chore: sidecar

frontend/rust-lib/Cargo.lock

@@ -1143,12 +1143,9 @@ dependencies = [
 
 [[package]]
 name = "crossbeam-utils"
-version = "0.8.16"
+version = "0.8.20"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5a22b2d63d4d1dc0b7f1b6b2747dd0088008a9be28b6ddf0b1e7d335e3037294"
+checksum = "22ec99545bb0ed0ea7bb9b8e1e9122ea386ff8a48c0922e43f36d45ab09e0e80"
-dependencies = [
- "cfg-if",
-]
 
 [[package]]
 name = "crunchy"
@@ -2158,12 +2155,15 @@ name = "flowy-sidecar"
 version = "0.1.0"
 dependencies = [
  "anyhow",
+ "crossbeam-utils",
  "ctor",
  "dotenv",
  "encoding_rs",
+ "log",
  "memchr",
  "once_cell",
  "os_pipe 1.2.0",
+ "parking_lot 0.12.1",
  "serde",
  "serde_json",
  "shared_child",

frontend/rust-lib/flowy-sidecar/src/error.rs

@@ -1,32 +1,158 @@
+use serde::{Deserialize, Deserializer, Serialize, Serializer};
+use serde_json::{json, Value};
+use std::{fmt, io};
+
 /// The error type of `tauri-utils`.
 #[derive(Debug, thiserror::Error)]
-#[non_exhaustive]
 pub enum Error {
-  /// Target triple architecture error
+  /// An IO error occurred on the underlying communication channel.
-  #[error("Unable to determine target-architecture")]
+  #[error(transparent)]
-  Architecture,
+  Io(#[from] io::Error),
-  /// Target triple OS error
+  /// The peer returned an error.
-  #[error("Unable to determine target-os")]
+  #[error("Remote error: {0}")]
-  Os,
+  RemoteError(RemoteError),
-  /// Target triple environment error
+  /// The peer closed the connection.
-  #[error("Unable to determine target-environment")]
+  #[error("Peer closed the connection.")]
-  Environment,
+  PeerDisconnect,
-  /// Tried to get resource on an unsupported platform
+  /// The peer sent a response containing the id, but was malformed.
-  #[error("Unsupported platform for reading resources")]
+  #[error("Invalid response.")]
-  UnsupportedPlatform,
+  InvalidResponse,
-  /// Get parent process error
+}
-  #[error("Could not get parent process")]
+
-  ParentProcess,
+#[derive(Debug)]
-  /// Get parent process PID error
+pub enum ReadError {
-  #[error("Could not get parent PID")]
+  /// An error occurred in the underlying stream
-  ParentPid,
+  Io(io::Error),
-  /// Get child process error
+  /// The message was not valid JSON.
-  #[error("Could not get child process")]
+  Json(serde_json::Error),
-  ChildProcess,
+  /// The message was not a JSON object.
-  /// IO error
+  NotObject(String),
-  #[error("{0}")]
+  /// The the method and params were not recognized by the handler.
-  Io(#[from] std::io::Error),
+  UnknownRequest(serde_json::Error),
-  /// Invalid pattern.
+  /// The peer closed the connection.
-  #[error("invalid pattern `{0}`. Expected either `brownfield` or `isolation`.")]
+  Disconnect,
-  InvalidPattern(String),
+}
+
+#[derive(Debug, Clone, PartialEq, thiserror::Error)]
+pub enum RemoteError {
+  /// The JSON was valid, but was not a correctly formed request.
+  ///
+  /// This Error is used internally, and should not be returned by
+  /// clients.
+  #[error("Invalid request: {0:?}")]
+  InvalidRequest(Option<Value>),
+  /// A custom error, defined by the client.
+  #[error("Custom error: {message}")]
+  Custom {
+    code: i64,
+    message: String,
+    data: Option<Value>,
+  },
+  /// An error that cannot be represented by an error object.
+  ///
+  /// This error is intended to accommodate clients that return arbitrary
+  /// error values. It should not be used for new errors.
+  #[error("Unknown error: {0}")]
+  Unknown(Value),
+}
+
+impl ReadError {
+  /// Returns `true` iff this is the `ReadError::Disconnect` variant.
+  pub fn is_disconnect(&self) -> bool {
+    matches!(*self, ReadError::Disconnect)
+  }
+}
+
+impl fmt::Display for ReadError {
+  fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+    match self {
+      ReadError::Io(ref err) => write!(f, "I/O Error: {:?}", err),
+      ReadError::Json(ref err) => write!(f, "JSON Error: {:?}", err),
+      ReadError::NotObject(s) => write!(f, "Expected JSON object, found: {}", s),
+      ReadError::UnknownRequest(ref err) => write!(f, "Unknown request: {:?}", err),
+      ReadError::Disconnect => write!(f, "Peer closed the connection."),
+    }
+  }
+}
+
+impl From<serde_json::Error> for ReadError {
+  fn from(err: serde_json::Error) -> ReadError {
+    ReadError::Json(err)
+  }
+}
+
+impl From<io::Error> for ReadError {
+  fn from(err: io::Error) -> ReadError {
+    ReadError::Io(err)
+  }
+}
+
+impl From<serde_json::Error> for RemoteError {
+  fn from(err: serde_json::Error) -> RemoteError {
+    RemoteError::InvalidRequest(Some(json!(err.to_string())))
+  }
+}
+
+impl From<RemoteError> for Error {
+  fn from(err: RemoteError) -> Error {
+    Error::RemoteError(err)
+  }
+}
+
+#[derive(Deserialize, Serialize)]
+struct ErrorHelper {
+  code: i64,
+  message: String,
+  #[serde(skip_serializing_if = "Option::is_none")]
+  data: Option<Value>,
+}
+
+impl<'de> Deserialize<'de> for RemoteError {
+  fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+  where
+    D: Deserializer<'de>,
+  {
+    let v = Value::deserialize(deserializer)?;
+    let resp = match ErrorHelper::deserialize(&v) {
+      Ok(resp) => resp,
+      Err(_) => return Ok(RemoteError::Unknown(v)),
+    };
+
+    Ok(match resp.code {
+      -32600 => RemoteError::InvalidRequest(resp.data),
+      _ => RemoteError::Custom {
+        code: resp.code,
+        message: resp.message,
+        data: resp.data,
+      },
+    })
+  }
+}
+
+impl Serialize for RemoteError {
+  fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+  where
+    S: Serializer,
+  {
+    let (code, message, data) = match *self {
+      RemoteError::InvalidRequest(ref d) => (-32600, "Invalid request", d),
+      RemoteError::Custom {
+        code,
+        ref message,
+        ref data,
+      } => (code, message.as_ref(), data),
+      RemoteError::Unknown(_) => panic!(
+        "The 'Unknown' error variant is \
+                 not intended for client use."
+      ),
+    };
+    let message = message.to_owned();
+    let data = data.to_owned();
+    let err = ErrorHelper {
+      code,
+      message,
+      data,
+    };
+    err.serialize(serializer)
+  }
 }

