Prep for forward declarations (#4859)

* Remove rarely used template argumnets from SortedMap/SortedSet

* Remove unused STATUS_CHECK_OK

* Rename QuerySnapshot::Listener to QuerySnapshotListener

This makes the type something that can be forward declared.

* Rename DocumentSnapshot::Listener to DocumentSnapshotListener

This makes the type something that can be forward declared.

* Rename ViewSnapshot::Listener to ViewSnapshotListener

This makes the type something that can be forward declared.

* Put most QueryListener implementation in .cc

* Actually use sync_engine_callback.h

Author: wilhuff

Firestore/Source/API/FIRDocumentReference.mm

@@ -1,5 +1,5 @@
 /*
- * Copyright 2017 Google
+ * Copyright 2017 Google LLC
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -45,6 +45,7 @@
 using firebase::firestore::api::CollectionReference;
 using firebase::firestore::api::DocumentReference;
 using firebase::firestore::api::DocumentSnapshot;
+using firebase::firestore::api::DocumentSnapshotListener;
 using firebase::firestore::api::Firestore;
 using firebase::firestore::api::ListenerRegistration;
 using firebase::firestore::api::Source;
@@ -213,7 +214,7 @@ - (void)getDocumentWithSource:(FIRFirestoreSource)source
   return [[FSTListenerRegistration alloc] initWithRegistration:std::move(result)];
 }
 
-- (DocumentSnapshot::Listener)wrapDocumentSnapshotBlock:(FIRDocumentSnapshotBlock)block {
+- (DocumentSnapshotListener)wrapDocumentSnapshotBlock:(FIRDocumentSnapshotBlock)block {
   class Converter : public EventListener<DocumentSnapshot> {
    public:
     explicit Converter(FIRDocumentSnapshotBlock block) : block_(block) {

Firestore/Source/API/FIRQuery.mm

@@ -1,5 +1,5 @@
 /*
- * Copyright 2017 Google
+ * Copyright 2017 Google LLC
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -36,6 +36,7 @@
 
 #include "Firestore/core/src/firebase/firestore/api/query_core.h"
 #include "Firestore/core/src/firebase/firestore/api/query_listener_registration.h"
+#include "Firestore/core/src/firebase/firestore/api/query_snapshot.h"
 #include "Firestore/core/src/firebase/firestore/core/bound.h"
 #include "Firestore/core/src/firebase/firestore/core/direction.h"
 #include "Firestore/core/src/firebase/firestore/core/filter.h"
@@ -59,6 +60,7 @@
 using firebase::firestore::api::Query;
 using firebase::firestore::api::QueryListenerRegistration;
 using firebase::firestore::api::QuerySnapshot;
+using firebase::firestore::api::QuerySnapshotListener;
 using firebase::firestore::api::SnapshotMetadata;
 using firebase::firestore::api::Source;
 using firebase::firestore::core::AsyncEventListener;
@@ -446,7 +448,7 @@ - (FieldValue)parsedQueryValue:(id)value allowArrays:(bool)allowArrays {
   return [self.firestore.dataConverter parsedQueryValue:value allowArrays:allowArrays];
 }
 
-- (QuerySnapshot::Listener)wrapQuerySnapshotBlock:(FIRQuerySnapshotBlock)block {
+- (QuerySnapshotListener)wrapQuerySnapshotBlock:(FIRQuerySnapshotBlock)block {
   class Converter : public EventListener<QuerySnapshot> {
    public:
     explicit Converter(FIRQuerySnapshotBlock block) : block_(block) {

Firestore/core/src/firebase/firestore/api/document_reference.cc

@@ -1,5 +1,5 @@
 /*
- * Copyright 2019 Google
+ * Copyright 2019 Google LLC
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -110,7 +110,7 @@ void DocumentReference::DeleteDocument(util::StatusCallback callback) {
 }
 
 void DocumentReference::GetDocument(Source source,
-                                    DocumentSnapshot::Listener&& callback) {
+                                    DocumentSnapshotListener&& callback) {
   if (source == Source::Cache) {
     firestore_->client()->GetDocumentFromLocalCache(*this, std::move(callback));
     return;
@@ -123,7 +123,7 @@ void DocumentReference::GetDocument(Source source,
 
   class ListenOnce : public EventListener<DocumentSnapshot> {
    public:
-    ListenOnce(Source source, DocumentSnapshot::Listener&& listener)
+    ListenOnce(Source source, DocumentSnapshotListener&& listener)
         : source_(source), listener_(std::move(listener)) {
     }
 
