Initial (g)RPC implementation

asynchronix/src/rpc/endpoint_registry.rs

@@ -0,0 +1,307 @@
+use std::collections::hash_map::Entry;
+use std::collections::HashMap;
+use std::fmt;
+use std::time::Duration;
+
+use rmp_serde::decode::Error as RmpDecodeError;
+use rmp_serde::encode::Error as RmpEncodeError;
+use serde::de::DeserializeOwned;
+use serde::Serialize;
+
+use crate::ports::{EventSinkStream, EventSource, QuerySource, ReplyReceiver};
+use crate::time::{Action, ActionKey};
+
+/// A registry that holds all sources and sinks meant to be accessed through
+/// remote procedure calls.
+#[derive(Default)]
+pub struct EndpointRegistry {
+    event_sources: HashMap<String, Box<dyn EventSourceAny>>,
+    query_sources: HashMap<String, Box<dyn QuerySourceAny>>,
+    sinks: HashMap<String, Box<dyn EventSinkStreamAny>>,
+}
+
+impl EndpointRegistry {
+    /// Creates an empty `EndpointRegistry`.
+    pub fn new() -> Self {
+        Self::default()
+    }
+
+    /// Adds an event source to the registry.
+    ///
+    /// If the specified name is already in use for another event source, the source
+    /// provided as argument is returned in the error.
+    pub fn add_event_source<T>(
+        &mut self,
+        source: EventSource<T>,
+        name: impl Into<String>,
+    ) -> Result<(), EventSource<T>>
+    where
+        T: DeserializeOwned + Clone + Send + 'static,
+    {
+        match self.event_sources.entry(name.into()) {
+            Entry::Vacant(s) => {
+                s.insert(Box::new(source));
+
+                Ok(())
+            }
+            Entry::Occupied(_) => Err(source),
+        }
+    }
+
+    /// Returns a mutable reference to the specified event source if it is in
+    /// the registry.
+    pub(crate) fn get_event_source_mut(&mut self, name: &str) -> Option<&mut dyn EventSourceAny> {
+        self.event_sources.get_mut(name).map(|s| s.as_mut())
+    }
+
+    /// Adds an query source to the registry.
+    ///
+    /// If the specified name is already in use for another query source, the source
+    /// provided as argument is returned in the error.
+    pub fn add_query_source<T, R>(
+        &mut self,
+        source: QuerySource<T, R>,
+        name: impl Into<String>,
+    ) -> Result<(), QuerySource<T, R>>
+    where
+        T: DeserializeOwned + Clone + Send + 'static,
+        R: Serialize + Send + 'static,
+    {
+        match self.query_sources.entry(name.into()) {
+            Entry::Vacant(s) => {
+                s.insert(Box::new(source));
+
+                Ok(())
+            }
+            Entry::Occupied(_) => Err(source),
+        }
+    }
+
+    /// Returns a mutable reference to the specified query source if it is in
+    /// the registry.
+    pub(crate) fn get_query_source_mut(&mut self, name: &str) -> Option<&mut dyn QuerySourceAny> {
+        self.query_sources.get_mut(name).map(|s| s.as_mut())
+    }
+
+    /// Adds a sink to the registry.
+    ///
+    /// If the specified name is already in use for another sink, the sink
+    /// provided as argument is returned in the error.
+    pub fn add_sink<S>(&mut self, sink: S, name: impl Into<String>) -> Result<(), S>
+    where
+        S: EventSinkStream + Send + 'static,
+        S::Item: Serialize,
+    {
+        match self.sinks.entry(name.into()) {
+            Entry::Vacant(s) => {
+                s.insert(Box::new(sink));
+
+                Ok(())
+            }
+            Entry::Occupied(_) => Err(sink),
+        }
+    }
+
+    /// Returns a mutable reference to the specified sink if it is in the
+    /// registry.
+    pub(crate) fn get_sink_mut(&mut self, name: &str) -> Option<&mut dyn EventSinkStreamAny> {
+        self.sinks.get_mut(name).map(|s| s.as_mut())
+    }
+}
+
+impl fmt::Debug for EndpointRegistry {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(
+            f,
+            "EndpointRegistry ({} sources, {} sinks)",
+            self.event_sources.len(),
+            self.sinks.len()
+        )
+    }
+}
+
+/// A type-erased `EventSource` that operates on MessagePack-encoded serialized
+/// events.
+pub(crate) trait EventSourceAny: Send + 'static {
+    /// Returns an action which, when processed, broadcasts an event to all
+    /// connected input ports.
+    ///
+    /// The argument is expected to conform to the serde MessagePack encoding.
+    fn event(&mut self, msgpack_arg: &[u8]) -> Result<Action, RmpDecodeError>;
+
+    /// Returns a cancellable action and a cancellation key; when processed, the
+    /// action broadcasts an event to all connected input ports.
+    ///
+    /// The argument is expected to conform to the serde MessagePack encoding.
+    fn keyed_event(&mut self, msgpack_arg: &[u8]) -> Result<(Action, ActionKey), RmpDecodeError>;
+
+    /// Returns a periodically recurring action which, when processed,
+    /// broadcasts an event to all connected input ports.
+    ///
+    /// The argument is expected to conform to the serde MessagePack encoding.
+    fn periodic_event(
+        &mut self,
+        period: Duration,
+        msgpack_arg: &[u8],
+    ) -> Result<Action, RmpDecodeError>;
+
+    /// Returns a cancellable, periodically recurring action and a cancellation
+    /// key; when processed, the action broadcasts an event to all connected
+    /// input ports.
+    ///
+    /// The argument is expected to conform to the serde MessagePack encoding.
