| $$ This is a pump file for generating file templates. Pump is a python |
| $$ script that is part of the Google Test suite of utilities. Description |
| $$ can be found here: |
| $$ |
| $$ http://code.google.com/p/googletest/wiki/PumpManual |
| $$ |
| |
| #ifndef GIN_FUNCTION_TEMPLATE_H_ |
| #define GIN_FUNCTION_TEMPLATE_H_ |
| |
| $var MAX_ARITY = 6 |
| |
| // Copyright 2013 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. |
| |
| #include "base/callback.h" |
| #include "base/logging.h" |
| #include "gin/arguments.h" |
| #include "gin/converter.h" |
| #include "gin/gin_export.h" |
| #include "gin/handle.h" |
| #include "gin/public/gin_embedders.h" |
| #include "gin/public/wrapper_info.h" |
| #include "gin/wrappable.h" |
| |
| #include "v8/include/v8.h" |
| |
| namespace gin { |
| |
| class PerIsolateData; |
| |
| enum CreateFunctionTemplateFlags { |
| HolderIsFirstArgument = 1 << 0, |
| }; |
| |
| namespace internal { |
| |
| template<typename T> |
| struct CallbackParamTraits { |
| typedef T LocalType; |
| }; |
| template<typename T> |
| struct CallbackParamTraits<const T&> { |
| typedef T LocalType; |
| }; |
| template<typename T> |
| struct CallbackParamTraits<const T*> { |
| typedef T* LocalType; |
| }; |
| |
| |
| // CallbackHolder and CallbackHolderBase are used to pass a base::Callback from |
| // CreateFunctionTemplate through v8 (via v8::FunctionTemplate) to |
| // DispatchToCallback, where it is invoked. |
| // |
| // v8::FunctionTemplate only supports passing void* as data so how do we know |
| // when to delete the base::Callback? That's where CallbackHolderBase comes in. |
| // It inherits from Wrappable, which delete itself when both (a) the refcount |
| // via base::RefCounted has dropped to zero, and (b) there are no more |
| // JavaScript references in V8. |
| |
| // This simple base class is used so that we can share a single object template |
| // among every CallbackHolder instance. |
| class GIN_EXPORT CallbackHolderBase : public Wrappable<CallbackHolderBase> { |
| public: |
| static WrapperInfo kWrapperInfo; |
| protected: |
| virtual ~CallbackHolderBase() {} |
| }; |
| |
| template<typename Sig> |
| class CallbackHolder : public CallbackHolderBase { |
| public: |
| CallbackHolder(const base::Callback<Sig>& callback, int flags) |
| : callback(callback), flags(flags) {} |
| base::Callback<Sig> callback; |
| int flags; |
| private: |
| virtual ~CallbackHolder() {} |
| }; |
| |
| |
| // This set of templates invokes a base::Callback, converts the return type to a |
| // JavaScript value, and returns that value to script via the provided |
| // gin::Arguments object. |
| // |
| // In C++, you can declare the function foo(void), but you can't pass a void |
| // expression to foo. As a result, we must specialize the case of Callbacks that |
| // have the void return type. |
| |
| $range ARITY 0..MAX_ARITY |
| $for ARITY [[ |
| $var INV_ARITY = MAX_ARITY - ARITY |
| $range ARG 1..INV_ARITY |
| $range VOID INV_ARITY+1..MAX_ARITY |
| |
| $if ARITY == 0 [[ |
| template<typename R$for ARG [[, typename P$(ARG) = void]]> |
| struct Invoker { |
| ]] $else [[ |
| template<typename R$for ARG [[, typename P$(ARG)]]> |
| struct Invoker<R$for ARG [[, P$(ARG)]]$for VOID [[, void]]> { |
| ]] |
| |
| inline static void Go( |
| Arguments* args, |
