mirror of
https://github.com/SerenityOS/serenity
synced 2024-09-06 17:06:31 +00:00
195 lines
5.4 KiB
C++
195 lines
5.4 KiB
C++
/*
|
|
* Copyright (c) 2018-2022, Andreas Kling <kling@serenityos.org>
|
|
* Copyright (c) 2022, the SerenityOS developers.
|
|
*
|
|
* SPDX-License-Identifier: BSD-2-Clause
|
|
*/
|
|
|
|
#pragma once
|
|
|
|
#include <AK/Error.h>
|
|
#include <AK/Iterator.h>
|
|
#include <AK/Span.h>
|
|
#include <AK/kmalloc.h>
|
|
#include <initializer_list>
|
|
|
|
namespace AK {
|
|
|
|
// FixedArray is an Array with a size only known at run-time.
|
|
// It guarantees to only allocate when being constructed, and to only deallocate when being destructed.
|
|
template<typename T>
|
|
class FixedArray {
|
|
public:
|
|
FixedArray() = default;
|
|
|
|
static ErrorOr<FixedArray<T>> try_create(std::initializer_list<T> initializer)
|
|
{
|
|
auto array = TRY(try_create(initializer.size()));
|
|
auto it = initializer.begin();
|
|
for (size_t i = 0; i < array.size(); ++i) {
|
|
array[i] = move(*it);
|
|
++it;
|
|
}
|
|
return array;
|
|
}
|
|
|
|
static ErrorOr<FixedArray<T>> try_create(size_t size)
|
|
{
|
|
if (size == 0)
|
|
return FixedArray<T>();
|
|
T* elements = static_cast<T*>(kmalloc_array(size, sizeof(T)));
|
|
if (!elements)
|
|
return Error::from_errno(ENOMEM);
|
|
for (size_t i = 0; i < size; ++i)
|
|
new (&elements[i]) T();
|
|
return FixedArray<T>(size, elements);
|
|
}
|
|
|
|
static FixedArray<T> must_create_but_fixme_should_propagate_errors(size_t size)
|
|
{
|
|
return MUST(try_create(size));
|
|
}
|
|
|
|
// NOTE:
|
|
// Even though it may look like there will be a template instantiation of this function for every size,
|
|
// the compiler will inline this anyway and therefore not generate any duplicate code.
|
|
|
|
template<size_t N>
|
|
static ErrorOr<FixedArray<T>> try_create(T (&&array)[N])
|
|
{
|
|
if (N == 0)
|
|
return FixedArray<T>();
|
|
T* elements = static_cast<T*>(kmalloc_array(N, sizeof(T)));
|
|
if (!elements)
|
|
return Error::from_errno(ENOMEM);
|
|
for (size_t i = 0; i < N; ++i)
|
|
new (&elements[i]) T(move(array[i]));
|
|
return FixedArray<T>(N, elements);
|
|
}
|
|
|
|
template<typename U>
|
|
static ErrorOr<FixedArray<T>> try_create(Span<U> span)
|
|
{
|
|
if (span.size() == 0)
|
|
return FixedArray<T>();
|
|
T* elements = static_cast<T*>(kmalloc_array(span.size(), sizeof(T)));
|
|
if (!elements)
|
|
return Error::from_errno(ENOMEM);
|
|
for (size_t i = 0; i < span.size(); ++i)
|
|
new (&elements[i]) T(span[i]);
|
|
return FixedArray<T>(span.size(), elements);
|
|
}
|
|
|
|
ErrorOr<FixedArray<T>> try_clone() const
|
|
{
|
|
if (m_size == 0)
|
|
return FixedArray<T>();
|
|
T* elements = static_cast<T*>(kmalloc_array(m_size, sizeof(T)));
|
|
if (!elements)
|
|
return Error::from_errno(ENOMEM);
|
|
for (size_t i = 0; i < m_size; ++i)
|
|
new (&elements[i]) T(m_elements[i]);
|
|
return FixedArray<T>(m_size, elements);
|
|
}
|
|
|
|
// Nobody can ever use these functions, since it would be impossible to make them OOM-safe due to their signatures. We just explicitly delete them.
|
|
FixedArray(FixedArray<T> const&) = delete;
|
|
FixedArray<T>& operator=(FixedArray<T> const&) = delete;
|
|
|
|
FixedArray(FixedArray<T>&& other)
|
|
: m_size(other.m_size)
|
|
, m_elements(other.m_elements)
|
|
{
|
|
other.m_size = 0;
|
|
other.m_elements = nullptr;
|
|
}
|
|
// This function would violate the contract, as it would need to deallocate this FixedArray. As it also has no use case, we delete it.
|
|
FixedArray<T>& operator=(FixedArray<T>&&) = delete;
|
|
|
|
~FixedArray()
|
|
{
|
|
if (!m_elements)
|
|
return;
|
|
for (size_t i = 0; i < m_size; ++i)
|
|
m_elements[i].~T();
|
|
kfree_sized(m_elements, sizeof(T) * m_size);
|
|
// NOTE: should prevent use-after-free early
|
|
m_size = 0;
|
|
m_elements = nullptr;
|
|
}
|
|
|
|
size_t size() const { return m_size; }
|
|
bool is_empty() const { return m_size == 0; }
|
|
T* data() { return m_elements; }
|
|
T const* data() const { return m_elements; }
|
|
|
|
T& at(size_t index)
|
|
{
|
|
VERIFY(index < m_size);
|
|
return m_elements[index];
|
|
}
|
|
|
|
T const& at(size_t index) const
|
|
{
|
|
VERIFY(index < m_size);
|
|
return m_elements[index];
|
|
}
|
|
|
|
T& operator[](size_t index)
|
|
{
|
|
return at(index);
|
|
}
|
|
|
|
T const& operator[](size_t index) const
|
|
{
|
|
return at(index);
|
|
}
|
|
|
|
bool contains_slow(T const& value) const
|
|
{
|
|
for (size_t i = 0; i < m_size; ++i) {
|
|
if (m_elements[i] == value)
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
void swap(FixedArray<T>& other)
|
|
{
|
|
::swap(m_size, other.m_size);
|
|
::swap(m_elements, other.m_elements);
|
|
}
|
|
|
|
void fill_with(T const& value)
|
|
{
|
|
for (size_t i = 0; i < m_size; ++i)
|
|
m_elements[i] = value;
|
|
}
|
|
|
|
using Iterator = SimpleIterator<FixedArray, T>;
|
|
using ConstIterator = SimpleIterator<FixedArray const, T const>;
|
|
|
|
Iterator begin() { return Iterator::begin(*this); }
|
|
ConstIterator begin() const { return ConstIterator::begin(*this); }
|
|
|
|
Iterator end() { return Iterator::end(*this); }
|
|
ConstIterator end() const { return ConstIterator::end(*this); }
|
|
|
|
Span<T> span() { return { data(), size() }; }
|
|
Span<T const> span() const { return { data(), size() }; }
|
|
|
|
private:
|
|
FixedArray(size_t size, T* elements)
|
|
: m_size(size)
|
|
, m_elements(elements)
|
|
{
|
|
}
|
|
|
|
size_t m_size { 0 };
|
|
T* m_elements { nullptr };
|
|
};
|
|
|
|
}
|
|
|
|
using AK::FixedArray;
|