sausage-plugin part 2: import! with typed clients (sausage_interface::client_rs), TCP endpoints with rpc.endpoint, examples

Part 1 fixes: complete stdout writes, buffered stdin, Rust type names
in schemas, enum variant docs, -32603 for serde errors in handlers,
crate docs and modules. End-to-end check of a generated consumer through
a fake core.

sdk/tests/plugins/probe/src/main.rs

@@ -16,14 +16,32 @@ struct Retired {
     /// The previous hash.
     previous: String,
 }
-#[rpc(grace_seconds = 12)]
+/// A large payload.
+#[schema]
+struct Echo {
+    /// The text to return unchanged.
+    text: String,
+}
+#[rpc(grace_seconds = 12,endpoints(control=Control))]
 impl Probe {
+    /// Publish a control endpoint until EOF.
+    async fn serve(&self) -> Result<()> {
+        sausage_plugin::listen("/endpoint", std::rc::Rc::new(Control)).await
+    }
     /// Add two numbers.
     ///
     /// The result is their sum.
     fn add(&self, p: Add) -> Result<i32> {
         Ok(p.a + p.b)
     }
+    /// Echo a payload larger than a host I/O buffer.
+    fn echo(&self, p: Echo) -> Result<String> {
+        Ok(p.text)
+    }
+    /// Return an internal serialization error.
+    fn serde_error(&self) -> Result<String> {
+        Ok(sausage_plugin::serde_json::from_str::<String>("invalid")?)
+    }
     /// Return a deliberate error.
     fn fail(&self) -> Result<String> {
         Err(sausage_plugin::Error::new(-32010, "deliberate"))
@@ -109,6 +127,20 @@ async fn join(
     })
     .await
 }
+struct Control;
+#[rpc]
+impl Control {
+    /// Report progress and return a stable counter.
+    fn stats(&self, ctx: &Ctx) -> Result<u64> {
+        ctx.notify("endpoint-progress", json!({"value":7}))?;
+        Ok(7)
+    }
+    /// End the endpoint process after the response.
+    fn stop(&self, ctx: &Ctx) -> Result<()> {
+        ctx.exit_after_response();
+        Ok(())
+    }
+}
 fn main() {
     sausage_plugin::run(Probe)
 }