Update to background thread execution for listDownloadModels call.

Author: annzimmer

firebase-ml-modeldownloader/src/main/java/com/google/firebase/ml/modeldownloader/internal/SharedPreferencesUtil.java

@@ -213,7 +213,7 @@ public synchronized Set<CustomModel> listDownloadedModels() {
         matcher = Pattern.compile(DOWNLOADING_MODEL_ID_PATTERN).matcher(key);
         if (matcher.find()) {
           String modelName = matcher.group(matcher.groupCount());
-          CustomModel extractModel = isDownloadCompleted(modelName);
+          CustomModel extractModel = maybeGetUpdatedModel(modelName);
           if (extractModel != null) {
             customModels.add(extractModel);
           }
@@ -223,7 +223,7 @@ public synchronized Set<CustomModel> listDownloadedModels() {
     return customModels;
   }
 
-  synchronized CustomModel isDownloadCompleted(String modelName) {
+  synchronized CustomModel maybeGetUpdatedModel(String modelName) {
     CustomModel downloadModel = getCustomModelDetails(modelName);
     // TODO(annz) check here if download currently in progress have completed.
     // if yes, then complete file relocation and return the updated model, otherwise return null

firebase-ml-modeldownloader/src/test/java/com/google/firebase/ml/modeldownloader/FirebaseModelDownloaderTest.java

@@ -29,8 +29,7 @@
 import java.util.Set;
 import java.util.concurrent.ExecutionException;
 import java.util.concurrent.ExecutorService;
-import java.util.concurrent.LinkedBlockingQueue;
-import java.util.concurrent.ThreadPoolExecutor;
+import java.util.concurrent.Executors;
 import java.util.concurrent.TimeUnit;
 import org.junit.After;
 import org.junit.Before;
@@ -69,7 +68,7 @@ public void setUp() {
     // default app
     FirebaseApp.initializeApp(ApplicationProvider.getApplicationContext(), FIREBASE_OPTIONS);
 
-    executor = new ThreadPoolExecutor(0, 1, 30L, TimeUnit.SECONDS, new LinkedBlockingQueue<>());
+    executor = Executors.newSingleThreadExecutor();
     firebaseModelDownloader = new FirebaseModelDownloader(FIREBASE_OPTIONS, mockPrefs, executor);
   }