Create EbmlEventSource trait since Iterators/Streams can't return borrows

src/bin/loop_server.rs

@@ -3,7 +3,7 @@ extern crate hyper;
 extern crate lab_ebml;
 
 use futures::future::FutureResult;
-use futures::stream::{iter, Stream};
+use futures::stream::Stream;
 use lab_ebml::chunk::{Chunk, WebmStream, ChunkingError};
 use lab_ebml::timecode_fixer::ChunkStream;
 use lab_ebml::webm::*;
@@ -28,13 +28,12 @@ impl Service for WebmServer {
     fn call(&self, req: Request) -> Self::Future {
         let response = match (req.method(), req.path()) {
             (&Get, "/loop") => {
-                let stream: BodyStream<Vec<u8>> = iter(parse_webm(SRC_FILE).into_iter().map(|x| Ok(x)))
-                    .chunk_webm()
-                    .chain(iter(parse_webm(SRC_FILE).into_iter().map(|x| Ok(x))).chunk_webm())
+                let stream: BodyStream<Vec<u8>> = parse_webm(SRC_FILE).into_iter().chunk_webm()
+                    .chain(parse_webm(SRC_FILE).into_iter().chunk_webm())
                     .fix_timecodes()
                     .map_err(|err| match err {
                         ChunkingError::IoError(io_err) => hyper::Error::Io(io_err),
-                        ChunkingError::OtherError(otx_err) => otx_err
+                        ChunkingError::OtherError(_) => hyper::Error::Incomplete
                     })
                     .boxed();
                 Response::new()
@@ -51,6 +50,6 @@ impl Service for WebmServer {
 }
 
 pub fn main() {
-    let addr = args().nth(1).unwrap().to_socket_addrs().unwrap().next().unwrap();
+    let addr = args().nth(1).expect("Need binding address+port").to_socket_addrs().unwrap().next().unwrap();
     Http::new().bind(&addr, move || Ok(WebmServer)).unwrap().run().unwrap();
 }

src/chunk.rs

@@ -1,7 +1,9 @@
 use futures::{Async, Stream};
 use std::io::Cursor;
+use std::marker::PhantomData;
 use std::mem;
 use std::sync::Arc;
+use ebml::EbmlEventSource;
 use webm::*;
 
 #[derive(Clone)]
@@ -85,12 +87,13 @@ pub enum ChunkingError<E> {
     OtherError(E)
 }
 
-pub struct WebmChunker<S> {
-    stream: S,
-    state: ChunkerState
+pub struct WebmChunker<'a, S: EbmlEventSource<'a>> {
+    source: S,
+    state: ChunkerState,
+    _marker: PhantomData<&'a [u8]>
 }
 
-impl<'a, S: Stream<Item = WebmElement<'a>>> Stream for WebmChunker<S>
+impl<'a, S: EbmlEventSource<'a, Event = WebmElement<'a>>> Stream for WebmChunker<'a, S>
 {
     type Item = Chunk;
     type Error = ChunkingError<S::Error>;
@@ -99,7 +102,7 @@ impl<'a, S: Stream<Item = WebmElement<'a>>> Stream for WebmChunker<S>
         loop {
             let (return_value, next_state) = match self.state {
                 ChunkerState::BuildingHeader(ref mut buffer) => {
-                    match self.stream.poll() {
+                    match self.source.poll_event() {
                         Err(passthru) => return Err(ChunkingError::OtherError(passthru)),
                         Ok(Async::NotReady) => return Ok(Async::NotReady),
                         Ok(Async::Ready(None)) => return Ok(Async::Ready(None)),
@@ -126,7 +129,7 @@ impl<'a, S: Stream<Item = WebmElement<'a>>> Stream for WebmChunker<S>
                     }
                 },
                 ChunkerState::BuildingCluster(ref mut cluster_head, ref mut buffer) => {
-                    match self.stream.poll() {
+                    match self.source.poll_event() {
                         Err(passthru) => return Err(ChunkingError::OtherError(passthru)),
                         Ok(Async::NotReady) => return Ok(Async::NotReady),
                         Ok(Async::Ready(Some(WebmElement::Cluster))) => {
@@ -205,15 +208,16 @@ impl<'a, S: Stream<Item = WebmElement<'a>>> Stream for WebmChunker<S>
     }
 }
 
-pub trait WebmStream<T> {
-    fn chunk_webm(self) -> WebmChunker<T>;
+pub trait WebmStream<'a, T: EbmlEventSource<'a, Event = WebmElement<'a>>> {
+    fn chunk_webm(self) -> WebmChunker<'a, T>;
 }
 
-impl<'a, T: Stream<Item = WebmElement<'a>>> WebmStream<T> for T {
-    fn chunk_webm(self) -> WebmChunker<T> {
+impl<'a, T: EbmlEventSource<'a, Event = WebmElement<'a>>> WebmStream<'a, T> for T {
+    fn chunk_webm(self) -> WebmChunker<'a, T> {
         WebmChunker {
-            stream: self,
-            state: ChunkerState::BuildingHeader(Cursor::new(Vec::new()))
+            source: self,
+            state: ChunkerState::BuildingHeader(Cursor::new(Vec::new())),
+            _marker: PhantomData
         }
     }
 }

src/ebml.rs

@@ -1,4 +1,5 @@
 use bytes::{BigEndian, ByteOrder, BufMut};
+use futures::Async;
 use std::error::Error as ErrorTrait;
 use std::fmt::{Display, Formatter, Result as FmtResult};
 use std::io::{Cursor, Error as IoError, ErrorKind, Result as IoResult, Write, Seek, SeekFrom};
@@ -259,6 +260,12 @@ pub trait FromEbml<'b>: Sized {
     }
 }
 
+pub trait EbmlEventSource<'a> {
+    type Event: FromEbml<'a>;
+    type Error;
+    fn poll_event(&mut self) -> Result<Async<Option<Self::Event>>, Self::Error>;
+}
+
 #[cfg(test)]
 mod tests {
     use bytes::{BytesMut};

src/iterator.rs

@@ -1,4 +1,5 @@
 use std::marker::PhantomData;
+use futures::Async;
 use ebml::*;
 
 pub struct EbmlIterator<'b, T: FromEbml<'b>> {
@@ -35,3 +36,19 @@ impl<'b, T: FromEbml<'b>> Iterator for EbmlIterator<'b, T> {
         }
     }
 }
+
+impl<'a, T: FromEbml<'a>> EbmlEventSource<'a> for EbmlIterator<'a, T> {
+    type Event = T;
+    type Error = Error;
+
+    fn poll_event(&mut self) -> Result<Async<Option<T>>, Error> {
+        match Self::Event::decode_element(&self.slice[self.position..]) {
+            Err(err) => Err(err),
+            Ok(None) => Ok(Async::Ready(None)),
+            Ok(Some((element, element_size))) => {
+                self.position += element_size;
+                Ok(Async::Ready(Some(element)))
+            }
+        }
+    }
+}