+    fn keyed_periodic_event(
+        &mut self,
+        period: Duration,
+        msgpack_arg: &[u8],
+    ) -> Result<(Action, ActionKey), RmpDecodeError>;
+
+    /// Human-readable name of the event type, as returned by
+    /// `any::type_name()`.
+    fn event_type_name(&self) -> &'static str;
+}
+
+impl<T> EventSourceAny for EventSource<T>
+where
+    T: DeserializeOwned + Clone + Send + 'static,
+{
+    fn event(&mut self, msgpack_arg: &[u8]) -> Result<Action, RmpDecodeError> {
+        rmp_serde::from_read(msgpack_arg).map(|arg| self.event(arg))
+    }
+    fn keyed_event(&mut self, msgpack_arg: &[u8]) -> Result<(Action, ActionKey), RmpDecodeError> {
+        rmp_serde::from_read(msgpack_arg).map(|arg| self.keyed_event(arg))
+    }
+    fn periodic_event(
+        &mut self,
+        period: Duration,
+        msgpack_arg: &[u8],
+    ) -> Result<Action, RmpDecodeError> {
+        rmp_serde::from_read(msgpack_arg).map(|arg| self.periodic_event(period, arg))
+    }
+    fn keyed_periodic_event(
+        &mut self,
+        period: Duration,
+        msgpack_arg: &[u8],
+    ) -> Result<(Action, ActionKey), RmpDecodeError> {
+        rmp_serde::from_read(msgpack_arg).map(|arg| self.keyed_periodic_event(period, arg))
+    }
+    fn event_type_name(&self) -> &'static str {
+        std::any::type_name::<T>()
+    }
+}
+
+/// A type-erased `QuerySource` that operates on MessagePack-encoded serialized
+/// queries and returns MessagePack-encoded replies.
+pub(crate) trait QuerySourceAny: Send + 'static {
+    /// Returns an action which, when processed, broadcasts a query to all
+    /// connected replier ports.
+    ///
+    ///
+    /// The argument is expected to conform to the serde MessagePack encoding.
+    fn query(
+        &mut self,
+        msgpack_arg: &[u8],
+    ) -> Result<(Action, Box<dyn ReplyReceiverAny>), RmpDecodeError>;
+
+    /// Human-readable name of the request type, as returned by
+    /// `any::type_name()`.
+    fn request_type_name(&self) -> &'static str;
+
+    /// Human-readable name of the reply type, as returned by
+    /// `any::type_name()`.
+    fn reply_type_name(&self) -> &'static str;
+}
+
+impl<T, R> QuerySourceAny for QuerySource<T, R>
+where
+    T: DeserializeOwned + Clone + Send + 'static,
+    R: Serialize + Send + 'static,
+{
+    fn query(
+        &mut self,
+        msgpack_arg: &[u8],
+    ) -> Result<(Action, Box<dyn ReplyReceiverAny>), RmpDecodeError> {
+        rmp_serde::from_read(msgpack_arg).map(|arg| {
+            let (action, reply_recv) = self.query(arg);
+            let reply_recv: Box<dyn ReplyReceiverAny> = Box::new(reply_recv);
+
+            (action, reply_recv)
+        })
+    }
+
+    fn request_type_name(&self) -> &'static str {
+        std::any::type_name::<T>()
+    }
+
+    fn reply_type_name(&self) -> &'static str {
+        std::any::type_name::<R>()
+    }
+}
+
+/// A type-erased `EventSinkStream`.
+pub(crate) trait EventSinkStreamAny: Send + 'static {
+    /// Human-readable name of the event type, as returned by
+    /// `any::type_name()`.
+    fn event_type_name(&self) -> &'static str;
+
+    /// Starts or resumes the collection of new events.
+    fn open(&mut self);
+
+    /// Pauses the collection of new events.
+    fn close(&mut self);
+
+    /// Encode and collect all events in a vector.
+    fn collect(&mut self) -> Result<Vec<Vec<u8>>, RmpEncodeError>;
+}
+
+impl<E> EventSinkStreamAny for E
+where
+    E: EventSinkStream + Send + 'static,
+    E::Item: Serialize,
+{
+    fn event_type_name(&self) -> &'static str {
+        std::any::type_name::<E::Item>()
+    }
+
+    fn open(&mut self) {
+        self.open();
+    }
+
+    fn close(&mut self) {
+        self.close();
+    }
+
+    fn collect(&mut self) -> Result<Vec<Vec<u8>>, RmpEncodeError> {
+        EventSinkStream::try_fold(self, Vec::new(), |mut encoded_events, event| {
+            rmp_serde::to_vec_named(&event).map(|encoded_event| {
+                encoded_events.push(encoded_event);
+
+                encoded_events
+            })
+        })
+    }
+}
+
+/// A type-erased `ReplyReceiver` that returns MessagePack-encoded replies..
+pub(crate) trait ReplyReceiverAny {
+    /// Take the replies, if any, encode them and collect them in a vector.
+    fn take_collect(&mut self) -> Option<Result<Vec<Vec<u8>>, RmpEncodeError>>;
+}
+
+impl<R: Serialize + 'static> ReplyReceiverAny for ReplyReceiver<R> {
+    fn take_collect(&mut self) -> Option<Result<Vec<Vec<u8>>, RmpEncodeError>> {
+        let replies = self.take()?;
+
+        let encoded_replies = (move || {
+            let mut encoded_replies = Vec::new();
+            for reply in replies {
+                let encoded_reply = rmp_serde::to_vec_named(&reply)?;
+                encoded_replies.push(encoded_reply);
+            }
+
+            Ok(encoded_replies)
+        })();
+
+        Some(encoded_replies)
+    }
+}