frontend/rust-lib/flowy-sidecar/src/manager.rs

@@ -0,0 +1,125 @@
+use crate::error::{ReadError, RemoteError};
+use crate::plugin::{start_plugin_process, Plugin, PluginId, PluginInfo, RpcCtx};
+use crate::rpc_loop::Handler;
+use crate::rpc_peer::PluginCommand;
+use anyhow::{anyhow, Result};
+use parking_lot::{Mutex, RwLock};
+use serde_json::{json, Value};
+use std::io;
+use std::sync::atomic::{AtomicI64, AtomicU8, Ordering};
+use std::sync::{Arc, Weak};
+use tracing::{trace, warn};
+
+pub struct SidecarManager {
+  state: Arc<Mutex<SidecarState>>,
+  plugin_id_counter: Arc<AtomicI64>,
+}
+
+impl SidecarManager {
+  pub fn new() -> Self {
+    SidecarManager {
+      state: Arc::new(Mutex::new(SidecarState {
+        plugins: Vec::new(),
+      })),
+      plugin_id_counter: Arc::new(Default::default()),
+    }
+  }
+
+  pub async fn create_plugin(&self, plugin_info: PluginInfo) -> Result<PluginId> {
+    let plugin_id = PluginId::from(self.plugin_id_counter.fetch_add(1, Ordering::SeqCst));
+    let weak_state = WeakSidecarState(Arc::downgrade(&self.state));
+    start_plugin_process(plugin_info, plugin_id, weak_state).await?;
+    Ok(plugin_id)
+  }
+
+  pub async fn kill_plugin(&self, id: PluginId) -> Result<()> {
+    let state = self.state.lock();
+    let plugin = state
+      .plugins
+      .iter()
+      .find(|p| p.id == id)
+      .ok_or(anyhow!("plugin not found"))?;
+    plugin.shutdown()
+    Ok(())
+  }
+
+  pub fn init_plugin(&self, id: PluginId, init_params: Value) -> Result<()> {
+    let state = self.state.lock();
+    let plugin = state
+      .plugins
+      .iter()
+      .find(|p| p.id == id)
+      .ok_or(anyhow!("plugin not found"))?;
+    plugin.initialize(init_params)?;
+
+    Ok(())
+  }
+
+  pub fn send_request(&self, id: PluginId, method: &str, request: Value) -> Result<()> {
+    let state = self.state.lock();
+    let plugin = state
+      .plugins
+      .iter()
+      .find(|p| p.id == id)
+      .ok_or(anyhow!("plugin not found"))?;
+    plugin.send_request(method, &request)?;
+    Ok(())
+  }
+}
+
+pub struct SidecarState {
+  plugins: Vec<Plugin>,
+}
+
+impl SidecarState {
+  pub fn plugin_connect(&mut self, plugin: Result<Plugin, io::Error>) {
+    match plugin {
+      Ok(plugin) => {
+        warn!("plugin connected: {:?}", plugin.id);
+        self.plugins.push(plugin);
+      },
+      Err(err) => {
+        warn!("plugin failed to connect: {:?}", err);
+      },
+    }
+  }
+
+  pub fn plugin_exit(&mut self, id: PluginId, error: Result<(), ReadError>) {
+    warn!("plugin {:?} exited with result {:?}", id, error);
+    let running_idx = self.plugins.iter().position(|p| p.id == id);
+    if let Some(idx) = running_idx {
+      let plugin = self.plugins.remove(idx);
+      plugin.shutdown();
+    }
+  }
+}
+
+#[derive(Clone)]
+pub struct WeakSidecarState(Weak<Mutex<SidecarState>>);
+
+impl WeakSidecarState {
+  pub fn upgrade(&self) -> Option<Arc<Mutex<SidecarState>>> {
+    self.0.upgrade()
+  }
+
+  pub fn plugin_connect(&self, plugin: Result<Plugin, io::Error>) {
+    if let Some(state) = self.upgrade() {
+      state.lock().plugin_connect(plugin)
+    }
+  }
+
+  pub fn plugin_exit(&self, plugin: PluginId, error: Result<(), ReadError>) {
+    if let Some(core) = self.upgrade() {
+      core.lock().plugin_exit(plugin, error)
+    }
+  }
+}
+
+impl Handler for WeakSidecarState {
+  type Request = PluginCommand<String>;
+
+  fn handle_request(&mut self, ctx: &RpcCtx, rpc: Self::Request) -> Result<Value, RemoteError> {
+    trace!("handling request: {:?}", rpc.cmd);
+    Ok(json!({}))
+  }
+}

