ladybird/AK/Vector.h
2018-10-17 10:57:23 +02:00

183 lines
4.6 KiB
C++

#pragma once
#include "Assertions.h"
#include "OwnPtr.h"
#include "kmalloc.h"
namespace AK {
template<typename T> class Vector;
template<typename T>
class VectorImpl {
public:
~VectorImpl() { }
static OwnPtr<VectorImpl> create(size_t capacity)
{
size_t size = sizeof(VectorImpl) + sizeof(T) * capacity;
void* slot = kmalloc(size);
return OwnPtr<VectorImpl>(new (slot) VectorImpl(capacity));
}
size_t size() const { return m_size; }
size_t capacity() const { return m_capacity; }
T& at(size_t i) { return *slot(i); }
const T& at(size_t i) const { return *slot(i); }
void remove(size_t index)
{
ASSERT(index < m_size);
at(index).~T();
for (size_t i = index + 1; i < m_size; ++i) {
new (slot(i - 1)) T(move(at(i)));
at(i).~T();
}
--m_size;
}
private:
friend class Vector<T>;
VectorImpl(size_t capacity) : m_capacity(capacity) { }
T* tail() { return reinterpret_cast<T*>(this + 1); }
T* slot(size_t i) { return &tail()[i]; }
const T* tail() const { return reinterpret_cast<const T*>(this + 1); }
const T* slot(size_t i) const { return &tail()[i]; }
size_t m_size { 0 };
size_t m_capacity;
};
template<typename T>
class Vector {
public:
Vector() { }
~Vector() { clear(); }
Vector(Vector&& other)
: m_impl(move(other.m_impl))
{
}
Vector& operator=(Vector&& other)
{
if (this != &other)
m_impl = move(other.m_impl);
return *this;
}
void clear()
{
for (size_t i = 0; i < size(); ++i) {
at(i).~T();
}
m_impl = nullptr;
}
bool isEmpty() const { return size() == 0; }
size_t size() const { return m_impl ? m_impl->size() : 0; }
size_t capacity() const { return m_impl ? m_impl->capacity() : 0; }
const T& at(size_t i) const { return m_impl->at(i); }
T& at(size_t i) { return m_impl->at(i); }
const T& operator[](size_t i) const { return at(i); }
T& operator[](size_t i) { return at(i); }
const T& first() const { return at(0); }
T& first() { return at(0); }
const T& last() const { return at(size() - 1); }
T& last() { return at(size() - 1); }
T takeLast()
{
ASSERT(!isEmpty());
T value = move(last());
last().~T();
--m_impl->m_size;
return value;
}
void remove(size_t index)
{
m_impl->remove(index);
}
void append(T&& value)
{
ensureCapacity(size() + 1);
new (m_impl->slot(m_impl->m_size)) T(move(value));
++m_impl->m_size;
}
void append(const T& value)
{
ensureCapacity(size() + 1);
new (m_impl->slot(m_impl->m_size)) T(value);
++m_impl->m_size;
}
void ensureCapacity(size_t neededCapacity)
{
if (capacity() >= neededCapacity)
return;
size_t newCapacity = paddedCapacity(neededCapacity);
auto newImpl = VectorImpl<T>::create(newCapacity);
if (m_impl) {
newImpl->m_size = m_impl->m_size;
for (size_t i = 0; i < size(); ++i) {
new (newImpl->slot(i)) T(move(m_impl->at(i)));
m_impl->at(i).~T();
}
}
m_impl = move(newImpl);
}
class Iterator {
public:
bool operator!=(const Iterator& other) { return m_index != other.m_index; }
Iterator& operator++() { ++m_index; return *this; }
T& operator*() { return m_vector[m_index]; }
private:
friend class Vector;
Iterator(Vector& vector, size_t index) : m_vector(vector), m_index(index) { }
Vector& m_vector;
size_t m_index { 0 };
};
Iterator begin() { return Iterator(*this, 0); }
Iterator end() { return Iterator(*this, size()); }
class ConstIterator {
public:
bool operator!=(const ConstIterator& other) { return m_index != other.m_index; }
ConstIterator& operator++() { ++m_index; return *this; }
const T& operator*() const { return m_vector[m_index]; }
private:
friend class Vector;
ConstIterator(const Vector& vector, const size_t index) : m_vector(vector), m_index(index) { }
const Vector& m_vector;
size_t m_index { 0 };
};
ConstIterator begin() const { return ConstIterator(*this, 0); }
ConstIterator end() const { return ConstIterator(*this, size()); }
private:
static size_t paddedCapacity(size_t capacity)
{
return max(size_t(4), capacity + (capacity / 4) + 4);
}
OwnPtr<VectorImpl<T>> m_impl;
};
}
using AK::Vector;