get() reimplementation

firebase-database/src/androidTest/java/com/google/firebase/database/QueryTest.java

@@ -15,6 +15,7 @@
 package com.google.firebase.database;
 
 import static android.os.AsyncTask.THREAD_POOL_EXECUTOR;
+import static com.google.android.gms.tasks.Tasks.await;
 import static org.junit.Assert.assertArrayEquals;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
@@ -28,7 +29,6 @@
 import androidx.test.platform.app.InstrumentationRegistry;
 import com.google.android.gms.tasks.OnCompleteListener;
 import com.google.android.gms.tasks.Task;
-import com.google.android.gms.tasks.Tasks;
 import com.google.firebase.FirebaseApp;
 import com.google.firebase.FirebaseOptions;
 import com.google.firebase.database.core.DatabaseConfig;
@@ -592,10 +592,10 @@ public void testStartAfterWithOrderByKey()
     DatabaseReference ref = IntegrationTestHelpers.getRandomNode();
     DatabaseReference childOne = ref.push();
     DatabaseReference childTwo = ref.push();
-    Tasks.await(childOne.setValue(1L));
-    Tasks.await(childTwo.setValue(2L));
+    await(childOne.setValue(1L));
+    await(childTwo.setValue(2L));
 
-    DataSnapshot snapshot = Tasks.await(ref.orderByKey().startAfter(childOne.getKey()).get());
+    DataSnapshot snapshot = await(ref.orderByKey().startAfter(childOne.getKey()).get());
 
     Map<String, Long> values = (Map<String, Long>) snapshot.getValue();
 
@@ -610,10 +610,10 @@ public void testEndBeforeWithOrderByKey()
     DatabaseReference ref = IntegrationTestHelpers.getRandomNode();
     DatabaseReference childOne = ref.push();
     DatabaseReference childTwo = ref.push();
-    Tasks.await(childOne.setValue(1L));
-    Tasks.await(childTwo.setValue(2L));
+    await(childOne.setValue(1L));
+    await(childTwo.setValue(2L));
 
-    DataSnapshot snapshot = Tasks.await(ref.orderByKey().endBefore(childTwo.getKey()).get());
+    DataSnapshot snapshot = await(ref.orderByKey().endBefore(childTwo.getKey()).get());
     Map<String, Long> values = (Map<String, Long>) snapshot.getValue();
 
     assertNotNull(values);
@@ -629,8 +629,8 @@ public void testEndBeforeWithOrderByKeyOverlappingListener()
     DatabaseReference ref = IntegrationTestHelpers.getRandomNode();
     DatabaseReference childOne = ref.push();
     DatabaseReference childTwo = ref.push();
-    Tasks.await(childOne.setValue(1L));
-    Tasks.await(childTwo.setValue(2L));
+    await(childOne.setValue(1L));
+    await(childTwo.setValue(2L));
 
     Semaphore semaphore = new Semaphore(0);
     ValueEventListener listener =
@@ -648,7 +648,7 @@ public void onCancelled(@NonNull DatabaseError error) {}
 
     IntegrationTestHelpers.waitFor(semaphore);
 
-    DataSnapshot snapshot = Tasks.await(ref.orderByKey().endBefore(childTwo.getKey()).get());
+    DataSnapshot snapshot = await(ref.orderByKey().endBefore(childTwo.getKey()).get());
     Map<String, Long> values = (Map<String, Long>) snapshot.getValue();
 
     assertNotNull(values);
@@ -663,8 +663,8 @@ public void testStartAfterWithOrderByKeyOverlappingListener()
     DatabaseReference ref = IntegrationTestHelpers.getRandomNode();
     DatabaseReference childOne = ref.push();
     DatabaseReference childTwo = ref.push();
-    Tasks.await(childOne.setValue(1L));
-    Tasks.await(childTwo.setValue(2L));
+    await(childOne.setValue(1L));
+    await(childTwo.setValue(2L));
 
     Semaphore semaphore = new Semaphore(0);
     ValueEventListener listener =
@@ -681,7 +681,7 @@ public void onCancelled(@NonNull DatabaseError error) {}
 
     IntegrationTestHelpers.waitFor(semaphore);
 
