refactor(sdk,base): Move LatestEventValue into matrix_sdk_base.

This patch moves `LatestEventValue` into the
`matrix_sdk_base::latest_event` module. If we want to store this value
in `RoomInfo`, it must be in this crate.

Because it's not allowed to `impl T` where `T` lives in a different
crate, this patch changes the `impl LatestEventValue` to `struct
LatestEventValueBuilder` + `impl LatestEventValueBuilder`. Luckily, all
methods on `LatestEventValue` are only constructors, so the change is
super straightforward.

crates/matrix-sdk-base/src/latest_event.rs

@@ -2,7 +2,7 @@
 //! use as a [crate::Room::latest_event].
 
 use matrix_sdk_common::deserialized_responses::TimelineEvent;
-use ruma::{MxcUri, OwnedEventId};
+use ruma::{MilliSecondsSinceUnixEpoch, MxcUri, OwnedEventId};
 #[cfg(feature = "e2e-encryption")]
 use ruma::{
     UserId,
@@ -21,7 +21,39 @@ use ruma::{
 };
 use serde::{Deserialize, Serialize};
 
-use crate::MinimalRoomMemberEvent;
+use crate::{MinimalRoomMemberEvent, store::SerializableEventContent};
+
+/// A latest event value!
+#[derive(Debug, Default, Clone, Serialize, Deserialize)]
+pub enum LatestEventValue {
+    /// No value has been computed yet, or no candidate value was found.
+    #[default]
+    None,
+
+    /// The latest event represents a remote event.
+    Remote(RemoteLatestEventValue),
+
+    /// The latest event represents a local event that is sending.
+    LocalIsSending(LocalLatestEventValue),
+
+    /// The latest event represents a local event that cannot be sent, either
+    /// because a previous local event, or this local event cannot be sent.
+    LocalCannotBeSent(LocalLatestEventValue),
+}
+
+/// Represents the value for [`LatestEventValue::Remote`].
+pub type RemoteLatestEventValue = TimelineEvent;
+
+/// Represents the value for [`LatestEventValue::LocalIsSending`] and
+/// [`LatestEventValue::LocalCannotBeSent`].
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct LocalLatestEventValue {
+    /// The time where the event has been created (by this module).
+    pub timestamp: MilliSecondsSinceUnixEpoch,
+
+    /// The content of the local event.
+    pub content: SerializableEventContent,
+}
 
 /// Represents a decision about whether an event could be stored as the latest
 /// event in a room. Variants starting with Yes indicate that this message could

crates/matrix-sdk/src/latest_events/latest_event.rs

@@ -15,6 +15,9 @@
 use std::{iter::once, ops::Not};
 
 use eyeball::{AsyncLock, SharedObservable, Subscriber};
+pub use matrix_sdk_base::latest_event::{
+    LatestEventValue, LocalLatestEventValue, RemoteLatestEventValue,
+};
 use matrix_sdk_base::{deserialized_responses::TimelineEvent, store::SerializableEventContent};
 use ruma::{
     events::{
@@ -24,7 +27,6 @@ use ruma::{
     },
     EventId, MilliSecondsSinceUnixEpoch, OwnedEventId, OwnedTransactionId, TransactionId, UserId,
 };
-use serde::{Deserialize, Serialize};
 use tracing::error;
 
 use crate::{event_cache::RoomEventCache, room::WeakRoom, send_queue::RoomSendQueueUpdate};
@@ -60,7 +62,7 @@ impl LatestEvent {
             _thread_id: thread_id.map(ToOwned::to_owned),
             buffer_of_values_for_local_events: LatestEventValuesForLocalEvents::new(),
             current_value: SharedObservable::new_async(
-                LatestEventValue::new_remote(room_event_cache, weak_room).await,
+                LatestEventValueBuilder::new_remote(room_event_cache, weak_room).await,
             ),
         }
     }
@@ -92,7 +94,8 @@ impl LatestEvent {
         }
 
         let new_value =
-            LatestEventValue::new_remote_with_power_levels(room_event_cache, power_levels).await;
+            LatestEventValueBuilder::new_remote_with_power_levels(room_event_cache, power_levels)
+                .await;
 
         self.update(new_value).await;
     }
@@ -105,7 +108,7 @@ impl LatestEvent {
         room_event_cache: &RoomEventCache,
         power_levels: &Option<(&UserId, RoomPowerLevels)>,
     ) {
-        let new_value = LatestEventValue::new_local(
+        let new_value = LatestEventValueBuilder::new_local(
             send_queue_update,
             &mut self.buffer_of_values_for_local_events,
             room_event_cache,
@@ -333,41 +336,15 @@ mod tests_latest_event {
     }
 }
 
