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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 19:33:14 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 19:33:14 +0000
commit36d22d82aa202bb199967e9512281e9a53db42c9 (patch)
tree105e8c98ddea1c1e4784a60a5a6410fa416be2de /toolkit/components/uniffi-js/UniFFIPointer.h
parentInitial commit. (diff)
downloadfirefox-esr-36d22d82aa202bb199967e9512281e9a53db42c9.tar.xz
firefox-esr-36d22d82aa202bb199967e9512281e9a53db42c9.zip
Adding upstream version 115.7.0esr.upstream/115.7.0esr
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'toolkit/components/uniffi-js/UniFFIPointer.h')
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1 files changed, 69 insertions, 0 deletions
diff --git a/toolkit/components/uniffi-js/UniFFIPointer.h b/toolkit/components/uniffi-js/UniFFIPointer.h
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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 */