Add request handling

scarb/src/ops/proc_macro_server/json_rpc.rs

@@ -0,0 +1,12 @@
+use serde::Serialize;
+
+#[derive(Serialize)]
+pub struct ErrResponse {
+    message: String,
+}
+
+impl ErrResponse {
+    pub fn new(message: String) -> Self {
+        Self { message }
+    }
+}

scarb/src/ops/proc_macro_server/mod.rs

@@ -1,13 +1,41 @@
 use crate::compiler::plugin::proc_macro::ProcMacroHost;
-use anyhow::Result;
+use anyhow::{anyhow, Result};
 use connection::Connection;
+use json_rpc::ErrResponse;
+use proc_macro_server_api::RpcResponse;
 
 mod connection;
+mod json_rpc;
 
 pub fn start_proc_macro_server(proc_macros: ProcMacroHost) -> Result<()> {
     let connection = Connection::new();
 
-    //TODO
+    for i in 0..4 {
+        let receiver = connection.receiver.clone();
+        let sender = connection.sender.clone();
+
+        std::thread::Builder::new()
+            .name(format!("proc-macro-server-worker-thread-{i}"))
+            .spawn(move || {
+                for request in receiver {
+                    let response = match request.method.as_str() {
+                        //TODO add method handlers
+                        _ => Err(anyhow!("method not found")),
+                    };
+
+                    let value = response.unwrap_or_else(|err| {
+                        serde_json::to_value(ErrResponse::new(err.to_string())).unwrap()
+                    });
+                    let res = RpcResponse {
+                        id: request.id,
+                        value,
+                    };
+
+                    sender.send(res).unwrap();
+                }
+            })
+            .expect("failed to spawn thread");
+    }
 
     connection.join();