add hasCachedResults flag

firebase · milaGGL · Oct 26, 2022 · Oct 15, 2022 · Oct 17, 2022 · Oct 18, 2022
commit 705bf4fd5880ff42278d74ca87a6580498975628
diff --git a/firebase-firestore/src/main/java/com/google/firebase/firestore/core/QueryListener.java b/firebase-firestore/src/main/java/com/google/firebase/firestore/core/QueryListener.java
@@ -87,7 +87,8 @@ public boolean onViewSnapshot(ViewSnapshot newSnapshot) {
               newSnapshot.isFromCache(),
               newSnapshot.getMutatedKeys(),
               newSnapshot.didSyncStateChange(),
-              /* excludesMetadataChanges= */ true);
+              /* excludesMetadataChanges= */ true,
+              newSnapshot.hasCachedResults());
     }
 
     if (!raisedInitialEvent) {
@@ -139,8 +140,11 @@ private boolean shouldRaiseInitialEvent(ViewSnapshot snapshot, OnlineState onlin
       return false;
     }
 
-    // Raise data from cache if we have any documents or we are offline
-    return !snapshot.getDocuments().isEmpty() || onlineState.equals(OnlineState.OFFLINE);
+    // Raise data from cache if we have any documents, have cached results before,
+    // or we are offline.
+    return (!snapshot.getDocuments().isEmpty()
+        || snapshot.hasCachedResults()
+        || onlineState.equals(OnlineState.OFFLINE));
   }
 
   private boolean shouldRaiseEvent(ViewSnapshot snapshot) {
@@ -171,7 +175,8 @@ private void raiseInitialEvent(ViewSnapshot snapshot) {
             snapshot.getDocuments(),
             snapshot.getMutatedKeys(),
             snapshot.isFromCache(),
-            snapshot.excludesMetadataChanges());
+            snapshot.excludesMetadataChanges(),
+            snapshot.hasCachedResults());
     raisedInitialEvent = true;
     listener.onEvent(snapshot, null);
   }

diff --git a/firebase-firestore/src/main/java/com/google/firebase/firestore/core/SyncEngine.java b/firebase-firestore/src/main/java/com/google/firebase/firestore/core/SyncEngine.java
@@ -54,6 +54,7 @@
 import com.google.firebase.firestore.util.Function;
 import com.google.firebase.firestore.util.Logger;
 import com.google.firebase.firestore.util.Util;
+import com.google.protobuf.ByteString;
 import io.grpc.Status;
 import java.io.IOException;
 import java.util.ArrayList;
@@ -204,13 +205,16 @@ public int listen(Query query) {
     TargetData targetData = localStore.allocateTarget(query.toTarget());
     remoteStore.listen(targetData);
 
-    ViewSnapshot viewSnapshot = initializeViewAndComputeSnapshot(query, targetData.getTargetId());
+    ViewSnapshot viewSnapshot =
+        initializeViewAndComputeSnapshot(
+            query, targetData.getTargetId(), targetData.getResumeToken());
     syncEngineListener.onViewSnapshots(Collections.singletonList(viewSnapshot));
 
     return targetData.getTargetId();
   }
 
-  private ViewSnapshot initializeViewAndComputeSnapshot(Query query, int targetId) {
+  private ViewSnapshot initializeViewAndComputeSnapshot(
+      Query query, int targetId, ByteString resumeToken) {
     QueryResult queryResult = localStore.executeQuery(query, /* usePreviousResults= */ true);
 
     SyncState currentTargetSyncState = SyncState.NONE;
@@ -223,7 +227,7 @@ private ViewSnapshot initializeViewAndComputeSnapshot(Query query, int targetId)
       currentTargetSyncState = this.queryViewsByQuery.get(mirrorQuery).getView().getSyncState();
       synthesizedCurrentChange =
           TargetChange.createSynthesizedTargetChangeForCurrentChange(
-              currentTargetSyncState == SyncState.SYNCED);
+              currentTargetSyncState == SyncState.SYNCED, resumeToken);
     }
 
