src/client/pxar_backup_stream.rs: use a channel instead of a pipe

This commit is contained in:
Dietmar Maurer 2020-01-22 11:37:16 +01:00
parent dcd033a53c
commit 02141b4d9b
1 changed files with 20 additions and 23 deletions

View File

@ -1,6 +1,6 @@
use std::collections::HashSet;
use std::io::Write;
use std::os::unix::io::FromRawFd;
//use std::os::unix::io::FromRawFd;
use std::path::{Path, PathBuf};
use std::pin::Pin;
use std::sync::{Arc, Mutex};
@ -17,15 +17,13 @@ use nix::dir::Dir;
use crate::pxar;
use crate::backup::CatalogWriter;
use crate::tools::wrapped_reader_stream::WrappedReaderStream;
/// Stream implementation to encode and upload .pxar archives.
///
/// The hyper client needs an async Stream for file upload, so we
/// spawn an extra thread to encode the .pxar data and pipe it to the
/// consumer.
pub struct PxarBackupStream {
stream: Option<WrappedReaderStream<std::fs::File>>,
rx: Option<std::sync::mpsc::Receiver<Result<Vec<u8>, Error>>>,
child: Option<thread::JoinHandle<()>>,
error: Arc<Mutex<Option<String>>>,
}
@ -33,13 +31,12 @@ pub struct PxarBackupStream {
impl Drop for PxarBackupStream {
fn drop(&mut self) {
self.stream = None;
self.rx = None;
self.child.take().unwrap().join().unwrap();
}
}
impl PxarBackupStream {
pin_utils::unsafe_pinned!(stream: Option<WrappedReaderStream<std::fs::File>>);
pub fn new<W: Write + Send + 'static>(
mut dir: Dir,
@ -51,10 +48,9 @@ impl PxarBackupStream {
entries_max: usize,
) -> Result<Self, Error> {
let (rx, tx) = nix::unistd::pipe()?;
let (tx, rx) = std::sync::mpsc::sync_channel(10);
let buffer_size = 1024*1024;
nix::fcntl::fcntl(rx, nix::fcntl::FcntlArg::F_SETPIPE_SZ(buffer_size as i32))?;
let buffer_size = 256*1024;
let error = Arc::new(Mutex::new(None));
let error2 = error.clone();
@ -63,7 +59,8 @@ impl PxarBackupStream {
let exclude_pattern = Vec::new();
let child = std::thread::Builder::new().name("PxarBackupStream".to_string()).spawn(move || {
let mut guard = catalog.lock().unwrap();
let mut writer = unsafe { std::fs::File::from_raw_fd(tx) };
let mut writer = std::io::BufWriter::with_capacity(buffer_size, crate::tools::StdChannelWriter::new(tx));
if let Err(err) = pxar::Encoder::encode(
path,
&mut dir,
@ -81,11 +78,8 @@ impl PxarBackupStream {
}
})?;
let pipe = unsafe { std::fs::File::from_raw_fd(rx) };
let stream = crate::tools::wrapped_reader_stream::WrappedReaderStream::new(pipe);
Ok(Self {
stream: Some(stream),
rx: Some(rx),
child: Some(child),
error,
})
@ -111,20 +105,23 @@ impl Stream for PxarBackupStream {
type Item = Result<Vec<u8>, Error>;
fn poll_next(mut self: Pin<&mut Self>, cx: &mut Context) -> Poll<Option<Self::Item>> {
fn poll_next(self: Pin<&mut Self>, _cx: &mut Context) -> Poll<Option<Self::Item>> {
{ // limit lock scope
let error = self.error.lock().unwrap();
if let Some(ref msg) = *error {
return Poll::Ready(Some(Err(format_err!("{}", msg))));
}
}
let res = self.as_mut()
.stream()
.as_pin_mut()
.unwrap()
.poll_next(cx);
Poll::Ready(futures::ready!(res)
.map(|v| v.map_err(Error::from))
)
match crate::tools::runtime::block_in_place(|| self.rx.as_ref().unwrap().recv()) {
Ok(data) => Poll::Ready(Some(data)),
Err(_) => {
let error = self.error.lock().unwrap();
if let Some(ref msg) = *error {
return Poll::Ready(Some(Err(format_err!("{}", msg))));
}
Poll::Ready(None) // channel closed, no error
}
}
}
}