Merge LRU tracking PRs (#1285)

* Implement IndexedDB LRU Reference Delegate, add LRU tests (#1224)
* Implement LRU Reference Delegate for Memory Persistence (#1237)
* Implement Eager Reference Delegate for Memory Persistence, drop old GC (#1256)
* Remove sequential forEach, replace with parallel forEach

Author: Greg Soltis

packages/firestore/src/core/firestore_client.ts

@@ -16,12 +16,9 @@
 
 import { CredentialsProvider } from '../api/credentials';
 import { User } from '../auth/user';
-import { EagerGarbageCollector } from '../local/eager_garbage_collector';
-import { GarbageCollector } from '../local/garbage_collector';
 import { IndexedDbPersistence } from '../local/indexeddb_persistence';
 import { LocalStore } from '../local/local_store';
 import { MemoryPersistence } from '../local/memory_persistence';
-import { NoOpGarbageCollector } from '../local/no_op_garbage_collector';
 import { Persistence } from '../local/persistence';
 import {
   DocumentKeySet,
@@ -83,7 +80,6 @@ export class FirestoreClient {
   // with the types rather than littering the code with '!' or unnecessary
   // undefined checks.
   private eventMgr: EventManager;
-  private garbageCollector: GarbageCollector;
   private persistence: Persistence;
   private localStore: LocalStore;
   private remoteStore: RemoteStore;
@@ -292,7 +288,6 @@ export class FirestoreClient {
 
     // TODO(http://b/33384523): For now we just disable garbage collection
     // when persistence is enabled.
-    this.garbageCollector = new NoOpGarbageCollector();
     const storagePrefix = IndexedDbPersistence.buildStoragePrefix(
       this.databaseInfo
     );
@@ -347,8 +342,7 @@ export class FirestoreClient {
    * @returns A promise that will successfully resolve.
    */
   private startMemoryPersistence(): Promise<void> {
-    this.garbageCollector = new EagerGarbageCollector();
-    this.persistence = new MemoryPersistence(this.clientId);
+    this.persistence = MemoryPersistence.createEagerPersistence(this.clientId);
     this.sharedClientState = new MemorySharedClientState();
     return Promise.resolve();
   }
@@ -363,11 +357,7 @@ export class FirestoreClient {
     return this.platform
       .loadConnection(this.databaseInfo)
       .then(async connection => {
-        this.localStore = new LocalStore(
-          this.persistence,
-          user,
-          this.garbageCollector
-        );
+        this.localStore = new LocalStore(this.persistence, user);
         const serializer = this.platform.newSerializer(
           this.databaseInfo.databaseId
         );

packages/firestore/src/core/sync_engine.ts

@@ -325,7 +325,6 @@ export class SyncEngine implements RemoteSyncer, SharedClientStateSyncer {
             this.remoteStore.unlisten(queryView.targetId);
             return this.removeAndCleanupQuery(queryView);
           })
-          .then(() => this.localStore.collectGarbage())
           .catch(err => this.ignoreIfPrimaryLeaseLoss(err));
       }
     } else {
@@ -584,7 +583,6 @@ export class SyncEngine implements RemoteSyncer, SharedClientStateSyncer {
       // NOTE: Both these methods are no-ops for batches that originated from
       // other clients.
       this.processUserCallback(batchId, error ? error : null);
-
       this.localStore.removeCachedMutationBatchMetadata(batchId);
     } else {
       fail(`Unknown batchState: ${batchState}`);
@@ -821,12 +819,7 @@ export class SyncEngine implements RemoteSyncer, SharedClientStateSyncer {
 
     await Promise.all(queriesProcessed);
     this.syncEngineListener!.onWatchChange(newSnaps);
-    this.localStore.notifyLocalViewChanges(docChangesInAllViews);
-    if (this.isPrimary) {
-      await this.localStore
-        .collectGarbage()
-        .catch(err => this.ignoreIfPrimaryLeaseLoss(err));
-    }
+    await this.localStore.notifyLocalViewChanges(docChangesInAllViews);
   }
 
   /**