src/backup/chunk_stream.rs: switch to async

Signed-off-by: Wolfgang Bumiller <w.bumiller@proxmox.com>
This commit is contained in:
Wolfgang Bumiller 2019-08-23 13:41:30 +02:00
parent f2d9b73c91
commit 32bef1e2d1

View File

@ -1,125 +1,124 @@
use std::pin::Pin;
use std::task::{Context, Poll};
use bytes::BytesMut;
use failure::*;
use futures::stream::Stream;
use futures::{Async, Poll};
use futures::ready;
use futures::stream::{Stream, TryStream};
use super::Chunker;
/// Split input stream into dynamic sized chunks
pub struct ChunkStream<S> {
pub struct ChunkStream<S: Unpin> {
input: S,
chunker: Chunker,
buffer: BytesMut,
scan_pos: usize,
}
impl <S> ChunkStream<S> {
impl<S: Unpin> ChunkStream<S> {
pub fn new(input: S, chunk_size: Option<usize>) -> Self {
Self { input, chunker: Chunker::new(chunk_size.unwrap_or(4*1024*1024)), buffer: BytesMut::new(), scan_pos: 0}
}
}
impl <S> Stream for ChunkStream<S>
where S: Stream,
S::Item: AsRef<[u8]>,
S::Error: Into<Error>,
impl<S: Unpin> Unpin for ChunkStream<S> {}
impl<S: Unpin> Stream for ChunkStream<S>
where
S: TryStream,
S::Ok: AsRef<[u8]>,
S::Error: Into<Error>,
{
type Item = BytesMut;
type Error = Error;
type Item = Result<BytesMut, Error>;
fn poll(&mut self) -> Poll<Option<BytesMut>, Error> {
fn poll_next(self: Pin<&mut Self>, cx: &mut Context) -> Poll<Option<Self::Item>> {
let this = self.get_mut();
loop {
if this.scan_pos < this.buffer.len() {
let boundary = this.chunker.scan(&this.buffer[this.scan_pos..]);
if self.scan_pos < self.buffer.len() {
let boundary = self.chunker.scan(&self.buffer[self.scan_pos..]);
let chunk_size = self.scan_pos + boundary;
let chunk_size = this.scan_pos + boundary;
if boundary == 0 {
self.scan_pos = self.buffer.len();
this.scan_pos = this.buffer.len();
// continue poll
} else if chunk_size <= self.buffer.len() {
let result = self.buffer.split_to(chunk_size);
self.scan_pos = 0;
return Ok(Async::Ready(Some(result)));
} else if chunk_size <= this.buffer.len() {
let result = this.buffer.split_to(chunk_size);
this.scan_pos = 0;
return Poll::Ready(Some(Ok(result)));
} else {
panic!("got unexpected chunk boundary from chunker");
}
}
match self.input.poll() {
Err(err) => {
return Err(err.into());
match ready!(Pin::new(&mut this.input).try_poll_next(cx)) {
Some(Err(err)) => {
return Poll::Ready(Some(Err(err.into())));
}
Ok(Async::NotReady) => {
return Ok(Async::NotReady);
}
Ok(Async::Ready(None)) => {
self.scan_pos = 0;
if self.buffer.len() > 0 {
return Ok(Async::Ready(Some(self.buffer.take())));
None => {
this.scan_pos = 0;
if this.buffer.len() > 0 {
return Poll::Ready(Some(Ok(this.buffer.take())));
} else {
return Ok(Async::Ready(None));
return Poll::Ready(None);
}
}
Ok(Async::Ready(Some(data))) => {
self.buffer.extend_from_slice(data.as_ref());
}
Some(Ok(data)) => {
this.buffer.extend_from_slice(data.as_ref());
}
}
}
}
}
/// Split input stream into fixed sized chunks
pub struct FixedChunkStream<S> {
pub struct FixedChunkStream<S: Unpin> {
input: S,
chunk_size: usize,
buffer: BytesMut,
}
impl <S> FixedChunkStream<S> {
impl<S: Unpin> FixedChunkStream<S> {
pub fn new(input: S, chunk_size: usize) -> Self {
Self { input, chunk_size, buffer: BytesMut::new() }
}
}
impl <S> Stream for FixedChunkStream<S>
where S: Stream,
S::Item: AsRef<[u8]>,
impl<S: Unpin> Unpin for FixedChunkStream<S> {}
impl<S: Unpin> Stream for FixedChunkStream<S>
where
S: TryStream,
S::Ok: AsRef<[u8]>,
{
type Item = Result<BytesMut, S::Error>;
type Item = BytesMut;
type Error = S::Error;
fn poll(&mut self) -> Poll<Option<BytesMut>, S::Error> {
fn poll_next(self: Pin<&mut Self>, cx: &mut Context) -> Poll<Option<Result<BytesMut, S::Error>>> {
let this = self.get_mut();
loop {
if self.buffer.len() == self.chunk_size {
return Ok(Async::Ready(Some(self.buffer.take())));
} else if self.buffer.len() > self.chunk_size {
let result = self.buffer.split_to(self.chunk_size);
return Ok(Async::Ready(Some(result)));
if this.buffer.len() == this.chunk_size {
return Poll::Ready(Some(Ok(this.buffer.take())));
} else if this.buffer.len() > this.chunk_size {
let result = this.buffer.split_to(this.chunk_size);
return Poll::Ready(Some(Ok(result)));
}
match self.input.poll() {
Err(err) => {
return Err(err);
match ready!(Pin::new(&mut this.input).try_poll_next(cx)) {
Some(Err(err)) => {
return Poll::Ready(Some(Err(err)));
}
Ok(Async::NotReady) => {
return Ok(Async::NotReady);
}
Ok(Async::Ready(None)) => {
None => {
// last chunk can have any size
if self.buffer.len() > 0 {
return Ok(Async::Ready(Some(self.buffer.take())));
if this.buffer.len() > 0 {
return Poll::Ready(Some(Ok(this.buffer.take())));
} else {
return Ok(Async::Ready(None));
return Poll::Ready(None);
}
}
Ok(Async::Ready(Some(data))) => {
self.buffer.extend_from_slice(data.as_ref());
Some(Ok(data)) => {
this.buffer.extend_from_slice(data.as_ref());
}
}
}