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Rust: import core_io crate into libstd_artiq.

Unfortunately the crate does not work out of the box with custom
Rust builds, and forking it makes little sense over just embedding
it here. See https://github.com/jethrogb/rust-core_io/issues/2.
This commit is contained in:
whitequark 2016-09-20 08:28:00 +00:00
parent 52f935dcfb
commit 1c7e1dd645
9 changed files with 4658 additions and 1 deletions

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// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
use core::prelude::v1::*;
use io::prelude::*;
use core::cmp;
use io::{self, SeekFrom, Error, ErrorKind};
/// A `Cursor` wraps another type and provides it with a
/// [`Seek`](trait.Seek.html) implementation.
///
/// Cursors are typically used with in-memory buffers to allow them to
/// implement `Read` and/or `Write`, allowing these buffers to be used
/// anywhere you might use a reader or writer that does actual I/O.
///
/// The standard library implements some I/O traits on various types which
/// are commonly used as a buffer, like `Cursor<Vec<u8>>` and `Cursor<&[u8]>`.
///
/// # Examples
///
/// We may want to write bytes to a [`File`][file] in our production
/// code, but use an in-memory buffer in our tests. We can do this with
/// `Cursor`:
///
/// [file]: ../fs/struct.File.html
///
/// ```no_run
/// use std::io::prelude::*;
/// use std::io::{self, SeekFrom};
/// use std::fs::File;
///
/// // a library function we've written
/// fn write_ten_bytes_at_end<W: Write + Seek>(writer: &mut W) -> io::Result<()> {
/// try!(writer.seek(SeekFrom::End(-10)));
///
/// for i in 0..10 {
/// try!(writer.write(&[i]));
/// }
///
/// // all went well
/// Ok(())
/// }
///
/// # fn foo() -> io::Result<()> {
/// // Here's some code that uses this library function.
/// //
/// // We might want to use a BufReader here for efficiency, but let's
/// // keep this example focused.
/// let mut file = try!(File::create("foo.txt"));
///
/// try!(write_ten_bytes_at_end(&mut file));
/// # Ok(())
/// # }
///
/// // now let's write a test
/// #[test]
/// fn test_writes_bytes() {
/// // setting up a real File is much more slow than an in-memory buffer,
/// // let's use a cursor instead
/// use std::io::Cursor;
/// let mut buff = Cursor::new(vec![0; 15]);
///
/// write_ten_bytes_at_end(&mut buff).unwrap();
///
/// assert_eq!(&buff.get_ref()[5..15], &[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]);
/// }
/// ```
#[derive(Clone, Debug)]
pub struct Cursor<T> {
inner: T,
pos: u64,
}
impl<T> Cursor<T> {
/// Creates a new cursor wrapping the provided underlying I/O object.
///
/// # Examples
///
/// ```
/// use std::io::Cursor;
///
/// let buff = Cursor::new(Vec::new());
/// # fn force_inference(_: &Cursor<Vec<u8>>) {}
/// # force_inference(&buff);
/// ```
pub fn new(inner: T) -> Cursor<T> {
Cursor { pos: 0, inner: inner }
}
/// Consumes this cursor, returning the underlying value.
///
/// # Examples
///
/// ```
/// use std::io::Cursor;
///
/// let buff = Cursor::new(Vec::new());
/// # fn force_inference(_: &Cursor<Vec<u8>>) {}
/// # force_inference(&buff);
///
/// let vec = buff.into_inner();
/// ```
pub fn into_inner(self) -> T { self.inner }
/// Gets a reference to the underlying value in this cursor.
///
/// # Examples
///
/// ```
/// use std::io::Cursor;
///
/// let buff = Cursor::new(Vec::new());
/// # fn force_inference(_: &Cursor<Vec<u8>>) {}
/// # force_inference(&buff);
///
/// let reference = buff.get_ref();
/// ```
pub fn get_ref(&self) -> &T { &self.inner }
/// Gets a mutable reference to the underlying value in this cursor.
///
/// Care should be taken to avoid modifying the internal I/O state of the
/// underlying value as it may corrupt this cursor's position.
///
/// # Examples
///
/// ```
/// use std::io::Cursor;
///
/// let mut buff = Cursor::new(Vec::new());
/// # fn force_inference(_: &Cursor<Vec<u8>>) {}
/// # force_inference(&buff);
///
/// let reference = buff.get_mut();
/// ```
pub fn get_mut(&mut self) -> &mut T { &mut self.inner }
/// Returns the current position of this cursor.
///
/// # Examples
///
/// ```
/// use std::io::Cursor;
/// use std::io::prelude::*;
/// use std::io::SeekFrom;
///
/// let mut buff = Cursor::new(vec![1, 2, 3, 4, 5]);
///
/// assert_eq!(buff.position(), 0);
///
/// buff.seek(SeekFrom::Current(2)).unwrap();
/// assert_eq!(buff.position(), 2);
///
/// buff.seek(SeekFrom::Current(-1)).unwrap();
/// assert_eq!(buff.position(), 1);
/// ```
pub fn position(&self) -> u64 { self.pos }
/// Sets the position of this cursor.
///
/// # Examples
///
/// ```
/// use std::io::Cursor;
///
/// let mut buff = Cursor::new(vec![1, 2, 3, 4, 5]);
///
/// assert_eq!(buff.position(), 0);
///
/// buff.set_position(2);
/// assert_eq!(buff.position(), 2);
///
/// buff.set_position(4);
/// assert_eq!(buff.position(), 4);
/// ```
pub fn set_position(&mut self, pos: u64) { self.pos = pos; }
}
impl<T> io::Seek for Cursor<T> where T: AsRef<[u8]> {
fn seek(&mut self, style: SeekFrom) -> io::Result<u64> {
let pos = match style {
SeekFrom::Start(n) => { self.pos = n; return Ok(n) }
SeekFrom::End(n) => self.inner.as_ref().len() as i64 + n,
SeekFrom::Current(n) => self.pos as i64 + n,
};
if pos < 0 {
Err(Error::new(ErrorKind::InvalidInput,
"invalid seek to a negative position"))
} else {
self.pos = pos as u64;
Ok(self.pos)
}
}
}
impl<T> Read for Cursor<T> where T: AsRef<[u8]> {
fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
let n = Read::read(&mut self.fill_buf()?, buf)?;
self.pos += n as u64;
Ok(n)
}
}
impl<T> BufRead for Cursor<T> where T: AsRef<[u8]> {
fn fill_buf(&mut self) -> io::Result<&[u8]> {
let amt = cmp::min(self.pos, self.inner.as_ref().len() as u64);
Ok(&self.inner.as_ref()[(amt as usize)..])