-/// A latest event value!
-#[derive(Debug, Default, Clone, Serialize, Deserialize)]
-pub enum LatestEventValue {
-    /// No value has been computed yet, or no candidate value was found.
-    #[default]
-    None,
+/// A builder of [`LatestEventValue`]s.
+struct LatestEventValueBuilder;
 
-    /// The latest event represents a remote event.
-    Remote(RemoteLatestEventValue),
-
-    /// The latest event represents a local event that is sending.
-    LocalIsSending(LocalLatestEventValue),
-
-    /// The latest event represents a local event that cannot be sent, either
-    /// because a previous local event, or this local event cannot be sent.
-    LocalCannotBeSent(LocalLatestEventValue),
-}
-
-/// Represents the value for [`LatestEventValue::Remote`].
-pub type RemoteLatestEventValue = TimelineEvent;
-
-/// Represents the value for [`LatestEventValue::LocalIsSending`] and
-/// [`LatestEventValue::LocalCannotBeSent`].
-#[derive(Debug, Clone, Serialize, Deserialize)]
-pub struct LocalLatestEventValue {
-    /// The time where the event has been created (by this module).
-    pub timestamp: MilliSecondsSinceUnixEpoch,
-
-    /// The content of the local event.
-    pub content: SerializableEventContent,
-}
-
-impl LatestEventValue {
+impl LatestEventValueBuilder {
     /// Create a new [`LatestEventValue::Remote`].
-    async fn new_remote(room_event_cache: &RoomEventCache, weak_room: &WeakRoom) -> Self {
+    async fn new_remote(
+        room_event_cache: &RoomEventCache,
+        weak_room: &WeakRoom,
+    ) -> LatestEventValue {
         // Get the power levels of the user for the current room if the `WeakRoom` is
         // still valid.
         let room = weak_room.get();
@@ -389,13 +366,13 @@ impl LatestEventValue {
     async fn new_remote_with_power_levels(
         room_event_cache: &RoomEventCache,
         power_levels: &Option<(&UserId, RoomPowerLevels)>,
-    ) -> Self {
+    ) -> LatestEventValue {
         room_event_cache
             .rfind_map_event_in_memory_by(|event| {
                 filter_timeline_event(event, power_levels).then(|| event.clone())
             })
             .await
-            .map(Self::Remote)
+            .map(LatestEventValue::Remote)
             .unwrap_or_default()
     }
 
@@ -406,7 +383,7 @@ impl LatestEventValue {
         buffer_of_values_for_local_events: &mut LatestEventValuesForLocalEvents,
         room_event_cache: &RoomEventCache,
         power_levels: &Option<(&UserId, RoomPowerLevels)>,
-    ) -> Self {
+    ) -> LatestEventValue {
         use crate::send_queue::{LocalEcho, LocalEchoContent};
 
         match send_queue_update {
@@ -421,29 +398,30 @@ impl LatestEventValue {
                     match serialized_event_content.deserialize() {
                         Ok(content) => {
                             if filter_any_message_like_event_content(content) {
-                                let value = Self::LocalIsSending(LocalLatestEventValue {
-                                    timestamp: MilliSecondsSinceUnixEpoch::now(),
-                                    content: serialized_event_content.clone(),
-                                });
+                                let value =
+                                    LatestEventValue::LocalIsSending(LocalLatestEventValue {
+                                        timestamp: MilliSecondsSinceUnixEpoch::now(),
+                                        content: serialized_event_content.clone(),
+                                    });
 
                                 buffer_of_values_for_local_events
                                     .push(transaction_id.to_owned(), value.clone());
 
                                 value
                             } else {
-                                Self::None
+                                LatestEventValue::None
                             }
                         }
 
                         Err(error) => {
                             error!(?error, "Failed to deserialize an event from `RoomSendQueueUpdate::NewLocalEvent`");
 
-                            Self::None
+                            LatestEventValue::None
                         }
                     }
                 }
 
-                LocalEchoContent::React { .. } => Self::None,
+                LocalEchoContent::React { .. } => LatestEventValue::None,
             },
 
