fix: refactor backfill and add support for search

src/api/client_server/search.rs

@@ -81,6 +81,14 @@ pub async fn search_events_route(
 
     let results: Vec<_> = results
         .iter()
+        .filter_map(|result| {
+            services()
+                .rooms
+                .timeline
+                .get_pdu_from_id(result)
+                .ok()?
+                .map(|pdu| pdu.to_room_event())
+        })
         .map(|result| {
             Ok::<_, Error>(SearchResult {
                 context: EventContextResult {
@@ -91,11 +99,7 @@ pub async fn search_events_route(
                     start: None,
                 },
                 rank: None,
-                result: services()
-                    .rooms
-                    .timeline
-                    .get_pdu_from_id(result)?
-                    .map(|pdu| pdu.to_room_event()),
+                result: Some(result),
             })
         })
         .filter_map(|r| r.ok())

src/database/key_value/rooms/search.rs

@@ -1,5 +1,3 @@
-use std::mem::size_of;
-
 use ruma::RoomId;
 
 use crate::{database::KeyValueDatabase, service, services, utils, Result};
@@ -15,7 +13,7 @@ impl service::rooms::search::Data for KeyValueDatabase {
                 let mut key = shortroomid.to_be_bytes().to_vec();
                 key.extend_from_slice(word.as_bytes());
                 key.push(0xff);
-                key.extend_from_slice(pdu_id);
+                key.extend_from_slice(pdu_id); // TODO: currently we save the room id a second time here
                 (key, Vec::new())
             });
 
@@ -34,7 +32,6 @@ impl service::rooms::search::Data for KeyValueDatabase {
             .expect("room exists")
             .to_be_bytes()
             .to_vec();
-        let prefix_clone = prefix.clone();
 
         let words: Vec<_> = search_string
             .split_terminator(|c: char| !c.is_alphanumeric())
@@ -46,6 +43,7 @@ impl service::rooms::search::Data for KeyValueDatabase {
             let mut prefix2 = prefix.clone();
             prefix2.extend_from_slice(word.as_bytes());
             prefix2.push(0xff);
+            let prefix3 = prefix2.clone();
 
             let mut last_possible_id = prefix2.clone();
             last_possible_id.extend_from_slice(&u64::MAX.to_be_bytes());
@@ -53,7 +51,7 @@ impl service::rooms::search::Data for KeyValueDatabase {
             self.tokenids
                 .iter_from(&last_possible_id, true) // Newest pdus first
                 .take_while(move |(k, _)| k.starts_with(&prefix2))
-                .map(|(key, _)| key[key.len() - size_of::<u64>()..].to_vec())
+                .map(move |(key, _)| key[prefix3.len()..].to_vec())
         });
 
         let common_elements = match utils::common_elements(iterators, |a, b| {
@@ -64,12 +62,6 @@ impl service::rooms::search::Data for KeyValueDatabase {
             None => return Ok(None),
         };
 
-        let mapped = common_elements.map(move |id| {
-            let mut pduid = prefix_clone.clone();
-            pduid.extend_from_slice(&id);
-            pduid
-        });
-
-        Ok(Some((Box::new(mapped), words)))
+        Ok(Some((Box::new(common_elements), words)))
     }
 }

src/database/key_value/rooms/timeline.rs

@@ -42,19 +42,8 @@ impl service::rooms::timeline::Data for KeyValueDatabase {
         Ok(self
             .eventid_pduid
             .get(event_id.as_bytes())?
-            .map(|pdu_id| Ok::<_, Error>(PduCount::Normal(pdu_count(&pdu_id)?)))
-            .transpose()?
-            .map_or_else(
-                || {
-                    Ok::<_, Error>(
-                        self.eventid_backfillpduid
-                            .get(event_id.as_bytes())?
-                            .map(|pdu_id| Ok::<_, Error>(PduCount::Backfilled(pdu_count(&pdu_id)?)))
-                            .transpose()?,
-                    )
-                },
-                |x| Ok(Some(x)),
-            )?)
+            .map(|pdu_id| pdu_count(&pdu_id))
+            .transpose()?)
     }
 