     // TODO(wuandy): Investigate if we can extract the logic of view change computation and

diff --git a/firebase-firestore/src/main/java/com/google/firebase/firestore/core/View.java b/firebase-firestore/src/main/java/com/google/firebase/firestore/core/View.java
@@ -311,7 +311,10 @@ public ViewChange applyChanges(DocumentChanges docChanges, TargetChange targetCh
               fromCache,
               docChanges.mutatedKeys,
               syncStatedChanged,
-              /* excludesMetadataChanges= */ false);
+              /* excludesMetadataChanges= */ false,
+              /* hasCachedResults= */ targetChange == null
+                  ? false
+                  : !targetChange.getResumeToken().isEmpty());
     }
     return new ViewChange(snapshot, limboDocumentChanges);
   }

diff --git a/firebase-firestore/src/main/java/com/google/firebase/firestore/core/ViewSnapshot.java b/firebase-firestore/src/main/java/com/google/firebase/firestore/core/ViewSnapshot.java
@@ -39,6 +39,7 @@ public enum SyncState {
   private final ImmutableSortedSet<DocumentKey> mutatedKeys;
   private final boolean didSyncStateChange;
   private boolean excludesMetadataChanges;
+  private boolean hasCachedResults;
 
   public ViewSnapshot(
       Query query,
@@ -48,7 +49,8 @@ public ViewSnapshot(
       boolean isFromCache,
       ImmutableSortedSet<DocumentKey> mutatedKeys,
       boolean didSyncStateChange,
-      boolean excludesMetadataChanges) {
+      boolean excludesMetadataChanges,
+      boolean hasCachedResults) {
     this.query = query;
     this.documents = documents;
     this.oldDocuments = oldDocuments;
@@ -57,6 +59,7 @@ public ViewSnapshot(
     this.mutatedKeys = mutatedKeys;
     this.didSyncStateChange = didSyncStateChange;
     this.excludesMetadataChanges = excludesMetadataChanges;
+    this.hasCachedResults = hasCachedResults;
   }
 
   /** Returns a view snapshot as if all documents in the snapshot were added. */
@@ -65,7 +68,8 @@ public static ViewSnapshot fromInitialDocuments(
       DocumentSet documents,
       ImmutableSortedSet<DocumentKey> mutatedKeys,
       boolean fromCache,
-      boolean excludesMetadataChanges) {
+      boolean excludesMetadataChanges,
+      boolean hasCachedResults) {
     List<DocumentViewChange> viewChanges = new ArrayList<>();
     for (Document doc : documents) {
       viewChanges.add(DocumentViewChange.create(DocumentViewChange.Type.ADDED, doc));
@@ -78,7 +82,8 @@ public static ViewSnapshot fromInitialDocuments(
         fromCache,
         mutatedKeys,
         /* didSyncStateChange= */ true,
-        excludesMetadataChanges);
+        excludesMetadataChanges,
+        hasCachedResults);
   }
 
   public Query getQuery() {
@@ -117,6 +122,10 @@ public boolean excludesMetadataChanges() {
     return excludesMetadataChanges;
   }
 
+  public boolean hasCachedResults() {
+    return hasCachedResults;
+  }
+
   @Override
   public final boolean equals(Object o) {
     if (this == o) {
@@ -149,6 +158,9 @@ public final boolean equals(Object o) {
     if (!oldDocuments.equals(that.oldDocuments)) {
       return false;
     }
+    if (hasCachedResults != that.hasCachedResults) {
+      return false;
+    }
     return changes.equals(that.changes);
   }
 
