Firestore Swift Cpp Experiment

FirebaseCombineSwift.podspec

@@ -59,6 +59,7 @@ for internal testing only. It should not be published.
 
   s.pod_target_xcconfig = {
     'HEADER_SEARCH_PATHS' => '"${PODS_TARGET_SRCROOT}"',
+    'SWIFT_OBJC_INTEROP_MODE' => 'objcxx',
   }
 
   s.test_spec 'unit' do |unit_tests|
@@ -81,7 +82,8 @@ for internal testing only. It should not be published.
     unit_tests.exclude_files = 'FirebaseCombineSwift/Tests/Unit/**/*Template.swift'
     unit_tests.requires_app_host = true
     unit_tests.pod_target_xcconfig = {
-      'SWIFT_OBJC_BRIDGING_HEADER' => '$(PODS_TARGET_SRCROOT)/FirebaseCombineSwift/Tests/Unit/FirebaseCombine-unit-Bridging-Header.h'
+      'SWIFT_OBJC_BRIDGING_HEADER' => '$(PODS_TARGET_SRCROOT)/FirebaseCombineSwift/Tests/Unit/FirebaseCombine-unit-Bridging-Header.h',
+      'SWIFT_OBJC_INTEROP_MODE' => 'objcxx',
     }
     unit_tests.dependency 'OCMock'
     unit_tests.dependency 'FirebaseAuthTestingSupport'

FirebaseCore/Sources/Public/FirebaseCore/FIRVersion.h

@@ -19,7 +19,16 @@
 NS_ASSUME_NONNULL_BEGIN
 
 /** Returns the current version of Firebase. */
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 NS_SWIFT_NAME(FirebaseVersion())
 NSString* FIRFirebaseVersion(void);
 
+#ifdef __cplusplus
+}
+#endif
+
 NS_ASSUME_NONNULL_END

FirebaseFirestore.podspec

@@ -31,6 +31,12 @@ Google Cloud Firestore is a NoSQL document database built for automatic scaling,
     'FirebaseFirestoreInternal/**/*.[mh]',
     'Firestore/Swift/Source/**/*.swift',
   ]
+
+  s.pod_target_xcconfig = {
+    # Enables C++ <-> Swift interop (by default it's only C)
+    "SWIFT_OBJC_INTEROP_MODE" => "objcxx",
+  }
+
   s.resource_bundles = {
     "#{s.module_name}_Privacy" => 'Firestore/Swift/Source/Resources/PrivacyInfo.xcprivacy'
   }

FirebaseFirestoreInternal.podspec

@@ -28,7 +28,10 @@ Google Cloud Firestore is a NoSQL document database built for automatic scaling,
   # Header files that constitute the interface to this module. Only Objective-C
   # headers belong here, since FirebaseFirestore is primarily an Objective-C
   # framework.
-  s.public_header_files = 'Firestore/Source/Public/FirebaseFirestore/*.h'
+  s.public_header_files = [
+    'Firestore/Source/Public/FirebaseFirestore/*.h',
+    'Firestore/core/interfaceForSwift/api/*.h'
+  ]
 
   # source_files contains most of the header and source files for the project.
   # This includes files named in `public_header_files`.
@@ -52,6 +55,7 @@ Google Cloud Firestore is a NoSQL document database built for automatic scaling,
     'Firestore/core/include/**/*.{cc,mm}',
     'Firestore/core/src/**/*.{cc,mm}',
     'FirebaseAuth/Interop/**/*.h',
+    'Firestore/core/interfaceForSwift/**/*.{cc,h}',
   ]
 
   # Internal headers that aren't necessarily globally unique. Most C++ internal

Firestore/Example/Tests/API/FIRAggregateQueryUnitTests.mm

@@ -40,7 +40,7 @@ @interface FIRAggregateQueryUnitTests : XCTestCase
 @implementation FIRAggregateQueryUnitTests
 
 - (void)testEquals {
-  std::shared_ptr<api::Firestore> firestore = FSTTestFirestore().wrapped;
+  std::shared_ptr<api::Firestore> firestore = FSTTestFirestore().cppFirestorePtr;
   FIRAggregateQuery *queryFoo =
       [[FIRQuery alloc] initWithQuery:Query("foo") firestore:firestore].count;
   FIRAggregateQuery *queryFooDup =