-    DataSnapshot snapshot = Tasks.await(ref.orderByKey().startAfter(childOne.getKey()).get());
+    DataSnapshot snapshot = await(ref.orderByKey().startAfter(childOne.getKey()).get());
     Map<String, Long> values = (Map<String, Long>) snapshot.getValue();
 
     assertNotNull(values);
@@ -4554,7 +4554,7 @@ public void testGetReturnsNullForEmptyNodeWhenOnline()
     FirebaseApp app =
         appForDatabaseUrl(IntegrationTestValues.getDatabaseUrl(), UUID.randomUUID().toString());
     FirebaseDatabase db = FirebaseDatabase.getInstance(app);
-    assertNull(Tasks.await(db.getReference(UUID.randomUUID().toString()).get()).getValue());
+    assertNull(await(db.getReference(UUID.randomUUID().toString()).get()).getValue());
   }
 
   @Test
@@ -4578,22 +4578,188 @@ public void testGetWaitsForConnection() throws DatabaseException, InterruptedExc
           }
         });
     try {
-      Tasks.await(node.get());
+      await(node.get());
       receivedValue.set(true);
     } catch (ExecutionException e) {
       fail("get threw an exception: " + e);
     }
   }
 
+  @Test
+  public void testGetResolvesToCacheWhenOfflineAndNoListeners()
+      throws DatabaseException, InterruptedException {
+    FirebaseApp app =
+        appForDatabaseUrl(IntegrationTestValues.getDatabaseUrl(), UUID.randomUUID().toString());
+    FirebaseDatabase db = FirebaseDatabase.getInstance(app);
+    DatabaseReference node =
+        db.getReference().child(Objects.requireNonNull(db.getReference().push().getKey()));
+    long val = 34;
+    node.setValue(val);
+    db.goOffline();
+    try {
+      DataSnapshot snapshot = await(node.get());
+      assertEquals(snapshot.getValue(), val); // TODO(mtewani): Check why this is always long?
+    } catch (ExecutionException e) {
+      fail("get threw an exception: " + e);
+    }
+  }
+
+  @Test
+  public void testGetResolvesToCacheWhenOnlineAndNoListeners()
+      throws DatabaseException, InterruptedException {
+    FirebaseApp app =
+        appForDatabaseUrl(IntegrationTestValues.getDatabaseUrl(), UUID.randomUUID().toString());
+    FirebaseDatabase db = FirebaseDatabase.getInstance(app);
+    DatabaseReference node =
+        db.getReference().child(Objects.requireNonNull(db.getReference().push().getKey()));
+    long val = 34;
+    try {
+      node.setValue(val);
+      DataSnapshot snapshot = await(node.get());
+      assertEquals(snapshot.getValue(), val); // TODO(mtewani): Check why this is always long?
+    } catch (ExecutionException e) {
+      fail("get threw an exception: " + e);
+    }
+  }
+
+  @Test
+  public void testGetResolvesToCacheWhenOnlineAndParentListener()
+      throws DatabaseException, InterruptedException {
+    FirebaseApp app =
+        appForDatabaseUrl(IntegrationTestValues.getDatabaseUrl(), UUID.randomUUID().toString());
+    FirebaseDatabase db = FirebaseDatabase.getInstance(app);
+    DatabaseReference topLevelNode = db.getReference();
+    Semaphore semaphore = new Semaphore(0);
+    long val = 34;
+    DatabaseReference node =
+        db.getReference().child(Objects.requireNonNull(db.getReference().push().getKey()));
+    ValueEventListener listener =
+        new ValueEventListener() {
+          @Override
+          public void onDataChange(@NonNull DataSnapshot snapshot) {
+            assertTrue(snapshot.hasChildren());
+            DataSnapshot childNode = null;
+            for (DataSnapshot child : snapshot.getChildren()) {
+              if (child.getKey().equals(node.getKey())) {
+                childNode = child;
+              }
+            }
+            assertEquals(childNode.getValue(), 34L);
+            semaphore.release();
+          }
+
+          @Override
+          public void onCancelled(@NonNull DatabaseError error) {
+            // no-op
+          }
+        };
+    node.setValue(val);
+    topLevelNode.addValueEventListener(listener);
+
+    try {
+      IntegrationTestHelpers.waitFor(semaphore);
+      DataSnapshot snapshot = await(node.get());
+      assertEquals(
+          snapshot.getValue(),
+          val); // TODO(mtewani): We might be getting this data straight from serverCache, so we may
