198 lines
6.5 KiB
Rust
198 lines
6.5 KiB
Rust
use bytes::{Buf, BufMut, Bytes, BytesMut};
|
|
use futures::{
|
|
stream::{Stream, StreamExt},
|
|
TryStreamExt,
|
|
};
|
|
use std::task::{Context, Poll};
|
|
|
|
use crate::ebml::{EbmlLayout, FromEbml};
|
|
use crate::error::WebmetroError;
|
|
|
|
pub struct EbmlStreamingParser<S> {
|
|
stream: S,
|
|
buffer: BytesMut,
|
|
buffer_size_limit: Option<usize>,
|
|
borrowed: Bytes,
|
|
}
|
|
|
|
impl<S> EbmlStreamingParser<S> {
|
|
/// add a "soft" buffer size limit; if the input buffer exceeds this size,
|
|
/// error the stream instead of resuming. It's still possible for the buffer
|
|
/// to exceed this size *after* a fill, so ensure input sizes are reasonable.
|
|
pub fn with_soft_limit(mut self, limit: usize) -> Self {
|
|
self.buffer_size_limit = Some(limit);
|
|
self
|
|
}
|
|
}
|
|
|
|
pub trait StreamEbml: Sized {
|
|
fn parse_ebml(self) -> EbmlStreamingParser<Self> {
|
|
EbmlStreamingParser {
|
|
stream: self,
|
|
buffer: BytesMut::new(),
|
|
buffer_size_limit: None,
|
|
borrowed: Bytes::new(),
|
|
}
|
|
}
|
|
}
|
|
|
|
impl<I: Buf, E, S: Stream<Item = Result<I, E>> + Unpin> StreamEbml for S where WebmetroError: From<E>
|
|
{}
|
|
|
|
impl<I: Buf, E, S: Stream<Item = Result<I, E>> + Unpin> EbmlStreamingParser<S>
|
|
where
|
|
WebmetroError: From<E>,
|
|
{
|
|
pub fn poll_event<'a, T: FromEbml<'a>>(
|
|
&'a mut self,
|
|
cx: &mut Context,
|
|
) -> Poll<Option<Result<T, WebmetroError>>> {
|
|
loop {
|
|
if let Some(info) = T::check_space(&self.buffer)? {
|
|
self.borrowed = self.buffer.split_to(info.element_len).freeze();
|
|
self.borrowed.advance(info.body_offset);
|
|
return Poll::Ready(Some(
|
|
T::decode(info.element_id, &self.borrowed).map_err(Into::into),
|
|
));
|
|
}
|
|
|
|
// need to refill buffer
|
|
|
|
if let Some(limit) = self.buffer_size_limit {
|
|
if limit <= self.buffer.len() {
|
|
return Poll::Ready(Some(Err(WebmetroError::ResourcesExceeded)));
|
|
}
|
|
}
|
|
|
|
match self.stream.poll_next_unpin(cx)? {
|
|
Poll::Ready(Some(buf)) => {
|
|
self.buffer.reserve(buf.remaining());
|
|
self.buffer.put(buf);
|
|
// ok can retry decoding now
|
|
}
|
|
Poll::Ready(None) => return Poll::Ready(None),
|
|
Poll::Pending => return Poll::Pending,
|
|
}
|
|
}
|
|
}
|
|
|
|
pub async fn next<'a, T: FromEbml<'a>>(&'a mut self) -> Result<Option<T>, WebmetroError> {
|
|
loop {
|
|
if let Some(info) = T::check_space(&self.buffer)? {
|
|
self.borrowed = self.buffer.split_to(info.element_len).freeze();
|
|
self.borrowed.advance(info.body_offset);
|
|
return Ok(Some(T::decode(info.element_id, &self.borrowed)?));
|
|
}
|
|
|
|
if let Some(limit) = self.buffer_size_limit {
|
|
if limit <= self.buffer.len() {
|
|
// hit our buffer limit and still nothing parsed
|
|
return Err(WebmetroError::ResourcesExceeded);
|
|
}
|
|
}
|
|
|
|
match self.stream.try_next().await? {
|
|
Some(refill) => {
|
|
self.buffer.reserve(refill.remaining());
|
|
self.buffer.put(refill);
|
|
}
|
|
None => {
|
|
// Nothing left, we're done
|
|
return Ok(None);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
#[cfg(test)]
|
|
mod tests {
|
|
use futures::{future::poll_fn, stream::StreamExt, FutureExt};
|
|
use matches::assert_matches;
|
|
use std::task::Poll::*;
|
|
|
|
use crate::stream_parser::*;
|
|
use crate::tests::ENCODE_WEBM_TEST_FILE;
|
|
use crate::webm::*;
|
|
|
|
#[test]
|
|
fn stream_webm_test() {
|
|
poll_fn(|cx| {
|
|
let pieces = vec![
|
|
&ENCODE_WEBM_TEST_FILE[0..20],
|
|
&ENCODE_WEBM_TEST_FILE[20..40],
|
|
&ENCODE_WEBM_TEST_FILE[40..],
|
|
];
|
|
|
|
let mut stream_parser = futures::stream::iter(pieces.iter())
|
|
.map(|bytes| Ok::<&[u8], WebmetroError>(&bytes[..]))