@@ -183,6 +195,8 @@ public String toString() {
         + didSyncStateChange
         + ", excludesMetadataChanges="
         + excludesMetadataChanges
+        + ", hasCachedResults="
+        + hasCachedResults
         + ")";
   }
 }
diff --git a/firebase-firestore/src/main/java/com/google/firebase/firestore/remote/TargetChange.java b/firebase-firestore/src/main/java/com/google/firebase/firestore/remote/TargetChange.java
@@ -31,9 +31,10 @@ public final class TargetChange {
   private final ImmutableSortedSet<DocumentKey> modifiedDocuments;
   private final ImmutableSortedSet<DocumentKey> removedDocuments;
 
-  public static TargetChange createSynthesizedTargetChangeForCurrentChange(boolean isCurrent) {
+  public static TargetChange createSynthesizedTargetChangeForCurrentChange(
+      boolean isCurrent, ByteString resumeToken) {
     return new TargetChange(
-        ByteString.EMPTY,
+        resumeToken,
         isCurrent,
         DocumentKey.emptyKeySet(),
         DocumentKey.emptyKeySet(),

diff --git a/firebase-firestore/src/roboUtil/java/com/google/firebase/firestore/TestUtil.java b/firebase-firestore/src/roboUtil/java/com/google/firebase/firestore/TestUtil.java
@@ -116,7 +116,8 @@ public static QuerySnapshot querySnapshot(
             isFromCache,
             mutatedKeys,
             /* didSyncStateChange= */ true,
-            /* excludesMetadataChanges= */ false);
+            /* excludesMetadataChanges= */ false,
+            /* hasCachedResults= */ false);
     return new QuerySnapshot(query(path), viewSnapshot, FIRESTORE);
   }
 

diff --git a/firebase-firestore/src/test/java/com/google/firebase/firestore/QuerySnapshotTest.java b/firebase-firestore/src/test/java/com/google/firebase/firestore/QuerySnapshotTest.java
@@ -126,7 +126,8 @@ public void testIncludeMetadataChanges() {
             /*isFromCache=*/ false,
             /*mutatedKeys=*/ keySet(),
             /*didSyncStateChange=*/ true,
-            /* excludesMetadataChanges= */ false);
+            /* excludesMetadataChanges= */ false,
+            /* hasCachedResults= */ false);
 
     QuerySnapshot snapshot =
         new QuerySnapshot(new Query(fooQuery, firestore), viewSnapshot, firestore);

diff --git a/firebase-firestore/src/test/java/com/google/firebase/firestore/core/QueryListenerTest.java b/firebase-firestore/src/test/java/com/google/firebase/firestore/core/QueryListenerTest.java
@@ -108,7 +108,8 @@ public void testRaisesCollectionEvents() {
             snap2.isFromCache(),
             snap2.getMutatedKeys(),
             /* didSyncStateChange= */ true,
-            /* excludesMetadataChanges= */ false);
+            /* excludesMetadataChanges= */ false,
+            /* hasCachedResults= */ false);
     assertEquals(asList(snap2Prime), otherAccum);
   }
 
@@ -262,7 +263,8 @@ public void testRaisesQueryMetadataEventsOnlyWhenHasPendingWritesOnTheQueryChang
             snap4.isFromCache(),
             snap4.getMutatedKeys(),
             snap4.didSyncStateChange(),
-            /* excludeMetadataChanges= */ true); // This test excludes document metadata changes
+            /* excludeMetadataChanges= */ true,
+            /* hasCachedResults= */ false); // This test excludes document metadata changes
 
     assertEquals(
         asList(
@@ -302,7 +304,9 @@ public void testMetadataOnlyDocumentChangesAreFilteredOut() {
             snap2.isFromCache(),
             snap2.getMutatedKeys(),
             snap2.didSyncStateChange(),
-            /* excludesMetadataChanges= */ true);
+            /* excludesMetadataChanges= */ true,
+            /* hasCachedResults= */ false);
+
     assertEquals(
         asList(applyExpectedMetadata(snap1, MetadataChanges.EXCLUDE), expectedSnapshot2),
         filteredAccum);
@@ -344,7 +348,8 @@ public void testWillWaitForSyncIfOnline() {
             /* isFromCache= */ false,
             snap3.getMutatedKeys(),
             /* didSyncStateChange= */ true,
-            /* excludesMetadataChanges= */ true);
+            /* excludesMetadataChanges= */ true,
+            /* hasCachedResults= */ false);
     assertEquals(asList(expectedSnapshot), events);
   }
 
