Add trailers implementation for responses.

crates/wasi-http/src/http_impl.rs

@@ -8,6 +8,7 @@ use bytes::{BufMut, Bytes, BytesMut};
 use http_body_util::{BodyExt, Full};
 use hyper::Method;
 use hyper::Request;
+use std::collections::HashMap;
 #[cfg(not(any(target_arch = "riscv64", target_arch = "s390x")))]
 use std::sync::Arc;
 use std::time::Duration;
@@ -201,6 +202,23 @@ impl WasiHttp {
             if let Some(chunk) = frame.data_ref() {
                 buf.put(chunk.clone());
             }
+            if let Some(trailers) = frame.trailers_ref() {
+                response.trailers = self.fields_id_base;
+                self.fields_id_base += 1;
+                let mut map: HashMap<String, Vec<String>> = HashMap::new();
+                for (name, value) in trailers.iter() {
+                    let key = name.to_string();
+                    match map.get_mut(&key) {
+                        Some(vec) => vec.push(value.to_str()?.to_string()),
+                        None => {
+                            let mut vec = Vec::new();
+                            vec.push(value.to_str()?.to_string());
+                            map.insert(key, vec);
+                        }
+                    };
+                }
+                self.fields.insert(response.trailers, map);
+            }
         }
         response.body = self.streams_id_base;
         self.streams_id_base = self.streams_id_base + 1;

crates/wasi-http/src/streams_impl.rs

@@ -2,8 +2,8 @@ use crate::poll::Pollable;
 use crate::streams::{InputStream, OutputStream, StreamError};
 use crate::WasiHttp;
 use anyhow::{anyhow, bail};
-use std::vec::Vec;
 use bytes::BufMut;
+use std::vec::Vec;
 
 impl crate::streams::Host for WasiHttp {
     fn read(
@@ -67,10 +67,10 @@ impl crate::streams::Host for WasiHttp {
                 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()));
-            },
+            }
         }
         Ok(Ok(buf.len().try_into()?))
     }

crates/wasi-http/src/struct.rs

@@ -34,6 +34,7 @@ pub struct ActiveResponse {
     pub status: u16,
     pub body: u32,
     pub response_headers: HashMap<String, Vec<String>>,
+    pub trailers: u32,
 }
 
 impl ActiveRequest {
@@ -60,6 +61,7 @@ impl ActiveResponse {
             status: 0,
             body: 0,
             response_headers: HashMap::new(),
+            trailers: 0,
         }
     }
 }

crates/wasi-http/src/types_impl.rs

@@ -101,8 +101,16 @@ impl crate::types::Host for WasiHttp {
         self.fields.insert(id, m.clone());
         Ok(id)
     }
-    fn finish_incoming_stream(&mut self, _s: IncomingStream) -> wasmtime::Result<Option<Trailers>> {
-        bail!("unimplemented: finish_incoming_stream")
+    fn finish_incoming_stream(&mut self, s: IncomingStream) -> wasmtime::Result<Option<Trailers>> {
+        for (_, value) in self.responses.iter() {
+            if value.body == s {
+                return match value.trailers {
+                    0 => Ok(None),
+                    _ => Ok(Some(value.trailers)),
+                };
+            }
+        }
+        bail!("unknown stream!")
     }
     fn finish_outgoing_stream(
         &mut self,