ladybird/Kernel/KBufferBuilder.cpp
Brian Gianforcaro 9ca8f0afaa Kernel: Replace make<T>() with adopt_own_if_nonnull() in KBufferBuilder
The make<T> factory function allocates internally and immediately
dereferences the pointer, and always returns a NonnullOwnPtr<T> making
it impossible to propagate an error on OOM.
2021-05-13 16:21:53 +02:00

123 lines
2.8 KiB
C++

/*
* Copyright (c) 2018-2021, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <AK/StdLibExtras.h>
#include <Kernel/KBufferBuilder.h>
namespace Kernel {
inline bool KBufferBuilder::check_expand(size_t size)
{
if (!m_buffer)
return false;
if ((m_size + size) < m_buffer->capacity())
return true;
if (!m_can_expand)
return false;
if (Checked<size_t>::addition_would_overflow(m_size, size))
return false;
size_t new_buffer_size = m_size + size;
if (Checked<size_t>::addition_would_overflow(new_buffer_size, 1 * MiB))
return false;
new_buffer_size = page_round_up(new_buffer_size + 1 * MiB);
return m_buffer->expand(new_buffer_size);
}
bool KBufferBuilder::flush()
{
if (!m_buffer)
return false;
m_buffer->set_size(m_size);
return true;
}
OwnPtr<KBuffer> KBufferBuilder::build()
{
if (!flush())
return {};
return adopt_own_if_nonnull(new KBuffer(move(m_buffer)));
}
KBufferBuilder::KBufferBuilder(bool can_expand)
: m_buffer(KBufferImpl::try_create_with_size(4 * MiB, Region::Access::Read | Region::Access::Write))
, m_can_expand(can_expand)
{
}
KBufferBuilder::KBufferBuilder(RefPtr<KBufferImpl>& buffer, bool can_expand)
: m_buffer(buffer)
, m_can_expand(can_expand)
{
if (!m_buffer)
m_buffer = buffer = KBufferImpl::try_create_with_size(4 * MiB, Region::Access::Read | Region::Access::Write);
}
void KBufferBuilder::append_bytes(ReadonlyBytes bytes)
{
if (!check_expand(bytes.size()))
return;
memcpy(insertion_ptr(), bytes.data(), bytes.size());
m_size += bytes.size();
}
void KBufferBuilder::append(const StringView& str)
{
if (str.is_empty())
return;
if (!check_expand(str.length()))
return;
memcpy(insertion_ptr(), str.characters_without_null_termination(), str.length());
m_size += str.length();
}
void KBufferBuilder::append(const char* characters, int length)
{
if (!length)
return;
if (!check_expand(length))
return;
memcpy(insertion_ptr(), characters, length);
m_size += length;
}
void KBufferBuilder::append(char ch)
{
if (!check_expand(1))
return;
insertion_ptr()[0] = ch;
m_size += 1;
}
void KBufferBuilder::append_escaped_for_json(const StringView& string)
{
for (auto ch : string) {
switch (ch) {
case '\e':
append("\\u001B");
break;
case '\b':
append("\\b");
break;
case '\n':
append("\\n");
break;
case '\t':
append("\\t");
break;
case '\"':
append("\\\"");
break;
case '\\':
append("\\\\");
break;
default:
append(ch);
}
}
}
}