feat(firestore): add support for multiple database instances (#11310)

melos.yaml

@@ -160,7 +160,7 @@ scripts:
   test:e2e:cloud_firestore:
     run: |
       cd packages/cloud_firestore/cloud_firestore/example
-      flutter test integration_test/cloud_firestore_e2e_test.dart
+      flutter test integration_test/e2e_test.dart
     description: |
       Run all e2e tests for cloud_firestore.
 

packages/cloud_firestore/cloud_firestore/android/src/main/java/io/flutter/plugins/firebase/firestore/FlutterFirebaseFirestoreExtension.java

@@ -0,0 +1,25 @@
+// Copyright 2023 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package io.flutter.plugins.firebase.firestore;
+
+import com.google.firebase.firestore.FirebaseFirestore;
+
+public class FlutterFirebaseFirestoreExtension {
+  private final FirebaseFirestore instance;
+  private final String databaseURL;
+
+  public FlutterFirebaseFirestoreExtension(FirebaseFirestore instance, String databaseURL) {
+    this.instance = instance;
+    this.databaseURL = databaseURL;
+  }
+
+  public FirebaseFirestore getInstance() {
+    return instance;
+  }
+
+  public String getDatabaseURL() {
+    return databaseURL;
+  }
+}

packages/cloud_firestore/cloud_firestore/android/src/main/java/io/flutter/plugins/firebase/firestore/FlutterFirebaseFirestoreMessageCodec.java

@@ -72,8 +72,18 @@ protected void writeValue(ByteArrayOutputStream stream, Object value) {
       writeDouble(stream, ((GeoPoint) value).getLongitude());
     } else if (value instanceof DocumentReference) {
       stream.write(DATA_TYPE_DOCUMENT_REFERENCE);
-      writeValue(stream, ((DocumentReference) value).getFirestore().getApp().getName());
+      FirebaseFirestore firestore = ((DocumentReference) value).getFirestore();
+      String appName = firestore.getApp().getName();
+      writeValue(stream, appName);
       writeValue(stream, ((DocumentReference) value).getPath());
+      String databaseURL;
+      // There is no way of getting database URL from Firebase android SDK API so we cache it ourselves
+      synchronized (FlutterFirebaseFirestorePlugin.firestoreInstanceCache) {
+        databaseURL =
+            FlutterFirebaseFirestorePlugin.getCachedFirebaseFirestoreInstanceForKey(firestore)
+                .getDatabaseURL();
+      }
+      writeValue(stream, databaseURL);
     } else if (value instanceof DocumentSnapshot) {
       writeDocumentSnapshot(stream, (DocumentSnapshot) value);
     } else if (value instanceof QuerySnapshot) {
@@ -277,20 +287,22 @@ protected Object readValueOfType(byte type, ByteBuffer buffer) {
 
   private FirebaseFirestore readFirestoreInstance(ByteBuffer buffer) {
     String appName = (String) readValue(buffer);
+    String databaseURL = (String) readValue(buffer);
     FirebaseFirestoreSettings settings = (FirebaseFirestoreSettings) readValue(buffer);
-
     synchronized (FlutterFirebaseFirestorePlugin.firestoreInstanceCache) {
-      if (FlutterFirebaseFirestorePlugin.getCachedFirebaseFirestoreInstanceForKey(appName)
+      if (FlutterFirebaseFirestorePlugin.getFirestoreInstanceByNameAndDatabaseUrl(
+              appName, databaseURL)
           != null) {
-        return FlutterFirebaseFirestorePlugin.getCachedFirebaseFirestoreInstanceForKey(appName);
+        return FlutterFirebaseFirestorePlugin.getFirestoreInstanceByNameAndDatabaseUrl(
+            appName, databaseURL);
       }
 
       FirebaseApp app = FirebaseApp.getInstance(appName);
-      FirebaseFirestore firestore = FirebaseFirestore.getInstance(app);
-
+      FirebaseFirestore firestore = FirebaseFirestore.getInstance(app, databaseURL);
       firestore.setFirestoreSettings(settings);
 
-      FlutterFirebaseFirestorePlugin.setCachedFirebaseFirestoreInstanceForKey(firestore, appName);
+      FlutterFirebaseFirestorePlugin.setCachedFirebaseFirestoreInstanceForKey(
+          firestore, databaseURL);
       return firestore;
     }
   }

packages/cloud_firestore/cloud_firestore/android/src/main/java/io/flutter/plugins/firebase/firestore/FlutterFirebaseFirestorePlugin.java

