Approach request optimization differently

packages/net/src/Subscribe.ts

@@ -66,6 +66,7 @@ export const calculateSubscriptionGroup = (sub: Subscription) => {
   const parts: string[] = []
 
   if (sub.request.timeout) parts.push(`timeout:${sub.request.timeout}`)
+  if (sub.request.authTimeout) parts.push(`authTimeout:${sub.request.authTimeout}`)
   if (sub.request.closeOnEose) parts.push('closeOnEose')
 
   return parts.join('|')
@@ -123,28 +124,31 @@ export const mergeSubscriptions = (subs: Subscription[]) => {
   return mergedSub
 }
 
-export const optimizeSubscriptions = (subs: Subscription[]) =>
-  Array.from(groupBy(calculateSubscriptionGroup, subs).values())
+export const optimizeSubscriptions = (subs: Subscription[]) => {
+  return Array.from(groupBy(calculateSubscriptionGroup, subs).values())
     .flatMap(group => {
-      const completedRelays = new Set()
+      const timeout = max(group.map(sub => sub.request.timeout || 0))
+      const authTimeout = max(group.map(sub => sub.request.authTimeout || 0))
+      const closeOnEose = group.every(sub => sub.request.closeOnEose)
+      const completedSubs = new Set<string>()
+      const abortedSubs = new Set<string>()
+      const closedSubs = new Set<string>()
+      const eosedSubs = new Set<string>()
       const mergedSubs = []
 
-      for (const relay of uniq(group.flatMap((sub: Subscription) => sub.request.relays))) {
-        const abortedSubs = new Set()
-        const callerSubs = group.filter((sub: Subscription) => sub.request.relays.includes(relay))
-        const mergedSub = makeSubscription({
-          relays: [relay],
-          closeOnEose: callerSubs.every(sub => sub.request.closeOnEose),
-          timeout: max(callerSubs.map(sub => sub.request.timeout || 0)),
-          authTimeout: max(callerSubs.map(sub => sub.request.authTimeout || 0)),
-          filters: unionFilters(callerSubs.flatMap((sub: Subscription) => sub.request.filters)),
+      for (const {relays, filters} of NetworkContext.optimizeSubscriptions(group)) {
+        const mergedSub = makeSubscription({filters,
+          relays,
+          timeout,
+          authTimeout,
+          closeOnEose
         })
 
-        for (const {id, controller, request} of callerSubs) {
+        for (const {id, controller, request} of group) {
           const onAbort = () => {
             abortedSubs.add(id)
 
-            if (abortedSubs.size === callerSubs.length) {
+            if (abortedSubs.size === group.length) {
               mergedSub.close()
             }
           }
@@ -154,7 +158,7 @@ export const optimizeSubscriptions = (subs: Subscription[]) =>
         }
 
         mergedSub.emitter.on(SubscriptionEvent.Event, (url: string, event: SignedEvent) => {
-          for (const sub of callerSubs) {
+          for (const sub of group) {
             if (!sub.tracker.track(event.id, url) && matchFilters(sub.request.filters, event)) {
               sub.emitter.emit(SubscriptionEvent.Event, url, event)
             }
@@ -162,53 +166,48 @@ export const optimizeSubscriptions = (subs: Subscription[]) =>
         })
 
         // Pass events back to caller
-        const propagateEvent = (type: SubscriptionEvent, checkFilter: boolean) =>
+        const propagateEvent = (type: SubscriptionEvent) =>
           mergedSub.emitter.on(type,  (url: string, event: SignedEvent) => {
-            for (const sub of callerSubs) {
-              if (!checkFilter || matchFilters(sub.request.filters, event)) {
+            for (const sub of group) {
+              if (matchFilters(sub.request.filters, event)) {
                 sub.emitter.emit(type, url, event)
               }
             }
           })
 
-        propagateEvent(SubscriptionEvent.Duplicate, true)
-        propagateEvent(SubscriptionEvent.DeletedEvent, false)
-        propagateEvent(SubscriptionEvent.FailedFilter, false)
-        propagateEvent(SubscriptionEvent.InvalidSignature, true)
+        propagateEvent(SubscriptionEvent.Duplicate)
+        propagateEvent(SubscriptionEvent.DeletedEvent)
+        propagateEvent(SubscriptionEvent.InvalidSignature)
 
-        // Propagate eose
-        mergedSub.emitter.on(SubscriptionEvent.Eose, (url: string) => {
-          for (const sub of callerSubs) {
-            sub.emitter.emit(SubscriptionEvent.Eose, url)
-          }
-        })
+        const propagateFinality = (type: SubscriptionEvent, subIds: Set<string>) =>
+          mergedSub.emitter.on(type, (...args: any[]) => {
+            subIds.add(mergedSub.id)
 
-        // Propagate close
-        mergedSub.emitter.on(SubscriptionEvent.Close, (url: string) => {
-          for (const sub of callerSubs) {
-            sub.emitter.emit(SubscriptionEvent.Close, url)
-          }
-        })
-
-        // Propagate subscription completion. Since we split subs by relay, we need to wait
-        // until all relays are completed before we notify
-        mergedSub.emitter.on(SubscriptionEvent.Complete, () => {
-          completedRelays.add(relay)
-
-          for (const sub of callerSubs) {
-            if (sub.request.relays.every(url => completedRelays.has(url))) {
-              sub.emitter.emit(SubscriptionEvent.Complete)
+            // Wait for all subscriptions to complete before reporting finality to the caller.
+            // This is sub-optimal, but because we're outsourcing filter/relay optimization
+            // we can't make any assumptions about which caller subscriptions have completed
+            // at any given time.
+            if (subIds.size === group.length) {
+              for (const sub of group) {
+                sub.emitter.emit(type, ...args)
+              }
             }
-          }
 
-          mergedSub.emitter.removeAllListeners()
-        })
+            if (type === SubscriptionEvent.Complete) {
+              mergedSub.emitter.removeAllListeners()
+            }
+          })
+
+        propagateFinality(SubscriptionEvent.Eose, eosedSubs)
+        propagateFinality(SubscriptionEvent.Close, closedSubs)
+        propagateFinality(SubscriptionEvent.Complete, completedSubs)
 
         mergedSubs.push(mergedSub)
       }
 
       return mergedSubs
     })
+}
 
 export const executeSubscription = (sub: Subscription) => {
   const {request, emitter, tracker, controller} = sub
@@ -328,10 +327,6 @@ export const executeSubscriptionBatched = (() => {
 export const subscribe = (request: SubscribeRequest) => {
   const subscription: Subscription = makeSubscription({delay: 50, ...request})
 
-  if (request.relays.length === 0) {
-    console.warn("Attempted to execute a subscription with zero relays")
-  }
-
   if (request.delay === 0) {
     executeSubscription(subscription)
   } else {