     /// Returns the json of a pdu.
@@ -83,21 +72,6 @@ impl service::rooms::timeline::Data for KeyValueDatabase {
                     .ok_or_else(|| Error::bad_database("Invalid pduid in eventid_pduid."))
             })
             .transpose()?
-            .map_or_else(
-                || {
-                    Ok::<_, Error>(
-                        self.eventid_backfillpduid
-                            .get(event_id.as_bytes())?
-                            .map(|pduid| {
-                                self.pduid_backfillpdu.get(&pduid)?.ok_or_else(|| {
-                                    Error::bad_database("Invalid pduid in eventid_pduid.")
-                                })
-                            })
-                            .transpose()?,
-                    )
-                },
-                |x| Ok(Some(x)),
-            )?
             .map(|pdu| {
                 serde_json::from_slice(&pdu).map_err(|_| Error::bad_database("Invalid PDU in db."))
             })
@@ -106,10 +80,7 @@ impl service::rooms::timeline::Data for KeyValueDatabase {
 
     /// Returns the pdu's id.
     fn get_pdu_id(&self, event_id: &EventId) -> Result<Option<Vec<u8>>> {
-        Ok(self.eventid_pduid.get(event_id.as_bytes())?.map_or_else(
-            || self.eventid_backfillpduid.get(event_id.as_bytes()),
-            |x| Ok(Some(x)),
-        )?)
+        Ok(self.eventid_pduid.get(event_id.as_bytes())?)
     }
 
     /// Returns the pdu.
@@ -124,21 +95,6 @@ impl service::rooms::timeline::Data for KeyValueDatabase {
                     .ok_or_else(|| Error::bad_database("Invalid pduid in eventid_pduid."))
             })
             .transpose()?
-            .map_or_else(
-                || {
-                    Ok::<_, Error>(
-                        self.eventid_backfillpduid
-                            .get(event_id.as_bytes())?
-                            .map(|pduid| {
-                                self.pduid_backfillpdu.get(&pduid)?.ok_or_else(|| {
-                                    Error::bad_database("Invalid pduid in eventid_pduid.")
-                                })
-                            })
-                            .transpose()?,
-                    )
-                },
-                |x| Ok(Some(x)),
-            )?
             .map(|pdu| {
                 serde_json::from_slice(&pdu).map_err(|_| Error::bad_database("Invalid PDU in db."))
             })
@@ -183,10 +139,7 @@ impl service::rooms::timeline::Data for KeyValueDatabase {
     ///
     /// This does __NOT__ check the outliers `Tree`.
     fn get_pdu_from_id(&self, pdu_id: &[u8]) -> Result<Option<PduEvent>> {
-        self.pduid_pdu
-            .get(pdu_id)?
-            .map_or_else(|| self.pduid_backfillpdu.get(pdu_id), |x| Ok(Some(x)))?
-            .map_or(Ok(None), |pdu| {
+        self.pduid_pdu.get(pdu_id)?.map_or(Ok(None), |pdu| {
             Ok(Some(
                 serde_json::from_slice(&pdu)
                     .map_err(|_| Error::bad_database("Invalid PDU in db."))?,
@@ -196,10 +149,7 @@ impl service::rooms::timeline::Data for KeyValueDatabase {
 
     /// Returns the pdu as a `BTreeMap<String, CanonicalJsonValue>`.
     fn get_pdu_json_from_id(&self, pdu_id: &[u8]) -> Result<Option<CanonicalJsonObject>> {
-        self.pduid_pdu
-            .get(pdu_id)?
-            .map_or_else(|| self.pduid_backfillpdu.get(pdu_id), |x| Ok(Some(x)))?
-            .map_or(Ok(None), |pdu| {
+        self.pduid_pdu.get(pdu_id)?.map_or(Ok(None), |pdu| {
             Ok(Some(
                 serde_json::from_slice(&pdu)
                     .map_err(|_| Error::bad_database("Invalid PDU in db."))?,
@@ -236,13 +186,12 @@ impl service::rooms::timeline::Data for KeyValueDatabase {
         event_id: &EventId,
         json: &CanonicalJsonObject,
     ) -> Result<()> {
-        self.pduid_backfillpdu.insert(
+        self.pduid_pdu.insert(
             pdu_id,
             &serde_json::to_vec(json).expect("CanonicalJsonObject is always a valid"),
         )?;
 
