Support very large channel membership lists (#11939)

Fixes the channel membership dialogue for the zed channel by not
downloading all 111k people in one go.

Release Notes:

- N/A

crates/collab/src/db/queries/channels.rs

@@ -3,7 +3,7 @@ use rpc::{
     proto::{channel_member::Kind, ChannelBufferVersion, VectorClockEntry},
     ErrorCode, ErrorCodeExt,
 };
-use sea_orm::TryGetableMany;
+use sea_orm::{DbBackend, TryGetableMany};
 
 impl Database {
     #[cfg(test)]
@@ -700,77 +700,73 @@ impl Database {
     pub async fn get_channel_participant_details(
         &self,
         channel_id: ChannelId,
+        filter: &str,
+        limit: u64,
         user_id: UserId,
-    ) -> Result<Vec<proto::ChannelMember>> {
-        let (role, members) = self
+    ) -> Result<(Vec<proto::ChannelMember>, Vec<proto::User>)> {
+        let members = self
             .transaction(move |tx| async move {
                 let channel = self.get_channel_internal(channel_id, &tx).await?;
-                let role = self
-                    .check_user_is_channel_participant(&channel, user_id, &tx)
+                self.check_user_is_channel_participant(&channel, user_id, &tx)
                     .await?;
-                Ok((
-                    role,
-                    self.get_channel_participant_details_internal(&channel, &tx)
-                        .await?,
-                ))
+                let mut query = channel_member::Entity::find()
+                    .find_also_related(user::Entity)
+                    .filter(channel_member::Column::ChannelId.eq(channel.root_id()));
+
+                if cfg!(any(test, sqlite)) && self.pool.get_database_backend() == DbBackend::Sqlite {
+                    query = query.filter(Expr::cust_with_values(
+                        "UPPER(github_login) LIKE ?",
+                        [Self::fuzzy_like_string(&filter.to_uppercase())],
+                    ))
+                } else {
+                    query = query.filter(Expr::cust_with_values(
+                        "github_login ILIKE $1",
+                        [Self::fuzzy_like_string(filter)],
+                    ))
+                }
+                let members = query.order_by(
+                        Expr::cust(
+                            "not role = 'admin', not role = 'member', not role = 'guest', not accepted, github_login",
+                        ),
+                        sea_orm::Order::Asc,
+                    )
+                    .limit(limit)
+                    .all(&*tx)
+                    .await?;
+
+                Ok(members)
             })
             .await?;
 
-        if role == ChannelRole::Admin {
-            Ok(members
-                .into_iter()
-                .map(|channel_member| proto::ChannelMember {
-                    role: channel_member.role.into(),
-                    user_id: channel_member.user_id.to_proto(),
-                    kind: if channel_member.accepted {
+        let mut users: Vec<proto::User> = Vec::with_capacity(members.len());
+
+        let members = members
+            .into_iter()
+            .map(|(member, user)| {
+                if let Some(user) = user {
+                    users.push(proto::User {
+                        id: user.id.to_proto(),
+                        avatar_url: format!(
+                            "https://github.com/{}.png?size=128",
+                            user.github_login
+                        ),
+                        github_login: user.github_login,
+                    })
+                }
+                proto::ChannelMember {
+                    role: member.role.into(),
+                    user_id: member.user_id.to_proto(),
+                    kind: if member.accepted {
                         Kind::Member
                     } else {
                         Kind::Invitee
                     }
                     .into(),
-                })
-                .collect())
-        } else {
-            return Ok(members
-                .into_iter()
-                .filter_map(|member| {
-                    if !member.accepted {
-                        return None;
-                    }
-                    Some(proto::ChannelMember {
-                        role: member.role.into(),
-                        user_id: member.user_id.to_proto(),
-                        kind: Kind::Member.into(),
-                    })
-                })
-                .collect());
-        }
-    }
+                }
+            })
+            .collect();
 
-    async fn get_channel_participant_details_internal(
-        &self,
-        channel: &channel::Model,
-        tx: &DatabaseTransaction,
-    ) -> Result<Vec<channel_member::Model>> {
-        Ok(channel_member::Entity::find()
-            .filter(channel_member::Column::ChannelId.eq(channel.root_id()))
-            .all(tx)
-            .await?)
-    }
-
-    /// Returns the participants in the given channel.
-    pub async fn get_channel_participants(
-        &self,
-        channel: &channel::Model,
-        tx: &DatabaseTransaction,
-    ) -> Result<Vec<UserId>> {
-        let participants = self
-            .get_channel_participant_details_internal(channel, tx)
-            .await?;
-        Ok(participants
-            .into_iter()
-            .map(|member| member.user_id)
-            .collect())
+        Ok((members, users))
     }
 
     /// Returns whether the given user is an admin in the specified channel.