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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this file,
* You can obtain one at http://mozilla.org/MPL/2.0/. */
#ifndef mozilla_dom_UniFFIPointer_h
#define mozilla_dom_UniFFIPointer_h
#include "nsISupports.h"
#include "nsWrapperCache.h"
#include "nsString.h"
#include "mozilla/ErrorResult.h"
#include "mozilla/dom/TypedArray.h"
#include "mozilla/dom/UniFFIPointerType.h"
namespace mozilla::dom {
class UniFFIPointer final : public nsISupports, public nsWrapperCache {
public:
NS_DECL_CYCLE_COLLECTING_ISUPPORTS
NS_DECL_CYCLE_COLLECTION_WRAPPERCACHE_CLASS(UniFFIPointer)
static already_AddRefed<UniFFIPointer> Create(
void* aPtr, const uniffi::UniFFIPointerType* aType);
static already_AddRefed<UniFFIPointer> Read(
const ArrayBuffer& aArrayBuff, uint32_t aPosition,
const uniffi::UniFFIPointerType* aType, ErrorResult& aError);
void Write(const ArrayBuffer& aArrayBuff, uint32_t aPosition,
const uniffi::UniFFIPointerType* aType, ErrorResult& aError) const;
UniFFIPointer(void* aPtr, const uniffi::UniFFIPointerType* aType);
JSObject* WrapObject(JSContext* aCx,
JS::Handle<JSObject*> aGivenProto) override;
nsISupports* GetParentObject() { return nullptr; }
/**
* returns the raw pointer `UniFFIPointer` holds
* This is safe because:
* - The pointer was allocated in Rust as a reference counted `Arc<T>`
* - Rust cloned the pointer without destructing it when passed into C++
* - Eventually, when the destructor of `UniFFIPointer` runs, we return
* ownership to Rust, which then decrements the count and deallocates the
* memory the pointer points to.
*/
void* GetPtr() const;
/**
* Returns true if the pointer type `this` holds is the same as the argument
* it does so using pointer comparison, as there is **exactly** one static
* `UniFFIPointerType` per type exposed in the UniFFI interface
*/
bool IsSamePtrType(const uniffi::UniFFIPointerType* type) const;
private:
const uniffi::UniFFIPointerType* mType;
void* mPtr;
protected:
/**
* Destructs the `UniFFIPointer`, making sure to give back ownership of the
* raw pointer back to Rust, which deallocates the pointer
*/
~UniFFIPointer();
};
} // namespace mozilla::dom
#endif /* mozilla_dom_UniFFIPointer_h */
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