}
fn consume(&mut self, amt: usize) { self.pos += amt as u64; }
}
impl<'a> Write for Cursor<&'a mut [u8]> {
#[inline]
fn write(&mut self, data: &[u8]) -> io::Result<usize> {
let pos = cmp::min(self.pos, self.inner.len() as u64);
let amt = (&mut self.inner[(pos as usize)..]).write(data)?;
self.pos += amt as u64;
Ok(amt)
}
fn flush(&mut self) -> io::Result<()> { Ok(()) }
}
impl Write for Cursor<Vec<u8>> {
fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
// Make sure the internal buffer is as least as big as where we
// currently are
let pos = self.position();
let amt = pos.saturating_sub(self.inner.len() as u64);
// use `resize` so that the zero filling is as efficient as possible
let len = self.inner.len();
self.inner.resize(len + amt as usize, 0);
// Figure out what bytes will be used to overwrite what's currently
// there (left), and what will be appended on the end (right)
{
let pos = pos as usize;
let space = self.inner.len() - pos;
let (left, right) = buf.split_at(cmp::min(space, buf.len()));
self.inner[pos..pos + left.len()].copy_from_slice(left);
self.inner.extend_from_slice(right);
}
// Bump us forward
self.set_position(pos + buf.len() as u64);
Ok(buf.len())
}
fn flush(&mut self) -> io::Result<()> { Ok(()) }
}
impl Write for Cursor<Box<[u8]>> {
#[inline]
fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
let pos = cmp::min(self.pos, self.inner.len() as u64);
let amt = (&mut self.inner[(pos as usize)..]).write(buf)?;
self.pos += amt as u64;
Ok(amt)
}
fn flush(&mut self) -> io::Result<()> { Ok(()) }
}
#[cfg(test)]
mod tests {
use io::prelude::*;
use io::{Cursor, SeekFrom};
use vec::Vec;
#[test]
fn test_vec_writer() {
let mut writer = Vec::new();
assert_eq!(writer.write(&[0]).unwrap(), 1);
assert_eq!(writer.write(&[1, 2, 3]).unwrap(), 3);
assert_eq!(writer.write(&[4, 5, 6, 7]).unwrap(), 4);
let b: &[_] = &[0, 1, 2, 3, 4, 5, 6, 7];
assert_eq!(writer, b);
}
#[test]
fn test_mem_writer() {
let mut writer = Cursor::new(Vec::new());
assert_eq!(writer.write(&[0]).unwrap(), 1);
assert_eq!(writer.write(&[1, 2, 3]).unwrap(), 3);
assert_eq!(writer.write(&[4, 5, 6, 7]).unwrap(), 4);
let b: &[_] = &[0, 1, 2, 3, 4, 5, 6, 7];
assert_eq!(&writer.get_ref()[..], b);
}
#[test]
fn test_box_slice_writer() {
let mut writer = Cursor::new(vec![0u8; 9].into_boxed_slice());
assert_eq!(writer.position(), 0);
assert_eq!(writer.write(&[0]).unwrap(), 1);
assert_eq!(writer.position(), 1);
assert_eq!(writer.write(&[1, 2, 3]).unwrap(), 3);
assert_eq!(writer.write(&[4, 5, 6, 7]).unwrap(), 4);
assert_eq!(writer.position(), 8);
assert_eq!(writer.write(&[]).unwrap(), 0);
assert_eq!(writer.position(), 8);
assert_eq!(writer.write(&[8, 9]).unwrap(), 1);
assert_eq!(writer.write(&[10]).unwrap(), 0);
let b: &[_] = &[0, 1, 2, 3, 4, 5, 6, 7, 8];
assert_eq!(&**writer.get_ref(), b);
}
#[test]
fn test_buf_writer() {
let mut buf = [0 as u8; 9];
{
let mut writer = Cursor::new(&mut buf[..]);
assert_eq!(writer.position(), 0);
assert_eq!(writer.write(&[0]).unwrap(), 1);
assert_eq!(writer.position(), 1);
assert_eq!(writer.write(&[1, 2, 3]).unwrap(), 3);
assert_eq!(writer.write(&[4, 5, 6, 7]).unwrap(), 4);
assert_eq!(writer.position(), 8);
assert_eq!(writer.write(&[]).unwrap(), 0);
assert_eq!(writer.position(), 8);
assert_eq!(writer.write(&[8, 9]).unwrap(), 1);
assert_eq!(writer.write(&[10]).unwrap(), 0);
}
let b: &[_] = &[0, 1, 2, 3, 4, 5, 6, 7, 8];
assert_eq!(buf, b);
}
#[test]
fn test_buf_writer_seek() {
let mut buf = [0 as u8; 8];
{
let mut writer = Cursor::new(&mut buf[..]);
assert_eq!(writer.position(), 0);
assert_eq!(writer.write(&[1]).unwrap(), 1);
assert_eq!(writer.position(), 1);
assert_eq!(writer.seek(SeekFrom::Start(2)).unwrap(), 2);
assert_eq!(writer.position(), 2);
assert_eq!(writer.write(&[2]).unwrap(), 1);
assert_eq!(writer.position(), 3);
assert_eq!(writer.seek(SeekFrom::Current(-2)).unwrap(), 1);
assert_eq!(writer.position(), 1);
assert_eq!(writer.write(&[3]).unwrap(), 1);
assert_eq!(writer.position(), 2);
assert_eq!(writer.seek(SeekFrom::End(-1)).unwrap(), 7);
assert_eq!(writer.position(), 7);
assert_eq!(writer.write(&[4]).unwrap(), 1);
assert_eq!(writer.position(), 8);
}
let b: &[_] = &[1, 3, 2, 0, 0, 0, 0, 4];
assert_eq!(buf, b);
}
#[test]
fn test_buf_writer_error() {
let mut buf = [0 as u8; 2];
let mut writer = Cursor::new(&mut buf[..]);
assert_eq!(writer.write(&[0]).unwrap(), 1);
assert_eq!(writer.write(&[0, 0]).unwrap(), 1);
assert_eq!(writer.write(&[0, 0]).unwrap(), 0);
}
#[test]
fn test_mem_reader() {
let mut reader = Cursor::new(vec!(0, 1, 2, 3, 4, 5, 6, 7));
let mut buf = [];
assert_eq!(reader.read(&mut buf).unwrap(), 0);
assert_eq!(reader.position(), 0);
let mut buf = [0];
assert_eq!(reader.read(&mut buf).unwrap(), 1);
assert_eq!(reader.position(), 1);
let b: &[_] = &[0];
assert_eq!(buf, b);
let mut buf = [0; 4];
assert_eq!(reader.read(&mut buf).unwrap(), 4);
assert_eq!(reader.position(), 5);
