ladybird/AK/FixedArray.h
Andreas Kling a7dbb3cf96 Kernel: Use a FixedArray for a process's extra GIDs
There's not really enough of these to justify using a HashTable.
2020-02-18 11:35:47 +01:00

149 lines
4.1 KiB
C++

/*
* 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/Vector.h>
namespace AK {
template<typename T>
class FixedArray {
public:
FixedArray() {}
explicit FixedArray(size_t size)
: m_size(size)
{
m_elements = (T*)kmalloc(sizeof(T) * m_size);
for (size_t i = 0; i < m_size; ++i)
new (&m_elements[i]) T();
}
~FixedArray()
{
clear();
}
FixedArray(const FixedArray& other)
: m_size(other.m_size)
{
m_elements = (T*)kmalloc(sizeof(T) * m_size);
for (size_t i = 0; i < m_size; ++i)
new (&m_elements[i]) T(other[i]);
}
FixedArray& operator=(const FixedArray& other)
{
FixedArray array(other);
swap(array);
return *this;
}
FixedArray(FixedArray&&) = delete;
FixedArray& operator=(FixedArray&&) = delete;
void clear()
{
if (!m_elements)
return;
for (size_t i = 0; i < m_size; ++i)
m_elements[i].~T();
kfree(m_elements);
m_elements = nullptr;
m_size = 0;
}
size_t size() const { return m_size; }
T* data()
{
return m_elements;
}
const T* data() const
{
return m_elements;
}
T& operator[](size_t index)
{
ASSERT(index < m_size);
return m_elements[index];
}
const T& operator[](size_t index) const
{
ASSERT(index < m_size);
return m_elements[index];
}
void resize(size_t new_size)
{
if (new_size == m_size)
return;
auto* new_elements = (T*)kmalloc(new_size * sizeof(T));
for (size_t i = 0; i < min(new_size, m_size); ++i)
new (&new_elements[i]) T(move(m_elements[i]));
for (size_t i = min(new_size, m_size); i < new_size; ++i)
new (&new_elements[i]) T();
for (size_t i = 0; i < m_size; ++i)
m_elements[i].~T();
if (m_elements)
kfree(m_elements);
m_elements = new_elements;
m_size = new_size;
}
bool contains(const T& value) const
{
for (size_t i = 0; i < m_size; ++i) {
if (m_elements[i] == value)
return true;
}
return false;
}
void swap(FixedArray& other)
{
::swap(m_elements, other.m_elements);
::swap(m_size, other.m_size);
}
using Iterator = VectorIterator<FixedArray, T>;
Iterator begin() { return Iterator(*this, 0); }
Iterator end() { return Iterator(*this, size()); }
using ConstIterator = VectorIterator<const FixedArray, const T>;
ConstIterator begin() const { return ConstIterator(*this, 0); }
ConstIterator end() const { return ConstIterator(*this, size()); }
private:
size_t m_size { 0 };
T* m_elements { nullptr };
};
}
using AK::FixedArray;