toolkit/components/uniffi-js/UniFFIPointer.h

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this file,
   5  * You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #ifndef mozilla_dom_UniFFIPointer_h
   8 #define mozilla_dom_UniFFIPointer_h
   9
  10 #include "nsISupports.h"
  11 #include "nsWrapperCache.h"
  12 #include "nsString.h"
  13 #include "mozilla/ErrorResult.h"
  14 #include "mozilla/dom/TypedArray.h"
  15 #include "mozilla/dom/UniFFIPointerType.h"
  16
  17 namespace mozilla::dom {
  18
  19 class UniFFIPointer final : public nsISupports, public nsWrapperCache {
  20  public:
  21   NS_DECL_CYCLE_COLLECTING_ISUPPORTS
  22   NS_DECL_CYCLE_COLLECTION_WRAPPERCACHE_CLASS(UniFFIPointer)
  23
  24   static already_AddRefed<UniFFIPointer> Create(
  25       void* aPtr, const uniffi::UniFFIPointerType* aType);
  26   static already_AddRefed<UniFFIPointer> Read(
  27       const ArrayBuffer& aArrayBuff, uint32_t aPosition,
  28       const uniffi::UniFFIPointerType* aType, ErrorResult& aError);
  29   void Write(const ArrayBuffer& aArrayBuff, uint32_t aPosition,
  30              const uniffi::UniFFIPointerType* aType, ErrorResult& aError) const;
  31
  32   UniFFIPointer(void* aPtr, const uniffi::UniFFIPointerType* aType);
  33
  34   JSObject* WrapObject(JSContext* aCx,
  35                        JS::Handle<JSObject*> aGivenProto) override;
  36   nsISupports* GetParentObject() {
  37     return xpc::NativeGlobal(xpc::PrivilegedJunkScope());
  38   }
  39
  40   /**
  41    * Clone the raw pointer that `UniFFIPointer` holds
  42    *
  43    * Use this when lowering the pointer to pass it across the FFI, for example:
  44    *   - When calling a method
  45    *   - When passing the object as an argument to a function
  46    */
  47   void* ClonePtr() const;
  48
  49   /**
  50    * Returns true if the pointer type `this` holds is the same as the argument
  51    * it does so using pointer comparison, as there is **exactly** one static
  52    * `UniFFIPointerType` per type exposed in the UniFFI interface
  53    */
  54   bool IsSamePtrType(const uniffi::UniFFIPointerType* type) const;
  55
  56  private:
  57   const uniffi::UniFFIPointerType* mType;
  58   void* mPtr;
  59
  60  protected:
  61   /**
  62    * Destructs the `UniFFIPointer`, making sure to give back ownership of the
  63    * raw pointer back to Rust, which deallocates the pointer
  64    */
  65   ~UniFFIPointer();
  66 };
  67 }  // namespace mozilla::dom
  68
  69 #endif /* mozilla_dom_UniFFIPointer_h */