ladybird/AK/OwnPtr.h
Lenny Maiorani f2336d0144 AK+Everywhere: Move custom deleter capability to OwnPtr
`OwnPtrWithCustomDeleter` was a decorator which provided the ability
to add a custom deleter to `OwnPtr` by wrapping and taking the deleter
as a run-time argument to the constructor. This solution means that no
additional space is needed for the `OwnPtr` because it doesn't need to
store a pointer to the deleter, but comes at the cost of having an
extra type that stores a pointer for every instance.

This logic is moved directly into `OwnPtr` by adding a template
argument that is defaulted to the default deleter for the type. This
means that the type itself stores the pointer to the deleter instead
of every instance and adds some type safety by encoding the deleter in
the type itself instead of taking a run-time argument.
2022-12-17 16:00:08 -05:00

234 lines
5.0 KiB
C++

/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <AK/Error.h>
#include <AK/Forward.h>
#include <AK/NonnullOwnPtr.h>
#include <AK/RefCounted.h>
#define OWNPTR_SCRUB_BYTE 0xf0
namespace AK {
template<typename T, typename TDeleter>
class [[nodiscard]] OwnPtr {
public:
OwnPtr() = default;
OwnPtr(decltype(nullptr))
: m_ptr(nullptr)
{
}
OwnPtr(OwnPtr&& other)
: m_ptr(other.leak_ptr())
{
}
template<typename U>
OwnPtr(NonnullOwnPtr<U>&& other)
: m_ptr(other.leak_ptr())
{
}
template<typename U>
OwnPtr(OwnPtr<U>&& other)
: m_ptr(other.leak_ptr())
{
}
~OwnPtr()
{
clear();
#ifdef SANITIZE_PTRS
m_ptr = (T*)(explode_byte(OWNPTR_SCRUB_BYTE));
#endif
}
OwnPtr(OwnPtr const&) = delete;
template<typename U>
OwnPtr(OwnPtr<U> const&) = delete;
OwnPtr& operator=(OwnPtr const&) = delete;
template<typename U>
OwnPtr& operator=(OwnPtr<U> const&) = delete;
template<typename U>
OwnPtr(NonnullOwnPtr<U> const&) = delete;
template<typename U>
OwnPtr& operator=(NonnullOwnPtr<U> const&) = delete;
template<typename U>
OwnPtr(RefPtr<U> const&) = delete;
template<typename U>
OwnPtr(NonnullRefPtr<U> const&) = delete;
template<typename U>
OwnPtr(WeakPtr<U> const&) = delete;
template<typename U>
OwnPtr& operator=(RefPtr<U> const&) = delete;
template<typename U>
OwnPtr& operator=(NonnullRefPtr<U> const&) = delete;
template<typename U>
OwnPtr& operator=(WeakPtr<U> const&) = delete;
OwnPtr& operator=(OwnPtr&& other)
{
OwnPtr ptr(move(other));
swap(ptr);
return *this;
}
template<typename U>
OwnPtr& operator=(OwnPtr<U>&& other)
{
OwnPtr ptr(move(other));
swap(ptr);
return *this;
}
template<typename U>
OwnPtr& operator=(NonnullOwnPtr<U>&& other)
{
OwnPtr ptr(move(other));
swap(ptr);
VERIFY(m_ptr);
return *this;
}
OwnPtr& operator=(T* ptr) = delete;
OwnPtr& operator=(nullptr_t)
{
clear();
return *this;
}
void clear()
{
TDeleter {}(m_ptr);
m_ptr = nullptr;
}
bool operator!() const { return !m_ptr; }
[[nodiscard]] T* leak_ptr()
{
T* leaked_ptr = m_ptr;
m_ptr = nullptr;
return leaked_ptr;
}
NonnullOwnPtr<T> release_nonnull()
{
VERIFY(m_ptr);
return NonnullOwnPtr<T>(NonnullOwnPtr<T>::Adopt, *leak_ptr());
}
template<typename U>
NonnullOwnPtr<U> release_nonnull()
{
VERIFY(m_ptr);
return NonnullOwnPtr<U>(NonnullOwnPtr<U>::Adopt, static_cast<U&>(*leak_ptr()));
}
T* ptr() const { return m_ptr; }
T* operator->() const
{
VERIFY(m_ptr);
return m_ptr;
}
T& operator*() const
{
VERIFY(m_ptr);
return *m_ptr;
}
operator T*() const { return m_ptr; }
operator bool() { return !!m_ptr; }
void swap(OwnPtr& other)
{
::swap(m_ptr, other.m_ptr);
}
template<typename U>
void swap(OwnPtr<U>& other)
{
::swap(m_ptr, other.m_ptr);
}
static OwnPtr lift(T* ptr)
{
return OwnPtr { ptr };
}
protected:
explicit OwnPtr(T* ptr)
: m_ptr(ptr)
{
static_assert(
requires { requires typename T::AllowOwnPtr()(); } || !requires { requires !typename T::AllowOwnPtr()(); declval<T>().ref(); declval<T>().unref(); }, "Use RefPtr<> for RefCounted types");
}
private:
T* m_ptr = nullptr;
};
template<typename T, typename U>
inline void swap(OwnPtr<T>& a, OwnPtr<U>& b)
{
a.swap(b);
}
template<typename T>
inline OwnPtr<T> adopt_own_if_nonnull(T* object)
{
if (object)
return OwnPtr<T>::lift(object);
return {};
}
template<typename T>
inline ErrorOr<NonnullOwnPtr<T>> adopt_nonnull_own_or_enomem(T* object)
{
auto result = adopt_own_if_nonnull(object);
if (!result)
return Error::from_errno(ENOMEM);
return result.release_nonnull();
}
template<typename T, class... Args>
requires(IsConstructible<T, Args...>) inline ErrorOr<NonnullOwnPtr<T>> try_make(Args&&... args)
{
return adopt_nonnull_own_or_enomem(new (nothrow) T(forward<Args>(args)...));
}
// FIXME: Remove once P0960R3 is available in Clang.
template<typename T, class... Args>
inline ErrorOr<NonnullOwnPtr<T>> try_make(Args&&... args)
{
return adopt_nonnull_own_or_enomem(new (nothrow) T { forward<Args>(args)... });
}
template<typename T>
struct Traits<OwnPtr<T>> : public GenericTraits<OwnPtr<T>> {
using PeekType = T*;
using ConstPeekType = T const*;
static unsigned hash(OwnPtr<T> const& p) { return ptr_hash(p.ptr()); }
static bool equals(OwnPtr<T> const& a, OwnPtr<T> const& b) { return a.ptr() == b.ptr(); }
};
}
#if USING_AK_GLOBALLY
using AK::adopt_nonnull_own_or_enomem;
using AK::adopt_own_if_nonnull;
using AK::OwnPtr;
using AK::try_make;
#endif