frontend/rust-lib/flowy-sidecar/src/parser.rs

@@ -0,0 +1,54 @@
+use crate::error::{ReadError, RemoteError};
+use crate::rpc_loop::RpcObject;
+use serde_json::Value;
+use std::io::BufRead;
+use tracing::trace;
+
+#[derive(Debug, Default)]
+pub struct MessageReader(String);
+
+impl MessageReader {
+  /// Attempts to read the next line from the stream and parse it as
+  /// an RPC object.
+  ///
+  /// # Errors
+  ///
+  /// This function will return an error if there is an underlying
+  /// I/O error, if the stream is closed, or if the message is not
+  /// a valid JSON object.
+  pub fn next<R: BufRead>(&mut self, reader: &mut R) -> Result<RpcObject, ReadError> {
+    self.0.clear();
+    let _ = reader.read_line(&mut self.0)?;
+    if self.0.is_empty() {
+      Err(ReadError::Disconnect)
+    } else {
+      self.parse(&self.0)
+    }
+  }
+
+  /// Attempts to parse a &str as an RPC Object.
+  ///
+  /// This should not be called directly unless you are writing tests.
+  #[doc(hidden)]
+  pub fn parse(&self, s: &str) -> Result<RpcObject, ReadError> {
+    trace!("parsing message: {}", s);
+    let val = serde_json::from_str::<Value>(s)?;
+    if !val.is_object() {
+      Err(ReadError::NotObject(s.to_string()))
+    } else {
+      Ok(val.into())
+    }
+  }
+}
+
+pub type RequestId = u64;
+#[derive(Debug, Clone, PartialEq)]
+/// An RPC call, which may be either a notification or a request.
+pub enum Call<R> {
+  Message(Value),
+  /// An id and an RPC Request
+  Request(RequestId, R),
+  /// A malformed request: the request contained an id, but could
+  /// not be parsed. The client will receive an error.
+  InvalidRequest(RequestId, RemoteError),
+}

