Make sync logic more robust

src/app/core/sync.ts

@@ -20,7 +20,7 @@ import {
   unionFilters,
 } from "@welshman/util"
 import type {Filter} from "@welshman/util"
-import {request, pull} from "@welshman/net"
+import {request, requestOne, Difference, DifferenceEvent} from "@welshman/net"
 import {
   pubkey,
   loadRelay,
@@ -64,26 +64,47 @@ type SyncOpts = {
   filters: Filter[]
 }
 
-export const pullWithFallback = ({url, signal, filters}: SyncOpts) => {
-  const relays = [url]
-  const events = repository.query(filters).filter(isSignedEvent)
+const pullOneWithFallback = async (url: string, filter: Filter, signal: AbortSignal) => {
+  const cachedEvents = repository.query([filter]).filter(isSignedEvent)
+  const since = last(cachedEvents.slice(10))?.created_at || 0
 
-  if (hasNegentropy(url)) {
-    pull({relays, signal, events, filters})
-  } else {
-    request({
-      relays,
-      signal,
-      autoClose: true,
-      filters: filters.map(assoc("since", last(events.slice(10))?.created_at || 0)),
-    })
+  const shouldFallback =
+    !hasNegentropy(url) ||
+    (await new Promise(resolve => {
+      const diff = new Difference({relay: url, filter, events: cachedEvents, signal})
+
+      diff.on(DifferenceEvent.Error, () => {
+        resolve(true)
+      })
+
+      diff.on(DifferenceEvent.Close, () => {
+        for (const ids of chunk(100, Array.from(diff.need))) {
+          requestOne({relay: url, signal, autoClose: true, filters: [{ids}]})
+        }
+
+        resolve(false)
+      })
+    }))
+
+  if (shouldFallback && !signal.aborted) {
+    request({relays: [url], signal, autoClose: true, filters: [{...filter, since}]})
+  }
+}
+
+export const pullWithFallback = async ({url, signal, filters}: SyncOpts) => {
+  await loadRelay(url)
+
+  if (signal.aborted) return
+
+  for (const filter of filters) {
+    pullOneWithFallback(url, filter, signal)
   }
 }
 
 const listen = ({url, signal, filters}: SyncOpts) => {
   const relays = [url]
 
-  request({relays, signal, filters: unionFilters(filters).map(assoc("limit", 0))})
+  request({relays, signal, filters: unionFilters(filters.map(assoc("limit", 0)))})
 }
 
 const pullAndListen = ({url, filters, signal}: SyncOpts) => {
@@ -232,69 +253,105 @@ const syncUserData = () => {
 
 // Spaces
 
-const syncSpace = (url: string) => {
+const syncSpace = (url: string, rooms: string[]) => {
   const controller = new AbortController()
 
-  // These are separated so that old versions of relay29 don't barf
-
+  // Relay-level kinds don't need #h tags
   pullAndListen({
     url,
     signal: controller.signal,
     filters: [{kinds: [RELAY_MEMBERS, RELAY_ADD_MEMBER, RELAY_REMOVE_MEMBER]}],
   })
 
+  // Room metadata uses #d tags, not #h, so no filtering needed
   pullAndListen({
     url,
     signal: controller.signal,
     filters: [{kinds: [ROOM_META, ROOM_ADMINS, ROOM_MEMBERS]}],
   })
 
-  pullAndListen({
-    url,
-    signal: controller.signal,
-    filters: [{kinds: [ROOM_DELETE, ROOM_ADD_MEMBER, ROOM_REMOVE_MEMBER]}],
-  })
-
+  // Room-scoped kinds: add #h tags when we know which rooms the user is in.
+  // This avoids sending broad filters that picky relays reject.
+  const roomKinds = [ROOM_DELETE, ROOM_ADD_MEMBER, ROOM_REMOVE_MEMBER]
   const since = ago(WEEK)
 
-  pullAndListen({
-    url,
-    signal: controller.signal,
-    filters: [{kinds: MESSAGE_KINDS, since}, makeCommentFilter(CONTENT_KINDS, {since})],
-  })
+  if (rooms.length > 0) {
+    pullAndListen({
+      url,
+      signal: controller.signal,
+      filters: [{kinds: roomKinds, "#h": rooms}],
+    })
 
-  listen({
-    url,
-    signal: controller.signal,
-    filters: [{kinds: REACTION_KINDS, limit: 0}],
-  })
+    pullAndListen({
+      url,
+      signal: controller.signal,
+      filters: [
+        {kinds: MESSAGE_KINDS, "#h": rooms, since},
+        makeCommentFilter(CONTENT_KINDS, {"#h": rooms, since}),
+      ],
+    })
+
+    listen({
+      url,
+      signal: controller.signal,
+      filters: [{kinds: REACTION_KINDS, "#h": rooms}],
+    })
+  } else {
+    pullAndListen({
+      url,
+      signal: controller.signal,
+      filters: [{kinds: roomKinds}],
+    })
+
+    pullAndListen({
+      url,
+      signal: controller.signal,
+      filters: [{kinds: MESSAGE_KINDS, since}, makeCommentFilter(CONTENT_KINDS, {since})],
+    })
+
+    listen({
+      url,
+      signal: controller.signal,
+      filters: [{kinds: REACTION_KINDS}],
+    })
+  }
 
   return () => controller.abort()
 }
 
 const syncSpaces = () => {
-  const store = derived([userSpaceUrls, page], identity)
+  const store = derived([userGroupList, page], identity)
   const unsubscribersByUrl = new Map<string, Unsubscriber>()
-  const unsubscribe = store.subscribe(([$userSpaceUrls, $page]) => {
-    const urls = Array.from($userSpaceUrls)
+  const roomsByUrl = new Map<string, string>()
+
+  const unsubscribe = store.subscribe(([$userGroupList, $page]) => {
+    const urls = new Set(getSpaceUrlsFromGroupList($userGroupList))
 
     if ($page.params.relay) {
-      urls.push(decodeRelay($page.params.relay))
+      urls.add(decodeRelay($page.params.relay))
     }
 
-    // stop syncing removed spaces
+    // Stop syncing removed spaces
     for (const [url, unsubscribe] of unsubscribersByUrl.entries()) {
-      if (!urls.includes(url)) {
+      if (!urls.has(url)) {
         unsubscribersByUrl.delete(url)
+        roomsByUrl.delete(url)
         unsubscribe()
       }
     }
 
-    // Start syncing newly added spaces
+    // Start or restart syncing for each space
     for (const url of urls) {
-      if (!unsubscribersByUrl.has(url)) {
-        unsubscribersByUrl.set(url, syncSpace(url))
-      }
+      const rooms = getSpaceRoomsFromGroupList(url, $userGroupList)
+      const roomsKey = rooms.join(",")
+
+      if (unsubscribersByUrl.has(url) && roomsByUrl.get(url) === roomsKey) continue
+
+      // Tear down existing sync if rooms changed
+      unsubscribersByUrl.get(url)?.()
+
+      roomsByUrl.set(url, roomsKey)
+      unsubscribersByUrl.set(url, syncSpace(url, rooms))
     }
   })