Firestore/Example/Tests/API/FIRQuerySnapshotTests.mm

@@ -99,7 +99,7 @@ - (void)testIncludeMetadataChanges {
       DocumentViewChange(doc2New, DocumentViewChange::Type::Modified),
   };
 
-  std::shared_ptr<Firestore> firestore = FSTTestFirestore().wrapped;
+  std::shared_ptr<Firestore> firestore = FSTTestFirestore().cppFirestorePtr;
   core::Query query = Query("foo");
   ViewSnapshot viewSnapshot(query, newDocuments, oldDocuments, std::move(documentChanges),
                             /*mutated_keys=*/DocumentKeySet(),

Firestore/Example/Tests/API/FIRQueryUnitTests.mm

@@ -38,7 +38,7 @@ @interface FIRQueryUnitTests : XCTestCase
 @implementation FIRQueryUnitTests
 
 - (void)testEquals {
-  std::shared_ptr<api::Firestore> firestore = FSTTestFirestore().wrapped;
+  std::shared_ptr<api::Firestore> firestore = FSTTestFirestore().cppFirestorePtr;
   FIRQuery *queryFoo = [[FIRQuery alloc] initWithQuery:Query("foo") firestore:firestore];
   FIRQuery *queryFooDup = [[FIRQuery alloc] initWithQuery:Query("foo") firestore:firestore];
   FIRQuery *queryBar = [[FIRQuery alloc] initWithQuery:Query("bar") firestore:firestore];
@@ -58,7 +58,7 @@ - (void)testEquals {
 }
 
 - (void)testFilteringWithPredicate {
-  std::shared_ptr<api::Firestore> firestore = FSTTestFirestore().wrapped;
+  std::shared_ptr<api::Firestore> firestore = FSTTestFirestore().cppFirestorePtr;
   FIRQuery *query = [[FIRQuery alloc] initWithQuery:Query("foo") firestore:firestore];
   FIRQuery *query1 = [query queryWhereField:@"f" isLessThanOrEqualTo:@1];
   FIRQuery *query2 = [query queryFilteredUsingPredicate:[NSPredicate predicateWithFormat:@"f<=1"]];

Firestore/Example/Tests/API/FSTAPIHelpers.mm

@@ -103,12 +103,12 @@
 
 FIRCollectionReference *FSTTestCollectionRef(const char *path) {
   return [[FIRCollectionReference alloc] initWithPath:Resource(path)
-                                            firestore:FSTTestFirestore().wrapped];
+                                            firestore:FSTTestFirestore().cppFirestorePtr];
 }
 
 FIRDocumentReference *FSTTestDocRef(const char *path) {
   return [[FIRDocumentReference alloc] initWithPath:Resource(path)
-                                          firestore:FSTTestFirestore().wrapped];
+                                          firestore:FSTTestFirestore().cppFirestorePtr];
 }
 
 /** A convenience method for creating a query snapshots for tests. */
@@ -157,7 +157,7 @@
                             /*sync_state_changed=*/true,
                             /*excludes_metadata_changes=*/false,
                             static_cast<bool>(hasCachedResults)};
-  return [[FIRQuerySnapshot alloc] initWithFirestore:FSTTestFirestore().wrapped
+  return [[FIRQuerySnapshot alloc] initWithFirestore:FSTTestFirestore().cppFirestorePtr
                                        originalQuery:Query(path)
                                             snapshot:std::move(viewSnapshot)
                                             metadata:std::move(metadata)];

Firestore/Example/Tests/Integration/API/FIRDatabaseTests.mm

@@ -1523,7 +1523,7 @@ - (void)testAppDeleteLeadsToFirestoreTermination {
 
   [self deleteApp:app];
 
-  XCTAssertTrue(firestore.wrapped->client()->is_terminated());
+  XCTAssertTrue(firestore.cppFirestorePtr->client()->is_terminated());
 }
 
 // Ensures b/172958106 doesn't regress.

