Schedule active context jobs upon initialization(b/139435527). (#707)

* Schedule active context jobs upon initialization(b/139435527).

* Fix tests

* Address review comments + javadoc.

Author: vkryachko

transport/transport-runtime/src/androidTest/java/com/google/android/datatransport/runtime/TestRuntimeComponent.java

@@ -20,11 +20,13 @@
 import com.google.android.datatransport.runtime.scheduling.jobscheduling.SchedulerConfig;
 import com.google.android.datatransport.runtime.scheduling.jobscheduling.Uploader;
 import com.google.android.datatransport.runtime.scheduling.persistence.EventStoreModule;
+import com.google.android.datatransport.runtime.scheduling.persistence.SQLiteEventStore;
 import com.google.android.datatransport.runtime.time.Clock;
 import com.google.android.datatransport.runtime.time.Monotonic;
 import com.google.android.datatransport.runtime.time.WallTime;
 import dagger.BindsInstance;
 import dagger.Component;
+import java.io.IOException;
 import javax.inject.Singleton;
 
 @Component(
@@ -38,6 +40,14 @@ abstract class TestRuntimeComponent extends TransportRuntimeComponent {
 
   abstract TransportRuntime getTransportRuntime();
 
+  abstract SQLiteEventStore getEventStore();
+
+  @Override
+  public void close() throws IOException {
+    getEventStore().clearDb();
+    super.close();
+  }
+
   @Component.Builder
   interface Builder {
     @BindsInstance

transport/transport-runtime/src/androidTest/java/com/google/android/datatransport/runtime/TestSchedulingModule.java

@@ -14,14 +14,27 @@
 
 package com.google.android.datatransport.runtime;
 
+import static org.mockito.Mockito.spy;
+
 import com.google.android.datatransport.runtime.scheduling.DefaultScheduler;
 import com.google.android.datatransport.runtime.scheduling.Scheduler;
+import com.google.android.datatransport.runtime.scheduling.jobscheduling.Uploader;
+import com.google.android.datatransport.runtime.scheduling.jobscheduling.WorkScheduler;
 import dagger.Binds;
 import dagger.Module;
+import dagger.Provides;
+import javax.inject.Provider;
+import javax.inject.Singleton;
 
 @Module
 abstract class TestSchedulingModule {
 
   @Binds
   abstract Scheduler scheduler(DefaultScheduler scheduler);
+
+  @Provides
+  @Singleton
+  static WorkScheduler workScheduler(Provider<Uploader> uploader) {
+    return spy(new TestWorkScheduler(uploader));
+  }
 }

transport/transport-runtime/src/androidTest/java/com/google/android/datatransport/runtime/TestWorkScheduler.java

@@ -14,23 +14,23 @@
 
 package com.google.android.datatransport.runtime;
 
-import android.content.Context;
+import com.google.android.datatransport.runtime.scheduling.jobscheduling.Uploader;
 import com.google.android.datatransport.runtime.scheduling.jobscheduling.WorkScheduler;
+import javax.inject.Provider;
 
 public class TestWorkScheduler implements WorkScheduler {
 
-  private final Context context;
+  private final Provider<Uploader> uploader;
 
-  public TestWorkScheduler(Context applicationContext) {
-    this.context = applicationContext;
+  TestWorkScheduler(Provider<Uploader> uploader) {
+    this.uploader = uploader;
   }
 
   @Override
   public void schedule(TransportContext transportContext, int attemptNumber) {
     if (attemptNumber > 2) {
       return;
     }
-    TransportRuntime.initialize(context);
-    TransportRuntime.getInstance().getUploader().upload(transportContext, attemptNumber, () -> {});
+    uploader.get().upload(transportContext, attemptNumber, () -> {});
   }
 }

transport/transport-runtime/src/androidTest/java/com/google/android/datatransport/runtime/UploaderIntegrationTest.java