let b: &[_] = &[1, 2, 3, 4];
assert_eq!(buf, b);
assert_eq!(reader.read(&mut buf).unwrap(), 3);
let b: &[_] = &[5, 6, 7];
assert_eq!(&buf[..3], b);
assert_eq!(reader.read(&mut buf).unwrap(), 0);
}
#[test]
fn test_boxed_slice_reader() {
let mut reader = Cursor::new(vec!(0, 1, 2, 3, 4, 5, 6, 7).into_boxed_slice());
let mut buf = [];
assert_eq!(reader.read(&mut buf).unwrap(), 0);
assert_eq!(reader.position(), 0);
let mut buf = [0];
assert_eq!(reader.read(&mut buf).unwrap(), 1);
assert_eq!(reader.position(), 1);
let b: &[_] = &[0];
assert_eq!(buf, b);
let mut buf = [0; 4];
assert_eq!(reader.read(&mut buf).unwrap(), 4);
assert_eq!(reader.position(), 5);
let b: &[_] = &[1, 2, 3, 4];
assert_eq!(buf, b);
assert_eq!(reader.read(&mut buf).unwrap(), 3);
let b: &[_] = &[5, 6, 7];
assert_eq!(&buf[..3], b);
assert_eq!(reader.read(&mut buf).unwrap(), 0);
}
#[test]
fn read_to_end() {
let mut reader = Cursor::new(vec!(0, 1, 2, 3, 4, 5, 6, 7));
let mut v = Vec::new();
reader.read_to_end(&mut v).unwrap();
assert_eq!(v, [0, 1, 2, 3, 4, 5, 6, 7]);
}
#[test]
fn test_slice_reader() {
let in_buf = vec![0, 1, 2, 3, 4, 5, 6, 7];
let mut reader = &mut &in_buf[..];
let mut buf = [];
assert_eq!(reader.read(&mut buf).unwrap(), 0);
let mut buf = [0];
assert_eq!(reader.read(&mut buf).unwrap(), 1);
assert_eq!(reader.len(), 7);
let b: &[_] = &[0];
assert_eq!(&buf[..], b);
let mut buf = [0; 4];
assert_eq!(reader.read(&mut buf).unwrap(), 4);
assert_eq!(reader.len(), 3);
let b: &[_] = &[1, 2, 3, 4];
assert_eq!(&buf[..], b);
assert_eq!(reader.read(&mut buf).unwrap(), 3);
let b: &[_] = &[5, 6, 7];
assert_eq!(&buf[..3], b);
assert_eq!(reader.read(&mut buf).unwrap(), 0);
}
#[test]
fn test_buf_reader() {
let in_buf = vec![0, 1, 2, 3, 4, 5, 6, 7];
let mut reader = Cursor::new(&in_buf[..]);
let mut buf = [];
assert_eq!(reader.read(&mut buf).unwrap(), 0);
assert_eq!(reader.position(), 0);
let mut buf = [0];
assert_eq!(reader.read(&mut buf).unwrap(), 1);
assert_eq!(reader.position(), 1);
let b: &[_] = &[0];
assert_eq!(buf, b);
let mut buf = [0; 4];
assert_eq!(reader.read(&mut buf).unwrap(), 4);
assert_eq!(reader.position(), 5);
let b: &[_] = &[1, 2, 3, 4];
assert_eq!(buf, b);
assert_eq!(reader.read(&mut buf).unwrap(), 3);
let b: &[_] = &[5, 6, 7];
assert_eq!(&buf[..3], b);
assert_eq!(reader.read(&mut buf).unwrap(), 0);
}
#[test]
fn test_read_char() {
let b = &b"Vi\xE1\xBB\x87t"[..];
let mut c = Cursor::new(b).chars();
assert_eq!(c.next().unwrap().unwrap(), 'V');
assert_eq!(c.next().unwrap().unwrap(), 'i');
assert_eq!(c.next().unwrap().unwrap(), 'ệ');
assert_eq!(c.next().unwrap().unwrap(), 't');
assert!(c.next().is_none());
}
#[test]
fn test_read_bad_char() {
let b = &b"\x80"[..];
let mut c = Cursor::new(b).chars();
assert!(c.next().unwrap().is_err());
}
#[test]
fn seek_past_end() {
let buf = [0xff];
let mut r = Cursor::new(&buf[..]);
assert_eq!(r.seek(SeekFrom::Start(10)).unwrap(), 10);
assert_eq!(r.read(&mut [0]).unwrap(), 0);
let mut r = Cursor::new(vec!(10));
assert_eq!(r.seek(SeekFrom::Start(10)).unwrap(), 10);
assert_eq!(r.read(&mut [0]).unwrap(), 0);
let mut buf = [0];
let mut r = Cursor::new(&mut buf[..]);
assert_eq!(r.seek(SeekFrom::Start(10)).unwrap(), 10);
assert_eq!(r.write(&[3]).unwrap(), 0);
let mut r = Cursor::new(vec![10].into_boxed_slice());
assert_eq!(r.seek(SeekFrom::Start(10)).unwrap(), 10);
assert_eq!(r.write(&[3]).unwrap(), 0);
}
#[test]
fn seek_before_0() {
let buf = [0xff];
let mut r = Cursor::new(&buf[..]);
assert!(r.seek(SeekFrom::End(-2)).is_err());
let mut r = Cursor::new(vec!(10));
assert!(r.seek(SeekFrom::End(-2)).is_err());
let mut buf = [0];
let mut r = Cursor::new(&mut buf[..]);
assert!(r.seek(SeekFrom::End(-2)).is_err());
let mut r = Cursor::new(vec!(10).into_boxed_slice());
assert!(r.seek(SeekFrom::End(-2)).is_err());
}
#[test]
fn test_seekable_mem_writer() {
let mut writer = Cursor::new(Vec::<u8>::new());
assert_eq!(writer.position(), 0);
assert_eq!(writer.write(&[0]).unwrap(), 1);
assert_eq!(writer.position(), 1);
assert_eq!(writer.write(&[1, 2, 3]).unwrap(), 3);
assert_eq!(writer.write(&[4, 5, 6, 7]).unwrap(), 4);
assert_eq!(writer.position(), 8);
let b: &[_] = &[0, 1, 2, 3, 4, 5, 6, 7];
assert_eq!(&writer.get_ref()[..], b);
assert_eq!(writer.seek(SeekFrom::Start(0)).unwrap(), 0);
assert_eq!(writer.position(), 0);
assert_eq!(writer.write(&[3, 4]).unwrap(), 2);
let b: &[_] = &[3, 4, 2, 3, 4, 5, 6, 7];
assert_eq!(&writer.get_ref()[..], b);
assert_eq!(writer.seek(SeekFrom::Current(1)).unwrap(), 3);
assert_eq!(writer.write(&[0, 1]).unwrap(), 2);
let b: &[_] = &[3, 4, 2, 0, 1, 5, 6, 7];
assert_eq!(&writer.get_ref()[..], b);
assert_eq!(writer.seek(SeekFrom::End(-1)).unwrap(), 7);
assert_eq!(writer.write(&[1, 2]).unwrap(), 2);
let b: &[_] = &[3, 4, 2, 0, 1, 5, 6, 1, 2];
assert_eq!(&writer.get_ref()[..], b);
assert_eq!(writer.seek(SeekFrom::End(1)).unwrap(), 10);
assert_eq!(writer.write(&[1]).unwrap(), 1);
