2424#include < stddef.h>
2525
2626#include < algorithm> // IWYU pragma: keep
27- #include < memory>
2827#include < string>
2928#include < type_traits>
3029#include < utility>
3433#include " absl/types/optional.h"
3534#include " absl/types/variant.h"
3635
37- #include < grpc/event_engine/event_engine.h>
3836#include < grpc/impl/codegen/grpc_types.h>
3937
4038#include " src/core/lib/avl/avl.h"
@@ -54,7 +52,7 @@ namespace grpc_core {
5452// ChannelArgs to automatically derive a vtable from a T*.
5553// To participate as a pointer, instances should expose the function:
5654// // Gets the vtable for this type
57- // static const grpc_arg_pointer_vtable * VTable();
55+ // static const grpc_channel_arg_vtable * VTable();
5856// // Performs any mutations required for channel args to own a pointer
5957// // Only needed if ChannelArgs::Set is to be called with a raw pointer.
6058// static void* TakeUnownedPointer(T* p);
@@ -88,32 +86,6 @@ struct ChannelArgTypeTraits<
8886 };
8987};
9088
91- // Specialization for shared_ptr
92- // Incurs an allocation because shared_ptr.release is not a thing.
93- template <typename T>
94- struct is_shared_ptr : std::false_type {};
95- template <typename T>
96- struct is_shared_ptr <std::shared_ptr<T>> : std::true_type {};
97- template <typename T>
98- struct ChannelArgTypeTraits <T,
99- absl::enable_if_t <is_shared_ptr<T>::value, void >> {
100- static void * TakeUnownedPointer (T* p) { return p; }
101- static const grpc_arg_pointer_vtable* VTable () {
102- static const grpc_arg_pointer_vtable tbl = {
103- // copy
104- [](void * p) -> void * { return new T (*static_cast <T*>(p)); },
105- // destroy
106- [](void * p) { delete static_cast <T*>(p); },
107- // compare
108- [](void * p1, void * p2) {
109- return QsortCompare (static_cast <const T*>(p1)->get (),
110- static_cast <const T*>(p2)->get ());
111- },
112- };
113- return &tbl;
114- };
115- };
116-
11789// If a type declares some member 'struct RawPointerChannelArgTag {}' then
11890// we automatically generate a vtable for it that does not do any ownership
11991// management and compares the type by pointer identity.
@@ -136,54 +108,6 @@ struct ChannelArgTypeTraits<T,
136108 };
137109};
138110
139- // GetObject support for shared_ptr and RefCountedPtr
140- template <typename T>
141- struct WrapInSharedPtr
142- : std::integral_constant<
143- bool , std::is_base_of<std::enable_shared_from_this<T>, T>::value> {};
144- template <>
145- struct WrapInSharedPtr <grpc_event_engine::experimental::EventEngine>
146- : std::true_type {};
147- template <typename T, typename Ignored = void /* for SFINAE */
148- struct GetObjectImpl ;
149- // std::shared_ptr implementation
150- template <typename T>
151- struct GetObjectImpl <T, absl::enable_if_t <WrapInSharedPtr<T>::value, void >> {
152- using Result = T*;
153- using ReffedResult = std::shared_ptr<T>;
154- using StoredType = std::shared_ptr<T>*;
155- static Result Get (StoredType p) { return p->get (); };
156- static ReffedResult GetReffed (StoredType p) { return ReffedResult (*p); };
157- };
158- // RefCountedPtr
159- template <typename T>
160- struct GetObjectImpl <T, absl::enable_if_t <!WrapInSharedPtr<T>::value, void >> {
161- using Result = T*;
162- using ReffedResult = RefCountedPtr<T>;
163- using StoredType = Result;
164- static Result Get (StoredType p) { return p; };
165- static ReffedResult GetReffed (StoredType p) {
166- if (p == nullptr ) return nullptr ;
167- return p->Ref ();
168- };
169- };
170-
