gecko-dev/toolkit/components/uniffi-js/OwnedRustBuffer.h

70 строки
2.5 KiB
C++

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim:set ts=2 sw=2 sts=2 et cindent: */
/* 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_OwnedRustBuffer_h
#define mozilla_OwnedRustBuffer_h
#include "mozilla/ErrorResult.h"
#include "mozilla/ResultVariant.h"
#include "mozilla/dom/TypedArray.h"
#include "mozilla/dom/UniFFIRust.h"
namespace mozilla::uniffi {
// RustBuffer that's owned by the JS code and handles the memory management
class OwnedRustBuffer final {
private:
RustBuffer mBuf;
void FreeData();
public:
// The default constructor creates an invalid OwnedRustBuffer
OwnedRustBuffer() : mBuf{0} {};
// Constructor for creating an OwnedRustBuffer from a raw RustBuffer struct
// that was returned by Rust (therefore we now own the RustBuffer).
explicit OwnedRustBuffer(const RustBuffer& aBuf);
// Manual implementation of move constructor and assignment operator.
OwnedRustBuffer(OwnedRustBuffer&& aOther);
OwnedRustBuffer& operator=(OwnedRustBuffer&& aOther);
// Delete copy & move constructor as this type is non-copyable.
OwnedRustBuffer(const OwnedRustBuffer&) = delete;
OwnedRustBuffer& operator=(const OwnedRustBuffer&) = delete;
// Destructor that frees the RustBuffer if it is still valid
~OwnedRustBuffer();
// Constructor for creating an OwnedRustBuffer from an ArrayBuffer. Will set
// aError to failed and construct an invalid OwnedRustBuffer if the
// conversion failed.
static Result<OwnedRustBuffer, nsCString> FromArrayBuffer(
const mozilla::dom::ArrayBuffer& aArrayBuffer);
// Moves the buffer out of this `OwnedArrayBuffer` into a raw `RustBuffer`
// struct. The raw struct must be passed into a Rust function, transfering
// ownership to Rust. After this call the buffer will no longer be valid.
RustBuffer IntoRustBuffer();
// Moves the buffer out of this `OwnedArrayBuffer` into a JS ArrayBuffer.
// This transfers ownership into the JS engine. After this call the buffer
// will no longer be valid.
JSObject* IntoArrayBuffer(JSContext* cx);
// Is this RustBuffer pointing to valid data?
bool IsValid() const { return mBuf.data != nullptr; }
private:
// Helper function used by IntoArrayBuffer.
static void ArrayBufferFreeFunc(void* contents, void* userData);
};
} // namespace mozilla::uniffi
#endif // mozilla_OwnedRustBuffer_h