Remove the index that is not necessary.

Author: ehsannas

packages/firestore/src/local/document_overlay_cache.ts

@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+import { DocumentKeySet } from '../model/collections';
 import { DocumentKey } from '../model/document_key';
 import { Mutation } from '../model/mutation';
 import { Overlay } from '../model/overlay';
@@ -53,9 +54,10 @@ export interface DocumentOverlayCache {
     overlays: Map<DocumentKey, Mutation>
   ): PersistencePromise<void>;
 
-  /** Removes the overlay whose largest-batch-id equals the given ID. */
+  /** Removes overlays for the given document keys and batch ID. */
   removeOverlaysForBatchId(
     transaction: PersistenceTransaction,
+    documentKeys: DocumentKeySet,
     batchId: number
   ): PersistencePromise<void>;
 

packages/firestore/src/local/indexeddb_document_overlay_cache.ts

@@ -16,6 +16,7 @@
  */
 
 import { User } from '../auth/user';
+import { DocumentKeySet } from '../model/collections';
 import { DocumentKey } from '../model/document_key';
 import { Mutation } from '../model/mutation';
 import { Overlay } from '../model/overlay';
@@ -85,18 +86,32 @@ export class IndexedDbDocumentOverlayCache implements DocumentOverlayCache {
 
   removeOverlaysForBatchId(
     transaction: PersistenceTransaction,
+    documentKeys: DocumentKeySet,
     batchId: number
   ): PersistencePromise<void> {
-    const range = IDBKeyRange.bound(
-      [this.userId, batchId],
-      [this.userId, batchId + 1],
-      /*lowerOpen=*/ false,
-      /*upperOpen=*/ true
-    );
-    return documentOverlayStore(transaction).deleteAll(
-      DbDocumentOverlay.batchIdOverlayIndex,
-      range
+    const collectionPaths = new Set<string>();
+
+    // Get the set of unique collection paths.
+    documentKeys.forEach(key =>
+      collectionPaths.add(encodeResourcePath(key.getCollectionPath()))
     );
+
+    const promises: Array<PersistencePromise<void>> = [];
+    collectionPaths.forEach(collectionPath => {
+      const range = IDBKeyRange.bound(
+        [this.userId, collectionPath, batchId],
+        [this.userId, collectionPath, batchId + 1],
+        /*lowerOpen=*/ false,
+        /*upperOpen=*/ true
+      );
+      promises.push(
+        documentOverlayStore(transaction).deleteAll(
+          DbDocumentOverlay.collectionPathOverlayIndex,
+          range
+        )
+      );
+    });
+    return PersistencePromise.waitFor(promises);
   }
 
   getOverlaysForCollection(

packages/firestore/src/local/indexeddb_schema.ts

@@ -810,11 +810,7 @@ export class DbDocumentOverlay {
 
   static keyPath = ['userId', 'collectionPath', 'documentId'];
 
-  // TODO(overlays): Remove this index if the other indexes suffice.
-  static batchIdOverlayIndex = 'batchIdOverlayIndex';
-  static batchIdOverlayIndexPath = ['userId', 'largestBatchId'];
-
-  static collectionPathOverlayIndex = 'collectionPathBatchIdIndex';
+  static collectionPathOverlayIndex = 'collectionPathOverlayIndex';
   static collectionPathOverlayIndexPath = [
     'userId',
     'collectionPath',

packages/firestore/src/local/indexeddb_schema_converter.ts

@@ -538,11 +538,6 @@ function createDocumentOverlayStore(db: IDBDatabase): void {
   const documentOverlayStore = db.createObjectStore(DbDocumentOverlay.store, {
     keyPath: DbDocumentOverlay.keyPath
   });
-  documentOverlayStore.createIndex(
-    DbDocumentOverlay.batchIdOverlayIndex,
-    DbDocumentOverlay.batchIdOverlayIndexPath,
-    { unique: false }
-  );
   documentOverlayStore.createIndex(
     DbDocumentOverlay.collectionPathOverlayIndex,
     DbDocumentOverlay.collectionPathOverlayIndexPath,

packages/firestore/src/local/memory_document_overlay_cache.ts

@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+import { DocumentKeySet } from '../model/collections';
 import { DocumentKey } from '../model/document_key';
 import { Mutation } from '../model/mutation';
 import { Overlay } from '../model/overlay';
@@ -57,6 +58,7 @@ export class MemoryDocumentOverlayCache implements DocumentOverlayCache {
 
   removeOverlaysForBatchId(
     transaction: PersistenceTransaction,
+    documentKeys: DocumentKeySet,
     batchId: number
   ): PersistencePromise<void> {
     const keys = this.overlayByBatchId.get(batchId);

packages/firestore/src/model/document_key.ts

@@ -56,6 +56,11 @@ export class DocumentKey {
     return this.path.get(this.path.length - 2);
   }
 
+  /** Returns the fully qualified path to the parent collection. */
+  getCollectionPath(): ResourcePath {
+    return this.path.popLast();
+  }
+
   isEqual(other: DocumentKey | null): boolean {
     return (
       other !== null && ResourcePath.comparator(this.path, other.path) === 0