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Cleanup BufWriter #296

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Merged
merged 1 commit into from Oct 10, 2019
Merged

Cleanup BufWriter #296

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103 changes: 9 additions & 94 deletions src/io/buf_writer.rs
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Original file line number Diff line number Diff line change
@@ -1,10 +1,11 @@
use crate::task::{Context, Poll};
use futures_core::ready;
use futures_io::{AsyncSeek, AsyncWrite, SeekFrom};
use std::fmt;
use std::io;
use std::pin::Pin;

use futures_core::ready;

use crate::io::{self, Seek, SeekFrom, Write};
use crate::task::{Context, Poll};

const DEFAULT_CAPACITY: usize = 8 * 1024;

/// Wraps a writer and buffers its output.
Expand Down Expand Up @@ -82,7 +83,7 @@ pub struct BufWriter<W> {
written: usize,
}

impl<W: AsyncWrite> BufWriter<W> {
impl<W: Write> BufWriter<W> {
pin_utils::unsafe_pinned!(inner: W);
pin_utils::unsafe_unpinned!(buf: Vec<u8>);

Expand Down Expand Up @@ -173,10 +174,6 @@ impl<W: AsyncWrite> BufWriter<W> {
&mut self.inner
}

// pub fn get_pin_mut(self: Pin<&mut Self>) -> Pin<&mut W> {
// self.inner()
// }

/// Consumes BufWriter, returning the underlying writer
///
/// This method will not write leftover data, it will be lost.
Expand All @@ -187,10 +184,6 @@ impl<W: AsyncWrite> BufWriter<W> {
self.inner
}

// pub fn poll_into_inner(self: Pin<&mut Self>, _cx: Context<'_>) -> Poll<io::Result<usize>> {
// unimplemented!("poll into inner method")
// }

/// Returns a reference to the internally buffered data.
///
/// # Examples
Expand Down Expand Up @@ -251,7 +244,7 @@ impl<W: AsyncWrite> BufWriter<W> {
}
}

impl<W: AsyncWrite> AsyncWrite for BufWriter<W> {
impl<W: Write> Write for BufWriter<W> {
fn poll_write(
mut self: Pin<&mut Self>,
cx: &mut Context<'_>,
Expand All @@ -278,7 +271,7 @@ impl<W: AsyncWrite> AsyncWrite for BufWriter<W> {
}
}

impl<W: AsyncWrite + fmt::Debug> fmt::Debug for BufWriter<W> {
impl<W: Write + fmt::Debug> fmt::Debug for BufWriter<W> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
f.debug_struct("BufReader")
.field("writer", &self.inner)
Expand All @@ -287,11 +280,10 @@ impl<W: AsyncWrite + fmt::Debug> fmt::Debug for BufWriter<W> {
}
}

impl<W: AsyncWrite + AsyncSeek> AsyncSeek for BufWriter<W> {
impl<W: Write + Seek> Seek for BufWriter<W> {
/// Seek to the offset, in bytes, in the underlying writer.
///
/// Seeking always writes out the internal buffer before seeking.

fn poll_seek(
mut self: Pin<&mut Self>,
cx: &mut Context<'_>,
Expand All @@ -301,80 +293,3 @@ impl<W: AsyncWrite + AsyncSeek> AsyncSeek for BufWriter<W> {
self.inner().poll_seek(cx, pos)
}
}

mod tests {
#![allow(unused_imports)]

use super::BufWriter;
use crate::io::{self, SeekFrom};
use crate::prelude::*;
use crate::task;

#[test]
fn test_buffered_writer() {
task::block_on(async {
let inner = Vec::new();
let mut writer = BufWriter::with_capacity(2, inner);

writer.write(&[0, 1]).await.unwrap();
assert_eq!(writer.buffer(), []);
assert_eq!(*writer.get_ref(), [0, 1]);

writer.write(&[2]).await.unwrap();
assert_eq!(writer.buffer(), [2]);
assert_eq!(*writer.get_ref(), [0, 1]);

writer.write(&[3]).await.unwrap();
assert_eq!(writer.buffer(), [2, 3]);
assert_eq!(*writer.get_ref(), [0, 1]);

writer.flush().await.unwrap();
assert_eq!(writer.buffer(), []);
assert_eq!(*writer.get_ref(), [0, 1, 2, 3]);

writer.write(&[4]).await.unwrap();
writer.write(&[5]).await.unwrap();
assert_eq!(writer.buffer(), [4, 5]);
assert_eq!(*writer.get_ref(), [0, 1, 2, 3]);

writer.write(&[6]).await.unwrap();
assert_eq!(writer.buffer(), [6]);
assert_eq!(*writer.get_ref(), [0, 1, 2, 3, 4, 5]);

writer.write(&[7, 8]).await.unwrap();
assert_eq!(writer.buffer(), []);
assert_eq!(*writer.get_ref(), [0, 1, 2, 3, 4, 5, 6, 7, 8]);

writer.write(&[9, 10, 11]).await.unwrap();
assert_eq!(writer.buffer(), []);
assert_eq!(*writer.get_ref(), [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11]);

writer.flush().await.unwrap();
assert_eq!(writer.buffer(), []);
assert_eq!(*writer.get_ref(), [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11]);
})
}