frontend/rust-lib/flowy-sidecar/src/plugin.rs

@@ -0,0 +1,142 @@
+use crate::error::Error;
+use crate::manager::WeakSidecarState;
+use crate::rpc_loop::RpcLoop;
+
+use anyhow::anyhow;
+use serde::{Deserialize, Serialize};
+use serde_json::{json, Value};
+use std::io::BufReader;
+use std::path::PathBuf;
+use std::process::{Child, Stdio};
+use std::sync::Arc;
+use std::thread;
+use std::time::Instant;
+use tracing::{error, info};
+
+#[derive(
+  Default, Debug, Clone, Copy, Hash, PartialEq, Eq, PartialOrd, Ord, Serialize, Deserialize,
+)]
+pub struct PluginId(pub(crate) i64);
+
+impl From<i64> for PluginId {
+  fn from(id: i64) -> Self {
+    PluginId(id)
+  }
+}
+
+pub trait Callback: Send {
+  fn call(self: Box<Self>, result: Result<Value, Error>);
+}
+
+/// The `Peer` trait represents the interface for the other side of the RPC
+/// channel. It is intended to be used behind a pointer, a trait object.
+pub trait Peer: Send + 'static {
+  fn box_clone(&self) -> Box<dyn Peer>;
+  fn send_rpc_request_async(&self, method: &str, params: &Value, f: Box<dyn Callback>);
+  /// Sends a request (synchronous RPC) to the peer, and waits for the result.
+  fn send_rpc_request(&self, method: &str, params: &Value) -> Result<Value, Error>;
+  /// Determines whether an incoming request (or notification) is
+  /// pending. This is intended to reduce latency for bulk operations
+  /// done in the background.
+  fn request_is_pending(&self) -> bool;
+
+  fn schedule_idle(&self, token: usize);
+  /// Like `schedule_idle`, with the guarantee that the handler's `idle`
+  /// fn will not be called _before_ the provided `Instant`.
+  ///
+  /// # Note
+  ///
+  /// This is not intended as a high-fidelity timer. Regular RPC messages
+  /// will always take priority over an idle task.
+  fn schedule_timer(&self, after: Instant, token: usize);
+}
+
+/// The `Peer` trait object.
+pub type RpcPeer = Box<dyn Peer>;
+
+pub struct RpcCtx {
+  pub peer: RpcPeer,
+}
+pub struct Plugin {
+  peer: RpcPeer,
+  pub(crate) id: PluginId,
+  pub(crate) name: String,
+  #[allow(dead_code)]
+  process: Child,
+}
+
+impl Plugin {
+  pub fn initialize(&self, value: Value) -> Result<(), Error> {
+    self.peer.send_rpc_request("initialize", &value)?;
+    Ok(())
+  }
+
+  pub fn send_request(&self, method: &str, params: &Value) -> Result<Value, Error> {
+    self.peer.send_rpc_request(method, params)
+  }
+
+  pub fn shutdown(&self) {
+    if let Err(err) = self.peer.send_rpc_request("shutdown", &json!({})) {
+      error!("error sending shutdown to plugin {}: {:?}", self.name, err);
+    }
+  }
+}
+
+pub struct PluginInfo {
+  pub name: String,
+  // pub absolute_chat_model_path: String,
+  pub exec_path: String,
+}
+
+pub(crate) async fn start_plugin_process(
+  plugin_info: PluginInfo,
+  id: PluginId,
+  state: WeakSidecarState,
+) -> Result<(), anyhow::Error> {
+  let (tx, rx) = tokio::sync::oneshot::channel();
+  let spawn_result = thread::Builder::new()
+    .name(format!("<{}> core host thread", &plugin_info.name))
+    .spawn(move || {
+      info!("Load {} plugin", &plugin_info.name);
+      let child = std::process::Command::new(&plugin_info.exec_path)
+        .stdin(Stdio::piped())
+        .stdout(Stdio::piped())
+        .spawn();
+
+      match child {
+        Ok(mut child) => {
+          let child_stdin = child.stdin.take().unwrap();
+          let child_stdout = child.stdout.take().unwrap();
+          let mut looper = RpcLoop::new(child_stdin);
+          let peer: RpcPeer = Box::new(looper.get_raw_peer());
+          let name = plugin_info.name.clone();
+          if let Err(err) = peer.send_rpc_request("ping", &Value::Array(Vec::new())) {
+            error!("plugin {} failed to respond to ping: {:?}", name, err);
+          }
+          let plugin = Plugin {
+            peer,
+            process: child,
+            name,
+            id,
+          };
+
+          state.plugin_connect(Ok(plugin));
+          let _ = tx.send(());
+          let mut state = state;
+          let err = looper.mainloop(|| BufReader::new(child_stdout), &mut state);
+          state.plugin_exit(id, err);
+        },
+        Err(err) => {
+          let _ = tx.send(());
+          state.plugin_connect(Err(err))
+        },
+      }
+    });
+
+  if let Err(err) = spawn_result {
+    error!("[RPC] thread spawn failed for {:?}, {:?}", id, err);
+    return Err(err.into());
+  }
+  rx.await?;
+  Ok(())
+}

