fix(memory): bound automation dispatch tokens

src/main/automations/dispatch-tokens.test.ts

@@ -0,0 +1,16 @@
+import { describe, expect, it } from 'vitest'
+import {
+  createAutomationDispatchToken,
+  getAutomationDispatchTokenCountForTests,
+  MAX_AUTOMATION_DISPATCH_TOKENS
+} from './dispatch-tokens'
+
+describe('automation dispatch tokens', () => {
+  it('bounds distinct token churn', () => {
+    for (let index = 0; index < MAX_AUTOMATION_DISPATCH_TOKENS + 4; index += 1) {
+      createAutomationDispatchToken(`automation-${index}`, `run-${index}`)
+    }
+
+    expect(getAutomationDispatchTokenCountForTests()).toBe(MAX_AUTOMATION_DISPATCH_TOKENS)
+  })
+})

src/main/automations/dispatch-tokens.ts

@@ -1,6 +1,7 @@
 import { randomUUID } from 'node:crypto'
 
 const DISPATCH_TOKEN_TTL_MS = 30 * 60_000
+export const MAX_AUTOMATION_DISPATCH_TOKENS = 1024
 
 type DispatchTokenRecord = {
   automationId: string
@@ -20,6 +21,16 @@ function pruneExpiredDispatchTokens(now = Date.now()): void {
   }
 }
 
+function trimDispatchTokens(): void {
+  while (dispatchTokens.size > MAX_AUTOMATION_DISPATCH_TOKENS) {
+    const oldestEvictable = [...dispatchTokens].find(([, record]) => !record.inFlight)
+    if (!oldestEvictable) {
+      return
+    }
+    dispatchTokens.delete(oldestEvictable[0])
+  }
+}
+
 export function createAutomationDispatchToken(automationId: string, runId: string): string {
   pruneExpiredDispatchTokens()
   const token = randomUUID()
@@ -29,9 +40,14 @@ export function createAutomationDispatchToken(automationId: string, runId: strin
     expiresAt: Date.now() + DISPATCH_TOKEN_TTL_MS,
     inFlight: false
   })
+  trimDispatchTokens()
   return token
 }
 
+export function getAutomationDispatchTokenCountForTests(): number {
+  return dispatchTokens.size
+}
+
 export function beginAutomationDispatchTokenUse(args: {
   automationId: string
   runId: string