|
|
.parse_ebml();
|
|
|
|
assert_matches!(
|
|
stream_parser.poll_event(cx),
|
|
Ready(Some(Ok(WebmElement::EbmlHead)))
|
|
);
|
|
assert_matches!(
|
|
stream_parser.poll_event(cx),
|
|
Ready(Some(Ok(WebmElement::Segment)))
|
|
);
|
|
assert_matches!(
|
|
stream_parser.poll_event(cx),
|
|
Ready(Some(Ok(WebmElement::Tracks(_))))
|
|
);
|
|
assert_matches!(
|
|
stream_parser.poll_event(cx),
|
|
Ready(Some(Ok(WebmElement::Cluster)))
|
|
);
|
|
assert_matches!(
|
|
stream_parser.poll_event(cx),
|
|
Ready(Some(Ok(WebmElement::Timecode(0))))
|
|
);
|
|
assert_matches!(
|
|
stream_parser.poll_event(cx),
|
|
Ready(Some(Ok(WebmElement::SimpleBlock(_))))
|
|
);
|
|
assert_matches!(
|
|
stream_parser.poll_event(cx),
|
|
Ready(Some(Ok(WebmElement::Cluster)))
|
|
);
|
|
assert_matches!(
|
|
stream_parser.poll_event(cx),
|
|
Ready(Some(Ok(WebmElement::Timecode(1000))))
|
|
);
|
|
|
|
std::task::Poll::Ready(())
|
|
})
|
|
.now_or_never()
|
|
.expect("Test tried to block on I/O");
|
|
}
|
|
|
|
#[test]
|
|
fn async_webm_test() {
|
|
let pieces = vec![
|
|
&ENCODE_WEBM_TEST_FILE[0..20],
|
|
&ENCODE_WEBM_TEST_FILE[20..40],
|
|
&ENCODE_WEBM_TEST_FILE[40..],
|
|
];
|
|
|
|
async {
|
|
let mut parser = futures::stream::iter(pieces.iter())
|
|
.map(|bytes| Ok::<&[u8], WebmetroError>(&bytes[..]))
|
|
.parse_ebml();
|
|
|
|
assert_matches!(parser.next().await?, Some(WebmElement::EbmlHead));
|
|
assert_matches!(parser.next().await?, Some(WebmElement::Segment));
|
|
assert_matches!(parser.next().await?, Some(WebmElement::Tracks(_)));
|
|
assert_matches!(parser.next().await?, Some(WebmElement::Cluster));
|
|
assert_matches!(parser.next().await?, Some(WebmElement::Timecode(0)));
|
|
assert_matches!(parser.next().await?, Some(WebmElement::SimpleBlock(_)));
|
|
assert_matches!(parser.next().await?, Some(WebmElement::Cluster));
|
|
assert_matches!(parser.next().await?, Some(WebmElement::Timecode(1000)));
|
|
|
|
Result::<(), WebmetroError>::Ok(())
|
|
}
|
|
.now_or_never()
|
|
.expect("Test tried to block on I/O")
|
|
.expect("Parse failed");
|
|
}
|
|
}
|