             // A local event has been cancelled before being sent.
@@ -525,7 +503,7 @@ impl LatestEventValue {
                         Err(error) => {
                             error!(?error, "Failed to deserialize an event from `RoomSendQueueUpdate::ReplacedLocalEvent`");
 
-                            return Self::None;
+                            return LatestEventValue::None;
                         }
                     }
                 }
@@ -571,7 +549,7 @@ impl LatestEventValue {
             // A media upload has made progress.
             //
             // Nothing to do here.
-            RoomSendQueueUpdate::MediaUpload { .. } => Self::None,
+            RoomSendQueueUpdate::MediaUpload { .. } => LatestEventValue::None,
         }
     }
 
@@ -585,7 +563,7 @@ impl LatestEventValue {
         buffer_of_values_for_local_events: &mut LatestEventValuesForLocalEvents,
         room_event_cache: &RoomEventCache,
         power_levels: &Option<(&UserId, RoomPowerLevels)>,
-    ) -> Self {
+    ) -> LatestEventValue {
         if let Some(value) = buffer_of_values_for_local_events.last() {
             value.clone()
         } else {
@@ -1385,7 +1363,7 @@ mod tests_latest_event_values_for_local_events {
 }
 
 #[cfg(all(not(target_family = "wasm"), test))]
-mod tests_latest_event_value {
+mod tests_latest_event_value_builder {
     use std::sync::Arc;
 
     use assert_matches::assert_matches;
@@ -1407,8 +1385,8 @@ mod tests_latest_event_value {
     };
 
     use super::{
-        LatestEventValue, LatestEventValuesForLocalEvents, RemoteLatestEventValue, RoomEventCache,
-        RoomSendQueueUpdate,
+        LatestEventValue, LatestEventValueBuilder, LatestEventValuesForLocalEvents,
+        RemoteLatestEventValue, RoomEventCache, RoomSendQueueUpdate,
     };
     use crate::{
         client::WeakClient,
@@ -1515,7 +1493,7 @@ mod tests_latest_event_value {
             // We get `event_id_1` because `event_id_2` isn't a candidate,
             // and `event_id_0` hasn't been read yet (because events are read
             // backwards).
-            LatestEventValue::new_remote(&room_event_cache, &weak_room).await => with body = "world"
+            LatestEventValueBuilder::new_remote(&room_event_cache, &weak_room).await => with body = "world"
         );
     }
 
@@ -1572,7 +1550,7 @@ mod tests_latest_event_value {
 
             // The `LatestEventValue` matches the new local event.
             assert_local_value_matches_room_message_with_body!(
-                LatestEventValue::new_local(&update, &mut buffer, &room_event_cache, &None).await,
+                LatestEventValueBuilder::new_local(&update, &mut buffer, &room_event_cache, &None).await,
                 LatestEventValue::LocalIsSending => with body = "A"
             );
         }
@@ -1586,7 +1564,7 @@ mod tests_latest_event_value {
 
             // The `LatestEventValue` matches the new local event.
             assert_local_value_matches_room_message_with_body!(
-                LatestEventValue::new_local(&update, &mut buffer, &room_event_cache, &None).await,
+                LatestEventValueBuilder::new_local(&update, &mut buffer, &room_event_cache, &None).await,
                 LatestEventValue::LocalIsSending => with body = "B"
             );
         }
@@ -1617,7 +1595,7 @@ mod tests_latest_event_value {
 
                 // The `LatestEventValue` matches the new local event.
                 assert_local_value_matches_room_message_with_body!(
-                    LatestEventValue::new_local(&update, &mut buffer, &room_event_cache, &None).await,
+                    LatestEventValueBuilder::new_local(&update, &mut buffer, &room_event_cache, &None).await,
                     LatestEventValue::LocalIsSending => with body = body
                 );
             }
@@ -1635,7 +1613,7 @@ mod tests_latest_event_value {
             // The `LatestEventValue` hasn't changed, it still matches the latest local
             // event.
             assert_local_value_matches_room_message_with_body!(
-                LatestEventValue::new_local(&update, &mut buffer, &room_event_cache, &None).await,
+                LatestEventValueBuilder::new_local(&update, &mut buffer, &room_event_cache, &None).await,
                 LatestEventValue::LocalIsSending => with body = "C"
             );
 
