ladybird/Kernel/KString.h
Ali Mohammad Pur d600f0d5b3 Kernel: Specialize Traits<(Nonnull)OwnPtr<T>> for KString
To make it behave like a string, since KString is always stored as a
(Nonnull)OwnPtr in the kernel.
2021-09-13 14:38:53 +04:30

96 lines
2.8 KiB
C++

/*
* Copyright (c) 2021, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <AK/Format.h>
#include <AK/OwnPtr.h>
namespace Kernel {
class KString {
AK_MAKE_NONCOPYABLE(KString);
AK_MAKE_NONMOVABLE(KString);
public:
[[nodiscard]] static KResultOr<NonnullOwnPtr<KString>> try_create_uninitialized(size_t, char*&);
[[nodiscard]] static NonnullOwnPtr<KString> must_create_uninitialized(size_t, char*&);
[[nodiscard]] static KResultOr<NonnullOwnPtr<KString>> try_create(StringView);
[[nodiscard]] static NonnullOwnPtr<KString> must_create(StringView);
void operator delete(void*);
KResultOr<NonnullOwnPtr<KString>> try_clone() const;
[[nodiscard]] bool is_empty() const { return m_length == 0; }
[[nodiscard]] size_t length() const { return m_length; }
[[nodiscard]] char const* characters() const { return m_characters; }
[[nodiscard]] StringView view() const { return { characters(), length() }; }
private:
explicit KString(size_t length)
: m_length(length)
{
}
size_t m_length { 0 };
char m_characters[0];
};
}
namespace AK {
template<>
struct Formatter<Kernel::KString> : Formatter<StringView> {
void format(FormatBuilder& builder, Kernel::KString const& value)
{
Formatter<StringView>::format(builder, value.view());
}
};
template<>
struct Formatter<OwnPtr<Kernel::KString>> : Formatter<StringView> {
void format(FormatBuilder& builder, OwnPtr<Kernel::KString> const& value)
{
if (value)
Formatter<StringView>::format(builder, value->view());
else
Formatter<StringView>::format(builder, "[out of memory]"sv);
}
};
template<>
struct Traits<NonnullOwnPtr<Kernel::KString>> : public GenericTraits<NonnullOwnPtr<Kernel::KString>> {
using PeekType = Kernel::KString*;
using ConstPeekType = Kernel::KString const*;
static unsigned hash(NonnullOwnPtr<Kernel::KString> const& p) { return string_hash(p->characters(), p->length()); }
static bool equals(NonnullOwnPtr<Kernel::KString> const& a, NonnullOwnPtr<Kernel::KString> const& b) { return a->view() == b->view(); }
};
template<>
struct Traits<OwnPtr<Kernel::KString>> : public GenericTraits<OwnPtr<Kernel::KString>> {
using PeekType = Kernel::KString*;
using ConstPeekType = Kernel::KString const*;
static unsigned hash(OwnPtr<Kernel::KString> const& p)
{
if (!p)
return ptr_hash(nullptr);
return string_hash(p->characters(), p->length());
}
static bool equals(OwnPtr<Kernel::KString> const& a, OwnPtr<Kernel::KString> const& b)
{
if (!a || !b)
return a.ptr() == b.ptr();
if (a == b)
return true;
return a->view() == b->view();
}
};
}