ladybird/AK/StringImpl.h
2022-04-01 21:24:45 +01:00

125 lines
3.2 KiB
C++

/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <AK/Badge.h>
#include <AK/RefCounted.h>
#include <AK/RefPtr.h>
#include <AK/Span.h>
#include <AK/Types.h>
#include <AK/kmalloc.h>
namespace AK {
enum ShouldChomp {
NoChomp,
Chomp
};
size_t allocation_size_for_stringimpl(size_t length);
class StringImpl : public RefCounted<StringImpl> {
public:
static NonnullRefPtr<StringImpl> create_uninitialized(size_t length, char*& buffer);
static RefPtr<StringImpl> create(char const* cstring, ShouldChomp = NoChomp);
static RefPtr<StringImpl> create(char const* cstring, size_t length, ShouldChomp = NoChomp);
static RefPtr<StringImpl> create(ReadonlyBytes, ShouldChomp = NoChomp);
static RefPtr<StringImpl> create_lowercased(char const* cstring, size_t length);
static RefPtr<StringImpl> create_uppercased(char const* cstring, size_t length);
NonnullRefPtr<StringImpl> to_lowercase() const;
NonnullRefPtr<StringImpl> to_uppercase() const;
void operator delete(void* ptr)
{
kfree_sized(ptr, allocation_size_for_stringimpl(static_cast<StringImpl*>(ptr)->m_length));
}
static StringImpl& the_empty_stringimpl();
~StringImpl();
size_t length() const { return m_length; }
// Includes NUL-terminator.
char const* characters() const { return &m_inline_buffer[0]; }
ALWAYS_INLINE ReadonlyBytes bytes() const { return { characters(), length() }; }
ALWAYS_INLINE StringView view() const { return { characters(), length() }; }
char const& operator[](size_t i) const
{
VERIFY(i < m_length);
return characters()[i];
}
bool operator==(StringImpl const& other) const
{
if (length() != other.length())
return false;
return __builtin_memcmp(characters(), other.characters(), length()) == 0;
}
unsigned hash() const
{
if (!m_has_hash)
compute_hash();
return m_hash;
}
unsigned existing_hash() const
{
return m_hash;
}
unsigned case_insensitive_hash() const;
bool is_fly() const { return m_fly; }
void set_fly(Badge<FlyString>, bool fly) const { m_fly = fly; }
private:
enum ConstructTheEmptyStringImplTag {
ConstructTheEmptyStringImpl
};
explicit StringImpl(ConstructTheEmptyStringImplTag)
: m_fly(true)
{
m_inline_buffer[0] = '\0';
}
enum ConstructWithInlineBufferTag {
ConstructWithInlineBuffer
};
StringImpl(ConstructWithInlineBufferTag, size_t length);
void compute_hash() const;
size_t m_length { 0 };
mutable unsigned m_hash { 0 };
mutable bool m_has_hash { false };
mutable bool m_fly { false };
char m_inline_buffer[0];
};
inline size_t allocation_size_for_stringimpl(size_t length)
{
return sizeof(StringImpl) + (sizeof(char) * length) + sizeof(char);
}
template<>
struct Formatter<StringImpl> : Formatter<StringView> {
ErrorOr<void> format(FormatBuilder& builder, StringImpl const& value)
{
return Formatter<StringView>::format(builder, { value.characters(), value.length() });
}
};
}
using AK::Chomp;
using AK::NoChomp;
using AK::StringImpl;