171- // Provide the canonical name for a type's channel arg key
172- template <typename T>
173- struct ChannelArgNameTraits {
174- static absl::string_view ChannelArgName () { return T::ChannelArgName (); }
175- };
176- template <typename T>
177- struct ChannelArgNameTraits <std::shared_ptr<T>> {
178- static absl::string_view ChannelArgName () { return T::ChannelArgName (); }
179- };
180-
181- // Specialization for the EventEngine
182- template <>
183- struct ChannelArgNameTraits <grpc_event_engine::experimental::EventEngine> {
184- static absl::string_view ChannelArgName () { return GRPC_ARG_EVENT_ENGINE; }
185- };
186-
187111class ChannelArgs {
188112 public:
189113 class Pointer {
@@ -278,40 +202,19 @@ class ChannelArgs {
278202 absl::remove_cvref_t <decltype (*store_value)>>::VTable ()));
279203 }
280204 template <typename T>
281- GRPC_MUST_USE_RESULT absl::enable_if_t <
282- std::is_same<
283- const grpc_arg_pointer_vtable*,
284- decltype (ChannelArgTypeTraits<std::shared_ptr<T>>::VTable())>::value,
285- ChannelArgs>
286- Set(absl::string_view name, std::shared_ptr<T> value) const {
287- auto * store_value = new std::shared_ptr<T>(value);
288- return Set (
289- name,
290- Pointer (ChannelArgTypeTraits<std::shared_ptr<T>>::TakeUnownedPointer (
291- store_value),
292- ChannelArgTypeTraits<std::shared_ptr<T>>::VTable ()));
293- }
294- template <typename T>
295205 GRPC_MUST_USE_RESULT ChannelArgs SetIfUnset (absl::string_view name, T value) {
296206 if (Contains (name)) return *this ;
297207 return Set (name, std::move (value));
298208 }
299209 GRPC_MUST_USE_RESULT ChannelArgs Remove (absl::string_view name) const ;
300210 bool Contains (absl::string_view name) const { return Get (name) != nullptr ; }
301211
302- template <typename T>
303- bool ContainsObject () const {
304- return Get (ChannelArgNameTraits<T>::ChannelArgName ()) != nullptr ;
305- }
306-
307212 absl::optional<int > GetInt (absl::string_view name) const ;
308213 absl::optional<absl::string_view> GetString (absl::string_view name) const ;
309214 void * GetVoidPointer (absl::string_view name) const ;
310215 template <typename T>
311- typename GetObjectImpl<T>::StoredType GetPointer (
312- absl::string_view name) const {
313- return static_cast <typename GetObjectImpl<T>::StoredType>(
314- GetVoidPointer (name));
216+ T* GetPointer (absl::string_view name) const {
217+ return static_cast <T*>(GetVoidPointer (name));
315218 }
316219 absl::optional<Duration > GetDurationFromIntMillis (
317220 absl::string_view name) const ;
@@ -331,18 +234,14 @@ class ChannelArgs {
331234 return Set (T::ChannelArgName (), std::move (p));
332235 }
333236 template <typename T>
334- GRPC_MUST_USE_RESULT ChannelArgs SetObject (std::shared_ptr<T> p) const {
335- return Set (ChannelArgNameTraits<T>::ChannelArgName (), std::move (p));
336- }
337- template <typename T>
338- typename GetObjectImpl<T>::Result GetObject () {
339- return GetObjectImpl<T>::Get (
340- GetPointer<T>(ChannelArgNameTraits<T>::ChannelArgName ()));
237+ T* GetObject () {
238+ return GetPointer<T>(T::ChannelArgName ());
341239 }
342240 template <typename T>
343- typename GetObjectImpl<T>::ReffedResult GetObjectRef () {
344- return GetObjectImpl<T>::GetReffed (
345- GetPointer<T>(ChannelArgNameTraits<T>::ChannelArgName ()));
241+ RefCountedPtr<T> GetObjectRef () {
242+ auto * p = GetObject<T>();
243+ if (p == nullptr ) return nullptr ;
244+ return p->Ref ();
346245 }
347246
348247 bool operator <(const ChannelArgs& other) const { return args_ < other.args_ ; }
0 commit comments