chore: global sync per minute safety limit (#2765)

packages/snjs/lib/Services/Sync/SyncFrequencyGuard.spec.ts

@@ -0,0 +1,38 @@
+import { SyncFrequencyGuard } from './SyncFrequencyGuard'
+
+describe('SyncFrequencyGuard', () => {
+  const createUseCase = () => new SyncFrequencyGuard(3)
+
+  it('should return false when sync calls threshold is not reached', () => {
+    const useCase = createUseCase()
+
+    expect(useCase.isSyncCallsThresholdReachedThisMinute()).toBe(false)
+  })
+
+  it('should return true when sync calls threshold is reached', () => {
+    const useCase = createUseCase()
+
+    useCase.incrementCallsPerMinute()
+    useCase.incrementCallsPerMinute()
+    useCase.incrementCallsPerMinute()
+
+    expect(useCase.isSyncCallsThresholdReachedThisMinute()).toBe(true)
+  })
+
+  it('should return false when sync calls threshold is reached but a new minute has started', () => {
+    const spyOnGetCallsPerMinuteKey = jest.spyOn(SyncFrequencyGuard.prototype as any, 'getCallsPerMinuteKey')
+    spyOnGetCallsPerMinuteKey.mockReturnValueOnce('2020-1-1T1:1')
+
+    const useCase = createUseCase()
+
+    useCase.incrementCallsPerMinute()
+    useCase.incrementCallsPerMinute()
+    useCase.incrementCallsPerMinute()
+
+    spyOnGetCallsPerMinuteKey.mockReturnValueOnce('2020-1-1T1:2')
+
+    expect(useCase.isSyncCallsThresholdReachedThisMinute()).toBe(false)
+
+    spyOnGetCallsPerMinuteKey.mockRestore()
+  })
+})

packages/snjs/lib/Services/Sync/SyncFrequencyGuard.ts

@@ -0,0 +1,40 @@
+import { SyncFrequencyGuardInterface } from './SyncFrequencyGuardInterface'
+
+export class SyncFrequencyGuard implements SyncFrequencyGuardInterface {
+  private callsPerMinuteMap: Map<string, number>
+
+  constructor(private syncCallsThresholdPerMinute: number) {
+    this.callsPerMinuteMap = new Map<string, number>()
+  }
+
+  isSyncCallsThresholdReachedThisMinute(): boolean {
+    const stringDateToTheMinute = this.getCallsPerMinuteKey()
+    const persistedCallsCount = this.callsPerMinuteMap.get(stringDateToTheMinute) || 0
+
+    return persistedCallsCount >= this.syncCallsThresholdPerMinute
+  }
+
+  incrementCallsPerMinute(): void {
+    const stringDateToTheMinute = this.getCallsPerMinuteKey()
+    const persistedCallsCount = this.callsPerMinuteMap.get(stringDateToTheMinute)
+    const newMinuteStarted = persistedCallsCount === undefined
+
+    if (newMinuteStarted) {
+      this.clear()
+
+      this.callsPerMinuteMap.set(stringDateToTheMinute, 1)
+    } else {
+      this.callsPerMinuteMap.set(stringDateToTheMinute, persistedCallsCount + 1)
+    }
+  }
+
+  clear(): void {
+    this.callsPerMinuteMap.clear()
+  }
+
+  private getCallsPerMinuteKey(): string {
+    const now = new Date()
+
+    return `${now.getFullYear()}-${now.getMonth()}-${now.getDate()}T${now.getHours()}:${now.getMinutes()}`
+  }
+}

packages/snjs/lib/Services/Sync/SyncFrequencyGuardInterface.ts

@@ -0,0 +1,5 @@
+export interface SyncFrequencyGuardInterface {
+  incrementCallsPerMinute(): void
+  isSyncCallsThresholdReachedThisMinute(): boolean
+  clear(): void
+}

packages/snjs/lib/Services/Sync/SyncService.ts

@@ -97,6 +97,7 @@ import {
 import { CreatePayloadFromRawServerItem } from './Account/Utilities'
 import { DecryptedServerConflictMap, TrustedServerConflictMap } from './Account/ServerConflictMap'
 import { ContentType } from '@standardnotes/domain-core'
+import { SyncFrequencyGuardInterface } from './SyncFrequencyGuardInterface'
 
 const DEFAULT_MAJOR_CHANGE_THRESHOLD = 15
 const INVALID_SESSION_RESPONSE_STATUS = 401
@@ -169,6 +170,7 @@ export class SyncService
     private readonly options: ApplicationSyncOptions,
     private logger: LoggerInterface,
     private sockets: WebSocketsService,
+    private syncFrequencyGuard: SyncFrequencyGuardInterface,
     protected override internalEventBus: InternalEventBusInterface,
   ) {
     super(internalEventBus)
@@ -643,7 +645,8 @@ export class SyncService
     const syncInProgress = this.opStatus.syncInProgress
     const databaseLoaded = this.databaseLoaded
     const canExecuteSync = !this.syncLock
-    const shouldExecuteSync = canExecuteSync && databaseLoaded && !syncInProgress
+    const syncLimitReached = this.syncFrequencyGuard.isSyncCallsThresholdReachedThisMinute()
+    const shouldExecuteSync = canExecuteSync && databaseLoaded && !syncInProgress && !syncLimitReached
 
     if (shouldExecuteSync) {
       this.syncLock = true
@@ -1296,6 +1299,8 @@ export class SyncService
 
     this.lastSyncDate = new Date()
 
+    this.syncFrequencyGuard.incrementCallsPerMinute()
+
     if (operation instanceof AccountSyncOperation && operation.numberOfItemsInvolved >= this.majorChangeThreshold) {
       void this.notifyEvent(SyncEvent.MajorDataChange)
     }