frontend/rust-lib/flowy-sidecar/src/rpc_loop.rs

@@ -0,0 +1,302 @@
+use crate::error::{Error, ReadError, RemoteError};
+use crate::parser::{Call, MessageReader, RequestId};
+use crate::plugin::RpcCtx;
+use crate::rpc_peer::{RawPeer, Response, RpcState};
+use serde::de::DeserializeOwned;
+use serde_json::Value;
+
+use std::io::{BufRead, Write};
+use std::sync::atomic::Ordering;
+use std::sync::Arc;
+use std::thread;
+use std::time::Duration;
+use tracing::{error, trace};
+
+const MAX_IDLE_WAIT: Duration = Duration::from_millis(5);
+#[derive(Debug, Clone)]
+pub struct RpcObject(pub Value);
+
+impl RpcObject {
+  /// Returns the 'id' of the underlying object, if present.
+  pub fn get_id(&self) -> Option<RequestId> {
+    self.0.get("id").and_then(Value::as_u64)
+  }
+
+  /// Returns the 'method' field of the underlying object, if present.
+  pub fn get_method(&self) -> Option<&str> {
+    self.0.get("method").and_then(Value::as_str)
+  }
+
+  /// Returns `true` if this object looks like an RPC response;
+  /// that is, if it has an 'id' field and does _not_ have a 'method'
+  /// field.
+  pub fn is_response(&self) -> bool {
+    self.0.get("id").is_some() && self.0.get("method").is_none()
+  }
+
+  /// Attempts to convert the underlying `Value` into an RPC response
+  /// object, and returns the result.
+  ///
+  /// The caller is expected to verify that the object is a response
+  /// before calling this method.
+  ///
+  /// # Errors
+  ///
+  /// If the `Value` is not a well formed response object, this will
+  /// return a `String` containing an error message. The caller should
+  /// print this message and exit.
+  pub fn into_response(mut self) -> Result<Response, String> {
+    let _ = self
+      .get_id()
+      .ok_or("Response requires 'id' field.".to_string())?;
+
+    if self.0.get("result").is_some() == self.0.get("error").is_some() {
+      return Err("RPC response must contain exactly one of 'error' or 'result' fields.".into());
+    }
+    let result = self.0.as_object_mut().and_then(|obj| obj.remove("result"));
+
+    match result {
+      Some(r) => Ok(Ok(r)),
+      None => {
+        let error = self
+          .0
+          .as_object_mut()
+          .and_then(|obj| obj.remove("error"))
+          .unwrap();
+        Err(format!("Error handling response: {:?}", error))
+      },
+    }
+  }
+
+  /// Attempts to convert the underlying `Value` into either an RPC
+  /// notification or request.
+  ///
+  /// # Errors
+  ///
+  /// Returns a `serde_json::Error` if the `Value` cannot be converted
+  /// to one of the expected types.
+  pub fn into_rpc<R>(self) -> Result<Call<R>, serde_json::Error>
+  where
+    R: DeserializeOwned,
+  {
+    let id = self.get_id();
+    match id {
+      Some(id) => match serde_json::from_value::<R>(self.0) {
+        Ok(resp) => Ok(Call::Request(id, resp)),
+        Err(err) => Ok(Call::InvalidRequest(id, err.into())),
+      },
+      None => Ok(Call::Message(self.0)),
+    }
+  }
+}
+
+impl From<Value> for RpcObject {
+  fn from(v: Value) -> RpcObject {
+    RpcObject(v)
+  }
+}
+
+pub trait Handler {
+  type Request: DeserializeOwned;
+  fn handle_request(&mut self, ctx: &RpcCtx, rpc: Self::Request) -> Result<Value, RemoteError>;
+  #[allow(unused_variables)]
+  fn idle(&mut self, ctx: &RpcCtx, token: usize) {}
+}
+
+/// A helper type which shuts down the runloop if a panic occurs while
+/// handling an RPC.
+struct PanicGuard<'a, W: Write + 'static>(&'a RawPeer<W>);
+
+impl<'a, W: Write + 'static> Drop for PanicGuard<'a, W> {
+  fn drop(&mut self) {
+    if thread::panicking() {
+      error!("[RPC] panic guard hit, closing run loop");
+      self.0.disconnect();
+    }
+  }
+}
+
+/// A structure holding the state of a main loop for handling RPC's.
+pub struct RpcLoop<W: Write + 'static> {
+  reader: MessageReader,
+  peer: RawPeer<W>,
+}
+
+impl<W: Write + Send> RpcLoop<W> {
+  /// Creates a new `RpcLoop` with the given output stream (which is used for
+  /// sending requests and notifications, as well as responses).
+  pub fn new(writer: W) -> Self {
+    let rpc_peer = RawPeer(Arc::new(RpcState::new(writer)));
+    RpcLoop {
+      reader: MessageReader::default(),
+      peer: rpc_peer,
+    }
+  }
+
+  /// Gets a reference to the peer.
+  pub fn get_raw_peer(&self) -> RawPeer<W> {
+    self.peer.clone()
+  }
+
+  /// Starts the event loop, reading lines from the reader until EOF,
+  /// or an error occurs.
+  ///
+  /// Returns `Ok()` in the EOF case, otherwise returns the
+  /// underlying `ReadError`.
+  ///
+  /// # Note:
+  /// The reader is supplied via a closure, as basically a workaround
+  /// so that the reader doesn't have to be `Send`. Internally, the
+  /// main loop starts a separate thread for I/O, and at startup that
+  /// thread calls the given closure.