let b: &[_] = &[3, 4, 2, 0, 1, 5, 6, 1, 2, 0, 1];
assert_eq!(&writer.get_ref()[..], b);
}
#[test]
fn vec_seek_past_end() {
let mut r = Cursor::new(Vec::new());
assert_eq!(r.seek(SeekFrom::Start(10)).unwrap(), 10);
assert_eq!(r.write(&[3]).unwrap(), 1);
}
#[test]
fn vec_seek_before_0() {
let mut r = Cursor::new(Vec::new());
assert!(r.seek(SeekFrom::End(-2)).is_err());
}
}

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// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
use alloc::boxed::Box;
use core::convert::Into;
use core::fmt;
use core::marker::{Send, Sync};
use core::option::Option::{self, Some, None};
use core::result;
use collections::string::String;
/// A specialized [`Result`](../result/enum.Result.html) type for I/O
/// operations.
///
/// This type is broadly used across `std::io` for any operation which may
/// produce an error.
///
/// This typedef is generally used to avoid writing out `io::Error` directly and
/// is otherwise a direct mapping to `Result`.
///
/// While usual Rust style is to import types directly, aliases of `Result`
/// often are not, to make it easier to distinguish between them. `Result` is
/// generally assumed to be `std::result::Result`, and so users of this alias
/// will generally use `io::Result` instead of shadowing the prelude's import
/// of `std::result::Result`.
///
/// # Examples
///
/// A convenience function that bubbles an `io::Result` to its caller:
///
/// ```
/// use std::io;
///
/// fn get_string() -> io::Result<String> {
/// let mut buffer = String::new();
///
/// try!(io::stdin().read_line(&mut buffer));
///
/// Ok(buffer)
/// }
/// ```
pub type Result<T> = result::Result<T, Error>;
/// The error type for I/O operations of the `Read`, `Write`, `Seek`, and
/// associated traits.
///
/// Errors mostly originate from the underlying OS, but custom instances of
/// `Error` can be created with crafted error messages and a particular value of
/// `ErrorKind`.
#[derive(Debug)]
pub struct Error {
repr: Repr,
}
enum Repr {
Os(i32),
Custom(Box<Custom>),
}
#[derive(Debug)]
struct Custom {
kind: ErrorKind,
error: String,
}
/// A list specifying general categories of I/O error.
///
/// This list is intended to grow over time and it is not recommended to
/// exhaustively match against it.
#[derive(Copy, PartialEq, Eq, Clone, Debug)]
#[allow(deprecated)]
pub enum ErrorKind {
/// An entity was not found, often a file.
NotFound,
/// The operation lacked the necessary privileges to complete.
PermissionDenied,
/// The connection was refused by the remote server.
ConnectionRefused,
/// The connection was reset by the remote server.
ConnectionReset,
/// The connection was aborted (terminated) by the remote server.
ConnectionAborted,
/// The network operation failed because it was not connected yet.
NotConnected,
/// A socket address could not be bound because the address is already in
/// use elsewhere.
AddrInUse,
/// A nonexistent interface was requested or the requested address was not
/// local.
AddrNotAvailable,
/// The operation failed because a pipe was closed.
BrokenPipe,
/// An entity already exists, often a file.
AlreadyExists,
/// The operation needs to block to complete, but the blocking operation was
/// requested to not occur.
WouldBlock,
/// A parameter was incorrect.
InvalidInput,
/// Data not valid for the operation were encountered.
///
/// Unlike `InvalidInput`, this typically means that the operation
/// parameters were valid, however the error was caused by malformed
/// input data.
///
/// For example, a function that reads a file into a string will error with
/// `InvalidData` if the file's contents are not valid UTF-8.
InvalidData,
/// The I/O operation's timeout expired, causing it to be canceled.
TimedOut,
/// An error returned when an operation could not be completed because a
/// call to `write` returned `Ok(0)`.
///
/// This typically means that an operation could only succeed if it wrote a
/// particular number of bytes but only a smaller number of bytes could be
/// written.
WriteZero,
/// This operation was interrupted.
///
/// Interrupted operations can typically be retried.
Interrupted,
/// Any I/O error not part of this list.
Other,
/// An error returned when an operation could not be completed because an
/// "end of file" was reached prematurely.
///
/// This typically means that an operation could only succeed if it read a
/// particular number of bytes but only a smaller number of bytes could be
/// read.
UnexpectedEof,
/// Any I/O error not part of this list.
#[doc(hidden)]
__Nonexhaustive,
}
impl Error {
/// Creates a new I/O error from a known kind of error as well as an
/// arbitrary error payload.
///
/// This function is used to generically create I/O errors which do not
/// originate from the OS itself. The `error` argument is an arbitrary
/// payload which will be contained in this `Error`.