-        self.eventid_backfillpduid
-            .insert(event_id.as_bytes(), pdu_id)?;
+        self.eventid_pduid.insert(event_id.as_bytes(), pdu_id)?;
         self.eventid_outlierpdu.remove(event_id.as_bytes())?;
 
         Ok(())
@@ -272,30 +221,13 @@ impl service::rooms::timeline::Data for KeyValueDatabase {
         room_id: &RoomId,
         until: PduCount,
     ) -> Result<Box<dyn Iterator<Item = Result<(PduCount, PduEvent)>> + 'a>> {
-        // Create the first part of the full pdu id
-        let prefix = services()
-            .rooms
-            .short
-            .get_shortroomid(room_id)?
-            .expect("room exists")
-            .to_be_bytes()
-            .to_vec();
-
-        let mut current_backfill = prefix.clone();
-        // +1 so we don't send the base event
-        let backfill_count = match until {
-            PduCount::Backfilled(x) => x + 1,
-            PduCount::Normal(_) => 0,
-        };
-        current_backfill.extend_from_slice(&backfill_count.to_be_bytes());
+        let (prefix, current) = count_to_id(&room_id, until, 1, true)?;
 
         let user_id = user_id.to_owned();
-        let user_id2 = user_id.to_owned();
-        let prefix2 = prefix.clone();
 
-        let backfill_iter = self
-            .pduid_backfillpdu
-            .iter_from(&current_backfill, false)
+        Ok(Box::new(
+            self.pduid_pdu
+                .iter_from(&current, true)
                 .take_while(move |(k, _)| k.starts_with(&prefix))
                 .map(move |(pdu_id, v)| {
                     let mut pdu = serde_json::from_slice::<PduEvent>(&v)
@@ -303,33 +235,10 @@ impl service::rooms::timeline::Data for KeyValueDatabase {
                     if pdu.sender != user_id {
                         pdu.remove_transaction_id()?;
                     }
-                let count = PduCount::Backfilled(pdu_count(&pdu_id)?);
+                    let count = pdu_count(&pdu_id)?;
                     Ok((count, pdu))
-            });
-
-        match until {
-            PduCount::Backfilled(_) => Ok(Box::new(backfill_iter)),
-            PduCount::Normal(x) => {
-                let mut current_normal = prefix2.clone();
-                // -1 so we don't send the base event
-                current_normal.extend_from_slice(&x.saturating_sub(1).to_be_bytes());
-                let normal_iter = self
-                    .pduid_pdu
-                    .iter_from(&current_normal, true)
-                    .take_while(move |(k, _)| k.starts_with(&prefix2))
-                    .map(move |(pdu_id, v)| {
-                        let mut pdu = serde_json::from_slice::<PduEvent>(&v)
-                            .map_err(|_| Error::bad_database("PDU in db is invalid."))?;
-                        if pdu.sender != user_id2 {
-                            pdu.remove_transaction_id()?;
-                        }
-                        let count = PduCount::Normal(pdu_count(&pdu_id)?);
-                        Ok((count, pdu))
-                    });
-
-                Ok(Box::new(normal_iter.chain(backfill_iter)))
-            }
-        }
+                }),
+        ))
     }
 
     fn pdus_after<'a>(
@@ -338,30 +247,13 @@ impl service::rooms::timeline::Data for KeyValueDatabase {
         room_id: &RoomId,
         from: PduCount,
     ) -> Result<Box<dyn Iterator<Item = Result<(PduCount, PduEvent)>> + 'a>> {
-        // Create the first part of the full pdu id
-        let prefix = services()
-            .rooms
-            .short
-            .get_shortroomid(room_id)?
-            .expect("room exists")
-            .to_be_bytes()
-            .to_vec();
-
-        let mut current_normal = prefix.clone();
-        // +1 so we don't send the base event
-        let normal_count = match from {
-            PduCount::Normal(x) => x + 1,
-            PduCount::Backfilled(_) => 0,
-        };
-        current_normal.extend_from_slice(&normal_count.to_be_bytes());
+        let (prefix, current) = count_to_id(&room_id, from, 1, false)?;
 
         let user_id = user_id.to_owned();
-        let user_id2 = user_id.to_owned();
-        let prefix2 = prefix.clone();
 