| const base::Callback<R($for ARG , [[P$(ARG)]])>& callback$for ARG [[, |
| const P$(ARG)& a$(ARG)]]) { |
| args->Return(callback.Run($for ARG, [[a$(ARG)]])); |
| } |
| }; |
| template<$for ARG , [[typename P$(ARG)]]> |
| struct Invoker<void$for ARG [[, P$(ARG)]]$for VOID [[, void]]> { |
| inline static void Go( |
| Arguments* args, |
| const base::Callback<void($for ARG , [[P$(ARG)]])>& callback$for ARG [[, |
| const P$(ARG)& a$(ARG)]]) { |
| callback.Run($for ARG, [[a$(ARG)]]); |
| } |
| }; |
| |
| |
| ]] |
| |
| template<typename T> |
| bool GetNextArgument(Arguments* args, int create_flags, bool is_first, |
| T* result) { |
| if (is_first && (create_flags & HolderIsFirstArgument) != 0) { |
| return args->GetHolder(result); |
| } else { |
| return args->GetNext(result); |
| } |
| } |
| |
| // For advanced use cases, we allow callers to request the unparsed Arguments |
| // object and poke around in it directly. |
| inline bool GetNextArgument(Arguments* args, int create_flags, bool is_first, |
| Arguments* result) { |
| *result = *args; |
| return true; |
| } |
| |
| // It's common for clients to just need the isolate, so we make that easy. |
| inline bool GetNextArgument(Arguments* args, int create_flags, |
| bool is_first, v8::Isolate** result) { |
| *result = args->isolate(); |
| return true; |
| } |
| |
| |
| // DispatchToCallback converts all the JavaScript arguments to C++ types and |
| // invokes the base::Callback. |
| template<typename Sig> |
| struct Dispatcher { |
| }; |
| |
| $range ARITY 0..MAX_ARITY |
| $for ARITY [[ |
| $range ARG 1..ARITY |
| |
| template<typename R$for ARG [[, typename P$(ARG)]]> |
| struct Dispatcher<R($for ARG , [[P$(ARG)]])> { |
| static void DispatchToCallback( |
| const v8::FunctionCallbackInfo<v8::Value>& info) { |
| Arguments args(info); |
| CallbackHolderBase* holder_base = NULL; |
| CHECK(args.GetData(&holder_base)); |
| |
| typedef CallbackHolder<R($for ARG , [[P$(ARG)]])> HolderT; |
| HolderT* holder = static_cast<HolderT*>(holder_base); |
| |
| $if ARITY != 0 [[ |
| |
| |
| $for ARG [[ typename CallbackParamTraits<P$(ARG)>::LocalType a$(ARG); |
| |
| ]] |
| if ($for ARG || |
| [[!GetNextArgument(&args, holder->flags, $if ARG == 1 [[true]] $else [[false]], &a$(ARG))]]) { |
| args.ThrowError(); |
| return; |
| } |
| |
| ]] |
| |
| Invoker<R$for ARG [[, P$(ARG)]]>::Go(&args, holder->callback$for ARG [[, a$(ARG)]]); |
| } |
| }; |
| |
| ]] |
| |
| } // namespace internal |
| |
| |
| // CreateFunctionTemplate creates a v8::FunctionTemplate that will create |
| // JavaScript functions that execute a provided C++ function or base::Callback. |
| // JavaScript arguments are automatically converted via gin::Converter, as is |
| // the return value of the C++ function, if any. |
| template<typename Sig> |
| v8::Local<v8::FunctionTemplate> CreateFunctionTemplate( |
| v8::Isolate* isolate, const base::Callback<Sig> callback, |
| int callback_flags = 0) { |
| typedef internal::CallbackHolder<Sig> HolderT; |
| gin::Handle<HolderT> holder = CreateHandle( |
| isolate, new HolderT(callback, callback_flags)); |
| return v8::FunctionTemplate::New( |
| &internal::Dispatcher<Sig>::DispatchToCallback, |
| ConvertToV8<internal::CallbackHolderBase*>(isolate, holder.get())); |
| } |
| |
| } // namespace gin |
| |
| #endif // GIN_FUNCTION_TEMPLATE_H_ |