///
/// # Examples
///
/// ```
/// use std::io::{Error, ErrorKind};
///
/// // errors can be created from strings
/// let custom_error = Error::new(ErrorKind::Other, "oh no!");
///
/// // errors can also be created from other errors
/// let custom_error2 = Error::new(ErrorKind::Interrupted, custom_error);
/// ```
pub fn new<E>(kind: ErrorKind, error: E) -> Error
where E: Into<String>
{
Self::_new(kind, error.into())
}
fn _new(kind: ErrorKind, error: String) -> Error {
Error {
repr: Repr::Custom(Box::new(Custom {
kind: kind,
error: error,
}))
}
}
/// Creates a new instance of an `Error` from a particular OS error code.
pub fn from_raw_os_error(code: i32) -> Error {
Error { repr: Repr::Os(code) }
}
/// Returns the OS error that this error represents (if any).
///
/// If this `Error` was constructed via `last_os_error` or
/// `from_raw_os_error`, then this function will return `Some`, otherwise
/// it will return `None`.
pub fn raw_os_error(&self) -> Option<i32> {
match self.repr {
Repr::Os(i) => Some(i),
Repr::Custom(..) => None,
}
}
/// Returns a reference to the inner error wrapped by this error (if any).
///
/// If this `Error` was constructed via `new` then this function will
/// return `Some`, otherwise it will return `None`.
pub fn get_ref(&self) -> Option<&String> {
match self.repr {
Repr::Os(..) => None,
Repr::Custom(ref c) => Some(&c.error),
}
}
/// Returns a mutable reference to the inner error wrapped by this error
/// (if any).
///
/// If this `Error` was constructed via `new` then this function will
/// return `Some`, otherwise it will return `None`.
pub fn get_mut(&mut self) -> Option<&mut String> {
match self.repr {
Repr::Os(..) => None,
Repr::Custom(ref mut c) => Some(&mut c.error),
}
}
/// Consumes the `Error`, returning its inner error (if any).
///
/// If this `Error` was constructed via `new` then this function will
/// return `Some`, otherwise it will return `None`.
pub fn into_inner(self) -> Option<String> {
match self.repr {
Repr::Os(..) => None,
Repr::Custom(c) => Some(c.error)
}
}
/// Returns the corresponding `ErrorKind` for this error.
pub fn kind(&self) -> ErrorKind {
match self.repr {
Repr::Os(_code) => ErrorKind::Other,
Repr::Custom(ref c) => c.kind,
}
}
}
impl fmt::Debug for Repr {
fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
match *self {
Repr::Os(ref code) =>
fmt.debug_struct("Os").field("code", code).finish(),
Repr::Custom(ref c) => fmt.debug_tuple("Custom").field(c).finish(),
}
}
}
impl fmt::Display for Error {
fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
match self.repr {
Repr::Os(code) => {
write!(fmt, "os error {}", code)
}
Repr::Custom(ref c) => c.error.fmt(fmt),
}
}
}
fn _assert_error_is_sync_send() {
fn _is_sync_send<T: Sync+Send>() {}
_is_sync_send::<Error>();
}
#[cfg(test)]
mod test {
use prelude::v1::*;
use super::{Error, ErrorKind};
use error;
use fmt;
use sys::os::error_string;
#[test]
fn test_debug_error() {
let code = 6;
let msg = error_string(code);
let err = Error { repr: super::Repr::Os(code) };
let expected = format!("Error {{ repr: Os {{ code: {:?}, message: {:?} }} }}", code, msg);
assert_eq!(format!("{:?}", err), expected);
}
#[test]
fn test_downcasting() {
#[derive(Debug)]
struct TestError;
impl fmt::Display for TestError {
fn fmt(&self, _: &mut fmt::Formatter) -> fmt::Result {
Ok(())
}
}
impl error::Error for TestError {
fn description(&self) -> &str {
"asdf"
}
}
// we have to call all of these UFCS style right now since method
// resolution won't implicitly drop the Send+Sync bounds
let mut err = Error::new(ErrorKind::Other, TestError);
assert!(err.get_ref().unwrap().is::<TestError>());
assert_eq!("asdf", err.get_ref().unwrap().description());
assert!(err.get_mut().unwrap().is::<TestError>());
let extracted = err.into_inner().unwrap();
extracted.downcast::<TestError>().unwrap();
}
}

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@ -0,0 +1,289 @@
// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
use alloc::boxed::Box;
use core::cmp;
use io::{self, SeekFrom, Read, Write, Seek, Error, ErrorKind};
use io::BufRead;
use core::fmt;
use core::mem;
use collections::string::String;
use collections::vec::Vec;
// =============================================================================
// Forwarding implementations
impl<'a, R: Read + ?Sized> Read for &'a mut R {
#[inline]
fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
(**self).read(buf)
}
#[inline]
fn read_to_end(&mut self, buf: &mut Vec<u8>) -> io::Result<usize> {
(**self).read_to_end(buf)
}
#[inline]
fn read_to_string(&mut self, buf: &mut String) -> io::Result<usize> {
(**self).read_to_string(buf)
}
#[inline]
fn read_exact(&mut self, buf: &mut [u8]) -> io::Result<()> {
(**self).read_exact(buf)
}
}
impl<'a, W: Write + ?Sized> Write for &'a mut W {
#[inline]
fn write(&mut self, buf: &[u8]) -> io::Result<usize> { (**self).write(buf) }
#[inline]
fn flush(&mut self) -> io::Result<()> { (**self).flush() }
#[inline]
fn write_all(&mut self, buf: &[u8]) -> io::Result<()> {
(**self).write_all(buf)
}
#[inline]
fn write_fmt(&mut self, fmt: fmt::Arguments) -> io::Result<()> {
(**self).write_fmt(fmt)
}
}
impl<'a, S: Seek + ?Sized> Seek for &'a mut S {