-        let normal_iter = self
-            .pduid_pdu
-            .iter_from(&current_normal, false)
+        Ok(Box::new(
+            self.pduid_pdu
+                .iter_from(&current, false)
                 .take_while(move |(k, _)| k.starts_with(&prefix))
                 .map(move |(pdu_id, v)| {
                     let mut pdu = serde_json::from_slice::<PduEvent>(&v)
@@ -369,33 +261,10 @@ impl service::rooms::timeline::Data for KeyValueDatabase {
                     if pdu.sender != user_id {
                         pdu.remove_transaction_id()?;
                     }
-                let count = PduCount::Normal(pdu_count(&pdu_id)?);
+                    let count = pdu_count(&pdu_id)?;
                     Ok((count, pdu))
-            });
-
-        match from {
-            PduCount::Normal(_) => Ok(Box::new(normal_iter)),
-            PduCount::Backfilled(x) => {
-                let mut current_backfill = prefix2.clone();
-                // -1 so we don't send the base event
-                current_backfill.extend_from_slice(&x.saturating_sub(1).to_be_bytes());
-                let backfill_iter = self
-                    .pduid_backfillpdu
-                    .iter_from(&current_backfill, true)
-                    .take_while(move |(k, _)| k.starts_with(&prefix2))
-                    .map(move |(pdu_id, v)| {
-                        let mut pdu = serde_json::from_slice::<PduEvent>(&v)
-                            .map_err(|_| Error::bad_database("PDU in db is invalid."))?;
-                        if pdu.sender != user_id2 {
-                            pdu.remove_transaction_id()?;
-                        }
-                        let count = PduCount::Backfilled(pdu_count(&pdu_id)?);
-                        Ok((count, pdu))
-                    });
-
-                Ok(Box::new(backfill_iter.chain(normal_iter)))
-            }
-        }
+                }),
+        ))
     }
 
     fn increment_notification_counts(
@@ -428,7 +297,58 @@ impl service::rooms::timeline::Data for KeyValueDatabase {
 }
 
 /// Returns the `count` of this pdu's id.
-fn pdu_count(pdu_id: &[u8]) -> Result<u64> {
-    utils::u64_from_bytes(&pdu_id[pdu_id.len() - size_of::<u64>()..])
-        .map_err(|_| Error::bad_database("PDU has invalid count bytes."))
+fn pdu_count(pdu_id: &[u8]) -> Result<PduCount> {
+    let last_u64 = utils::u64_from_bytes(&pdu_id[pdu_id.len() - size_of::<u64>()..])
+        .map_err(|_| Error::bad_database("PDU has invalid count bytes."))?;
+    let second_last_u64 = utils::u64_from_bytes(
+        &pdu_id[pdu_id.len() - 2 * size_of::<u64>()..pdu_id.len() - size_of::<u64>()],
+    );
+
+    if matches!(second_last_u64, Ok(0)) {
+        Ok(PduCount::Backfilled(u64::MAX - last_u64))
+    } else {
+        Ok(PduCount::Normal(last_u64))
+    }
+}
+
+fn count_to_id(
+    room_id: &RoomId,
+    count: PduCount,
+    offset: u64,
+    subtract: bool,
+) -> Result<(Vec<u8>, Vec<u8>)> {
+    let prefix = services()
+        .rooms
+        .short
+        .get_shortroomid(room_id)?
+        .expect("room exists")
+        .to_be_bytes()
+        .to_vec();
+    let mut pdu_id = prefix.clone();
+    // +1 so we don't send the base event
+    let count_raw = match count {
+        PduCount::Normal(x) => {
+            if subtract {
+                x - offset
+            } else {
+                x + offset
+            }
+        }
+        PduCount::Backfilled(x) => {
+            pdu_id.extend_from_slice(&0_u64.to_be_bytes());
+            let num = u64::MAX - x;
+            if subtract {
+                if num > 0 {
+                    num - offset
+                } else {
+                    num
+                }
+            } else {
+                num + offset
+            }
+        }
+    };
+    pdu_id.extend_from_slice(&count_raw.to_be_bytes());
+
+    Ok((prefix, pdu_id))
 }

