ladybird/Kernel/KString.cpp
Andreas Kling 279383a8f3 Kernel: Add KString, a single-owner string with OOM failure exposion
This is a simple string class for use in the kernel. It encapsulates
a length + character array in a single-allocation object.

Main differences from AK::String:

- Single-owner (no reference counting.)
- Allocation failures are exposed, not hidden.

The basic idea is to allow better and more precise string management
in the kernel.
2021-05-28 09:37:09 +02:00

40 lines
1 KiB
C++

/*
* Copyright (c) 2021, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <Kernel/KString.h>
namespace Kernel {
OwnPtr<KString> KString::try_create(StringView const& string)
{
char* characters = nullptr;
size_t length = string.length();
auto new_string = KString::try_create_uninitialized(length, characters);
if (!new_string)
return {};
if (!string.is_empty())
__builtin_memcpy(characters, string.characters_without_null_termination(), length);
characters[length] = '\0';
return new_string;
}
OwnPtr<KString> KString::try_create_uninitialized(size_t length, char*& characters)
{
size_t allocation_size = sizeof(KString) + (sizeof(char) * length) + sizeof(char);
auto* slot = kmalloc(allocation_size);
if (!slot)
return {};
auto* new_string = new (slot) KString(length);
characters = new_string->m_characters;
return adopt_own(*new_string);
}
OwnPtr<KString> KString::try_clone() const
{
return try_create(view());
}
}