ladybird/AK/FlyString.cpp
Timothy Flynn 1d4f287582 AK: Implement FlyString for the new String class
This implements a FlyString that will de-duplicate String instances. The
FlyString will store the raw encoded data of the String instance: If the
String is a short string, FlyString holds the String::ShortString bytes;
otherwise FlyString holds a pointer to the Detail::StringData.

FlyString itself does not know about String's storage or how to refcount
its Detail::StringData. It defers to String to implement these details.
2023-01-12 11:23:58 +01:00

170 lines
3.4 KiB
C++

/*
* Copyright (c) 2023, Tim Flynn <trflynn89@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <AK/FlyString.h>
#include <AK/HashMap.h>
#include <AK/Singleton.h>
#include <AK/StringView.h>
#include <AK/Utf8View.h>
namespace AK {
static auto& all_fly_strings()
{
static Singleton<HashMap<StringView, uintptr_t>> table;
return *table;
}
FlyString::FlyString()
: m_data(String {}.to_fly_string_data({}))
{
}
FlyString::~FlyString()
{
String::unref_fly_string_data({}, m_data);
}
ErrorOr<FlyString> FlyString::from_utf8(StringView string)
{
return FlyString { TRY(String::from_utf8(string)) };
}
FlyString::FlyString(String const& string)
{
if (string.is_short_string()) {
m_data = string.to_fly_string_data({});
return;
}
auto it = all_fly_strings().find(string.bytes_as_string_view());
if (it == all_fly_strings().end()) {
m_data = string.to_fly_string_data({});
all_fly_strings().set(string.bytes_as_string_view(), m_data);
string.did_create_fly_string({});
} else {
m_data = it->value;
}
String::ref_fly_string_data({}, m_data);
}
FlyString::FlyString(FlyString const& other)
: m_data(other.m_data)
{
String::ref_fly_string_data({}, m_data);
}
FlyString& FlyString::operator=(FlyString const& other)
{
if (this != &other) {
m_data = other.m_data;
String::ref_fly_string_data({}, m_data);
}
return *this;
}
FlyString::FlyString(FlyString&& other)
: m_data(other.m_data)
{
other.m_data = String {}.to_fly_string_data({});
}
FlyString& FlyString::operator=(FlyString&& other)
{
m_data = other.m_data;
other.m_data = String {}.to_fly_string_data({});
return *this;
}
bool FlyString::is_empty() const
{
return bytes_as_string_view().is_empty();
}
unsigned FlyString::hash() const
{
return bytes_as_string_view().hash();
}
FlyString::operator String() const
{
return to_string();
}
String FlyString::to_string() const
{
return String::fly_string_data_to_string({}, m_data);
}
Utf8View FlyString::code_points() const
{
return Utf8View { bytes_as_string_view() };
}
ReadonlyBytes FlyString::bytes() const
{
return bytes_as_string_view().bytes();
}
StringView FlyString::bytes_as_string_view() const
{
return String::fly_string_data_to_string_view({}, m_data);
}
bool FlyString::operator==(FlyString const& other) const
{
return m_data == other.m_data;
}
bool FlyString::operator==(String const& other) const
{
if (m_data == other.to_fly_string_data({}))
return true;
return bytes_as_string_view() == other.bytes_as_string_view();
}
bool FlyString::operator==(StringView string) const
{
return bytes_as_string_view() == string;
}
bool FlyString::operator==(char const* string) const
{
return bytes_as_string_view() == string;
}
void FlyString::did_destroy_fly_string_data(Badge<Detail::StringData>, StringView string_data)
{
all_fly_strings().remove(string_data);
}
uintptr_t FlyString::data(Badge<String>) const
{
return m_data;
}
size_t FlyString::number_of_fly_strings()
{
return all_fly_strings().size();
}
unsigned Traits<FlyString>::hash(FlyString const& fly_string)
{
return fly_string.bytes_as_string_view().hash();
}
ErrorOr<void> Formatter<FlyString>::format(FormatBuilder& builder, FlyString const& fly_string)
{
return Formatter<StringView>::format(builder, fly_string.bytes_as_string_view());
}
}