Make streams owned by request/response that they are tied to. (bytecodealliance#6228)

* Make streams owned by request/response that they are tied to.

* Address comments, fix tests.

* Address comment.

* Update crates/wasi-http/src/streams_impl.rs

Co-authored-by: Pat Hickey <pat@moreproductive.org>

* Switch to BytesMut

---------

Co-authored-by: Pat Hickey <pat@moreproductive.org>

Author: 2 people

crates/wasi-http/src/http_impl.rs

@@ -1,5 +1,5 @@
 use crate::r#struct::ActiveResponse;
-pub use crate::r#struct::WasiHttp;
+use crate::r#struct::{Stream, WasiHttp};
 use crate::types::{RequestOptions, Scheme};
 #[cfg(not(any(target_arch = "riscv64", target_arch = "s390x")))]
 use anyhow::anyhow;
@@ -183,8 +183,10 @@ impl WasiHttp {
         let body = Full::<Bytes>::new(
             self.streams
                 .get(&request.body)
-                .unwrap_or(&Bytes::new())
-                .clone(),
+                .unwrap_or(&Stream::default())
+                .data
+                .clone()
+                .freeze(),
         );
         let t = timeout(first_bytes_timeout, sender.send_request(call.body(body)?)).await?;
         let mut res = t?;
@@ -222,7 +224,7 @@ impl WasiHttp {
         }
         response.body = self.streams_id_base;
         self.streams_id_base = self.streams_id_base + 1;
-        self.streams.insert(response.body, buf.freeze());
+        self.streams.insert(response.body, buf.freeze().into());
         self.responses.insert(response_id, response);
         Ok(response_id)
     }

crates/wasi-http/src/streams_impl.rs

@@ -2,7 +2,6 @@ use crate::poll::Pollable;
 use crate::streams::{InputStream, OutputStream, StreamError};
 use crate::WasiHttp;
 use anyhow::{anyhow, bail};
-use bytes::BufMut;
 use std::vec::Vec;
 
 impl crate::streams::Host for WasiHttp {
@@ -11,10 +10,14 @@ impl crate::streams::Host for WasiHttp {
         stream: InputStream,
         len: u64,
     ) -> wasmtime::Result<Result<(Vec<u8>, bool), StreamError>> {
-        let s = self
+        let st = self
             .streams
             .get_mut(&stream)
             .ok_or_else(|| anyhow!("stream not found: {stream}"))?;
+        if st.closed {
+            bail!("stream is dropped!");
+        }
+        let s = &mut st.data;
         if len == 0 {
             Ok(Ok((bytes::Bytes::new().to_vec(), s.len() > 0)))
         } else if s.len() > len.try_into()? {
@@ -31,10 +34,14 @@ impl crate::streams::Host for WasiHttp {
         stream: InputStream,
         len: u64,
     ) -> wasmtime::Result<Result<(u64, bool), StreamError>> {
-        let s = self
+        let st = self
             .streams
             .get_mut(&stream)
             .ok_or_else(|| anyhow!("stream not found: {stream}"))?;
+        if st.closed {
+            bail!("stream is dropped!");
+        }
+        let s = &mut st.data;
         if len == 0 {
             Ok(Ok((0, s.len() > 0)))
         } else if s.len() > len.try_into()? {
@@ -52,7 +59,11 @@ impl crate::streams::Host for WasiHttp {
     }
 
     fn drop_input_stream(&mut self, stream: InputStream) -> wasmtime::Result<()> {
-        self.streams.remove(&stream);
+        let st = self
+            .streams
+            .get_mut(&stream)
+            .ok_or_else(|| anyhow!("stream not found: {stream}"))?;
+        st.closed = true;
         Ok(())
     }
 
@@ -61,18 +72,13 @@ impl crate::streams::Host for WasiHttp {
         this: OutputStream,
         buf: Vec<u8>,
     ) -> wasmtime::Result<Result<u64, StreamError>> {
-        match self.streams.get(&this) {
-            Some(data) => {
-                let mut new = bytes::BytesMut::with_capacity(data.len() + buf.len());
-                new.put(data.clone());
-                new.put(bytes::Bytes::from(buf.clone()));
-                self.streams.insert(this, new.freeze());
-            }
-            None => {
-                self.streams.insert(this, bytes::Bytes::from(buf.clone()));
-            }
+        let len = buf.len();
+        let st = self.streams.entry(this).or_default();
+        if st.closed {
+            bail!("cannot write to closed stream");
         }
-        Ok(Ok(buf.len().try_into()?))
+        st.data.extend_from_slice(buf.as_slice());
+        Ok(Ok(len.try_into()?))
     }
 
