[Multi-Tab] Don't write document change log when multi-tab is disabled

packages/firestore/src/local/indexeddb_persistence.ts

@@ -440,15 +440,30 @@ export class IndexedDbPersistence implements Persistence {
   }
 
   getMutationQueue(user: User): MutationQueue {
+    assert(
+      this.started,
+      'Cannot initialize MutationQueue before persistence is started.'
+    );
     return IndexedDbMutationQueue.forUser(user, this.serializer);
   }
 
   getQueryCache(): QueryCache {
+    assert(
+      this.started,
+      'Cannot initialize QueryCache before persistence is started.'
+    );
     return new IndexedDbQueryCache(this.serializer);
   }
 
   getRemoteDocumentCache(): RemoteDocumentCache {
-    return new IndexedDbRemoteDocumentCache(this.serializer);
+    assert(
+      this.started,
+      'Cannot initialize RemoteDocumentCache before persistence is started.'
+    );
+    return new IndexedDbRemoteDocumentCache(
+      this.serializer,
+      /*keepDocumentChangeLog=*/ this.allowTabSynchronization
+    );
   }
 
   runTransaction<T>(

packages/firestore/src/local/indexeddb_remote_document_cache.ts

@@ -37,12 +37,23 @@ import { PersistencePromise } from './persistence_promise';
 import { RemoteDocumentCache } from './remote_document_cache';
 import { SimpleDb, SimpleDbStore } from './simple_db';
 import { SnapshotVersion } from '../core/snapshot_version';
+import { assert } from '../util/assert';
 
 export class IndexedDbRemoteDocumentCache implements RemoteDocumentCache {
   /** The last id read by `getNewDocumentChanges()`. */
   private lastReturnedDocumentChangesId = 0;
 
-  constructor(private serializer: LocalSerializer) {}
+  /**
+   * @param {LocalSerializer} serializer The document serializer.
+   * @param keepDocumentChangeLog Whether to keep a document change log in
+   * IndexedDb. This change log is required for Multi-Tab synchronization, but
+   * not needed in clients that don't share access to their remote document
+   * cache.
+   */
+  constructor(
+    private readonly serializer: LocalSerializer,
+    private readonly keepDocumentChangeLog: boolean
+  ) {}
 
   start(transaction: PersistenceTransaction): PersistencePromise<void> {
     // If there are no existing changes, we set `lastReturnedDocumentChangesId`
@@ -77,11 +88,14 @@ export class IndexedDbRemoteDocumentCache implements RemoteDocumentCache {
         changedKeys = changedKeys.add(maybeDocument.key);
       }
 
-      promises.push(
-        documentChangesStore(transaction).put({
-          changes: this.serializer.toDbResourcePaths(changedKeys)
-        })
-      );
+      if (this.keepDocumentChangeLog) {
+        // TODO(multitab): GC the documentChanges store.
+        promises.push(
+          documentChangesStore(transaction).put({
+            changes: this.serializer.toDbResourcePaths(changedKeys)
+          })
+        );
+      }
     }
 
     return PersistencePromise.waitFor(promises);
@@ -134,6 +148,10 @@ export class IndexedDbRemoteDocumentCache implements RemoteDocumentCache {
   getNewDocumentChanges(
     transaction: PersistenceTransaction
   ): PersistencePromise<MaybeDocumentMap> {
+    assert(
+      this.keepDocumentChangeLog,
+      'Can only call getNewDocumentChanges() when document change log is enabled'
+    );
     let changedKeys = documentKeySet();
     let changedDocs = maybeDocumentMap();
 

packages/firestore/test/unit/local/persistence_test_helpers.ts

@@ -51,12 +51,10 @@ const LOCAL_STORAGE_PREFIX = 'firestore_';
  * any previous contents if they existed.
  */
 export async function testIndexedDbPersistence(
-  queue?: AsyncQueue,
-  clientId?: ClientId
+  synchronizeTabs?: boolean
 ): Promise<IndexedDbPersistence> {
-  queue = queue || new AsyncQueue();
-  clientId = clientId || AutoId.newId();
-
+  const queue = new AsyncQueue();
+  const clientId = AutoId.newId();
   const prefix = `${TEST_PERSISTENCE_PREFIX}/`;
   await SimpleDb.delete(prefix + IndexedDbPersistence.MAIN_DATABASE);
   const partition = new DatabaseId('project');
@@ -71,7 +69,7 @@ export async function testIndexedDbPersistence(
     queue,
     serializer
   );
-  await persistence.start();
+  await persistence.start(synchronizeTabs);
   return persistence;
 }
 

packages/firestore/test/unit/local/remote_document_cache.test.ts

@@ -52,9 +52,12 @@ describe('IndexedDbRemoteDocumentCache', () => {
   }
 
   beforeEach(() => {
-    return persistenceHelpers.testIndexedDbPersistence().then(p => {
-      persistence = p;
-    });
+    // We turn on `synchronizeTabs` to test the document change log.
+    return persistenceHelpers
+      .testIndexedDbPersistence(/* synchronizeTabs= */ true)
+      .then(p => {
+        persistence = p;
+      });
   });
 
   afterEach(() => persistence.shutdown(/* deleteData= */ true));