+  ///
+  /// Calls to the handler happen on the caller's thread.
+  ///
+  /// Calls to the handler are guaranteed to preserve the order as
+  /// they appear on on the channel. At the moment, there is no way
+  /// for there to be more than one incoming request to be outstanding.
+  pub fn mainloop<R, BufferReadFn, H>(
+    &mut self,
+    buffer_read_fn: BufferReadFn,
+    handler: &mut H,
+  ) -> Result<(), ReadError>
+  where
+    R: BufRead,
+    BufferReadFn: Send + FnOnce() -> R,
+    H: Handler,
+  {
+    let exit = crossbeam_utils::thread::scope(|scope| {
+      let peer = self.get_raw_peer();
+      peer.reset_needs_exit();
+
+      let ctx = RpcCtx {
+        peer: Box::new(peer.clone()),
+      };
+
+      // 1. Spawn a new thread for reading data from a stream.
+      // 2. Continuously read data from the stream.
+      // 3. Parse the data as JSON.
+      // 4. Handle the JSON data as either a response or another type of JSON object.
+      // 5. Manage errors and connection status.
+      scope.spawn(move |_| {
+        let mut stream = buffer_read_fn();
+        loop {
+          if self.peer.needs_exit() {
+            trace!("read loop exit");
+            break;
+          }
+
+          let json = match self.reader.next(&mut stream) {
+            Ok(json) => json,
+            Err(err) => {
+              // When the data can't be parsed into JSON. It means the data is not in the correct format.
+              // Probably the data comes from other stdout.
+              if self.peer.0.is_blocking() {
+                self.peer.disconnect();
+              }
+
+              error!("[RPC] failed to parse JSON: {:?}", err);
+              self.peer.put_rpc_object(Err(err));
+              break;
+            },
+          };
+          if json.is_response() {
+            let id = json.get_id().unwrap();
+            match json.into_response() {
+              Ok(resp) => {
+                let resp = resp.map_err(Error::from);
+                self.peer.handle_response(id, resp);
+              },
+              Err(msg) => {
+                error!("[RPC] failed to parse response: {}", msg);
+                self.peer.handle_response(id, Err(Error::InvalidResponse));
+              },
+            }
+          } else {
+            self.peer.put_rpc_object(Ok(json));
+          }
+        }
+      });
+
+      loop {
+        let _guard = PanicGuard(&peer);
+        let read_result = next_read(&peer, handler, &ctx);
+        let json = match read_result {
+          Ok(json) => json,
+          Err(err) => {
+            // finish idle work before disconnecting;
+            // this is mostly useful for integration tests.
+            if let Some(idle_token) = peer.try_get_idle() {
+              handler.idle(&ctx, idle_token);
+            }
+            peer.disconnect();
+            return err;
+          },
+        };
+
+        match json.into_rpc::<H::Request>() {
+          Ok(Call::Request(id, cmd)) => {
+            // Handle request sent from the client. For example from python executable.
+            let result = handler.handle_request(&ctx, cmd);
+            peer.respond(result, id);
+          },
+          Ok(Call::InvalidRequest(id, err)) => peer.respond(Err(err), id),
+          Err(err) => {
+            peer.disconnect();
+            return ReadError::UnknownRequest(err);
+          },
+          Ok(Call::Message(msg)) => {
+            trace!("[RPC] received message: {}", msg);
+          },
+        }
+      }
+    })
+    .unwrap();
+
+    if exit.is_disconnect() {
+      Ok(())
+    } else {
+      Err(exit)
+    }
+  }
+}
+
+/// Returns the next read result, checking for idle work when no
+/// result is available.
+fn next_read<W, H>(peer: &RawPeer<W>, handler: &mut H, ctx: &RpcCtx) -> Result<RpcObject, ReadError>
+where
+  W: Write + Send,
+  H: Handler,
+{
+  loop {
+    if let Some(result) = peer.try_get_rx() {
+      return result;
+    }
+    // handle timers before general idle work
+    let time_to_next_timer = match peer.check_timers() {
+      Some(Ok(token)) => {
+        do_idle(handler, ctx, token);
+        continue;
+      },
+      Some(Err(duration)) => Some(duration),
+      None => None,
+    };
+
+    if let Some(idle_token) = peer.try_get_idle() {
+      do_idle(handler, ctx, idle_token);
+      continue;
+    }
+
+    // we don't want to block indefinitely if there's no current idle work,
+    // because idle work could be scheduled from another thread.
+    let idle_timeout = time_to_next_timer
+      .unwrap_or(MAX_IDLE_WAIT)
+      .min(MAX_IDLE_WAIT);
+
+    if let Some(result) = peer.get_rx_timeout(idle_timeout) {
+      return result;
+    }
+  }
+}
+
+fn do_idle<H: Handler>(handler: &mut H, ctx: &RpcCtx, token: usize) {}