Firestore/Source/API/FIRAggregateQuerySnapshot.mm

@@ -92,7 +92,7 @@ - (id)valueForAggregateField:(FIRAggregateField *)aggregateField {
                          [aggregateField name], path);
   }
   FSTUserDataWriter *dataWriter =
-      [[FSTUserDataWriter alloc] initWithFirestore:_query.query.firestore.wrapped
+      [[FSTUserDataWriter alloc] initWithFirestore:_query.query.firestore.cppFirestorePtr
                            serverTimestampBehavior:serverTimestampBehavior];
   return [dataWriter convertedValue:*fieldValue];
 }

Firestore/Source/API/FIRCallbackWrapper.mm

@@ -0,0 +1,66 @@
+/*
+ * Copyright 2024 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.
+ */
+
+#import "FIRCallbackWrapper.h"
+
+#include <memory>
+#include <utility>
+#include <vector>
+
+#include "Firestore/core/interfaceForSwift/api/pipeline.h"
+#include "Firestore/core/interfaceForSwift/api/pipeline_result.h"
+#include "Firestore/core/src/core/event_listener.h"
+#include "Firestore/core/src/util/error_apple.h"
+#include "Firestore/core/src/util/statusor.h"
+
+using firebase::firestore::api::PipelineResult;
+using firebase::firestore::api::PipelineSnapshotListener;
+using firebase::firestore::core::EventListener;
+using firebase::firestore::util::MakeNSError;
+using firebase::firestore::util::StatusOr;
+
+@implementation FIRCallbackWrapper
+
++ (PipelineSnapshotListener)
+    wrapPipelineCallback:(std::shared_ptr<api::Firestore>)firestore
+              completion:(void (^)(std::shared_ptr<std::vector<PipelineResult>> result,
+                                   NSError *_Nullable error))completion {
+  class Converter : public EventListener<std::vector<PipelineResult>> {
+   public:
+    explicit Converter(std::shared_ptr<api::Firestore> firestore, PipelineBlock completion)
+        : firestore_(firestore), completion_(completion) {
+    }
+
+    void OnEvent(StatusOr<std::vector<PipelineResult>> maybe_snapshot) override {
+      if (maybe_snapshot.ok()) {
+        completion_(
+            std::make_shared<std::vector<PipelineResult>>(
+                std::initializer_list<PipelineResult>{PipelineResult::GetTestResult(firestore_)}),
+            nullptr);
+      } else {
+        completion_(nullptr, MakeNSError(maybe_snapshot.status()));
+      }
+    }
+
+   private:
+    std::shared_ptr<api::Firestore> firestore_;
+    PipelineBlock completion_;
+  };
+
+  return absl::make_unique<Converter>(firestore, completion);
+}
+
+@end

Firestore/Source/API/FIRDocumentSnapshot.mm

@@ -86,10 +86,10 @@ - (instancetype)initWithFirestore:(FIRFirestore *)firestore
                          metadata:(SnapshotMetadata)metadata {
   DocumentSnapshot wrapped;
   if (document.has_value()) {
-    wrapped =
-        DocumentSnapshot::FromDocument(firestore.wrapped, document.value(), std::move(metadata));
+    wrapped = DocumentSnapshot::FromDocument(firestore.cppFirestorePtr, document.value(),
+                                             std::move(metadata));
   } else {
-    wrapped = DocumentSnapshot::FromNoDocument(firestore.wrapped, std::move(documentKey),
+    wrapped = DocumentSnapshot::FromNoDocument(firestore.cppFirestorePtr, std::move(documentKey),
                                                std::move(metadata));
   }
   _serializer.reset(new Serializer(firestore.databaseID));

Firestore/Source/API/FIRFirestore+Internal.h

@@ -79,8 +79,6 @@ NS_ASSUME_NONNULL_BEGIN
 
 - (const std::shared_ptr<firebase::firestore::util::AsyncQueue> &)workerQueue;
 
-@property(nonatomic, assign, readonly) std::shared_ptr<api::Firestore> wrapped;
-
 @property(nonatomic, assign, readonly) const model::DatabaseId &databaseID;
 @property(nonatomic, strong, readonly) FSTUserDataReader *dataReader;
 

Firestore/Source/API/FIRFirestore.mm

@@ -531,7 +531,7 @@ - (void)getQueryNamed:(NSString *)name completion:(void (^)(FIRQuery *_Nullable
 
 @implementation FIRFirestore (Internal)
 
-- (std::shared_ptr<Firestore>)wrapped {
+- (std::shared_ptr<Firestore>)cppFirestorePtr {
   return _firestore;
 }
 

Firestore/Source/API/FIRQuery.mm

@@ -203,7 +203,7 @@ - (void)getDocumentsWithSource:(FIRFirestoreSource)publicSource
 - (id<FIRListenerRegistration>)addSnapshotListenerInternalWithOptions:(ListenOptions)internalOptions
                                                              listener:
                                                                  (FIRQuerySnapshotBlock)listener {
-  std::shared_ptr<Firestore> firestore = self.firestore.wrapped;
+  std::shared_ptr<Firestore> firestore = self.firestore.cppFirestorePtr;
   const core::Query &query = self.query;
 
   // Convert from ViewSnapshots to QuerySnapshots.