@@ -19,7 +19,6 @@
 import static org.mockito.ArgumentMatchers.eq;
 import static org.mockito.Mockito.doThrow;
 import static org.mockito.Mockito.mock;
-import static org.mockito.Mockito.spy;
 import static org.mockito.Mockito.times;
 import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
@@ -53,17 +52,17 @@ public class UploaderIntegrationTest {
   private final TransportBackend mockBackend = mock(TransportBackend.class);
   private final BackendRegistry mockRegistry = mock(BackendRegistry.class);
   private final Context context = InstrumentationRegistry.getInstrumentation().getContext();
-  private final WorkScheduler spyScheduler = spy(new TestWorkScheduler(context));
 
-  private final TransportRuntimeComponent component =
+  private final UploaderTestRuntimeComponent component =
       DaggerUploaderTestRuntimeComponent.builder()
           .setApplicationContext(context)
           .setBackendRegistry(mockRegistry)
-          .setWorkScheduler(spyScheduler)
           .setEventClock(() -> 3)
           .setUptimeClock(() -> 1)
           .build();
 
+  private final WorkScheduler spyScheduler = component.getWorkScheduler();
+
   @Rule public final TransportRuntimeRule runtimeRule = new TransportRuntimeRule(component);
 
   @Before

transport/transport-runtime/src/androidTest/java/com/google/android/datatransport/runtime/UploaderTestRuntimeComponent.java

@@ -17,13 +17,14 @@
 import android.content.Context;
 import com.google.android.datatransport.runtime.backends.BackendRegistry;
 import com.google.android.datatransport.runtime.scheduling.jobscheduling.WorkScheduler;
-import com.google.android.datatransport.runtime.scheduling.persistence.EventStore;
+import com.google.android.datatransport.runtime.scheduling.persistence.SQLiteEventStore;
 import com.google.android.datatransport.runtime.scheduling.persistence.SpyEventStoreModule;
 import com.google.android.datatransport.runtime.time.Clock;
 import com.google.android.datatransport.runtime.time.Monotonic;
 import com.google.android.datatransport.runtime.time.WallTime;
 import dagger.BindsInstance;
 import dagger.Component;
+import java.io.IOException;
 import javax.inject.Singleton;
 
 @Component(
@@ -37,16 +38,21 @@ abstract class UploaderTestRuntimeComponent extends TransportRuntimeComponent {
 
   abstract TransportRuntime getTransportRuntime();
 
-  abstract EventStore getEventStore();
+  abstract SQLiteEventStore getEventStore();
+
+  abstract WorkScheduler getWorkScheduler();
+
+  @Override
+  public void close() throws IOException {
+    getEventStore().clearDb();
+    super.close();
+  }
 
   @Component.Builder
   interface Builder {
     @BindsInstance
     Builder setApplicationContext(Context applicationContext);
 
-    @BindsInstance
-    Builder setWorkScheduler(WorkScheduler workScheduler);
-
     @BindsInstance
     Builder setBackendRegistry(BackendRegistry registry);
 

transport/transport-runtime/src/androidTest/java/com/google/android/datatransport/runtime/scheduling/persistence/SpyEventStoreModule.java

@@ -17,6 +17,9 @@
 import static org.mockito.Mockito.spy;
 
 import com.google.android.datatransport.runtime.synchronization.SynchronizationGuard;
+import com.google.android.datatransport.runtime.time.Clock;
+import com.google.android.datatransport.runtime.time.Monotonic;
+import com.google.android.datatransport.runtime.time.WallTime;
 import dagger.Binds;
 import dagger.Module;
 import dagger.Provides;
@@ -32,10 +35,17 @@ static EventStoreConfig storeConfig() {
 
   @Provides
   @Singleton
-  static EventStore eventStore(SQLiteEventStore store) {
-    return spy(store);
+  static SQLiteEventStore sqliteEventStore(
+      @WallTime Clock wallClock,
+      @Monotonic Clock clock,
+      EventStoreConfig config,
+      SchemaManager schemaManager) {
+    return spy(new SQLiteEventStore(wallClock, clock, config, schemaManager));
   }
 