+      // need to rewrite it
+    } catch (ExecutionException e) {
+      fail("get threw an exception: " + e);
+    }
+  }
+
+  public void testGetResolvesToCacheWhenOnlineAndSameLevelListener()
+      throws DatabaseException, InterruptedException {
+    FirebaseApp app =
+        appForDatabaseUrl(IntegrationTestValues.getDatabaseUrl(), UUID.randomUUID().toString());
+    FirebaseDatabase db = FirebaseDatabase.getInstance(app);
+    Semaphore semaphore = new Semaphore(0);
+    long val = 34;
+    DatabaseReference node =
+        db.getReference().child(Objects.requireNonNull(db.getReference().push().getKey()));
+    node.setValue(val);
+    ValueEventListener listener =
+        new ValueEventListener() {
+          @Override
+          public void onDataChange(@NonNull DataSnapshot snapshot) {
+            assertEquals(snapshot.getValue(), 34L);
+            semaphore.release();
+          }
+
+          @Override
+          public void onCancelled(@NonNull DatabaseError error) {
+            // no-op
+          }
+        };
+    node.addValueEventListener(listener);
+
+    try {
+      IntegrationTestHelpers.waitFor(semaphore);
+      DataSnapshot snapshot = await(node.get());
+      assertEquals(
+          snapshot.getValue(),
+          val); // TODO(mtewani): We might be getting this data straight from serverCache, so we may
+      // need to rewrite it
+    } catch (ExecutionException e) {
+      fail("get threw an exception: " + e);
+    }
+  }
+
+  public void testGetResolvesToCacheWhenOnlineAndChildLevelListener()
+      throws DatabaseException, InterruptedException {
+    FirebaseApp app =
+        appForDatabaseUrl(IntegrationTestValues.getDatabaseUrl(), UUID.randomUUID().toString());
+    FirebaseDatabase db = FirebaseDatabase.getInstance(app);
+    Semaphore semaphore = new Semaphore(0);
+    long val = 34;
+    DatabaseReference node =
+        db.getReference().child(Objects.requireNonNull(db.getReference().push().getKey()));
+    DatabaseReference childNode =
+        db.getReference().child(Objects.requireNonNull(node.push().getKey()));
+    node.setValue(val);
+    ValueEventListener listener = new ValueEventListener() { // TODO: move to child reference
+          @Override
+          public void onDataChange(@NonNull DataSnapshot snapshot) {
+            assertEquals(snapshot.getValue(), 34L);
+            semaphore.release();
+          }
+
+          @Override
+          public void onCancelled(@NonNull DatabaseError error) {
+            // no-op
+          }
+        };
+    childNode.addValueEventListener(listener);
+
+    try {
+      IntegrationTestHelpers.waitFor(semaphore);
+      DataSnapshot snapshot = await(node.get());
+      assertEquals(
+          snapshot.getValue(),
+          val); // TODO(mtewani): We might be getting this data straight from serverCache, so we may
+      // need to rewrite it
+    } catch (ExecutionException e) {
+      fail("get threw an exception: " + e);
+    }
+  }
+  /*
+   * Test:
+   *   1. Resolve to cache when offline
+   *   2. Resolve to non-cache when online
+   *   3. What happens when you have a listener on the same path as the get
+   *   4. What happens when you have a listener on the child path as the get
+   *   5. What happens when you have a listener on the parent path as the get
+   */
+
   @Test
   public void testGetSendsServerGetForNodeWithNoListenerWhenOnline()
       throws DatabaseException, InterruptedException, ExecutionException {
     FirebaseApp app =
         appForDatabaseUrl(IntegrationTestValues.getDatabaseUrl(), UUID.randomUUID().toString());
     FirebaseDatabase db = FirebaseDatabase.getInstance(app);
     DatabaseReference node = db.getReference();
-    Tasks.await(node.setValue(42));
-    assertEquals(42L, Tasks.await(node.get()).getValue());
+    await(node.setValue(42));
+    assertEquals(42L, await(node.get()).getValue());
   }
 
   @Test
@@ -4618,7 +4784,7 @@ public void testGetProbesInMemoryCacheForActiveListenerWhenOffline()
     try {
       new WriteFuture(writer, 42L).timedGet();
 