frontend/rust-lib/flowy-sidecar/src/rpc_peer.rs

@@ -0,0 +1,279 @@
+use crate::error::{Error, ReadError, RemoteError};
+use crate::plugin::{Callback, Peer, PluginId};
+use crate::rpc_loop::RpcObject;
+use parking_lot::{Condvar, Mutex};
+use serde::{de, ser, Deserialize, Deserializer, Serialize, Serializer};
+use serde_json::{json, Value};
+use std::collections::{BTreeMap, BinaryHeap, VecDeque};
+use std::io::Write;
+use std::sync::atomic::{AtomicBool, AtomicUsize, Ordering};
+use std::sync::{mpsc, Arc};
+use std::time::{Duration, Instant};
+use std::{cmp, io};
+use tracing::{error, trace, warn};
+
+pub struct PluginCommand<T> {
+  pub plugin_id: PluginId,
+  pub cmd: T,
+}
+
+impl<T: Serialize> Serialize for PluginCommand<T> {
+  fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+  where
+    S: Serializer,
+  {
+    let mut v = serde_json::to_value(&self.cmd).map_err(ser::Error::custom)?;
+    v["params"]["plugin_id"] = json!(self.plugin_id);
+    v.serialize(serializer)
+  }
+}
+
+impl<'de, T: Deserialize<'de>> Deserialize<'de> for PluginCommand<T> {
+  fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+  where
+    D: Deserializer<'de>,
+  {
+    #[derive(Deserialize)]
+    struct PluginIdHelper {
+      plugin_id: PluginId,
+    }
+    let v = Value::deserialize(deserializer)?;
+    let plugin_id = PluginIdHelper::deserialize(&v)
+      .map_err(de::Error::custom)?
+      .plugin_id;
+    let cmd = T::deserialize(v).map_err(de::Error::custom)?;
+    Ok(PluginCommand { plugin_id, cmd })
+  }
+}
+
+pub struct RpcState<W: Write> {
+  rx_queue: Mutex<VecDeque<Result<RpcObject, ReadError>>>,
+  rx_cvar: Condvar,
+  writer: Mutex<W>,
+  id: AtomicUsize,
+  pending: Mutex<BTreeMap<usize, ResponseHandler>>,
+  idle_queue: Mutex<VecDeque<usize>>,
+  timers: Mutex<BinaryHeap<Timer>>,
+  needs_exit: AtomicBool,
+  is_blocking: AtomicBool,
+}
+
+impl<W: Write> RpcState<W> {
+  pub fn new(writer: W) -> Self {
+    RpcState {
+      rx_queue: Mutex::new(VecDeque::new()),
+      rx_cvar: Condvar::new(),
+      writer: Mutex::new(writer),
+      id: AtomicUsize::new(0),
+      pending: Mutex::new(BTreeMap::new()),
+      idle_queue: Mutex::new(VecDeque::new()),
+      timers: Mutex::new(BinaryHeap::new()),
+      needs_exit: AtomicBool::new(false),
+      is_blocking: Default::default(),
+    }
+  }
+
+  pub fn is_blocking(&self) -> bool {
+    self.is_blocking.load(Ordering::Acquire)
+  }
+}
+
+pub struct RawPeer<W: Write + 'static>(pub(crate) Arc<RpcState<W>>);
+
+impl<W: Write + Send + 'static> Peer for RawPeer<W> {
+  fn box_clone(&self) -> Box<dyn Peer> {
+    Box::new((*self).clone())
+  }
+
+  fn send_rpc_request_async(&self, method: &str, params: &Value, f: Box<dyn Callback>) {
+    self.send_rpc(method, params, ResponseHandler::Callback(f));
+  }
+
+  fn send_rpc_request(&self, method: &str, params: &Value) -> Result<Value, Error> {
+    let (tx, rx) = mpsc::channel();
+    self.0.is_blocking.store(true, Ordering::Release);
+    self.send_rpc(method, params, ResponseHandler::Chan(tx));
+    rx.recv().unwrap_or(Err(Error::PeerDisconnect))
+  }
+
+  fn request_is_pending(&self) -> bool {
+    let queue = self.0.rx_queue.lock();
+    !queue.is_empty()
+  }
+
+  fn schedule_idle(&self, token: usize) {
+    self.0.idle_queue.lock().push_back(token);
+  }
+
+  fn schedule_timer(&self, after: Instant, token: usize) {
+    self.0.timers.lock().push(Timer {
+      fire_after: after,
+      token,
+    });
+  }
+}
+
+impl<W: Write> RawPeer<W> {
+  fn send(&self, v: &Value) -> Result<(), io::Error> {
+    let mut s = serde_json::to_string(v).unwrap();
+    s.push('\n');
+    self.0.writer.lock().write_all(s.as_bytes())
+  }
+
+  pub(crate) fn respond(&self, result: Response, id: u64) {
+    let mut response = json!({ "id": id });
+    match result {
+      Ok(result) => response["result"] = result,
+      Err(error) => response["error"] = json!(error),
+    };
+    if let Err(e) = self.send(&response) {
+      error!("[RPC] error {} sending response to RPC {:?}", e, id);
+    }
+  }
+
+  fn send_rpc(&self, method: &str, params: &Value, rh: ResponseHandler) {
+    trace!("[RPC] method:{} params: {:?}", method, params);
+    let id = self.0.id.fetch_add(1, Ordering::Relaxed);
+    {
+      let mut pending = self.0.pending.lock();
+      pending.insert(id, rh);
+    }
+    if let Err(e) = self.send(&json!({
+        "id": id,
+        "method": method,
+        "params": params,
+    })) {
+      let mut pending = self.0.pending.lock();
+      if let Some(rh) = pending.remove(&id) {
+        rh.invoke(Err(Error::Io(e)));
+      }
+    }
+  }
+
+  pub(crate) fn handle_response(&self, id: u64, resp: Result<Value, Error>) {
+    let id = id as usize;
+    let handler = {
+      let mut pending = self.0.pending.lock();
+      pending.remove(&id)
+    };
+    match handler {
+      Some(response_handler) => response_handler.invoke(resp),
+      None => warn!("[RPC] id {} not found in pending", id),
+    }
+  }
+
+  /// Get a message from the receive queue if available.
+  pub(crate) fn try_get_rx(&self) -> Option<Result<RpcObject, ReadError>> {
+    let mut queue = self.0.rx_queue.lock();
+    queue.pop_front()
+  }
+
+  /// Get a message from the receive queue, waiting for at most `Duration`
+  /// and returning `None` if no message is available.
+  pub(crate) fn get_rx_timeout(&self, dur: Duration) -> Option<Result<RpcObject, ReadError>> {
+    let mut queue = self.0.rx_queue.lock();
+    let result = self.0.rx_cvar.wait_for(&mut queue, dur);
+    if result.timed_out() {
+      return None;
+    }
+    queue.pop_front()
+  }
+
+  /// Adds a message to the receive queue. The message should only
+  /// be `None` if the read thread is exiting.
+  pub(crate) fn put_rpc_object(&self, json: Result<RpcObject, ReadError>) {
+    let mut queue = self.0.rx_queue.lock();
+    queue.push_back(json);
+    self.0.rx_cvar.notify_one();
+  }
+
+  pub(crate) fn try_get_idle(&self) -> Option<usize> {
+    self.0.idle_queue.lock().pop_front()
+  }
+
+  /// Checks status of the most imminent timer. If that timer has expired,
+  /// returns `Some(Ok(_))`, with the corresponding token.
+  /// If a timer exists but has not expired, returns `Some(Err(_))`,
+  /// with the error value being the `Duration` until the timer is ready.
+  /// Returns `None` if no timers are registered.
+  pub(crate) fn check_timers(&self) -> Option<Result<usize, Duration>> {
+    let mut timers = self.0.timers.lock();
+    match timers.peek() {
+      None => return None,
+      Some(t) => {
+        let now = Instant::now();
+        if t.fire_after > now {
+          return Some(Err(t.fire_after - now));
+        }
+      },
+    }
+    Some(Ok(timers.pop().unwrap().token))
+  }
+
+  /// send disconnect error to pending requests.
+  pub(crate) fn disconnect(&self) {
+    trace!("[RPC] disconnecting peer");
+    let mut pending = self.0.pending.lock();
+    let ids = pending.keys().cloned().collect::<Vec<_>>();
+    for id in &ids {
+      let callback = pending.remove(id).unwrap();
+      callback.invoke(Err(Error::PeerDisconnect));
+    }
+    self.0.needs_exit.store(true, Ordering::Relaxed);
+  }
+
+  /// Returns `true` if an error has occured in the main thread.
+  pub(crate) fn needs_exit(&self) -> bool {
+    self.0.needs_exit.load(Ordering::Relaxed)
+  }
+
+  pub(crate) fn reset_needs_exit(&self) {
+    self.0.needs_exit.store(false, Ordering::SeqCst);
+  }
+}
+
+impl Clone for Box<dyn Peer> {
+  fn clone(&self) -> Box<dyn Peer> {
+    self.box_clone()
+  }
+}
+
+impl<W: Write> Clone for RawPeer<W> {
+  fn clone(&self) -> Self {
+    RawPeer(self.0.clone())
+  }
+}
+
+pub type Response = Result<Value, RemoteError>;
+enum ResponseHandler {
+  Chan(mpsc::Sender<Result<Value, Error>>),
+  Callback(Box<dyn Callback>),
+}
+
+impl ResponseHandler {
+  fn invoke(self, result: Result<Value, Error>) {
+    match self {
+      ResponseHandler::Chan(tx) => {
+        let _ = tx.send(result);
+      },
+      ResponseHandler::Callback(f) => f.call(result),
+    }
+  }
+}
+#[derive(Debug, PartialEq, Eq)]
+struct Timer {
+  fire_after: Instant,
+  token: usize,
+}
+
+impl Ord for Timer {
+  fn cmp(&self, other: &Timer) -> cmp::Ordering {
+    other.fire_after.cmp(&self.fire_after)
+  }
+}
+
+impl PartialOrd for Timer {
+  fn partial_cmp(&self, other: &Timer) -> Option<cmp::Ordering> {
+    Some(self.cmp(other))
+  }
+}

