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pub(crate) use self::imp::Decoder;
#[cfg(not(feature = "gzip"))]
mod imp {
use std::pin::Pin;
use std::task::{Context, Poll};
use bytes::Bytes;
use futures_core::Stream;
use http::HeaderMap;
use super::super::Body;
pub(crate) struct Decoder {
inner: super::super::body::ImplStream,
}
impl Decoder {
#[cfg(feature = "blocking")]
pub(crate) fn empty() -> Decoder {
Decoder::plain_text(Body::empty())
}
/// A plain text decoder.
///
/// This decoder will emit the underlying chunks as-is.
fn plain_text(body: Body) -> Decoder {
Decoder {
inner: body.into_stream(),
}
}
pub(crate) fn detect(_: &mut HeaderMap, body: Body, _: bool) -> Decoder {
Decoder::plain_text(body)
}
}
impl Stream for Decoder {
type Item = crate::Result<Bytes>;
fn poll_next(mut self: Pin<&mut Self>, cx: &mut Context) -> Poll<Option<Self::Item>> {
Pin::new(&mut self.inner).poll_next(cx)
}
}
}
#[cfg(feature = "gzip")]
mod imp {
use std::future::Future;
use std::pin::Pin;
use std::task::{Context, Poll};
use std::{fmt, mem};
use async_compression::stream::GzipDecoder;
use bytes::Bytes;
use futures_core::Stream;
use futures_util::stream::Peekable;
use http::header::{CONTENT_ENCODING, CONTENT_LENGTH, TRANSFER_ENCODING};
use http::HeaderMap;
use log::warn;
use super::super::Body;
use crate::error;
/// A response decompressor over a non-blocking stream of chunks.
///
/// The inner decoder may be constructed asynchronously.
pub(crate) struct Decoder {
inner: Inner,
}
enum Inner {
/// A `PlainText` decoder just returns the response content as is.
PlainText(super::super::body::ImplStream),
/// A `Gzip` decoder will uncompress the gzipped response content before returning it.
Gzip(GzipDecoder<Peekable<IoStream>>),
/// A decoder that doesn't have a value yet.
Pending(Pending),
}
/// A future attempt to poll the response body for EOF so we know whether to use gzip or not.
struct Pending(Peekable<IoStream>);
struct IoStream(super::super::body::ImplStream);
impl fmt::Debug for Decoder {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
f.debug_struct("Decoder").finish()
}
}
impl Decoder {
#[cfg(feature = "blocking")]
pub(crate) fn empty() -> Decoder {
Decoder {
inner: Inner::PlainText(Body::empty().into_stream()),
}
}
/// A plain text decoder.
///
/// This decoder will emit the underlying chunks as-is.
fn plain_text(body: Body) -> Decoder {
Decoder {
inner: Inner::PlainText(body.into_stream()),
}
}
/// A gzip decoder.
///
/// This decoder will buffer and decompress chunks that are gzipped.
fn gzip(body: Body) -> Decoder {
use futures_util::StreamExt;
Decoder {
inner: Inner::Pending(Pending(IoStream(body.into_stream()).peekable())),
}
}
/// Constructs a Decoder from a hyper request.
///
/// A decoder is just a wrapper around the hyper request that knows
/// how to decode the content body of the request.
///
/// Uses the correct variant by inspecting the Content-Encoding header.
pub(crate) fn detect(headers: &mut HeaderMap, body: Body, check_gzip: bool) -> Decoder {
if !check_gzip {
return Decoder::plain_text(body);
}
let content_encoding_gzip: bool;
let mut is_gzip = {
content_encoding_gzip = headers
.get_all(CONTENT_ENCODING)
.iter()
.any(|enc| enc == "gzip");
content_encoding_gzip
|| headers
.get_all(TRANSFER_ENCODING)
.iter()
.any(|enc| enc == "gzip")
};
if is_gzip {
if let Some(content_length) = headers.get(CONTENT_LENGTH) {
if content_length == "0" {
warn!("gzip response with content-length of 0");
is_gzip = false;
}
}
}
if content_encoding_gzip {
headers.remove(CONTENT_ENCODING);
headers.remove(CONTENT_LENGTH);
}
if is_gzip {
Decoder::gzip(body)
} else {
Decoder::plain_text(body)
}
}
}
impl Stream for Decoder {
type Item = Result<Bytes, error::Error>;
fn poll_next(mut self: Pin<&mut Self>, cx: &mut Context) -> Poll<Option<Self::Item>> {
// Do a read or poll for a pending decoder value.
let new_value = match self.inner {
Inner::Pending(ref mut future) => match Pin::new(future).poll(cx) {
Poll::Ready(Ok(inner)) => inner,
Poll::Ready(Err(e)) => {
return Poll::Ready(Some(Err(crate::error::decode_io(e))))
}
Poll::Pending => return Poll::Pending,
},
Inner::PlainText(ref mut body) => return Pin::new(body).poll_next(cx),
Inner::Gzip(ref mut decoder) => {
return match futures_core::ready!(Pin::new(decoder).poll_next(cx)) {
Some(Ok(bytes)) => Poll::Ready(Some(Ok(bytes))),
Some(Err(err)) => Poll::Ready(Some(Err(crate::error::decode_io(err)))),
None => Poll::Ready(None),
}
}
};
self.inner = new_value;
self.poll_next(cx)
}
}
impl Future for Pending {
type Output = Result<Inner, std::io::Error>;
fn poll(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
use futures_util::StreamExt;
match futures_core::ready!(Pin::new(&mut self.0).peek(cx)) {
Some(Ok(_)) => {
// fallthrough
}
Some(Err(_e)) => {
// error was just a ref, so we need to really poll to move it
return Poll::Ready(Err(futures_core::ready!(
Pin::new(&mut self.0).poll_next(cx)
)
.expect("just peeked Some")
.unwrap_err()));
}
None => return Poll::Ready(Ok(Inner::PlainText(Body::empty().into_stream()))),
};
let body = mem::replace(
&mut self.0,
IoStream(Body::empty().into_stream()).peekable(),
);
Poll::Ready(Ok(Inner::Gzip(GzipDecoder::new(body))))
}
}
impl Stream for IoStream {
type Item = Result<Bytes, std::io::Error>;
fn poll_next(mut self: Pin<&mut Self>, cx: &mut Context) -> Poll<Option<Self::Item>> {
match futures_core::ready!(Pin::new(&mut self.0).poll_next(cx)) {
Some(Ok(chunk)) => Poll::Ready(Some(Ok(chunk))),
Some(Err(err)) => Poll::Ready(Some(Err(err.into_io()))),
None => Poll::Ready(None),
}
}
}
}
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