Move request dispatcher to a separate file

crates/rust-analyzer/src/main_loop.rs

@@ -6,26 +6,26 @@ use std::{
 };
 
 use crossbeam_channel::{never, select, Receiver};
-use lsp_server::{Connection, ErrorCode, Notification, Request, RequestId, Response};
+use lsp_server::{Connection, Notification, Request, RequestId, Response};
 use lsp_types::{notification::Notification as _, request::Request as _, NumberOrString};
 use ra_db::VfsPath;
 use ra_ide::{Canceled, FileId};
 use ra_prof::profile;
 use ra_project_model::{PackageRoot, ProjectWorkspace};
-use serde::{de::DeserializeOwned, Serialize};
 
 use crate::{
     config::{Config, FilesWatcher, LinkedProject},
     diagnostics::DiagnosticTask,
+    dispatch::RequestDispatcher,
     from_proto,
-    global_state::{file_id_to_url, GlobalState, GlobalStateSnapshot, Status},
+    global_state::{file_id_to_url, GlobalState, Status},
     handlers, lsp_ext,
     lsp_utils::{
         apply_document_changes, is_canceled, notification_cast, notification_is, notification_new,
         show_message,
     },
     request_metrics::RequestMetrics,
-    LspError, Result,
+    Result,
 };
 
 pub fn main_loop(config: Config, connection: Connection) -> Result<()> {
@@ -241,7 +241,7 @@ impl GlobalState {
 
     fn on_request(&mut self, request_received: Instant, req: Request) -> Result<()> {
         let mut pool_dispatcher =
-            PoolDispatcher { req: Some(req), global_state: self, request_received };
+            RequestDispatcher { req: Some(req), global_state: self, request_received };
         pool_dispatcher
             .on_sync::<lsp_ext::CollectGarbage>(|s, ()| Ok(s.collect_garbage()))?
             .on_sync::<lsp_ext::JoinLines>(|s, p| handlers::handle_join_lines(s.snapshot(), p))?
@@ -426,7 +426,8 @@ impl GlobalState {
         log::error!("unhandled notification: {:?}", not);
         Ok(())
     }
-    fn on_task(&mut self, task: Task) {
+    // TODO
+    pub(crate) fn on_task(&mut self, task: Task) {
         match task {
             Task::Respond(response) => {
                 if let Some((method, start)) = self.req_queue.incoming.complete(response.id.clone())
@@ -480,6 +481,7 @@ impl GlobalState {
     }
 }
 
+// TODO
 #[derive(Debug)]
 pub(crate) enum Task {
     Respond(Response),
@@ -645,126 +647,3 @@ fn report_progress(
         });
     global_state.send(notification.into());
 }
-
-struct PoolDispatcher<'a> {
-    req: Option<Request>,
-    global_state: &'a mut GlobalState,
-    request_received: Instant,
-}
-
-impl<'a> PoolDispatcher<'a> {
-    /// Dispatches the request onto the current thread
-    fn on_sync<R>(
-        &mut self,
-        f: fn(&mut GlobalState, R::Params) -> Result<R::Result>,
-    ) -> Result<&mut Self>
-    where
-        R: lsp_types::request::Request + 'static,
-        R::Params: DeserializeOwned + panic::UnwindSafe + 'static,
-        R::Result: Serialize + 'static,
-    {
-        let (id, params) = match self.parse::<R>() {
-            Some(it) => it,
-            None => {
-                return Ok(self);
-            }
-        };
-        let world = panic::AssertUnwindSafe(&mut *self.global_state);
-        let task = panic::catch_unwind(move || {
-            let result = f(world.0, params);
-            result_to_task::<R>(id, result)
-        })
-        .map_err(|_| format!("sync task {:?} panicked", R::METHOD))?;
-        self.global_state.on_task(task);
-        Ok(self)
-    }
-
-    /// Dispatches the request onto thread pool
-    fn on<R>(
-        &mut self,
-        f: fn(GlobalStateSnapshot, R::Params) -> Result<R::Result>,
-    ) -> Result<&mut Self>
-    where
-        R: lsp_types::request::Request + 'static,
-        R::Params: DeserializeOwned + Send + 'static,
-        R::Result: Serialize + 'static,
-    {
-        let (id, params) = match self.parse::<R>() {
-            Some(it) => it,
-            None => {
-                return Ok(self);
-            }
-        };
-
-        self.global_state.task_pool.0.spawn({
-            let world = self.global_state.snapshot();
-            move || {
-                let result = f(world, params);
-                result_to_task::<R>(id, result)
-            }
-        });
-
-        Ok(self)
-    }
-
-    fn parse<R>(&mut self) -> Option<(RequestId, R::Params)>
-    where
-        R: lsp_types::request::Request + 'static,
-        R::Params: DeserializeOwned + 'static,
-    {
-        let req = self.req.take()?;
-        let (id, params) = match req.extract::<R::Params>(R::METHOD) {
-            Ok(it) => it,
-            Err(req) => {
-                self.req = Some(req);
-                return None;
-            }
-        };
-        self.global_state
-            .req_queue
-            .incoming
-            .register(id.clone(), (R::METHOD, self.request_received));
-        Some((id, params))
-    }
-
-    fn finish(&mut self) {
-        match self.req.take() {
-            None => (),
-            Some(req) => {
-                log::error!("unknown request: {:?}", req);
-                let resp = Response::new_err(
-                    req.id,
-                    ErrorCode::MethodNotFound as i32,
-                    "unknown request".to_string(),
-                );
-                self.global_state.send(resp.into());
-            }
-        }
-    }
-}
-
-fn result_to_task<R>(id: RequestId, result: Result<R::Result>) -> Task
-where
-    R: lsp_types::request::Request + 'static,
-    R::Params: DeserializeOwned + 'static,
-    R::Result: Serialize + 'static,
-{
-    let response = match result {
-        Ok(resp) => Response::new_ok(id, &resp),
-        Err(e) => match e.downcast::<LspError>() {
-            Ok(lsp_error) => Response::new_err(id, lsp_error.code, lsp_error.message),
-            Err(e) => {
-                if is_canceled(&*e) {
-                    Response::new_err(
-                        id,
-                        ErrorCode::ContentModified as i32,
-                        "content modified".to_string(),
-                    )
-                } else {
-                    Response::new_err(id, ErrorCode::InternalError as i32, e.to_string())
-                }
-            }
-        },
-    };
-    Task::Respond(response)
-}