     fn write_zeroes(
@@ -111,7 +117,11 @@ impl crate::streams::Host for WasiHttp {
     }
 
     fn drop_output_stream(&mut self, stream: OutputStream) -> wasmtime::Result<()> {
-        self.streams.remove(&stream);
+        let st = self
+            .streams
+            .get_mut(&stream)
+            .ok_or_else(|| anyhow!("stream not found: {stream}"))?;
+        st.closed = true;
         Ok(())
     }
 }

crates/wasi-http/src/struct.rs

@@ -1,7 +1,13 @@
 use crate::types::{Method, Scheme};
-use bytes::Bytes;
+use bytes::{BufMut, Bytes, BytesMut};
 use std::collections::HashMap;
 
+#[derive(Clone, Default)]
+pub struct Stream {
+    pub closed: bool,
+    pub data: BytesMut,
+}
+
 #[derive(Clone)]
 pub struct WasiHttp {
     pub request_id_base: u32,
@@ -11,7 +17,7 @@ pub struct WasiHttp {
     pub requests: HashMap<u32, ActiveRequest>,
     pub responses: HashMap<u32, ActiveResponse>,
     pub fields: HashMap<u32, HashMap<String, Vec<String>>>,
-    pub streams: HashMap<u32, Bytes>,
+    pub streams: HashMap<u32, Stream>,
 }
 
 #[derive(Clone)]
@@ -66,6 +72,23 @@ impl ActiveResponse {
     }
 }
 
+impl Stream {
+    pub fn new() -> Self {
+        Self::default()
+    }
+}
+
+impl From<Bytes> for Stream {
+    fn from(bytes: Bytes) -> Self {
+        let mut buf = BytesMut::with_capacity(bytes.len());
+        buf.put(bytes);
+        Self {
+            closed: false,
+            data: buf,
+        }
+    }
+}
+
 impl WasiHttp {
     pub fn new() -> Self {
         Self {

crates/wasi-http/src/types_impl.rs

@@ -1,13 +1,13 @@
 use crate::poll::Pollable;
-use crate::r#struct::ActiveRequest;
+use crate::r#struct::{ActiveRequest, Stream};
 use crate::types::{
     Error, Fields, FutureIncomingResponse, Headers, IncomingRequest, IncomingResponse,
     IncomingStream, Method, OutgoingRequest, OutgoingResponse, OutgoingStream, ResponseOutparam,
     Scheme, StatusCode, Trailers,
 };
 use crate::WasiHttp;
 use anyhow::{anyhow, bail};
-use std::collections::HashMap;
+use std::collections::{hash_map::Entry, HashMap};
 
 impl crate::types::Host for WasiHttp {
     fn drop_fields(&mut self, fields: Fields) -> wasmtime::Result<()> {
@@ -123,7 +123,10 @@ impl crate::types::Host for WasiHttp {
         bail!("unimplemented: drop_incoming_request")
     }
     fn drop_outgoing_request(&mut self, request: OutgoingRequest) -> wasmtime::Result<()> {
-        self.requests.remove(&request);
+        if let Entry::Occupied(e) = self.requests.entry(request) {
+            let r = e.remove();
+            self.streams.remove(&r.body);
+        }
         Ok(())
     }
     fn incoming_request_method(&mut self, _request: IncomingRequest) -> wasmtime::Result<Method> {
@@ -192,6 +195,7 @@ impl crate::types::Host for WasiHttp {
         if req.body == 0 {
             req.body = self.streams_id_base;
             self.streams_id_base = self.streams_id_base + 1;
+            self.streams.insert(req.body, Stream::default());
         }
         Ok(Ok(req.body))
     }
@@ -206,7 +210,10 @@ impl crate::types::Host for WasiHttp {
         bail!("unimplemented: set_response_outparam")
     }
     fn drop_incoming_response(&mut self, response: IncomingResponse) -> wasmtime::Result<()> {
-        self.responses.remove(&response);
+        if let Entry::Occupied(e) = self.responses.entry(response) {
+            let r = e.remove();
+            self.streams.remove(&r.body);
+        }
         Ok(())
     }
     fn drop_outgoing_response(&mut self, _response: OutgoingResponse) -> wasmtime::Result<()> {