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/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#pragma once
#include <AK/Badge.h>
#include <AK/RefCounted.h>
#include <AK/RefPtr.h>
#include <AK/Types.h>
#include <AK/kmalloc.h>
namespace AK {
enum ShouldChomp {
NoChomp,
Chomp
};
class StringImpl : public RefCounted<StringImpl> {
public:
static NonnullRefPtr<StringImpl> create_uninitialized(size_t length, char*& buffer);
static RefPtr<StringImpl> create(const char* cstring, ShouldChomp = NoChomp);
static RefPtr<StringImpl> create(const char* cstring, size_t length, ShouldChomp = NoChomp);
NonnullRefPtr<StringImpl> to_lowercase() const;
NonnullRefPtr<StringImpl> to_uppercase() const;
void operator delete(void* ptr)
{
kfree(ptr);
}
static StringImpl& the_empty_stringimpl();
~StringImpl();
size_t length() const { return m_length; }
const char* characters() const { return &m_inline_buffer[0]; }
const char& operator[](size_t i) const
{
ASSERT(i < m_length);
return characters()[i];
}
unsigned hash() const
{
if (!m_has_hash)
compute_hash();
return m_hash;
}
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 constexpr u32 string_hash(const char* characters, size_t length)
{
u32 hash = 0;
for (size_t i = 0; i < length; ++i) {
hash += (u32)characters[i];
hash += (hash << 10);
hash ^= (hash >> 6);
}
hash += hash << 3;
hash ^= hash >> 11;
hash += hash << 15;
return hash;
}
}
using AK::Chomp;
using AK::string_hash;
using AK::StringImpl;
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