-      assertEquals(Tasks.await(reader.get()).getValue(), 42L);
+      assertEquals(await(reader.get()).getValue(), 42L);
 
       Semaphore semaphore = new Semaphore(0);
       listener =
@@ -4635,7 +4801,7 @@ public void onCancelled(@NonNull DatabaseError error) {}
       reader.addValueEventListener(listener);
       IntegrationTestHelpers.waitFor(semaphore);
       readerDb.goOffline();
-      assertEquals(Tasks.await(reader.get()).getValue(), 42L);
+      assertEquals(await(reader.get()).getValue(), 42L);
     } finally {
       if (listener != null) {
         reader.removeEventListener(listener);
@@ -4651,7 +4817,7 @@ public void testGetWithPendingWrites() throws ExecutionException, InterruptedExc
     try {
       Map<String, Object> expected = new MapBuilder().put("foo", "bar").build();
       node.setValue(expected);
-      DataSnapshot snapshot = Tasks.await(node.get());
+      DataSnapshot snapshot = await(node.get());
       assertEquals(snapshot.getValue(), expected);
     } finally {
       node.getDatabase().goOnline();
@@ -4664,7 +4830,7 @@ public void testGetChildOfPendingWrites() throws ExecutionException, Interrupted
     node.getDatabase().goOffline();
     try {
       node.setValue(new MapBuilder().put("foo", "bar").build());
-      DataSnapshot snapshot = Tasks.await(node.child("foo").get());
+      DataSnapshot snapshot = await(node.child("foo").get());
       assertEquals(snapshot.getValue(), "bar");
     } finally {
       node.getDatabase().goOnline();
@@ -4710,7 +4876,7 @@ public void onCancelled(@NonNull DatabaseError error) {}
     readerDb.goOffline();
     try {
       reader.removeEventListener(listener);
-      assertEquals(Tasks.await(reader.get()).getValue(), 42L);
+      assertEquals(await(reader.get()).getValue(), 42L);
     } finally {
       readerDb.goOnline();
     }
@@ -4735,7 +4901,7 @@ public void testGetUpdatesPersistenceCacheWhenEnabled()
     writer = writer.child(key);
 
     assertNull(new WriteFuture(writer, 42L).timedGet());
-    assertEquals(42L, Tasks.await(reader.get()).getValue());
+    assertEquals(42L, await(reader.get()).getValue());
 
     readerDb.goOffline();
     try {
@@ -4783,7 +4949,7 @@ public void onCancelled(@NonNull DatabaseError error) {}
     reader.removeEventListener(listener);
 
     assertNull(new WriteFuture(writer, 43L).timedGet());
-    assertEquals(43L, Tasks.await(reader.get()).getValue());
+    assertEquals(43L, await(reader.get()).getValue());
   }
 
   @Test

firebase-database/src/main/java/com/google/firebase/database/android/SqlPersistenceStorageEngine.java

@@ -58,7 +58,7 @@
 /**
  * This class is an Android/SQL-backed implementation of PersistenceStorageEngine.
  *
- * <p>The implementation uses 3 tables for persistence: - writes: A list of all currently
+ * <p>The implementation uses 4 tables for persistence: - writes: A list of all currently
  * outstanding (visible) writes. A row represents a single write containing a unique-across-restarts
  * write id, the path string, the type which can be 'o' for an overwrite or 'm' for a merge, and the
  * serialized node wrapped. Part number is NULL for normal writes. Large writes (>256K) are split
@@ -1058,6 +1058,7 @@ private Cursor loadNestedQuery(Path path, String[] columns) {
     arguments[path.size() + 1] = pathPrefixStart;
     arguments[path.size() + 2] = pathPrefixEnd;
     String orderBy = PATH_COLUMN_NAME;
+    // TODO: We need to modify this to make sure that we limit based on trackedquerykeys
 
     return database.query(SERVER_CACHE_TABLE, columns, whereClause, arguments, null, null, orderBy);
   }

firebase-database/src/main/java/com/google/firebase/database/core/Path.java

@@ -75,6 +75,8 @@ public Path(String pathString) {
         count++;
       }
     }
+    // We are essentially doing the same work twice; once here, and once again in the constructor on
+    // line 60
     pieces = new ChildKey[count];
     int j = 0;
     for (String segment : segments) {