src/database/mod.rs

@@ -74,9 +74,7 @@ pub struct KeyValueDatabase {
 
     //pub rooms: rooms::Rooms,
     pub(super) pduid_pdu: Arc<dyn KvTree>, // PduId = ShortRoomId + Count
-    pub(super) pduid_backfillpdu: Arc<dyn KvTree>, // PduId = ShortRoomId + Count
     pub(super) eventid_pduid: Arc<dyn KvTree>,
-    pub(super) eventid_backfillpduid: Arc<dyn KvTree>,
     pub(super) roomid_pduleaves: Arc<dyn KvTree>,
     pub(super) alias_roomid: Arc<dyn KvTree>,
     pub(super) aliasid_alias: Arc<dyn KvTree>, // AliasId = RoomId + Count
@@ -297,9 +295,7 @@ impl KeyValueDatabase {
             presenceid_presence: builder.open_tree("presenceid_presence")?,
             userid_lastpresenceupdate: builder.open_tree("userid_lastpresenceupdate")?,
             pduid_pdu: builder.open_tree("pduid_pdu")?,
-            pduid_backfillpdu: builder.open_tree("pduid_backfillpdu")?,
             eventid_pduid: builder.open_tree("eventid_pduid")?,
-            eventid_backfillpduid: builder.open_tree("eventid_backfillpduid")?,
             roomid_pduleaves: builder.open_tree("roomid_pduleaves")?,
 
             alias_roomid: builder.open_tree("alias_roomid")?,

src/service/rooms/timeline/mod.rs

@@ -1045,6 +1045,24 @@ impl Service {
     ) -> Result<()> {
         let (event_id, value, room_id) = server_server::parse_incoming_pdu(&pdu)?;
 
+        // Lock so we cannot backfill the same pdu twice at the same time
+        let mutex = Arc::clone(
+            services()
+                .globals
+                .roomid_mutex_federation
+                .write()
+                .unwrap()
+                .entry(room_id.to_owned())
+                .or_default(),
+        );
+        let mutex_lock = mutex.lock().await;
+
+        // Skip the PDU if we already have it as a timeline event
+        if let Some(pdu_id) = services().rooms.timeline.get_pdu_id(&event_id)? {
+            info!("We already know {event_id} at {pdu_id:?}");
+            return Ok(());
+        }
+
         services()
             .rooms
             .event_handler
@@ -1052,6 +1070,7 @@ impl Service {
             .await?;
 
         let value = self.get_pdu_json(&event_id)?.expect("We just created it");
+        let pdu = self.get_pdu(&event_id)?.expect("We just created it");
 
         let shortroomid = services()
             .rooms
@@ -1072,14 +1091,36 @@ impl Service {
 
         let count = services().globals.next_count()?;
         let mut pdu_id = shortroomid.to_be_bytes().to_vec();
-        pdu_id.extend_from_slice(&count.to_be_bytes());
+        pdu_id.extend_from_slice(&0_u64.to_be_bytes());
+        pdu_id.extend_from_slice(&(u64::MAX - count).to_be_bytes());
 
         // Insert pdu
         self.db.prepend_backfill_pdu(&pdu_id, &event_id, &value)?;
 
         drop(insert_lock);
 
-        info!("Appended incoming pdu");
+        match pdu.kind {
+            RoomEventType::RoomMessage => {
+                #[derive(Deserialize)]
+                struct ExtractBody {
+                    body: Option<String>,
+                }
+
+                let content = serde_json::from_str::<ExtractBody>(pdu.content.get())
+                    .map_err(|_| Error::bad_database("Invalid content in pdu."))?;
+
+                if let Some(body) = content.body {
+                    services()
+                        .rooms
+                        .search
+                        .index_pdu(shortroomid, &pdu_id, &body)?;
+                }
+            }
+            _ => {}
+        }
+        drop(mutex_lock);
+
+        info!("Prepended backfill pdu");
         Ok(())
     }
 }