@@ -54,8 +54,8 @@
 
 public class FlutterFirebaseFirestorePlugin
     implements FlutterFirebasePlugin, MethodCallHandler, FlutterPlugin, ActivityAware {
-  protected static final HashMap<String, FirebaseFirestore> firestoreInstanceCache =
-      new HashMap<>();
+  protected static final HashMap<FirebaseFirestore, FlutterFirebaseFirestoreExtension>
+      firestoreInstanceCache = new HashMap<>();
 
   public static final String DEFAULT_ERROR_CODE = "firebase_firestore";
 
@@ -79,27 +79,41 @@ public class FlutterFirebaseFirestorePlugin
   public static final Map<Integer, DocumentSnapshot.ServerTimestampBehavior>
       serverTimestampBehaviorHashMap = new HashMap<>();
 
-  protected static FirebaseFirestore getCachedFirebaseFirestoreInstanceForKey(String key) {
+  protected static FlutterFirebaseFirestoreExtension getCachedFirebaseFirestoreInstanceForKey(
+      FirebaseFirestore firestore) {
     synchronized (firestoreInstanceCache) {
-      return firestoreInstanceCache.get(key);
+      return firestoreInstanceCache.get(firestore);
     }
   }
 
   protected static void setCachedFirebaseFirestoreInstanceForKey(
-      FirebaseFirestore firestore, String key) {
+      FirebaseFirestore firestore, String databaseURL) {
     synchronized (firestoreInstanceCache) {
-      FirebaseFirestore existingInstance = firestoreInstanceCache.get(key);
+      FlutterFirebaseFirestoreExtension existingInstance = firestoreInstanceCache.get(firestore);
       if (existingInstance == null) {
-        firestoreInstanceCache.put(key, firestore);
+        firestoreInstanceCache.put(
+            firestore, new FlutterFirebaseFirestoreExtension(firestore, databaseURL));
       }
     }
   }
 
-  private static void destroyCachedFirebaseFirestoreInstanceForKey(String key) {
+  protected static FirebaseFirestore getFirestoreInstanceByNameAndDatabaseUrl(
+      String appName, String databaseURL) {
+    for (Map.Entry<FirebaseFirestore, FlutterFirebaseFirestoreExtension> entry :
+        firestoreInstanceCache.entrySet()) {
+      if (entry.getValue().getInstance().getApp().getName().equals(appName)
+          && entry.getValue().getDatabaseURL().equals(databaseURL)) {
+        return entry.getKey();
+      }
+    }
+    return null;
+  }
+
+  private static void destroyCachedFirebaseFirestoreInstanceForKey(FirebaseFirestore firestore) {
     synchronized (firestoreInstanceCache) {
-      FirebaseFirestore existingInstance = firestoreInstanceCache.get(key);
+      FlutterFirebaseFirestoreExtension existingInstance = firestoreInstanceCache.get(firestore);
       if (existingInstance != null) {
-        firestoreInstanceCache.remove(key);
+        firestoreInstanceCache.remove(firestore);
       }
     }
   }
@@ -511,7 +525,7 @@ private Task<Void> terminate(Map<String, Object> arguments) {
             FirebaseFirestore firestore =
                 (FirebaseFirestore) Objects.requireNonNull(arguments.get("firestore"));
             Tasks.await(firestore.terminate());
-            destroyCachedFirebaseFirestoreInstanceForKey(firestore.getApp().getName());
+            destroyCachedFirebaseFirestoreInstanceForKey(firestore);
 
             taskCompletionSource.setResult(null);
           } catch (Exception e) {
@@ -742,12 +756,12 @@ public Task<Void> didReinitializeFirebaseCore() {
         () -> {
           try {
             // Context is ignored by API so we don't send it over even though annotated non-null.
-
-            for (FirebaseApp app : FirebaseApp.getApps(null)) {
-              FirebaseFirestore firestore = FirebaseFirestore.getInstance(app);
+            for (Map.Entry<FirebaseFirestore, FlutterFirebaseFirestoreExtension> entry :
+                firestoreInstanceCache.entrySet()) {
+              FirebaseFirestore firestore = entry.getKey();
               Tasks.await(firestore.terminate());
               FlutterFirebaseFirestorePlugin.destroyCachedFirebaseFirestoreInstanceForKey(
-                  app.getName());
+                  firestore);
             }
 
             removeEventListeners();

packages/cloud_firestore/cloud_firestore/example/integration_test/e2e_test.dart

@@ -21,6 +21,7 @@ import 'snapshot_metadata_e2e.dart';
 import 'timestamp_e2e.dart';
 import 'transaction_e2e.dart';
 import 'write_batch_e2e.dart';
+import 'second_database.dart';
 
 bool kUseFirestoreEmulator = true;
 
@@ -52,5 +53,6 @@ void main() {
     runWriteBatchTests();
     runLoadBundleTests();
     runSecondAppTests();
+    runSecondDatabaseTests();
   });
 }