@@ -1652,7 +1630,7 @@ mod tests_latest_event_value {
             // The `LatestEventValue` has changed, it matches the previous (so the first)
             // local event.
             assert_local_value_matches_room_message_with_body!(
-                LatestEventValue::new_local(&update, &mut buffer, &room_event_cache, &None).await,
+                LatestEventValueBuilder::new_local(&update, &mut buffer, &room_event_cache, &None).await,
                 LatestEventValue::LocalIsSending => with body = "A"
             );
 
@@ -1669,7 +1647,8 @@ mod tests_latest_event_value {
 
             // The `LatestEventValue` has changed, it's empty!
             assert_matches!(
-                LatestEventValue::new_local(&update, &mut buffer, &room_event_cache, &None).await,
+                LatestEventValueBuilder::new_local(&update, &mut buffer, &room_event_cache, &None)
+                    .await,
                 LatestEventValue::None
             );
 
@@ -1697,7 +1676,7 @@ mod tests_latest_event_value {
 
                 // The `LatestEventValue` matches the new local event.
                 assert_local_value_matches_room_message_with_body!(
-                    LatestEventValue::new_local(&update, &mut buffer, &room_event_cache, &None).await,
+                    LatestEventValueBuilder::new_local(&update, &mut buffer, &room_event_cache, &None).await,
                     LatestEventValue::LocalIsSending => with body = body
                 );
             }
@@ -1716,7 +1695,7 @@ mod tests_latest_event_value {
             // The `LatestEventValue` hasn't changed, it still matches the latest local
             // event.
             assert_local_value_matches_room_message_with_body!(
-                LatestEventValue::new_local(&update, &mut buffer, &room_event_cache, &None).await,
+                LatestEventValueBuilder::new_local(&update, &mut buffer, &room_event_cache, &None).await,
                 LatestEventValue::LocalIsSending => with body = "B"
             );
 
@@ -1733,7 +1712,7 @@ mod tests_latest_event_value {
 
             // The `LatestEventValue` hasn't changed.
             assert_local_value_matches_room_message_with_body!(
-                LatestEventValue::new_local(&update, &mut buffer, &room_event_cache, &None).await,
+                LatestEventValueBuilder::new_local(&update, &mut buffer, &room_event_cache, &None).await,
                 LatestEventValue::LocalIsSending => with body = "B"
             );
 
@@ -1761,7 +1740,7 @@ mod tests_latest_event_value {
 
                 // The `LatestEventValue` matches the new local event.
                 assert_local_value_matches_room_message_with_body!(
-                    LatestEventValue::new_local(&update, &mut buffer, &room_event_cache, &None).await,
+                    LatestEventValueBuilder::new_local(&update, &mut buffer, &room_event_cache, &None).await,
                     LatestEventValue::LocalIsSending => with body = body
                 );
             }
@@ -1787,7 +1766,7 @@ mod tests_latest_event_value {
             // The `LatestEventValue` hasn't changed, it still matches the latest local
             // event.
             assert_local_value_matches_room_message_with_body!(
-                LatestEventValue::new_local(&update, &mut buffer, &room_event_cache, &None).await,
+                LatestEventValueBuilder::new_local(&update, &mut buffer, &room_event_cache, &None).await,
                 LatestEventValue::LocalIsSending => with body = "B"
             );
 
@@ -1812,7 +1791,7 @@ mod tests_latest_event_value {
             // The `LatestEventValue` has changed, it still matches the latest local
             // event but with its new content.
             assert_local_value_matches_room_message_with_body!(
-                LatestEventValue::new_local(&update, &mut buffer, &room_event_cache, &None).await,
+                LatestEventValueBuilder::new_local(&update, &mut buffer, &room_event_cache, &None).await,
                 LatestEventValue::LocalIsSending => with body = "B."
             );
 
@@ -1838,7 +1817,7 @@ mod tests_latest_event_value {
 
             // The `LatestEventValue` matches the new local event.
             assert_local_value_matches_room_message_with_body!(
-                LatestEventValue::new_local(&update, &mut buffer, &room_event_cache, &None).await,
+                LatestEventValueBuilder::new_local(&update, &mut buffer, &room_event_cache, &None).await,
                 LatestEventValue::LocalIsSending => with body = "A"
             );
 
@@ -1865,7 +1844,8 @@ mod tests_latest_event_value {
 
             // The `LatestEventValue` has changed!
             assert_matches!(
-                LatestEventValue::new_local(&update, &mut buffer, &room_event_cache, &None).await,
+                LatestEventValueBuilder::new_local(&update, &mut buffer, &room_event_cache, &None)
+                    .await,
                 LatestEventValue::None
             );
 
