Revert "Replace absl::optional usage in API (#8902)" (#8906)

This reverts commit 453a5cb.

Author: wu-hui

Firestore/Source/API/FIRCollectionReference.mm

@@ -25,7 +25,6 @@
 
 #include "Firestore/core/src/api/collection_reference.h"
 #include "Firestore/core/src/api/document_reference.h"
-#include "Firestore/core/src/api/optional.h"
 #include "Firestore/core/src/core/user_data.h"
 #include "Firestore/core/src/model/resource_path.h"
 #include "Firestore/core/src/util/error_apple.h"
@@ -34,7 +33,6 @@
 
 using firebase::firestore::api::CollectionReference;
 using firebase::firestore::api::DocumentReference;
-using firebase::firestore::api::Optional;
 using firebase::firestore::core::ParsedSetData;
 using firebase::firestore::model::ResourcePath;
 using firebase::firestore::util::MakeCallback;
@@ -93,7 +91,7 @@ - (NSString *)collectionID {
 }
 
 - (FIRDocumentReference *_Nullable)parent {
-  Optional<DocumentReference> parent = self.reference.parent();
+  absl::optional<DocumentReference> parent = self.reference.parent();
   if (!parent) {
     return nil;
   }

Firestore/Source/API/FIRDocumentSnapshot+Internal.h

@@ -19,7 +19,6 @@
 #include <memory>
 
 #include "Firestore/core/src/api/api_fwd.h"
-#include "Firestore/core/src/api/optional.h"
 #include "Firestore/core/src/model/model_fwd.h"
 
 @class FIRFirestore;
@@ -49,7 +48,7 @@ NS_ASSUME_NONNULL_BEGIN
 /** Internal FIRDocumentSnapshot API we don't want exposed in our public header files. */
 @interface FIRDocumentSnapshot (Internal)
 
-- (const api::Optional<model::Document> &)internalDocument;
+- (const absl::optional<model::Document> &)internalDocument;
 
 @end
 

Firestore/Source/API/FIRDocumentSnapshot.mm

@@ -34,7 +34,6 @@
 #include "Firestore/core/src/api/document_reference.h"
 #include "Firestore/core/src/api/document_snapshot.h"
 #include "Firestore/core/src/api/firestore.h"
-#include "Firestore/core/src/api/optional.h"
 #include "Firestore/core/src/api/settings.h"
 #include "Firestore/core/src/model/database_id.h"
 #include "Firestore/core/src/model/document_key.h"
@@ -51,7 +50,6 @@
 using firebase::firestore::api::Firestore;
 using firebase::firestore::api::MakeFIRGeoPoint;
 using firebase::firestore::api::MakeFIRTimestamp;
-using firebase::firestore::api::Optional;
 using firebase::firestore::api::SnapshotMetadata;
 using firebase::firestore::model::DatabaseId;
 using firebase::firestore::model::Document;
@@ -128,7 +126,7 @@ - (BOOL)exists {
   return _snapshot.exists();
 }
 
-- (const Optional<Document> &)internalDocument {
+- (const absl::optional<Document> &)internalDocument {
   return _snapshot.internal_document();
 }
 
@@ -155,7 +153,7 @@ - (FIRSnapshotMetadata *)metadata {
 
 - (nullable NSDictionary<NSString *, id> *)dataWithServerTimestampBehavior:
     (FIRServerTimestampBehavior)serverTimestampBehavior {
-  Optional<google_firestore_v1_Value> data = _snapshot.GetValue(FieldPath::EmptyPath());
+  absl::optional<google_firestore_v1_Value> data = _snapshot.GetValue(FieldPath::EmptyPath());
   if (!data) return nil;
 
   FSTUserDataWriter *dataWriter =
@@ -178,7 +176,7 @@ - (nullable id)valueForField:(id)field
   } else {
     ThrowInvalidArgument("Subscript key must be an NSString or FIRFieldPath.");
   }
-  Optional<google_firestore_v1_Value> fieldValue = _snapshot.GetValue(fieldPath);
+  absl::optional<google_firestore_v1_Value> fieldValue = _snapshot.GetValue(fieldPath);
   if (!fieldValue) return nil;
   FSTUserDataWriter *dataWriter =
       [[FSTUserDataWriter alloc] initWithFirestore:_snapshot.firestore()

Firestore/core/src/api/collection_reference.cc

@@ -67,13 +67,12 @@ const std::string& CollectionReference::collection_id() const {
   return query().path().last_segment();
 }
 
-Optional<DocumentReference> CollectionReference::parent() const {
+absl::optional<DocumentReference> CollectionReference::parent() const {
   ResourcePath parent_path = query().path().PopLast();
   if (parent_path.empty()) {
-    return {};
+    return absl::nullopt;
   } else {
-    return Optional<DocumentReference>(
-        DocumentReference(DocumentKey(std::move(parent_path)), firestore()));
+    return DocumentReference(DocumentKey(std::move(parent_path)), firestore());
   }
 }
 

Firestore/core/src/api/collection_reference.h

@@ -21,9 +21,9 @@
 #include <string>
 
 #include "Firestore/core/src/api/api_fwd.h"
-#include "Firestore/core/src/api/optional.h"
 #include "Firestore/core/src/api/query_core.h"
 #include "Firestore/core/src/core/core_fwd.h"
+#include "absl/types/optional.h"
 
 namespace firebase {
 namespace firestore {
@@ -52,7 +52,7 @@ class CollectionReference : public Query {
    * For subcollections, `parent` returns the containing `DocumentReference`.
    * For root collections, nullopt is returned.
    */
-  Optional<DocumentReference> parent() const;
+  absl::optional<DocumentReference> parent() const;
 
