ladybird/Kernel/KString.cpp
Brian Gianforcaro 4cc41ea186 Kernel: Add an error propagating KString::format(..) API :^)
In the continuous effort of better handling OOM in the kernel,
we want to move away from all AK::String usage. One of the final
pieces left to accomplish this goal is replacing all of the usages
of `String::formatted` with something that can actually propagate
failure.

The StringBuilder API was enhanced in the recent past to propagate
failure and thus a slightly modified version of what exists in
`AK::format` will work well for implementing failable format with
`KString`.
2021-11-30 11:16:35 +01:00

71 lines
2.1 KiB
C++

/*
* Copyright (c) 2021, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <AK/Format.h>
#include <AK/StringBuilder.h>
#include <Kernel/KString.h>
extern bool g_in_early_boot;
namespace Kernel {
ErrorOr<NonnullOwnPtr<KString>> KString::try_create(StringView string)
{
char* characters = nullptr;
size_t length = string.length();
auto new_string = TRY(KString::try_create_uninitialized(length, characters));
if (!string.is_empty())
__builtin_memcpy(characters, string.characters_without_null_termination(), length);
characters[length] = '\0';
return new_string;
}
ErrorOr<NonnullOwnPtr<KString>> KString::vformatted(StringView fmtstr, AK::TypeErasedFormatParams& params)
{
StringBuilder builder;
TRY(AK::vformat(builder, fmtstr, params));
return try_create(builder.string_view());
}
NonnullOwnPtr<KString> KString::must_create(StringView string)
{
// We can only enforce success during early boot.
VERIFY(g_in_early_boot);
return KString::try_create(string).release_value();
}
ErrorOr<NonnullOwnPtr<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 ENOMEM;
auto new_string = TRY(adopt_nonnull_own_or_enomem(new (slot) KString(length)));
characters = new_string->m_characters;
return new_string;
}
NonnullOwnPtr<KString> KString::must_create_uninitialized(size_t length, char*& characters)
{
// We can only enforce success during early boot.
VERIFY(g_in_early_boot);
return KString::try_create_uninitialized(length, characters).release_value();
}
ErrorOr<NonnullOwnPtr<KString>> KString::try_clone() const
{
return try_create(view());
}
void KString::operator delete(void* string)
{
if (!string)
return;
size_t allocation_size = sizeof(KString) + (sizeof(char) * static_cast<KString*>(string)->m_length) + sizeof(char);
kfree_sized(string, allocation_size);
}
}