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$$ This is a pump file for generating file templates. Pump is a python
$$ 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 = 4
// 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/public/gin_embedders.h"
#include "gin/public/wrapper_info.h"
#include "gin/wrappable.h"
#include "v8/include/v8.h"
namespace gin {
class PerIsolateData;
namespace internal {
template<typename T>
struct RemoveConstRef {
typedef T Type;
};
template<typename T>
struct RemoveConstRef<const T&> {
typedef T Type;
};
// 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.
class CallbackHolderBase : public Wrappable {
public:
virtual WrapperInfo* GetWrapperInfo() OVERRIDE;
static WrapperInfo kWrapperInfo;
protected:
virtual ~CallbackHolderBase() {}
};
template<typename Sig>
class CallbackHolder : public CallbackHolderBase {
public:
CallbackHolder(const base::Callback<Sig>& callback)
: callback(callback) {}
base::Callback<Sig> callback;
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)]]);
}
};
]]
// DispatchToCallback converts all the JavaScript arguments to C++ types and
// invokes the base::Callback.
$range ARITY 0..MAX_ARITY
$for ARITY [[
$range ARG 1..ARITY
template<typename R$for ARG [[, typename 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 [[
$for ARG [[ typename RemoveConstRef<P$(ARG)>::Type a$(ARG);
]]
if (
$for ARG ||
[[!args.GetNext(&a$(ARG))]]) {
args.ThrowError();
return;
}
]]
Invoker<R$for ARG [[, P$(ARG)]]>::Go(&args, holder->callback$for ARG [[, a$(ARG)]]);
}
]]
} // namespace internal
// This should be called once per-isolate to initialize the function template
// system.
void InitFunctionTemplates(PerIsolateData* isolate_data);
// This has to be outside the internal namespace because template
// specializations must be declared in the same namespace as the original
// template.
template<>
struct Converter<internal::CallbackHolderBase*>
: public WrappableConverter<internal::CallbackHolderBase> {};
// Creates a v8::FunctionTemplate that will run the provided base::Callback each
// time it is called. JavaScript arguments and return values are converted via
// gin::Converter.
$range ARITY 0..MAX_ARITY
$for ARITY [[
$range ARG 1..ARITY
template<typename R$for ARG [[, typename P$(ARG)]]>
v8::Local<v8::FunctionTemplate> CreateFunctionTemplate(
v8::Isolate* isolate,
const base::Callback<R($for ARG , [[P$(ARG)]])> callback) {
typedef internal::CallbackHolder<R($for ARG , [[P$(ARG)]])> HolderT;
scoped_refptr<HolderT> holder(new HolderT(callback));
return v8::FunctionTemplate::New(
isolate,
&internal::DispatchToCallback<R$for ARG [[, P$(ARG)]]>,
ConvertToV8<internal::CallbackHolderBase*>(isolate, holder.get()));
}
]]
} // namespace gin
#endif // GIN_FUNCTION_TEMPLATE_H_