@@ -382,7 +387,9 @@ public void testWillRaiseInitialEventWhenGoingOffline() {
             /* isFromCache= */ true,
             snap1.getMutatedKeys(),
             /* didSyncStateChange= */ true,
-            /* excludesMetadataChanges= */ true);
+            /* excludesMetadataChanges= */ true,
+            /* hasCachedResults= */ false);
+
     ViewSnapshot expectedSnapshot2 =
         new ViewSnapshot(
             snap2.getQuery(),
@@ -392,7 +399,8 @@ public void testWillRaiseInitialEventWhenGoingOffline() {
             /* isFromCache= */ true,
             snap2.getMutatedKeys(),
             /* didSyncStateChange= */ false,
-            /* excludesMetadataChanges= */ true);
+            /* excludesMetadataChanges= */ true,
+            /* hasCachedResults= */ false);
     assertEquals(asList(expectedSnapshot1, expectedSnapshot2), events);
   }
 
@@ -419,7 +427,8 @@ public void testWillRaiseInitialEventWhenGoingOfflineAndThereAreNoDocs() {
             /* isFromCache= */ true,
             snap1.getMutatedKeys(),
             /* didSyncStateChange= */ true,
-            /* excludesMetadataChanges= */ true);
+            /* excludesMetadataChanges= */ true,
+            /* hasCachedResults= */ false);
     assertEquals(asList(expectedSnapshot), events);
   }
 
@@ -445,7 +454,8 @@ public void testWillRaiseInitialEventWhenStartingOfflineAndThereAreNoDocs() {
             /* isFromCache= */ true,
             snap1.getMutatedKeys(),
             /* didSyncStateChange= */ true,
-            /* excludesMetadataChanges= */ true);
+            /* excludesMetadataChanges= */ true,
+            /* hasCachedResults= */ false);
     assertEquals(asList(expectedSnapshot), events);
   }
 
@@ -458,6 +468,7 @@ private ViewSnapshot applyExpectedMetadata(ViewSnapshot snap, MetadataChanges me
         snap.isFromCache(),
         snap.getMutatedKeys(),
         snap.didSyncStateChange(),
-        MetadataChanges.EXCLUDE.equals(metadata));
+        MetadataChanges.EXCLUDE.equals(metadata),
+        snap.hasCachedResults());
   }
 }
diff --git a/firebase-firestore/src/test/java/com/google/firebase/firestore/core/ViewSnapshotTest.java b/firebase-firestore/src/test/java/com/google/firebase/firestore/core/ViewSnapshotTest.java
@@ -49,6 +49,7 @@ public void testConstructor() {
     boolean hasPendingWrites = true;
     boolean syncStateChanges = true;
     boolean excludesMetadataChanges = true;
+    boolean hasCachedResults = false;
 
     ViewSnapshot snapshot =
         new ViewSnapshot(
@@ -59,7 +60,8 @@ public void testConstructor() {
             fromCache,
             mutatedKeys,
             syncStateChanges,
-            excludesMetadataChanges);
+            excludesMetadataChanges,
+            hasCachedResults);
 
     assertEquals(query, snapshot.getQuery());
     assertEquals(docs, snapshot.getDocuments());
@@ -70,5 +72,6 @@ public void testConstructor() {
     assertEquals(hasPendingWrites, snapshot.hasPendingWrites());
     assertEquals(syncStateChanges, snapshot.didSyncStateChange());
     assertEquals(excludesMetadataChanges, snapshot.excludesMetadataChanges());
+    assertEquals(hasCachedResults, snapshot.hasCachedResults());
   }
 }