#[inline]
fn seek(&mut self, pos: SeekFrom) -> io::Result<u64> { (**self).seek(pos) }
}
impl<'a, B: BufRead + ?Sized> BufRead for &'a mut B {
#[inline]
fn fill_buf(&mut self) -> io::Result<&[u8]> { (**self).fill_buf() }
#[inline]
fn consume(&mut self, amt: usize) { (**self).consume(amt) }
#[inline]
fn read_until(&mut self, byte: u8, buf: &mut Vec<u8>) -> io::Result<usize> {
(**self).read_until(byte, buf)
}
#[inline]
fn read_line(&mut self, buf: &mut String) -> io::Result<usize> {
(**self).read_line(buf)
}
}
impl<R: Read + ?Sized> Read for Box<R> {
#[inline]
fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
(**self).read(buf)
}
#[inline]
fn read_to_end(&mut self, buf: &mut Vec<u8>) -> io::Result<usize> {
(**self).read_to_end(buf)
}
#[inline]
fn read_to_string(&mut self, buf: &mut String) -> io::Result<usize> {
(**self).read_to_string(buf)
}
#[inline]
fn read_exact(&mut self, buf: &mut [u8]) -> io::Result<()> {
(**self).read_exact(buf)
}
}
impl<W: Write + ?Sized> Write for Box<W> {
#[inline]
fn write(&mut self, buf: &[u8]) -> io::Result<usize> { (**self).write(buf) }
#[inline]
fn flush(&mut self) -> io::Result<()> { (**self).flush() }
#[inline]
fn write_all(&mut self, buf: &[u8]) -> io::Result<()> {
(**self).write_all(buf)
}
#[inline]
fn write_fmt(&mut self, fmt: fmt::Arguments) -> io::Result<()> {
(**self).write_fmt(fmt)
}
}
impl<S: Seek + ?Sized> Seek for Box<S> {
#[inline]
fn seek(&mut self, pos: SeekFrom) -> io::Result<u64> { (**self).seek(pos) }
}
impl<B: BufRead + ?Sized> BufRead for Box<B> {
#[inline]
fn fill_buf(&mut self) -> io::Result<&[u8]> { (**self).fill_buf() }
#[inline]
fn consume(&mut self, amt: usize) { (**self).consume(amt) }
#[inline]
fn read_until(&mut self, byte: u8, buf: &mut Vec<u8>) -> io::Result<usize> {
(**self).read_until(byte, buf)
}
#[inline]
fn read_line(&mut self, buf: &mut String) -> io::Result<usize> {
(**self).read_line(buf)
}
}
// =============================================================================
// In-memory buffer implementations
impl<'a> Read for &'a [u8] {
#[inline]
fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
let amt = cmp::min(buf.len(), self.len());
let (a, b) = self.split_at(amt);
buf[..amt].copy_from_slice(a);
*self = b;
Ok(amt)
}
#[inline]
fn read_exact(&mut self, buf: &mut [u8]) -> io::Result<()> {
if buf.len() > self.len() {
return Err(Error::new(ErrorKind::UnexpectedEof,
"failed to fill whole buffer"));
}
let (a, b) = self.split_at(buf.len());
buf.copy_from_slice(a);
*self = b;
Ok(())
}
}
impl<'a> BufRead for &'a [u8] {
#[inline]
fn fill_buf(&mut self) -> io::Result<&[u8]> { Ok(*self) }
#[inline]
fn consume(&mut self, amt: usize) { *self = &self[amt..]; }
}
impl<'a> Write for &'a mut [u8] {
#[inline]
fn write(&mut self, data: &[u8]) -> io::Result<usize> {
let amt = cmp::min(data.len(), self.len());
let (a, b) = mem::replace(self, &mut []).split_at_mut(amt);
a.copy_from_slice(&data[..amt]);
*self = b;
Ok(amt)
}
#[inline]
fn write_all(&mut self, data: &[u8]) -> io::Result<()> {
if self.write(data)? == data.len() {
Ok(())
} else {
Err(Error::new(ErrorKind::WriteZero, "failed to write whole buffer"))
}
}
#[inline]
fn flush(&mut self) -> io::Result<()> { Ok(()) }
}
impl Write for Vec<u8> {
#[inline]
fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
self.extend_from_slice(buf);
Ok(buf.len())
}
#[inline]
fn write_all(&mut self, buf: &[u8]) -> io::Result<()> {
self.extend_from_slice(buf);
Ok(())
}
#[inline]
fn flush(&mut self) -> io::Result<()> { Ok(()) }
}
#[cfg(test)]
mod tests {
use io::prelude::*;
use vec::Vec;
use test;
#[bench]
fn bench_read_slice(b: &mut test::Bencher) {
let buf = [5; 1024];
let mut dst = [0; 128];
b.iter(|| {
let mut rd = &buf[..];
for _ in 0..8 {
let _ = rd.read(&mut dst);
test::black_box(&dst);
}
})
}
#[bench]
fn bench_write_slice(b: &mut test::Bencher) {
let mut buf = [0; 1024];
let src = [5; 128];
b.iter(|| {
let mut wr = &mut buf[..];
for _ in 0..8 {
let _ = wr.write_all(&src);
test::black_box(&wr);
}
})
}
#[bench]
fn bench_read_vec(b: &mut test::Bencher) {
let buf = vec![5; 1024];
let mut dst = [0; 128];
b.iter(|| {
let mut rd = &buf[..];
for _ in 0..8 {
let _ = rd.read(&mut dst);
test::black_box(&dst);
}
})
}
#[bench]
fn bench_write_vec(b: &mut test::Bencher) {
let mut buf = Vec::with_capacity(1024);
let src = [5; 128];
b.iter(|| {
let mut wr = &mut buf[..];
for _ in 0..8 {
let _ = wr.write_all(&src);
test::black_box(&wr);
}
})
}
}

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// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
//
// Original implementation taken from rust-memchr
// Copyright 2015 Andrew Gallant, bluss and Nicolas Koch
pub use self::fallback::{memchr,memrchr};
#[allow(dead_code)]
mod fallback {
use core::cmp;
use core::mem;
const LO_U64: u64 = 0x0101010101010101;
const HI_U64: u64 = 0x8080808080808080;
// use truncation
const LO_USIZE: usize = LO_U64 as usize;
const HI_USIZE: usize = HI_U64 as usize;
/// Return `true` if `x` contains any zero byte.
///
/// From *Matters Computational*, J. Arndt
///
/// "The idea is to subtract one from each of the bytes and then look for
/// bytes where the borrow propagated all the way to the most significant
/// bit."