+  @Binds
+  abstract EventStore eventStore(SQLiteEventStore store);
+
   @Binds
   abstract SynchronizationGuard synchronizationGuard(SQLiteEventStore store);
 

transport/transport-runtime/src/main/java/com/google/android/datatransport/runtime/TransportRuntime.java

@@ -20,6 +20,7 @@
 import com.google.android.datatransport.TransportFactory;
 import com.google.android.datatransport.runtime.scheduling.Scheduler;
 import com.google.android.datatransport.runtime.scheduling.jobscheduling.Uploader;
+import com.google.android.datatransport.runtime.scheduling.jobscheduling.WorkInitializer;
 import com.google.android.datatransport.runtime.time.Clock;
 import com.google.android.datatransport.runtime.time.Monotonic;
 import com.google.android.datatransport.runtime.time.WallTime;
@@ -48,11 +49,14 @@ public class TransportRuntime implements TransportInternal {
       @WallTime Clock eventClock,
       @Monotonic Clock uptimeClock,
       Scheduler scheduler,
-      Uploader uploader) {
+      Uploader uploader,
+      WorkInitializer initializer) {
     this.eventClock = eventClock;
     this.uptimeClock = uptimeClock;
     this.scheduler = scheduler;
     this.uploader = uploader;
+
+    initializer.ensureContextsScheduled();
   }
 
   /**

transport/transport-runtime/src/main/java/com/google/android/datatransport/runtime/scheduling/jobscheduling/WorkInitializer.java

@@ -0,0 +1,62 @@
+// Copyright 2019 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.android.datatransport.runtime.scheduling.jobscheduling;
+
+import com.google.android.datatransport.runtime.TransportContext;
+import com.google.android.datatransport.runtime.scheduling.persistence.EventStore;
+import com.google.android.datatransport.runtime.synchronization.SynchronizationGuard;
+import java.util.concurrent.Executor;
+import javax.inject.Inject;
+
+/**
+ * Re-schedules any contexts that have pending events and are not currently scheduled.
+ *
+ * <p>The reasons for them not to be scheduled include:
+ *
+ * <ul>
+ *   <li>Host application update to newer version
+ *   <li>Device restart
+ * </ul>
+ *
+ * Note: there is no way for us to know how many attempts had been previously tried, so we
+ * re-schedule from attempt 1.
+ */
+public class WorkInitializer {
+  private final Executor executor;
+  private final EventStore store;
+  private final WorkScheduler scheduler;
+  private final SynchronizationGuard guard;
+
+  @Inject
+  WorkInitializer(
+      Executor executor, EventStore store, WorkScheduler scheduler, SynchronizationGuard guard) {
+    this.executor = executor;
+    this.store = store;
+    this.scheduler = scheduler;
+    this.guard = guard;
+  }
+
+  public void ensureContextsScheduled() {
+    executor.execute(
+        () ->
+            guard.runCriticalSection(
+                () -> {
+                  for (TransportContext context : store.loadActiveContexts()) {
+                    scheduler.schedule(context, 1);
+                  }
+                  return null;
+                }));
+  }
+}

transport/transport-runtime/src/main/java/com/google/android/datatransport/runtime/scheduling/persistence/EventStore.java

@@ -50,6 +50,9 @@ public interface EventStore extends Closeable {
   /** Load all pending events for a given backend. */
   Iterable<PersistedEvent> loadBatch(TransportContext transportContext);
 
+  /** Load all {@link TransportContext}s that have pending events. */
+  Iterable<TransportContext> loadActiveContexts();
+
   /** Remove events that have been stored for more than 7 days. */
   int cleanUp();
 }

transport/transport-runtime/src/main/java/com/google/android/datatransport/runtime/scheduling/persistence/SQLiteEventStore.java