   /**
    * A string containing the slash-separated path to this `CollectionReference`

Firestore/core/src/api/common.h

@@ -22,7 +22,6 @@
 #include "Firestore/core/src/api/collection_reference.h"
 #include "Firestore/core/src/api/document_snapshot.h"
 #include "Firestore/core/src/api/firestore.h"
-#include "Firestore/core/src/api/optional.h"
 #include "Firestore/core/src/api/query_listener_registration.h"
 #include "Firestore/core/src/api/source.h"
 #include "Firestore/core/src/core/firestore_client.h"
@@ -220,9 +219,7 @@ std::unique_ptr<ListenerRegistration> DocumentReference::AddSnapshotListener(
                    : false;
 
       DocumentSnapshot result{
-          firestore_, key_,
-          document ? Optional<Document>(document.value())
-                   : Optional<Document>(),
+          firestore_, key_, document,
           SnapshotMetadata{has_pending_writes, snapshot.from_cache()}};
       user_listener_->OnEvent(std::move(result));
     }

Firestore/core/src/api/document_reference.cc

@@ -21,6 +21,7 @@
 #include "Firestore/core/src/api/document_reference.h"
 #include "Firestore/core/src/model/resource_path.h"
 #include "Firestore/core/src/util/hashing.h"
+#include "absl/types/optional.h"
 
 namespace firebase {
 namespace firestore {
@@ -35,22 +36,21 @@ DocumentSnapshot DocumentSnapshot::FromDocument(
     std::shared_ptr<Firestore> firestore,
     model::Document document,
     SnapshotMetadata metadata) {
-  return DocumentSnapshot{std::move(firestore), document->key(),
-                          Optional<model::Document>(document),
+  return DocumentSnapshot{std::move(firestore), document->key(), document,
                           std::move(metadata)};
 }
 
 DocumentSnapshot DocumentSnapshot::FromNoDocument(
     std::shared_ptr<Firestore> firestore,
     model::DocumentKey key,
     SnapshotMetadata metadata) {
-  return DocumentSnapshot{std::move(firestore), std::move(key),
-                          Optional<model::Document>(), std::move(metadata)};
+  return DocumentSnapshot{std::move(firestore), std::move(key), absl::nullopt,
+                          std::move(metadata)};
 }
 
 DocumentSnapshot::DocumentSnapshot(std::shared_ptr<Firestore> firestore,
                                    model::DocumentKey document_key,
-                                   Optional<Document> document,
+                                   absl::optional<Document> document,
                                    SnapshotMetadata metadata)
     : firestore_{std::move(firestore)},
       internal_key_{std::move(document_key)},
@@ -67,7 +67,7 @@ bool DocumentSnapshot::exists() const {
   return internal_document_.has_value();
 }
 
-const Optional<Document>& DocumentSnapshot::internal_document() const {
+const absl::optional<Document>& DocumentSnapshot::internal_document() const {
   return internal_document_;
 }
 
@@ -79,15 +79,10 @@ const std::string& DocumentSnapshot::document_id() const {
   return internal_key_.path().last_segment();
 }
 
-Optional<google_firestore_v1_Value> DocumentSnapshot::GetValue(
+absl::optional<google_firestore_v1_Value> DocumentSnapshot::GetValue(
     const FieldPath& field_path) const {
-  if (internal_document_) {
-    auto value = (*internal_document_)->field(field_path);
-    if (value) {
-      return Optional<google_firestore_v1_Value>(value.value());
-    }
-  }
-  return {};
+  return internal_document_ ? (*internal_document_)->field(field_path)
+                            : absl::nullopt;
 }
 
 bool operator==(const DocumentSnapshot& lhs, const DocumentSnapshot& rhs) {

Firestore/core/src/api/document_snapshot.cc

@@ -21,12 +21,12 @@
 #include <string>
 #include <utility>
 
-#include "Firestore/core/src/api/optional.h"
 #include "Firestore/core/src/api/snapshot_metadata.h"
 #include "Firestore/core/src/core/event_listener.h"
 #include "Firestore/core/src/model/document.h"
 #include "Firestore/core/src/model/document_key.h"
 #include "Firestore/core/src/model/model_fwd.h"
+#include "absl/types/optional.h"
 
 namespace firebase {
 namespace firestore {
@@ -50,7 +50,7 @@ class DocumentSnapshot {
   size_t Hash() const;
 
   bool exists() const;
-  const Optional<model::Document>& internal_document() const;
+  const absl::optional<model::Document>& internal_document() const;
   const std::string& document_id() const;
 
   const SnapshotMetadata& metadata() const {
@@ -59,7 +59,7 @@ class DocumentSnapshot {
 
   DocumentReference CreateReference() const;
 
-  Optional<google_firestore_v1_Value> GetValue(
+  absl::optional<google_firestore_v1_Value> GetValue(
       const model::FieldPath& field_path) const;
 
   const std::shared_ptr<Firestore>& firestore() const {
@@ -76,13 +76,13 @@ class DocumentSnapshot {
 
   DocumentSnapshot(std::shared_ptr<Firestore> firestore,
                    model::DocumentKey document_key,
-                   Optional<model::Document> document,
+                   absl::optional<model::Document> document,
                    SnapshotMetadata metadata);
 
  private:
   std::shared_ptr<Firestore> firestore_;
   model::DocumentKey internal_key_;
-  Optional<model::Document> internal_document_;
+  absl::optional<model::Document> internal_document_;
   SnapshotMetadata metadata_;
 };