feat: WIP relationships and threads

src/database/key_value/rooms/threads.rs

@@ -0,0 +1,78 @@
+use std::mem;
+
+use ruma::{api::client::threads::get_threads::v1::IncludeThreads, OwnedUserId, RoomId, UserId};
+
+use crate::{database::KeyValueDatabase, service, services, utils, Error, PduEvent, Result};
+
+impl service::rooms::threads::Data for KeyValueDatabase {
+    fn threads_until<'a>(
+        &'a self,
+        user_id: &'a UserId,
+        room_id: &'a RoomId,
+        until: u64,
+        include: &'a IncludeThreads,
+    ) -> Result<Box<dyn Iterator<Item = Result<(u64, PduEvent)>> + 'a>> {
+        let prefix = services()
+            .rooms
+            .short
+            .get_shortroomid(room_id)?
+            .expect("room exists")
+            .to_be_bytes()
+            .to_vec();
+
+        let mut current = prefix.clone();
+        current.extend_from_slice(&(until - 1).to_be_bytes());
+
+        Ok(Box::new(
+            self.threadid_userids
+                .iter_from(&current, true)
+                .take_while(move |(k, _)| k.starts_with(&prefix))
+                .map(move |(pduid, users)| {
+                    let count = utils::u64_from_bytes(&pduid[(mem::size_of::<u64>())..])
+                        .map_err(|_| Error::bad_database("Invalid pduid in threadid_userids."))?;
+                    let mut pdu = services()
+                        .rooms
+                        .timeline
+                        .get_pdu_from_id(&pduid)?
+                        .ok_or_else(|| {
+                            Error::bad_database("Invalid pduid reference in threadid_userids")
+                        })?;
+                    if pdu.sender != user_id {
+                        pdu.remove_transaction_id()?;
+                    }
+                    Ok((count, pdu))
+                }),
+        ))
+    }
+
+    fn update_participants(&self, root_id: &[u8], participants: &[OwnedUserId]) -> Result<()> {
+        let users = participants
+            .iter()
+            .map(|user| user.as_bytes())
+            .collect::<Vec<_>>()
+            .join(&[0xff][..]);
+
+        self.threadid_userids.insert(&root_id, &users)?;
+
+        Ok(())
+    }
+
+    fn get_participants(&self, root_id: &[u8]) -> Result<Option<Vec<OwnedUserId>>> {
+        if let Some(users) = self.threadid_userids.get(&root_id)? {
+            Ok(Some(
+                users
+                    .split(|b| *b == 0xff)
+                    .map(|bytes| {
+                        UserId::parse(utils::string_from_bytes(bytes).map_err(|_| {
+                            Error::bad_database("Invalid UserId bytes in threadid_userids.")
+                        })?)
+                        .map_err(|_| Error::bad_database("Invalid UserId in threadid_userids."))
+                    })
+                    .filter_map(|r| r.ok())
+                    .collect(),
+            ))
+        } else {
+            Ok(None)
+        }
+    }
+}