Add deleteAllIndexes

Author: cherylEnkidu

firebase-firestore/src/main/java/com/google/firebase/firestore/PersistentCacheIndexManager.java

@@ -52,4 +52,8 @@ public void enableIndexAutoCreation() {
   public void disableIndexAutoCreation() {
     client.disableIndexAutoCreation();
   }
+
+  public void deleteAllIndexes() {
+    client.deleteAllFieldIndexes();
+  }
 }

firebase-firestore/src/main/java/com/google/firebase/firestore/core/FirestoreClient.java

@@ -363,6 +363,11 @@ public void disableIndexAutoCreation() {
     asyncQueue.enqueueAndForget(() -> localStore.disableIndexAutoCreation());
   }
 
+  public void deleteAllFieldIndexes() {
+    verifyNotTerminated();
+    asyncQueue.enqueueAndForget(() -> localStore.deleteAllFieldIndexes());
+  }
+
   public void removeSnapshotsInSyncListener(EventListener<Void> listener) {
     // Checks for shutdown but does not raise error, allowing remove after shutdown to be a no-op.
     if (isTerminated()) {

firebase-firestore/src/main/java/com/google/firebase/firestore/local/IndexManager.java

@@ -78,6 +78,9 @@ enum IndexType {
   /** Removes the given field index and deletes all index values. */
   void deleteFieldIndex(FieldIndex index);
 
+  /** Removes all field indexes and deletes all index values. */
+  void deleteAllFieldIndexes();
+
   /** Creates a full matched field index which serves the given target. */
   void createTargetIndices(Target target);
 

firebase-firestore/src/main/java/com/google/firebase/firestore/local/LocalStore.java

@@ -802,6 +802,10 @@ public void configureFieldIndexes(List<FieldIndex> newFieldIndexes) {
         });
   }
 
+  public void deleteAllFieldIndexes() {
+    persistence.runTransaction("Delete All Indexes", () -> indexManager.deleteAllFieldIndexes());
+  }
+
   public void enableIndexAutoCreation() {
     queryEngine.enableIndexAutoCreation();
   }

firebase-firestore/src/main/java/com/google/firebase/firestore/local/MemoryIndexManager.java

@@ -60,6 +60,11 @@ public void deleteFieldIndex(FieldIndex index) {
     // Field indices are not supported with memory persistence.
   }
 
+  @Override
+  public void deleteAllFieldIndexes() {
+    // Field indices are not supported with memory persistence.
+  }
+
   @Override
   public void createTargetIndices(Target target) {}
 

firebase-firestore/src/main/java/com/google/firebase/firestore/local/SQLiteIndexManager.java

@@ -233,6 +233,16 @@ public void deleteFieldIndex(FieldIndex index) {
     }
   }
 
+  @Override
+  public void deleteAllFieldIndexes() {
+    db.execute("DELETE FROM index_configuration");
+    db.execute("DELETE FROM index_entries");
+    db.execute("DELETE FROM index_state");
+
+    nextIndexToUpdate.clear();
+    memoizedIndexes.clear();
+  }
+
   @Override
   public void createTargetIndices(Target target) {
     hardAssert(started, "IndexManager not started");

firebase-firestore/src/test/java/com/google/firebase/firestore/local/LocalStoreTestCase.java

@@ -232,6 +232,10 @@ protected void disableIndexAutoCreation() {
     queryEngine.disableIndexAutoCreation();
   }
 
+  protected void deleteAllIndexes() {
+    localStore.deleteAllFieldIndexes();
+  }
+
   private void releaseTarget(int targetId) {
     localStore.releaseTarget(targetId);
   }

firebase-firestore/src/test/java/com/google/firebase/firestore/local/SQLiteLocalStoreTest.java

@@ -503,6 +503,66 @@ public void testDisableIndexAutoCreationWorks() {
     assertRemoteDocumentsRead(/* byKey= */ 0, /* byCollection= */ 2);
   }
 
+  @Test
+  public void testDeleteAllIndexesWorksWithIndexAutoCreation() {
+    Query query = query("coll").filter(filter("matches", "==", true));
+    int targetId = allocateQuery(query);
+
+    enableIndexAutoCreation();
+
+    applyRemoteEvent(addedRemoteEvent(doc("coll/a", 10, map("matches", true)), targetId));
+    applyRemoteEvent(addedRemoteEvent(doc("coll/b", 10, map("matches", false)), targetId));
+    applyRemoteEvent(addedRemoteEvent(doc("coll/c", 10, map("matches", false)), targetId));
+    applyRemoteEvent(addedRemoteEvent(doc("coll/d", 10, map("matches", false)), targetId));
+    applyRemoteEvent(addedRemoteEvent(doc("coll/e", 10, map("matches", true)), targetId));
+
+    // First time query is running without indexes.
+    // Based on current heuristic, collection document counts (5) > 2 * resultSize (2).
+    // Full matched index should be created.
+    executeQuery(query);
+    assertRemoteDocumentsRead(/* byKey= */ 0, /* byCollection= */ 2);
+    assertQueryReturned("coll/a", "coll/e");
+
+    disableIndexAutoCreation();
+
+    backfillIndexes();
+
+    executeQuery(query);
+    assertRemoteDocumentsRead(/* byKey= */ 2, /* byCollection= */ 0);
+    assertQueryReturned("coll/a", "coll/e");
+
+    deleteAllIndexes();
+
+    executeQuery(query);
+    assertRemoteDocumentsRead(/* byKey= */ 0, /* byCollection= */ 2);
+    assertQueryReturned("coll/a", "coll/e");
+  }
+
+  @Test
+  public void testDeleteAllIndexesWorksWithManualAddedIndexes() {
+    FieldIndex index =
+        fieldIndex(
+            "coll", 0, FieldIndex.INITIAL_STATE, "matches", FieldIndex.Segment.Kind.ASCENDING);
+    configureFieldIndexes(singletonList(index));
+
+    Query query = query("coll").filter(filter("matches", "==", true));
+    int targetId = allocateQuery(query);
+
+    applyRemoteEvent(addedRemoteEvent(doc("coll/a", 10, map("matches", true)), targetId));
+
+    backfillIndexes();
+
+    executeQuery(query);
+    assertRemoteDocumentsRead(/* byKey= */ 1, /* byCollection= */ 0);
+    assertQueryReturned("coll/a");
+
+    deleteAllIndexes();
+
+    executeQuery(query);
+    assertRemoteDocumentsRead(/* byKey= */ 0, /* byCollection= */ 1);
+    assertQueryReturned("coll/a");
+  }
+
   @Test
   public void testIndexAutoCreationWorksWithMutation() {
     Query query = query("coll").filter(filter("matches", "==", true));