@@ -1893,7 +1873,7 @@ mod tests_latest_event_value {
 
                 // The `LatestEventValue` matches the new local event.
                 assert_local_value_matches_room_message_with_body!(
-                    LatestEventValue::new_local(&update, &mut buffer, &room_event_cache, &None).await,
+                    LatestEventValueBuilder::new_local(&update, &mut buffer, &room_event_cache, &None).await,
                     LatestEventValue::LocalIsSending => with body = body
                 );
             }
@@ -1913,7 +1893,7 @@ mod tests_latest_event_value {
             // The `LatestEventValue` has changed, it still matches the latest local
             // event but it's marked as “cannot be sent”.
             assert_local_value_matches_room_message_with_body!(
-                LatestEventValue::new_local(&update, &mut buffer, &room_event_cache, &None).await,
+                LatestEventValueBuilder::new_local(&update, &mut buffer, &room_event_cache, &None).await,
                 LatestEventValue::LocalCannotBeSent => with body = "B"
             );
 
@@ -1934,7 +1914,7 @@ mod tests_latest_event_value {
             // The `LatestEventValue` has changed, it still matches the latest local
             // event but it's “is sending”.
             assert_local_value_matches_room_message_with_body!(
-                LatestEventValue::new_local(&update, &mut buffer, &room_event_cache, &None).await,
+                LatestEventValueBuilder::new_local(&update, &mut buffer, &room_event_cache, &None).await,
                 LatestEventValue::LocalIsSending => with body = "B"
             );
 
@@ -1963,7 +1943,7 @@ mod tests_latest_event_value {
 
                 // The `LatestEventValue` matches the new local event.
                 assert_local_value_matches_room_message_with_body!(
-                    LatestEventValue::new_local(&update, &mut buffer, &room_event_cache, &None).await,
+                    LatestEventValueBuilder::new_local(&update, &mut buffer, &room_event_cache, &None).await,
                     LatestEventValue::LocalIsSending => with body = body
                 );
             }
@@ -1983,7 +1963,7 @@ mod tests_latest_event_value {
             // The `LatestEventValue` has changed, it still matches the latest local
             // event but it's marked as “cannot be sent”.
             assert_local_value_matches_room_message_with_body!(
-                LatestEventValue::new_local(&update, &mut buffer, &room_event_cache, &None).await,
+                LatestEventValueBuilder::new_local(&update, &mut buffer, &room_event_cache, &None).await,
                 LatestEventValue::LocalCannotBeSent => with body = "B"
             );
 
@@ -2001,7 +1981,7 @@ mod tests_latest_event_value {
             // The `LatestEventValue` has changed, it still matches the latest local
             // event but it's “is sending”.
             assert_local_value_matches_room_message_with_body!(
-                LatestEventValue::new_local(&update, &mut buffer, &room_event_cache, &None).await,
+                LatestEventValueBuilder::new_local(&update, &mut buffer, &room_event_cache, &None).await,
                 LatestEventValue::LocalIsSending => with body = "B"
             );
 
@@ -2029,7 +2009,7 @@ mod tests_latest_event_value {
 
             // The `LatestEventValue` matches the new local event.
             assert_local_value_matches_room_message_with_body!(
-                LatestEventValue::new_local(&update, &mut buffer, &room_event_cache, &None).await,
+                LatestEventValueBuilder::new_local(&update, &mut buffer, &room_event_cache, &None).await,
                 LatestEventValue::LocalIsSending => with body = "A"
             );
 
@@ -2049,7 +2029,8 @@ mod tests_latest_event_value {
             // The `LatestEventValue` has changed somehow, it tells no new
             // `LatestEventValue` is computed.
             assert_matches!(
-                LatestEventValue::new_local(&update, &mut buffer, &room_event_cache, &None).await,
+                LatestEventValueBuilder::new_local(&update, &mut buffer, &room_event_cache, &None)
+                    .await,
                 LatestEventValue::None
             );
 
@@ -2109,7 +2090,7 @@ mod tests_latest_event_value {
 
         // We get a `Remote` because there is no `Local*` values!
         assert_remote_value_matches_room_message_with_body!(
-            LatestEventValue::new_local(
+            LatestEventValueBuilder::new_local(
                 // An update that won't be create a new `LatestEventValue`.
                 &RoomSendQueueUpdate::SentEvent {
                     transaction_id: OwnedTransactionId::from("txnid"),