ladybird/AK/StringBuilder.cpp
2021-11-11 01:27:46 +01:00

161 lines
3.6 KiB
C++

/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <AK/ByteBuffer.h>
#include <AK/Checked.h>
#include <AK/Memory.h>
#include <AK/PrintfImplementation.h>
#include <AK/StdLibExtras.h>
#include <AK/String.h>
#include <AK/StringBuilder.h>
#include <AK/StringView.h>
#include <AK/UnicodeUtils.h>
#include <AK/Utf16View.h>
#include <AK/Utf32View.h>
namespace AK {
inline ErrorOr<void> StringBuilder::will_append(size_t size)
{
Checked<size_t> needed_capacity = m_buffer.size();
needed_capacity += size;
VERIFY(!needed_capacity.has_overflow());
// Prefer to completely use the existing capacity first
if (needed_capacity <= m_buffer.capacity())
return {};
Checked<size_t> expanded_capacity = needed_capacity;
expanded_capacity *= 2;
VERIFY(!expanded_capacity.has_overflow());
TRY(m_buffer.try_ensure_capacity(expanded_capacity.value()));
return {};
}
StringBuilder::StringBuilder(size_t initial_capacity)
{
m_buffer.ensure_capacity(initial_capacity);
}
void StringBuilder::append(StringView str)
{
if (str.is_empty())
return;
MUST(will_append(str.length()));
MUST(m_buffer.try_append(str.characters_without_null_termination(), str.length()));
}
void StringBuilder::append(char const* characters, size_t length)
{
append(StringView { characters, length });
}
void StringBuilder::append(char ch)
{
MUST(will_append(1));
MUST(m_buffer.try_append(&ch, 1));
}
void StringBuilder::appendvf(char const* fmt, va_list ap)
{
printf_internal([this](char*&, char ch) {
append(ch);
},
nullptr, fmt, ap);
}
ByteBuffer StringBuilder::to_byte_buffer() const
{
// FIXME: Handle OOM failure.
return ByteBuffer::copy(data(), length()).release_value();
}
String StringBuilder::to_string() const
{
if (is_empty())
return String::empty();
return String((char const*)data(), length());
}
String StringBuilder::build() const
{
return to_string();
}
StringView StringBuilder::string_view() const
{
return StringView { data(), m_buffer.size() };
}
void StringBuilder::clear()
{
m_buffer.clear();
}
void StringBuilder::append_code_point(u32 code_point)
{
auto nwritten = AK::UnicodeUtils::code_point_to_utf8(code_point, [this](char c) { append(c); });
if (nwritten < 0) {
append(0xef);
append(0xbf);
append(0xbd);
}
}
void StringBuilder::append(Utf16View const& utf16_view)
{
for (size_t i = 0; i < utf16_view.length_in_code_units();) {
auto code_point = utf16_view.code_point_at(i);
append_code_point(code_point);
i += (code_point > 0xffff ? 2 : 1);
}
}
void StringBuilder::append(Utf32View const& utf32_view)
{
for (size_t i = 0; i < utf32_view.length(); ++i) {
auto code_point = utf32_view.code_points()[i];
append_code_point(code_point);
}
}
void StringBuilder::append_as_lowercase(char ch)
{
if (ch >= 'A' && ch <= 'Z')
append(ch + 0x20);
else
append(ch);
}
void StringBuilder::append_escaped_for_json(StringView string)
{
for (auto ch : string) {
switch (ch) {
case '\b':
append("\\b");
break;
case '\n':
append("\\n");
break;
case '\t':
append("\\t");
break;
case '\"':
append("\\\"");
break;
case '\\':
append("\\\\");
break;
default:
if (ch >= 0 && ch <= 0x1f)
append(String::formatted("\\u{:04x}", ch));
else
append(ch);
}
}
}
}