refactor: debounce and batch simultaneous audit log requests

backend/src/utils/findMatchingAuditLogEntry.ts

@@ -0,0 +1,68 @@
+import { Guild, GuildAuditLogsAction, GuildAuditLogsEntry } from "discord.js";
+import { SECONDS, sleep } from "../utils";
+
+const BATCH_DEBOUNCE_TIME = 2 * SECONDS;
+const BATCH_FETCH_COUNT_INCREMENT = 10;
+
+type Batch = {
+  _waitUntil: number;
+  _fetchCount: number;
+  _promise: Promise<GuildAuditLogsEntry[]>;
+  join: () => Promise<GuildAuditLogsEntry[]>;
+};
+
+const batches = new Map<string, Batch>();
+
+/**
+ * Find a recent audit log entry matching the given criteria.
+ * This function will debounce and batch simultaneous calls into one audit log request.
+ */
+export async function findMatchingAuditLogEntry(
+  guild: Guild,
+  action?: GuildAuditLogsAction,
+  targetId?: string,
+): Promise<GuildAuditLogsEntry | undefined> {
+  let candidates: GuildAuditLogsEntry[];
+
+  if (batches.has(guild.id)) {
+    candidates = await batches.get(guild.id)!.join();
+  } else {
+    const batch: Batch = {
+      _waitUntil: Date.now(),
+      _fetchCount: 0,
+      _promise: new Promise(async (resolve) => {
+        await sleep(BATCH_DEBOUNCE_TIME);
+
+        do {
+          await sleep(Math.max(0, batch._waitUntil - Date.now()));
+        } while (Date.now() < batch._waitUntil);
+
+        const result = await guild
+          .fetchAuditLogs({
+            limit: batch._fetchCount,
+          })
+          .catch((err) => {
+            // tslint:disable-next-line:no-console
+            console.warn(`[DEBUG] Audit log error in ${guild.id} (${guild.name}): ${err.message}`);
+            return null;
+          });
+        const _candidates = Array.from(result?.entries.values() ?? []);
+
+        batches.delete(guild.id);
+        resolve(_candidates);
+      }),
+      join() {
+        batch._waitUntil = Date.now() + BATCH_DEBOUNCE_TIME;
+        batch._fetchCount = Math.min(100, batch._fetchCount + BATCH_FETCH_COUNT_INCREMENT);
+        return batch._promise;
+      },
+    };
+    batches.set(guild.id, batch);
+    candidates = await batch.join();
+  }
+
+  return candidates.find(
+    (entry) =>
+      (action == null || entry.action === action) && (targetId == null || (entry.target as any)?.id === targetId),
+  );
+}

backend/src/utils/safeFindRelevantAuditLogEntry.ts

@@ -1,30 +0,0 @@
-import { GuildPluginData } from "knub";
-import { LogType } from "../data/LogType";
-import { LogsPlugin } from "../plugins/Logs/LogsPlugin";
-import { findRelevantAuditLogEntry, isDiscordAPIError } from "../utils";
-
-/**
- * Wrapper for findRelevantAuditLogEntry() that handles permission errors gracefully.
- * Calling plugin must have LogsPlugin as a dependency (or be LogsPlugin itself).
- */
-export async function safeFindRelevantAuditLogEntry(
-  pluginData: GuildPluginData<any>,
-  actionType: number,
-  userId: string,
-  attempts?: number,
-  attemptDelay?: number,
-) {
-  try {
-    return await findRelevantAuditLogEntry(pluginData.guild, actionType, userId, attempts, attemptDelay);
-  } catch (e) {
-    if (isDiscordAPIError(e) && e.code === 50013) {
-      const logs = pluginData.getPlugin(LogsPlugin);
-      logs.logBotAlert({
-        body: "Missing permissions to read audit log",
-      });
-      return;
-    }
-
-    throw e;
-  }
-}