#[inline]
fn contains_zero_byte(x: usize) -> bool {
x.wrapping_sub(LO_USIZE) & !x & HI_USIZE != 0
}
#[cfg(target_pointer_width = "32")]
#[inline]
fn repeat_byte(b: u8) -> usize {
let mut rep = (b as usize) << 8 | b as usize;
rep = rep << 16 | rep;
rep
}
#[cfg(target_pointer_width = "64")]
#[inline]
fn repeat_byte(b: u8) -> usize {
let mut rep = (b as usize) << 8 | b as usize;
rep = rep << 16 | rep;
rep = rep << 32 | rep;
rep
}
/// Return the first index matching the byte `a` in `text`.
pub fn memchr(x: u8, text: &[u8]) -> Option<usize> {
// Scan for a single byte value by reading two `usize` words at a time.
//
// Split `text` in three parts
// - unaligned initial part, before the first word aligned address in text
// - body, scan by 2 words at a time
// - the last remaining part, < 2 word size
let len = text.len();
let ptr = text.as_ptr();
let usize_bytes = mem::size_of::<usize>();
// search up to an aligned boundary
let align = (ptr as usize) & (usize_bytes- 1);
let mut offset;
if align > 0 {
offset = cmp::min(usize_bytes - align, len);
if let Some(index) = text[..offset].iter().position(|elt| *elt == x) {
return Some(index);
}
} else {
offset = 0;
}
// search the body of the text
let repeated_x = repeat_byte(x);
if len >= 2 * usize_bytes {
while offset <= len - 2 * usize_bytes {
unsafe {
let u = *(ptr.offset(offset as isize) as *const usize);
let v = *(ptr.offset((offset + usize_bytes) as isize) as *const usize);
// break if there is a matching byte
let zu = contains_zero_byte(u ^ repeated_x);
let zv = contains_zero_byte(v ^ repeated_x);
if zu || zv {
break;
}
}
offset += usize_bytes * 2;
}
}
// find the byte after the point the body loop stopped
text[offset..].iter().position(|elt| *elt == x).map(|i| offset + i)
}
/// Return the last index matching the byte `a` in `text`.
pub fn memrchr(x: u8, text: &[u8]) -> Option<usize> {
// Scan for a single byte value by reading two `usize` words at a time.
//
// Split `text` in three parts
// - unaligned tail, after the last word aligned address in text
// - body, scan by 2 words at a time
// - the first remaining bytes, < 2 word size
let len = text.len();
let ptr = text.as_ptr();
let usize_bytes = mem::size_of::<usize>();
// search to an aligned boundary
let end_align = (ptr as usize + len) & (usize_bytes - 1);
let mut offset;
if end_align > 0 {
offset = len - cmp::min(usize_bytes - end_align, len);
if let Some(index) = text[offset..].iter().rposition(|elt| *elt == x) {
return Some(offset + index);
}
} else {
offset = len;
}
// search the body of the text
let repeated_x = repeat_byte(x);
while offset >= 2 * usize_bytes {
unsafe {
let u = *(ptr.offset(offset as isize - 2 * usize_bytes as isize) as *const usize);
let v = *(ptr.offset(offset as isize - usize_bytes as isize) as *const usize);
// break if there is a matching byte
let zu = contains_zero_byte(u ^ repeated_x);
let zv = contains_zero_byte(v ^ repeated_x);
if zu || zv {
break;
}
}
offset -= 2 * usize_bytes;
}
// find the byte before the point the body loop stopped
text[..offset].iter().rposition(|elt| *elt == x)
}
// test fallback implementations on all plattforms
#[test]
fn matches_one() {
assert_eq!(Some(0), memchr(b'a', b"a"));
}
#[test]
fn matches_begin() {
assert_eq!(Some(0), memchr(b'a', b"aaaa"));
}
#[test]
fn matches_end() {
assert_eq!(Some(4), memchr(b'z', b"aaaaz"));
}
#[test]
fn matches_nul() {
assert_eq!(Some(4), memchr(b'\x00', b"aaaa\x00"));
}
#[test]
fn matches_past_nul() {
assert_eq!(Some(5), memchr(b'z', b"aaaa\x00z"));
}
#[test]
fn no_match_empty() {
assert_eq!(None, memchr(b'a', b""));
}
#[test]
fn no_match() {
assert_eq!(None, memchr(b'a', b"xyz"));
}
#[test]
fn matches_one_reversed() {
assert_eq!(Some(0), memrchr(b'a', b"a"));
}
#[test]
fn matches_begin_reversed() {
assert_eq!(Some(3), memrchr(b'a', b"aaaa"));
}
#[test]
fn matches_end_reversed() {
assert_eq!(Some(0), memrchr(b'z', b"zaaaa"));
}
#[test]
fn matches_nul_reversed() {
assert_eq!(Some(4), memrchr(b'\x00', b"aaaa\x00"));
}
#[test]
fn matches_past_nul_reversed() {
assert_eq!(Some(0), memrchr(b'z', b"z\x00aaaa"));
}
#[test]
fn no_match_empty_reversed() {
assert_eq!(None, memrchr(b'a', b""));
}
#[test]
fn no_match_reversed() {
assert_eq!(None, memrchr(b'a', b"xyz"));
}
}
#[cfg(test)]
mod tests {
// test the implementations for the current plattform
use super::{memchr, memrchr};
#[test]
fn matches_one() {
assert_eq!(Some(0), memchr(b'a', b"a"));
}
#[test]
fn matches_begin() {
assert_eq!(Some(0), memchr(b'a', b"aaaa"));
}
#[test]
fn matches_end() {
assert_eq!(Some(4), memchr(b'z', b"aaaaz"));
}
#[test]
fn matches_nul() {
assert_eq!(Some(4), memchr(b'\x00', b"aaaa\x00"));
}
#[test]
fn matches_past_nul() {
assert_eq!(Some(5), memchr(b'z', b"aaaa\x00z"));
}
#[test]
fn no_match_empty() {
assert_eq!(None, memchr(b'a', b""));
}
#[test]
fn no_match() {
assert_eq!(None, memchr(b'a', b"xyz"));
}
#[test]
fn matches_one_reversed() {
assert_eq!(Some(0), memrchr(b'a', b"a"));
}
#[test]
fn matches_begin_reversed() {
assert_eq!(Some(3), memrchr(b'a', b"aaaa"));
}
#[test]
fn matches_end_reversed() {
assert_eq!(Some(0), memrchr(b'z', b"zaaaa"));
}
#[test]
fn matches_nul_reversed() {
assert_eq!(Some(4), memrchr(b'\x00', b"aaaa\x00"));
}
#[test]
fn matches_past_nul_reversed() {
assert_eq!(Some(0), memrchr(b'z', b"z\x00aaaa"));
}
#[test]
fn no_match_empty_reversed() {
assert_eq!(None, memrchr(b'a', b""));
}
#[test]
fn no_match_reversed() {
assert_eq!(None, memrchr(b'a', b"xyz"));
}
}

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// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
//! The I/O Prelude
//!