@@ -173,7 +173,7 @@ void DocumentReference::GetDocument(Source source,
 
    private:
     Source source_;
-    DocumentSnapshot::Listener listener_;
+    DocumentSnapshotListener listener_;
 
     std::promise<std::unique_ptr<ListenerRegistration>> registration_promise_;
   };
@@ -187,12 +187,12 @@ void DocumentReference::GetDocument(Source source,
 }
 
 std::unique_ptr<ListenerRegistration> DocumentReference::AddSnapshotListener(
-    ListenOptions options, DocumentSnapshot::Listener&& user_listener) {
+    ListenOptions options, DocumentSnapshotListener&& user_listener) {
   // Convert from ViewSnapshots to DocumentSnapshots.
   class Converter : public EventListener<ViewSnapshot> {
    public:
     Converter(DocumentReference* parent,
-              DocumentSnapshot::Listener&& user_listener)
+              DocumentSnapshotListener&& user_listener)
         : firestore_(parent->firestore_),
           key_(parent->key_),
           user_listener_(std::move(user_listener)) {
@@ -224,7 +224,7 @@ std::unique_ptr<ListenerRegistration> DocumentReference::AddSnapshotListener(
    private:
     std::shared_ptr<Firestore> firestore_;
     DocumentKey key_;
-    DocumentSnapshot::Listener user_listener_;
+    DocumentSnapshotListener user_listener_;
   };
   auto view_listener =
       absl::make_unique<Converter>(this, std::move(user_listener));

Firestore/core/src/firebase/firestore/api/document_reference.h

@@ -1,5 +1,5 @@
 /*
- * Copyright 2019 Google
+ * Copyright 2019 Google LLC
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -80,10 +80,10 @@ class DocumentReference {
 
   void DeleteDocument(util::StatusCallback callback);
 
-  void GetDocument(Source source, DocumentSnapshot::Listener&& callback);
+  void GetDocument(Source source, DocumentSnapshotListener&& callback);
 
   std::unique_ptr<ListenerRegistration> AddSnapshotListener(
-      core::ListenOptions options, DocumentSnapshot::Listener&& listener);
+      core::ListenOptions options, DocumentSnapshotListener&& listener);
 
  private:
   std::shared_ptr<Firestore> firestore_;

Firestore/core/src/firebase/firestore/api/document_snapshot.h

@@ -1,5 +1,5 @@
 /*
- * Copyright 2019 Google
+ * Copyright 2019 Google LLC
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -38,8 +38,6 @@ class Firestore;
 
 class DocumentSnapshot {
  public:
-  using Listener = std::unique_ptr<core::EventListener<DocumentSnapshot>>;
-
   DocumentSnapshot() = default;
 
   static DocumentSnapshot FromDocument(std::shared_ptr<Firestore> firestore,
@@ -90,6 +88,9 @@ class DocumentSnapshot {
   SnapshotMetadata metadata_;
 };
 
+using DocumentSnapshotListener =
+    std::unique_ptr<core::EventListener<DocumentSnapshot>>;
+
 inline bool operator!=(const DocumentSnapshot& lhs,
                        const DocumentSnapshot& rhs) {
   return !(lhs == rhs);

Firestore/core/src/firebase/firestore/api/query_core.cc

@@ -1,5 +1,5 @@
 /*
- * Copyright 2019 Google
+ * Copyright 2019 Google LLC
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -69,7 +69,7 @@ size_t Query::Hash() const {
   return util::Hash(firestore_.get(), query());
 }
 
-void Query::GetDocuments(Source source, QuerySnapshot::Listener&& callback) {
+void Query::GetDocuments(Source source, QuerySnapshotListener&& callback) {
   ValidateHasExplicitOrderByForLimitToLast();
   if (source == Source::Cache) {
     firestore_->client()->GetDocumentsFromLocalCache(*this,
@@ -84,7 +84,7 @@ void Query::GetDocuments(Source source, QuerySnapshot::Listener&& callback) {
 
   class ListenOnce : public EventListener<QuerySnapshot> {
    public:
-    ListenOnce(Source source, QuerySnapshot::Listener&& listener)
+    ListenOnce(Source source, QuerySnapshotListener&& listener)
         : source_(source), listener_(std::move(listener)) {
     }
 
