buf {
assert_eq!(*n, value);
}
}
fn validate(buf: &Vec<u8>, good_read_len: usize) {
assert_all_eq(buf, 1u8);
let cap = buf.capacity();
let end_slice = unsafe { from_raw_parts(buf.as_ptr().offset(good_read_len as isize),
cap - good_read_len) };
assert_all_eq(end_slice, 10u8);
}
#[test]
fn read_to_end_uninit_error() {
let mut er = error_repeat(1,100);
let mut vec = init_vec_data();
if let Err(_) = unsafe { read_to_end_uninitialized(&mut er, &mut vec) } {
validate(&vec, 100);
} else {
assert!(false);
}
}
#[test]
fn read_to_end_uninit_zero_len_vec() {
let mut er = repeat(1).take(100);
let mut vec = Vec::new();
let n = unsafe{ read_to_end_uninitialized(&mut er, &mut vec).unwrap() };
assert_all_eq(&vec, 1u8);
assert_eq!(vec.len(), n);
}
#[test]
fn read_to_end_uninit_good() {
let mut er = repeat(1).take(100);
let mut vec = init_vec_data();
let n = unsafe{ read_to_end_uninitialized(&mut er, &mut vec).unwrap() };
validate(&vec, 100);
assert_eq!(vec.len(), n);
}
#[bench]
fn bench_uninitialized(b: &mut ::test::Bencher) {
b.iter(|| {
let mut lr = repeat(1).take(10000000);
let mut vec = Vec::with_capacity(1024);
unsafe { read_to_end_uninitialized(&mut lr, &mut vec) }
});
}
}