//! The purpose of this module is to alleviate imports of many common I/O traits
//! by adding a glob import to the top of I/O heavy modules:
//!
//! ```
//! # #![allow(unused_imports)]
//! use std::io::prelude::*;
//! ```
pub use super::{Read, Write, Seek};
pub use super::BufRead;
pub use alloc::boxed::Box;
pub use collections::vec::Vec;

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// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
#![allow(missing_copy_implementations)]
use io::{self, Read, Write, ErrorKind};
use io::BufRead;
/// Copies the entire contents of a reader into a writer.
///
/// This function will continuously read data from `reader` and then
/// write it into `writer` in a streaming fashion until `reader`
/// returns EOF.
///
/// On success, the total number of bytes that were copied from
/// `reader` to `writer` is returned.
///
/// # Errors
///
/// This function will return an error immediately if any call to `read` or
/// `write` returns an error. All instances of `ErrorKind::Interrupted` are
/// handled by this function and the underlying operation is retried.
///
/// # Examples
///
/// ```
/// use std::io;
///
/// # fn foo() -> io::Result<()> {
/// let mut reader: &[u8] = b"hello";
/// let mut writer: Vec<u8> = vec![];
///
/// try!(io::copy(&mut reader, &mut writer));
///
/// assert_eq!(reader, &writer[..]);
/// # Ok(())
/// # }
/// ```
pub fn copy<R: ?Sized, W: ?Sized>(reader: &mut R, writer: &mut W) -> io::Result<u64>
where R: Read, W: Write
{
let mut buf = [0; super::DEFAULT_BUF_SIZE];
let mut written = 0;
loop {
let len = match reader.read(&mut buf) {
Ok(0) => return Ok(written),
Ok(len) => len,
Err(ref e) if e.kind() == ErrorKind::Interrupted => continue,
Err(e) => return Err(e),
};
writer.write_all(&buf[..len])?;
written += len as u64;
}
}
/// A reader which is always at EOF.
///
/// This struct is generally created by calling [`empty()`][empty]. Please see
/// the documentation of `empty()` for more details.
///
/// [empty]: fn.empty.html
pub struct Empty { _priv: () }
/// Constructs a new handle to an empty reader.
///
/// All reads from the returned reader will return `Ok(0)`.
///
/// # Examples
///
/// A slightly sad example of not reading anything into a buffer:
///
/// ```
/// use std::io::{self, Read};
///
/// let mut buffer = String::new();
/// io::empty().read_to_string(&mut buffer).unwrap();
/// assert!(buffer.is_empty());
/// ```
pub fn empty() -> Empty { Empty { _priv: () } }
impl Read for Empty {
fn read(&mut self, _buf: &mut [u8]) -> io::Result<usize> { Ok(0) }
}
impl BufRead for Empty {
fn fill_buf(&mut self) -> io::Result<&[u8]> { Ok(&[]) }
fn consume(&mut self, _n: usize) {}
}
/// A reader which yields one byte over and over and over and over and over and...
///
/// This struct is generally created by calling [`repeat()`][repeat]. Please
/// see the documentation of `repeat()` for more details.
///
/// [repeat]: fn.repeat.html
pub struct Repeat { byte: u8 }
/// Creates an instance of a reader that infinitely repeats one byte.
///
/// All reads from this reader will succeed by filling the specified buffer with
/// the given byte.
///
/// # Examples
///
/// ```
/// use std::io::{self, Read};
///
/// let mut buffer = [0; 3];
/// io::repeat(0b101).read_exact(&mut buffer).unwrap();
/// assert_eq!(buffer, [0b101, 0b101, 0b101]);
/// ```
pub fn repeat(byte: u8) -> Repeat { Repeat { byte: byte } }
impl Read for Repeat {
fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
for slot in &mut *buf {
*slot = self.byte;
}
Ok(buf.len())
}
}
/// A writer which will move data into the void.
///
/// This struct is generally created by calling [`sink()`][sink]. Please
/// see the documentation of `sink()` for more details.
///
/// [sink]: fn.sink.html
pub struct Sink { _priv: () }
/// Creates an instance of a writer which will successfully consume all data.
///
/// All calls to `write` on the returned instance will return `Ok(buf.len())`
/// and the contents of the buffer will not be inspected.
///
/// # Examples
///
/// ```rust
/// use std::io::{self, Write};
///
/// let mut buffer = vec![1, 2, 3, 5, 8];
/// let num_bytes = io::sink().write(&mut buffer).unwrap();
/// assert_eq!(num_bytes, 5);
/// ```
pub fn sink() -> Sink { Sink { _priv: () } }
impl Write for Sink {
fn write(&mut self, buf: &[u8]) -> io::Result<usize> { Ok(buf.len()) }
fn flush(&mut self) -> io::Result<()> { Ok(()) }
}
#[cfg(test)]
mod tests {
use prelude::v1::*;
use io::prelude::*;
use io::{copy, sink, empty, repeat};
#[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 Read, &mut w as &mut Write).unwrap(), 1 << 17);
}
#[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 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);
}
}

View File

@ -1,9 +1,12 @@
#![feature(lang_items, asm, alloc, collections, libc, needs_panic_runtime)] #![feature(lang_items, asm, alloc, collections, libc, needs_panic_runtime,
question_mark, unicode)]
#![no_std] #![no_std]
#![needs_panic_runtime] #![needs_panic_runtime]
extern crate rustc_unicode;
extern crate alloc_artiq; extern crate alloc_artiq;
extern crate alloc; extern crate alloc;
#[macro_use]
extern crate collections; extern crate collections;
extern crate libc; extern crate libc;
@ -18,10 +21,13 @@ pub mod prelude {
pub mod v1 { pub mod v1 {
pub use core::prelude::v1::*; pub use core::prelude::v1::*;
pub use collections::*; pub use collections::*;
pub use io::{Read, Write, Seek};
pub use io::BufRead;
} }
} }
pub mod time; pub mod time;
pub mod io;
use core::fmt::Write; use core::fmt::Write;