@@ -119,7 +119,7 @@ void Query::GetDocuments(Source source, QuerySnapshot::Listener&& callback) {
 
    private:
     Source source_;
-    QuerySnapshot::Listener listener_;
+    QuerySnapshotListener listener_;
 
     std::promise<std::unique_ptr<ListenerRegistration>> registration_promise_;
   };
@@ -134,12 +134,12 @@ void Query::GetDocuments(Source source, QuerySnapshot::Listener&& callback) {
 }
 
 std::unique_ptr<ListenerRegistration> Query::AddSnapshotListener(
-    ListenOptions options, QuerySnapshot::Listener&& user_listener) {
+    ListenOptions options, QuerySnapshotListener&& user_listener) {
   ValidateHasExplicitOrderByForLimitToLast();
   // Convert from ViewSnapshots to QuerySnapshots.
   class Converter : public EventListener<ViewSnapshot> {
    public:
-    Converter(Query* parent, QuerySnapshot::Listener&& user_listener)
+    Converter(Query* parent, QuerySnapshotListener&& user_listener)
         : firestore_(parent->firestore()),
           query_(parent->query()),
           user_listener_(std::move(user_listener)) {
@@ -164,7 +164,7 @@ std::unique_ptr<ListenerRegistration> Query::AddSnapshotListener(
    private:
     std::shared_ptr<Firestore> firestore_;
     core::Query query_;
-    QuerySnapshot::Listener user_listener_;
+    QuerySnapshotListener user_listener_;
   };
   auto view_listener =
       absl::make_unique<Converter>(this, std::move(user_listener));

Firestore/core/src/firebase/firestore/api/query_core.h

@@ -1,5 +1,5 @@
 /*
- * Copyright 2019 Google
+ * Copyright 2019 Google LLC
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -66,7 +66,7 @@ class Query {
    * @param callback a callback to execute once the documents have been
    *     successfully read.
    */
-  void GetDocuments(Source source, QuerySnapshot::Listener&& callback);
+  void GetDocuments(Source source, QuerySnapshotListener&& callback);
 
   /**
    * Attaches a listener for QuerySnapshot events.
@@ -78,7 +78,7 @@ class Query {
    * @return A ListenerRegistration that can be used to remove this listener.
    */
   std::unique_ptr<ListenerRegistration> AddSnapshotListener(
-      core::ListenOptions options, QuerySnapshot::Listener&& listener);
+      core::ListenOptions options, QuerySnapshotListener&& listener);
 
   /**
    * Creates and returns a new `Query` with the additional filter that documents

Firestore/core/src/firebase/firestore/api/query_snapshot.h

@@ -1,5 +1,5 @@
 /*
- * Copyright 2019 Google
+ * Copyright 2019 Google LLC
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -40,8 +40,6 @@ class Query;
  */
 class QuerySnapshot {
  public:
-  using Listener = std::unique_ptr<core::EventListener<QuerySnapshot>>;
-
   QuerySnapshot(std::shared_ptr<Firestore> firestore,
                 core::Query query,
                 core::ViewSnapshot&& snapshot,
@@ -97,6 +95,9 @@ class QuerySnapshot {
   SnapshotMetadata metadata_;
 };
 
+using QuerySnapshotListener =
+    std::unique_ptr<core::EventListener<QuerySnapshot>>;
+
 }  // namespace api
 }  // namespace firestore
 }  // namespace firebase

Firestore/core/src/firebase/firestore/core/event_manager.cc

@@ -1,5 +1,5 @@
 /*
- * Copyright 2019 Google
+ * Copyright 2019 Google LLC
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -17,6 +17,7 @@
 #include <utility>
 
 #include "Firestore/core/src/firebase/firestore/core/event_manager.h"
+#include "Firestore/core/src/firebase/firestore/core/sync_engine.h"
 #include "Firestore/core/src/firebase/firestore/util/hard_assert.h"
 
 namespace firebase {

Firestore/core/src/firebase/firestore/core/event_manager.h

@@ -1,5 +1,5 @@
 /*
- * Copyright 2019 Google
+ * Copyright 2019 Google LLC
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -24,7 +24,7 @@
 
 #include "Firestore/core/src/firebase/firestore/core/query.h"
 #include "Firestore/core/src/firebase/firestore/core/query_listener.h"
-#include "Firestore/core/src/firebase/firestore/core/sync_engine.h"
+#include "Firestore/core/src/firebase/firestore/core/sync_engine_callback.h"
 #include "Firestore/core/src/firebase/firestore/core/view_snapshot.h"
 #include "Firestore/core/src/firebase/firestore/model/types.h"
 #include "Firestore/core/src/firebase/firestore/util/empty.h"
@@ -37,6 +37,8 @@ namespace firebase {
 namespace firestore {
 namespace core {
 
+class QueryEventSource;
+
 /**
  * EventManager is responsible for mapping queries to query event listeners.
  * It handles "fan-out". (Identical queries will re-use the same watch on the