From 7167553afeffae2d504f324574dc333450d097e9 Mon Sep 17 00:00:00 2001
From: Alex Gleason <alex@alexgleason.me>
Date: Sun, 10 Dec 2023 13:53:51 -0600
Subject: [PATCH] stats: switch to a system based on diff tuples

---
 src/stats.ts | 64 ++++++++++++++++++++++++++++++++++++++--------------
 1 file changed, 47 insertions(+), 17 deletions(-)

diff --git a/src/stats.ts b/src/stats.ts
index edd7479..2496ed6 100644
--- a/src/stats.ts
+++ b/src/stats.ts
@@ -1,29 +1,59 @@
 import { db, type EventStatsRow, type PubkeyStatsRow } from '@/db.ts';
-import { Event } from '@/deps.ts';
+import { Event, findReplyTag } from '@/deps.ts';
 
 type PubkeyStat = keyof Omit<PubkeyStatsRow, 'pubkey'>;
 type EventStat = keyof Omit<EventStatsRow, 'event_id'>;
 
+type PubkeyStatDiff = ['pubkey_stats', pubkey: string, stat: PubkeyStat, diff: number];
+type EventStatDiff = ['event_stats', eventId: string, stat: EventStat, diff: number];
+type StatDiff = PubkeyStatDiff | EventStatDiff;
+
 /** Store stats for the event in LMDB. */
 function updateStats(event: Event) {
-  return updateStatsQuery(event)?.execute();
+  const statDiffs = getStatsDiff(event);
+  if (!statDiffs.length) return;
+
+  const pubkeyDiffs = statDiffs.filter(([table]) => table === 'pubkey_stats') as PubkeyStatDiff[];
+  const eventDiffs = statDiffs.filter(([table]) => table === 'event_stats') as EventStatDiff[];
+
+  return db.transaction().execute(() => {
+    return Promise.all([
+      pubkeyStatsQuery(pubkeyDiffs).execute(),
+      eventStatsQuery(eventDiffs).execute(),
+    ]);
+  });
 }
 
-function updateStatsQuery(event: Event) {
-  const firstE = findFirstTag(event, 'e');
+/** Calculate stats changes ahead of time so we can build an efficient query. */
+function getStatsDiff(event: Event): StatDiff[] {
+  const statDiffs: StatDiff[] = [];
+
+  const firstE = event.tags.find(([name]) => name === 'e')?.[1];
+  const replyTag = findReplyTag(event as Event<1>);
 
   switch (event.kind) {
     case 1:
-      return incrementPubkeyStatsQuery([event.pubkey], 'notes_count', 1);
+      statDiffs.push(['pubkey_stats', event.pubkey, 'notes_count', 1]);
+      if (replyTag && replyTag[1]) {
+        statDiffs.push(['event_stats', replyTag[1], 'replies_count', 1]);
+      }
+      break;
     case 6:
-      return firstE ? incrementEventStatsQuery([firstE], 'reposts_count', 1) : undefined;
+      if (firstE) {
+        statDiffs.push(['event_stats', firstE, 'reposts_count', 1]);
+      }
+      break;
     case 7:
-      return firstE ? incrementEventStatsQuery([firstE], 'reactions_count', 1) : undefined;
+      if (firstE) {
+        statDiffs.push(['event_stats', firstE, 'reactions_count', 1]);
+      }
   }
+
+  return statDiffs;
 }
 
-function incrementPubkeyStatsQuery(pubkeys: string[], stat: PubkeyStat, diff: number) {
-  const values: PubkeyStatsRow[] = pubkeys.map((pubkey) => {
+function pubkeyStatsQuery(diffs: PubkeyStatDiff[]) {
+  const values: PubkeyStatsRow[] = diffs.map(([_, pubkey, stat, diff]) => {
     const row: PubkeyStatsRow = {
       pubkey,
       followers_count: 0,
@@ -40,13 +70,15 @@ function incrementPubkeyStatsQuery(pubkeys: string[], stat: PubkeyStat, diff: nu
       oc
         .column('pubkey')
         .doUpdateSet((eb) => ({
-          [stat]: eb(stat, '+', diff),
+          followers_count: eb('followers_count', '+', eb.ref('excluded.followers_count')),
+          following_count: eb('following_count', '+', eb.ref('excluded.following_count')),
+          notes_count: eb('notes_count', '+', eb.ref('excluded.notes_count')),
         }))
     );
 }
 
-function incrementEventStatsQuery(eventIds: string[], stat: EventStat, diff: number) {
-  const values: EventStatsRow[] = eventIds.map((event_id) => {
+function eventStatsQuery(diffs: EventStatDiff[]) {
+  const values: EventStatsRow[] = diffs.map(([_, event_id, stat, diff]) => {
     const row: EventStatsRow = {
       event_id,
       replies_count: 0,
@@ -63,13 +95,11 @@ function incrementEventStatsQuery(eventIds: string[], stat: EventStat, diff: num
       oc
         .column('event_id')
         .doUpdateSet((eb) => ({
-          [stat]: eb(stat, '+', diff),
+          replies_count: eb('replies_count', '+', eb.ref('excluded.replies_count')),
+          reposts_count: eb('reposts_count', '+', eb.ref('excluded.reposts_count')),
+          reactions_count: eb('reactions_count', '+', eb.ref('excluded.reactions_count')),
         }))
     );
 }
 
-function findFirstTag({ tags }: Event, name: string): string | undefined {
-  return tags.find(([n]) => n === name)?.[1];
-}
-
 export { updateStats };