@@ -21,6 +21,7 @@
 import android.os.SystemClock;
 import android.util.Base64;
 import androidx.annotation.Nullable;
+import androidx.annotation.RestrictTo;
 import androidx.annotation.VisibleForTesting;
 import androidx.annotation.WorkerThread;
 import com.google.android.datatransport.runtime.EventInternal;
@@ -274,6 +275,28 @@ public Iterable<PersistedEvent> loadBatch(TransportContext transportContext) {
         });
   }
 
+  @Override
+  public Iterable<TransportContext> loadActiveContexts() {
+    return inTransaction(
+        db ->
+            tryWithCursor(
+                db.rawQuery(
+                    "SELECT t.backend_name, t.priority, t.extras FROM transport_contexts AS t, events AS e WHERE e.context_id = t._id",
+                    new String[] {}),
+                cursor -> {
+                  List<TransportContext> results = new ArrayList<>();
+                  while (cursor.moveToNext()) {
+                    results.add(
+                        TransportContext.builder()
+                            .setBackendName(cursor.getString(0))
+                            .setPriority(cursor.getInt(1))
+                            .setExtras(maybeBase64Decode(cursor.getString(2)))
+                            .build());
+                  }
+                  return results;
+                }));
+  }
+
   @Override
   public int cleanUp() {
     long oneWeekAgo = wallClock.getTime() - config.getEventCleanUpAge();
@@ -286,6 +309,23 @@ public void close() {
     schemaManager.close();
   }
 
+  @RestrictTo(RestrictTo.Scope.TESTS)
+  public void clearDb() {
+    inTransaction(
+        db -> {
+          db.delete("events", null, new String[] {});
+          db.delete("transport_contexts", null, new String[] {});
+          return null;
+        });
+  }
+
+  private static byte[] maybeBase64Decode(@Nullable String value) {
+    if (value == null) {
+      return null;
+    }
+    return Base64.decode(value, Base64.DEFAULT);
+  }
+
   /** Loads all events for a backend. */
   private List<PersistedEvent> loadEvents(SQLiteDatabase db, TransportContext transportContext) {
     List<PersistedEvent> events = new ArrayList<>();

transport/transport-runtime/src/test/java/com/google/android/datatransport/runtime/TransportRuntimeTest.java

@@ -30,6 +30,7 @@
 import com.google.android.datatransport.runtime.backends.TransportBackend;
 import com.google.android.datatransport.runtime.scheduling.ImmediateScheduler;
 import com.google.android.datatransport.runtime.scheduling.jobscheduling.Uploader;
+import com.google.android.datatransport.runtime.scheduling.jobscheduling.WorkInitializer;
 import java.util.Collections;
 import org.junit.Test;
 import org.junit.runner.RunWith;
@@ -40,9 +41,11 @@
 public class TransportRuntimeTest {
   private static final String TEST_KEY = "test";
   private static final String TEST_VALUE = "test-value";
-  private TransportInternal transportInternalMock = mock(TransportInternal.class);
-  private TransportBackend mockBackend = mock(TransportBackend.class);
-  private BackendRegistry mockRegistry = mock(BackendRegistry.class);
+
+  private final TransportInternal transportInternalMock = mock(TransportInternal.class);
+  private final TransportBackend mockBackend = mock(TransportBackend.class);
+  private final BackendRegistry mockRegistry = mock(BackendRegistry.class);
+  private final WorkInitializer mockInitializer = mock(WorkInitializer.class);
 
   @Test
   public void testTransportInternalSend() {
@@ -75,7 +78,10 @@ public void testTransportRuntimeBackendDiscovery() {
             () -> eventMillis,
             () -> uptimeMillis,
             new ImmediateScheduler(Runnable::run, mockRegistry),
-            new Uploader(null, null, null, null, null, null, () -> 2));
+            new Uploader(null, null, null, null, null, null, () -> 2),
+            mockInitializer);
+    verify(mockInitializer, times(1)).ensureContextsScheduled();
+
     when(mockRegistry.get(mockBackendName)).thenReturn(mockBackend);
     when(mockBackend.decorate(any()))
         .thenAnswer(