federation-api: Add get_missing_events endpoint v1

ruma-federation-api/CHANGELOG.md

@@ -13,6 +13,7 @@ Improvements:
   backfill::get_backfill::v1,
   device::get_devices::v1,
   directory::get_public_rooms_filtered::v1,
+  event::get_missing_events::v1,
   keys::{
       claim_keys::v1,
       query_keys::v1,

ruma-federation-api/src/event.rs

@@ -0,0 +1,3 @@
+//! Endpoints to get general information about events
+
+pub mod get_missing_events;

ruma-federation-api/src/event/get_missing_events.rs

@@ -0,0 +1,3 @@
+//! Retrieves previous events that the sender is missing.
+
+pub mod v1;

ruma-federation-api/src/event/get_missing_events/v1.rs

@@ -0,0 +1,75 @@
+//! [POST /_matrix/federation/v1/get_missing_events/{roomId}](https://matrix.org/docs/spec/server_server/r0.1.4#post-matrix-federation-v1-get-missing-events-roomid)
+
+use js_int::{uint, UInt};
+use ruma_api::ruma_api;
+use ruma_events::pdu::Pdu;
+use ruma_identifiers::{EventId, RoomId};
+
+ruma_api! {
+    metadata: {
+        description: "Retrieves previous events that the sender is missing.",
+        method: POST,
+        name: "get_missing_events",
+        path: "/_matrix/federation/v1/get_missing_events/:room_id",
+        rate_limited: false,
+        requires_authentication: true,
+    }
+
+    #[non_exhaustive]
+    request: {
+        /// The room ID to search in.
+        #[ruma_api(path)]
+        room_id: &'a RoomId,
+
+        /// The maximum number of events to retrieve. Defaults to 10.
+        #[serde(default = "default_limit", skip_serializing_if = "is_default_limit")]
+        limit: UInt,
+
+        /// The minimum depth of events to retrieve. Defaults to 0.
+        #[serde(default, skip_serializing_if = "ruma_serde::is_default")]
+        min_depth: UInt,
+
+        /// The latest event IDs that the sender already has. These are skipped when retrieving the previous events of `latest_events`.
+        earliest_events: &'a [EventId],
+
+        /// The event IDs to retrieve the previous events for.
+        latest_events: &'a [EventId],
+    }
+
+    response: {
+        /// The missing events.
+        events: Vec<Pdu>
+    }
+}
+
+impl<'a> Request<'a> {
+    /// Creates a new `Request` for events in the given room with the given constraints.
+    pub fn new(
+        room_id: &'a RoomId,
+        earliest_events: &'a [EventId],
+        latest_events: &'a [EventId],
+    ) -> Self {
+        Self {
+            room_id,
+            limit: default_limit(),
+            min_depth: UInt::default(),
+            earliest_events,
+            latest_events,
+        }
+    }
+}
+
+impl Response {
+    /// Creates a new `Response` with the given events.
+    pub fn new(events: Vec<Pdu>) -> Self {
+        Self { events }
+    }
+}
+
+fn default_limit() -> UInt {
+    uint!(10)
+}
+
+fn is_default_limit(val: &UInt) -> bool {
+    *val == default_limit()
+}

ruma-federation-api/src/lib.rs

@@ -9,6 +9,7 @@ pub mod backfill;
 pub mod device;
 pub mod directory;
 pub mod discovery;
+pub mod event;
 pub mod keys;
 pub mod membership;
 pub mod openid;