feat(@aws-amplify/datastore): selective sync enhancements (aws-amplif…

…y#7083)
MLH-Fellowship · Jan 20, 2021 · 589d140 · 589d140
1 parent ed6914e
commit 589d140
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Showing 2 changed files with 39 additions and 39 deletions.
diff --git a/packages/datastore/src/datastore/datastore.ts b/packages/datastore/src/datastore/datastore.ts
@@ -551,7 +551,6 @@ class DataStore {
 		SchemaModel,
 		ModelPredicate<any>
 	> = new WeakMap<SchemaModel, ModelPredicate<any>>();
-	private syncModelsUpdated: Set<string> = new Set<string>();
 
 	getModuleName() {
 		return 'DataStore';
@@ -599,8 +598,7 @@ class DataStore {
 				this.syncPageSize,
 				this.conflictHandler,
 				this.errorHandler,
-				this.syncPredicates,
-				this.syncModelsUpdated
+				this.syncPredicates
 			);
 
 			// tslint:disable-next-line:max-line-length
@@ -1035,6 +1033,7 @@ class DataStore {
 		this.initialized = undefined; // Should re-initialize when start() is called.
 		this.storage = undefined;
 		this.sync = undefined;
+		this.syncPredicates = new WeakMap<SchemaModel, ModelPredicate<any>>();
 	};
 
 	stop = async function stop() {
@@ -1113,6 +1112,10 @@ class DataStore {
 					// conditionProducer is either a predicate, e.g. (c) => c.field('eq', 1)
 					// OR a function/promise that returns a predicate
 					const condition = await this.unwrapPromise(conditionProducer);
+					if (isPredicatesAll(condition)) {
+						return [modelDefinition, null];
+					}
+
 					const predicate = this.createFromCondition(
 						modelDefinition,
 						condition
@@ -1123,34 +1126,9 @@ class DataStore {
 			)
 		);
 
-		this.compareSyncPredicates(syncPredicates);
-
 		return this.weakMapFromEntries(syncPredicates);
 	}
 
-	private compareSyncPredicates(
-		syncPredicates: [SchemaModel, ModelPredicate<any>][]
-	) {
-		this.syncModelsUpdated = new Set<string>();
-
-		syncPredicates.forEach(([modelDefinition, predicate]) => {
-			const previousPredicate = ModelPredicateCreator.getPredicates(
-				this.syncPredicates.get(modelDefinition),
-				false
-			);
-
-			const newPredicate = ModelPredicateCreator.getPredicates(
-				predicate,
-				false
-			);
-
-			const predicateChanged =
-				JSON.stringify(previousPredicate) !== JSON.stringify(newPredicate);
-
-			predicateChanged && this.syncModelsUpdated.add(modelDefinition.name);
-		});
-	}
-
 	private createFromCondition(
 		modelDefinition: SchemaModel,
 		condition: ProducerModelPredicate<PersistentModel>
@@ -1188,12 +1166,15 @@ class DataStore {
 				const { name } = modelDefinition;
 				logger.warn(
 					`You can only utilize one Sync Expression per model. 
-					Subsequent sync expressions for the ${name} model will be ignored.`
+          Subsequent sync expressions for the ${name} model will be ignored.`
 				);
 				return map;
 			}
 
-			map.set(modelDefinition, predicate);
+			if (predicate) {
+				map.set(modelDefinition, predicate);
+			}
+
 			return map;
 		}, new WeakMap<SchemaModel, ModelPredicate<any>>());
 	}

diff --git a/packages/datastore/src/sync/index.ts b/packages/datastore/src/sync/index.ts
@@ -69,6 +69,7 @@ declare class ModelMetadata {
 	public readonly fullSyncInterval: number;
 	public readonly lastSync?: number;
 	public readonly lastFullSync?: number;
+	public readonly lastSyncPredicate?: null | string;
 }
 
 export enum ControlMessage {
@@ -104,8 +105,7 @@ export class SyncEngine {
 		private readonly syncPageSize: number,
 		conflictHandler: ConflictHandler,
 		errorHandler: ErrorHandler,
-		private readonly syncPredicates: WeakMap<SchemaModel, ModelPredicate<any>>,
-		private readonly syncModelsUpdated: ReadonlySet<string>
+		private readonly syncPredicates: WeakMap<SchemaModel, ModelPredicate<any>>
 	) {
 		const MutationEvent = this.modelClasses[
 			'MutationEvent'
@@ -410,7 +410,14 @@ export class SyncEngine {
 	): Promise<Map<SchemaModel, [string, number]>> {
 		const modelLastSync: Map<SchemaModel, [string, number]> = new Map(
 			(await this.getModelsMetadata()).map(
-				({ namespace, model, lastSync, lastFullSync, fullSyncInterval }) => {
+				({
+					namespace,
+					model,
+					lastSync,
+					lastFullSync,
+					fullSyncInterval,
+					lastSyncPredicate,
+				}) => {
 					const nextFullSync = lastFullSync + fullSyncInterval;
 					const syncFrom =
 						!lastFullSync || nextFullSync < currentTimeStamp
@@ -694,34 +701,45 @@ export class SyncEngine {
 		const ModelMetadata = this.modelClasses
 			.ModelMetadata as PersistentModelConstructor<ModelMetadata>;
 
-		const models: [string, string][] = [];
+		const models: [string, SchemaModel][] = [];
+		let savedModel;
 
 		Object.values(this.schema.namespaces).forEach(namespace => {
 			Object.values(namespace.models)
 				.filter(({ syncable }) => syncable)
 				.forEach(model => {
-					models.push([namespace.name, model.name]);
+					models.push([namespace.name, model]);
 				});
 		});
 
 		const promises = models.map(async ([namespace, model]) => {
-			const modelMetadata = await this.getModelMetadata(namespace, model);
-			let savedModel: ModelMetadata;
+			const modelMetadata = await this.getModelMetadata(namespace, model.name);
+			const syncPredicate = ModelPredicateCreator.getPredicates(
+				this.syncPredicates.get(model),
+				false
+			);
+			const lastSyncPredicate = syncPredicate
+				? JSON.stringify(syncPredicate)
+				: null;
 
 			if (modelMetadata === undefined) {
 				[[savedModel]] = await this.storage.save(
 					this.modelInstanceCreator(ModelMetadata, {
-						model,
+						model: model.name,
 						namespace,
 						lastSync: null,
 						fullSyncInterval,
 						lastFullSync: null,
+						lastSyncPredicate,
 					}),
 					undefined,
 					ownSymbol
 				);
 			} else {
-				const syncPredicateUpdated = this.syncModelsUpdated.has(model);
+				const prevSyncPredicate = modelMetadata.lastSyncPredicate
+					? JSON.stringify(modelMetadata.lastSyncPredicate)
+					: null;
+				const syncPredicateUpdated = prevSyncPredicate !== lastSyncPredicate;
 
 				[[savedModel]] = await this.storage.save(
 					(this.modelClasses.ModelMetadata as PersistentModelConstructor<
@@ -733,6 +751,7 @@ export class SyncEngine {
 						if (syncPredicateUpdated) {
 							draft.lastSync = null;
 							draft.lastFullSync = null;
+							draft.lastSyncPredicate = lastSyncPredicate;
 						}
 					})
 				);