frontend/rust-lib/flowy-sidecar/tests/chat_bin_test.rs

@@ -1,5 +1,6 @@
 use anyhow::Result;
-use flowy_sidecar::process::SidecarCommand;
+use flowy_sidecar::manager::SidecarManager;
+use flowy_sidecar::plugin::PluginInfo;
 use serde_json::json;
 use std::sync::Once;
 use tracing::info;
@@ -10,26 +11,46 @@ use tracing_subscriber::EnvFilter;
 #[tokio::test]
 async fn load_chat_model_test() {
   if let Ok(config) = LocalAIConfiguration::new() {
-    let (mut rx, mut child) = SidecarCommand::new_sidecar(&config.chat_bin_path)
+    let manager = SidecarManager::new();
-      .unwrap()
+    let info = PluginInfo {
-      .spawn()
+      name: "chat".to_string(),
+      exec_path: config.chat_bin_path.clone(),
+    };
+    let plugin_id = manager.create_plugin(info).await.unwrap();
+    manager
+      .init_plugin(
+        plugin_id,
+        json!({
+            "absolute_chat_model_path":config.chat_model_absolute_path(),
+        }),
+      )
       .unwrap();
 
-    tokio::spawn(async move {
-      while let Some(event) = rx.recv().await {
-        info!("event: {:?}", event);
-      }
-    });
 
-    let json = json!({
+    tokio::spawn(async move {
-        "plugin_id": "example_plugin_id",
+      tokio::time::sleep(tokio::time::Duration::from_secs(15)).await;
-        "method": "initialize",
+      manager.kill_plugin(plugin_id).await.unwrap();
-        "params": {
+    })
-            "absolute_chat_model_path":config.chat_model_absolute_path(),
+
-        }
+    // let (mut rx, mut child) = SidecarCommand::new_sidecar(&config.chat_bin_path)
-    });
+    //   .unwrap()
-    child.write_json(json).unwrap();
+    //   .spawn()
-    tokio::time::sleep(tokio::time::Duration::from_secs(15)).await;
+    //   .unwrap();
+    //
+    // tokio::spawn(async move {
+    //   while let Some(event) = rx.recv().await {
+    //     info!("event: {:?}", event);
+    //   }
+    // });
+    //
+    // let json = json!({
+    //     "plugin_id": "example_plugin_id",
+    //     "method": "initialize",
+    //     "params": {
+    //         "absolute_chat_model_path":config.chat_model_absolute_path(),
+    //     }
+    // });
+    // child.write_json(json).unwrap();
 
     // let chat_id = uuid::Uuid::new_v4().to_string();
     // let json =