Firestore/Source/Public/FirebaseFirestore/FIRCallbackWrapper.h

@@ -0,0 +1,64 @@
+/*
+ * Copyright 2024 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.
+ */
+
+#import <Foundation/Foundation.h>
+#include <memory>
+#include <vector>
+
+namespace firebase {
+namespace firestore {
+namespace api {
+class Firestore;
+class PipelineResult;
+}  // namespace api
+
+namespace core {
+template <typename T>
+class EventListener;
+}  // namespace core
+
+}  // namespace firestore
+}  // namespace firebase
+
+namespace api = firebase::firestore::api;
+namespace core = firebase::firestore::core;
+
+NS_ASSUME_NONNULL_BEGIN
+
+typedef void (^PipelineBlock)(std::shared_ptr<std::vector<api::PipelineResult>> result,
+                              NSError *_Nullable error)
+    NS_SWIFT_UNAVAILABLE("Use Swift's closure syntax instead.");
+
+typedef std::shared_ptr<std::vector<api::PipelineResult>> PipelineResultVectorPtr;
+
+NS_SWIFT_SENDABLE
+NS_SWIFT_NAME(CallbackWrapper)
+@interface FIRCallbackWrapper : NSObject
+
+// Note: Marking callbacks in callback-based APIs as `Sendable` can help prevent crashes when they
+// are invoked on a different thread than the one they were originally defined in. If this callback
+// is expected to be called on a different thread, it should be marked as `Sendable` to ensure
+// thread safety.
++ (std::unique_ptr<core::EventListener<std::vector<api::PipelineResult>>>)
+    wrapPipelineCallback:(std::shared_ptr<api::Firestore>)firestore
+              completion:(void (^NS_SWIFT_SENDABLE)(
+                             std::shared_ptr<std::vector<api::PipelineResult>> result,
+                             NSError *_Nullable error))completion
+    NS_SWIFT_NAME(wrapPipelineCallback(firestore:completion:));
+
+@end
+
+NS_ASSUME_NONNULL_END

Firestore/Source/Public/FirebaseFirestore/FIRFirestore.h

@@ -15,6 +15,7 @@
  */
 
 #import <Foundation/Foundation.h>
+#include <memory>
 
 #import "FIRListenerRegistration.h"
 
@@ -30,6 +31,16 @@
 @class FIRWriteBatch;
 @class FIRPersistentCacheIndexManager;
 
+namespace firebase {
+namespace firestore {
+namespace api {
+class Firestore;
+}  // namespace api
+}  // namespace firestore
+}  // namespace firebase
+
+namespace cppApi = firebase::firestore::api;
+
 NS_ASSUME_NONNULL_BEGIN
 
 /**
@@ -91,6 +102,8 @@ NS_SWIFT_NAME(Firestore)
  */
 + (instancetype)firestoreForDatabase:(NSString *)database NS_SWIFT_NAME(firestore(database:));
 
+@property(nonatomic, assign, readonly) std::shared_ptr<cppApi::Firestore> cppFirestorePtr;
+
 /**
  * Custom settings used to configure this `Firestore` object.
  */

Firestore/Source/Public/FirebaseFirestore/FirebaseFirestore.h

@@ -18,6 +18,7 @@
 #import "FIRAggregateQuery.h"
 #import "FIRAggregateQuerySnapshot.h"
 #import "FIRAggregateSource.h"
+#import "FIRCallbackWrapper.h"
 #import "FIRCollectionReference.h"
 #import "FIRDocumentChange.h"
 #import "FIRDocumentReference.h"

Firestore/Swift/Source/AsyncAwait/Firestore+AsyncAwait.swift

@@ -15,6 +15,7 @@
  */
 
 #if SWIFT_PACKAGE
+  import FirebaseFirestoreCpp
   @_exported import FirebaseFirestoreInternalWrapper
 #else
   @_exported import FirebaseFirestoreInternal
@@ -115,4 +116,8 @@
       }
     }
   }
+
+  func pipeline() -> PipelineSource {
+    return PipelineSource(firebase.firestore.api.FirestorePipeline.pipeline(cppFirestorePtr))
+  }
 }