#[test]
fn test_buffered_writer_inner_into_inner_does_not_flush() {
task::block_on(async {
let mut w = BufWriter::with_capacity(3, Vec::new());
w.write(&[0, 1]).await.unwrap();
assert_eq!(*w.get_ref(), []);
let w = w.into_inner();
assert_eq!(w, []);
})
}

#[test]
fn test_buffered_writer_seek() {
task::block_on(async {
let mut w = BufWriter::with_capacity(3, io::Cursor::new(Vec::new()));
w.write_all(&[0, 1, 2, 3, 4, 5]).await.unwrap();
w.write_all(&[6, 7]).await.unwrap();
assert_eq!(w.seek(SeekFrom::Current(0)).await.ok(), Some(8));
assert_eq!(&w.get_ref().get_ref()[..], &[0, 1, 2, 3, 4, 5, 6, 7][..]);
assert_eq!(w.seek(SeekFrom::Start(2)).await.ok(), Some(2));
})
}
}
71 changes: 71 additions & 0 deletions tests/buf_writer.rs
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Original file line number Diff line number Diff line change
@@ -0,0 +1,71 @@
use async_std::io::{self, BufWriter, SeekFrom};
use async_std::prelude::*;
use async_std::task;

#[test]
fn test_buffered_writer() {
task::block_on(async {
let inner = Vec::new();
let mut writer = BufWriter::with_capacity(2, inner);

writer.write(&[0, 1]).await.unwrap();
assert_eq!(writer.buffer(), []);
assert_eq!(*writer.get_ref(), [0, 1]);

writer.write(&[2]).await.unwrap();
assert_eq!(writer.buffer(), [2]);
assert_eq!(*writer.get_ref(), [0, 1]);

writer.write(&[3]).await.unwrap();
assert_eq!(writer.buffer(), [2, 3]);
assert_eq!(*writer.get_ref(), [0, 1]);

writer.flush().await.unwrap();
assert_eq!(writer.buffer(), []);
assert_eq!(*writer.get_ref(), [0, 1, 2, 3]);

writer.write(&[4]).await.unwrap();
writer.write(&[5]).await.unwrap();
assert_eq!(writer.buffer(), [4, 5]);
assert_eq!(*writer.get_ref(), [0, 1, 2, 3]);

writer.write(&[6]).await.unwrap();
assert_eq!(writer.buffer(), [6]);
assert_eq!(*writer.get_ref(), [0, 1, 2, 3, 4, 5]);

writer.write(&[7, 8]).await.unwrap();
assert_eq!(writer.buffer(), []);
assert_eq!(*writer.get_ref(), [0, 1, 2, 3, 4, 5, 6, 7, 8]);

writer.write(&[9, 10, 11]).await.unwrap();
assert_eq!(writer.buffer(), []);
assert_eq!(*writer.get_ref(), [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11]);

writer.flush().await.unwrap();
assert_eq!(writer.buffer(), []);
assert_eq!(*writer.get_ref(), [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11]);
})
}

#[test]
fn test_buffered_writer_inner_into_inner_does_not_flush() {
task::block_on(async {
let mut w = BufWriter::with_capacity(3, Vec::new());
w.write(&[0, 1]).await.unwrap();
assert_eq!(*w.get_ref(), []);
let w = w.into_inner();
assert_eq!(w, []);
})
}

#[test]
fn test_buffered_writer_seek() {
task::block_on(async {
let mut w = BufWriter::with_capacity(3, io::Cursor::new(Vec::new()));
w.write_all(&[0, 1, 2, 3, 4, 5]).await.unwrap();
w.write_all(&[6, 7]).await.unwrap();
assert_eq!(w.seek(SeekFrom::Current(0)).await.ok(), Some(8));
assert_eq!(&w.get_ref().get_ref()[..], &[0, 1, 2, 3, 4, 5, 6, 7][..]);
assert_eq!(w.seek(SeekFrom::Start(2)).await.ok(), Some(2));
})
}