ladybird/AK/Vector.h
Andreas Kling 214b67defd AK: Add Vector::remove_first_matching(Callback).
This is a nice little helper to remove one item based on a matching
callback without having to do iteration yourself.
2019-03-18 20:51:40 +01:00

322 lines
8.3 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()
{
for (int i = 0; i < m_size; ++i)
at(i).~T();
}
static OwnPtr<VectorImpl> create(int capacity)
{
int size = sizeof(VectorImpl) + sizeof(T) * capacity;
void* slot = kmalloc(size);
new (slot) VectorImpl(capacity);
return OwnPtr<VectorImpl>((VectorImpl*)slot);
}
int size() const { return m_size; }
int capacity() const { return m_capacity; }
T& at(int i) { ASSERT(i < m_size); return *slot(i); }
const T& at(int i) const { ASSERT(i < m_size); return *slot(i); }
void remove(int index)
{
ASSERT(index < m_size);
at(index).~T();
for (int 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(int capacity) : m_capacity(capacity) { }
T* tail() { return reinterpret_cast<T*>(this + 1); }
T* slot(int i) { return &tail()[i]; }
const T* tail() const { return reinterpret_cast<const T*>(this + 1); }
const T* slot(int i) const { return &tail()[i]; }
int m_size { 0 };
int m_capacity;
};
template<typename T>
class Vector {
public:
Vector() { }
~Vector() { clear(); }
Vector(Vector&& other)
: m_impl(move(other.m_impl))
{
}
Vector(const Vector& other)
{
ensure_capacity(other.size());
for (int i = 0; i < other.size(); ++i)
unchecked_append(other[i]);
}
Vector& operator=(Vector&& other)
{
if (this != &other)
m_impl = move(other.m_impl);
return *this;
}
void clear()
{
m_impl = nullptr;
}
void clear_with_capacity()
{
if (!m_impl)
return;
for (int i = 0; i < size(); ++i)
at(i).~T();
m_impl->m_size = 0;
}
bool contains_slow(const T& value) const
{
for (int i = 0; i < size(); ++i) {
if (at(i) == value)
return true;
}
return false;
}
bool is_empty() const { return size() == 0; }
int size() const { return m_impl ? m_impl->size() : 0; }
int capacity() const { return m_impl ? m_impl->capacity() : 0; }
T* data() { return m_impl ? m_impl->slot(0) : nullptr; }
const T* data() const { return m_impl ? m_impl->slot(0) : nullptr; }
const T& at(int i) const { return m_impl->at(i); }
T& at(int i) { return m_impl->at(i); }
const T& operator[](int i) const { return at(i); }
T& operator[](int 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 take_last()
{
ASSERT(!is_empty());
T value = move(last());
last().~T();
--m_impl->m_size;
return value;
}
T take_first()
{
ASSERT(!is_empty());
T value = move(first());
remove(0);
return value;
}
void remove(int index)
{
m_impl->remove(index);
}
void insert(int index, T&& value)
{
ASSERT(index <= size());
if (index == size())
return append(move(value));
ensure_capacity(size() + 1);
++m_impl->m_size;
for (int i = size() - 1; i > index; --i) {
new (m_impl->slot(i)) T(move(m_impl->at(i - 1)));
m_impl->at(i - 1).~T();
}
new (m_impl->slot(index)) T(move(value));
}
Vector& operator=(const Vector<T>& other)
{
if (this != &other) {
clear();
ensure_capacity(other.size());
for (const auto& v : other)
unchecked_append(v);
}
return *this;
}
void append(Vector<T>&& other)
{
if (!m_impl) {
m_impl = move(other.m_impl);
return;
}
Vector<T> tmp = move(other);
ensure_capacity(size() + tmp.size());
for (auto&& v : tmp) {
unchecked_append(move(v));
}
}
template<typename Callback>
void remove_first_matching(Callback callback)
{
for (int i = 0; i < size(); ++i) {
if (callback(at(i))) {
remove(i);
return;
}
}
}
void unchecked_append(T&& value)
{
ASSERT((size() + 1) <= capacity());
new (m_impl->slot(m_impl->m_size)) T(move(value));
++m_impl->m_size;
}
void unchecked_append(const T& value)
{
new (m_impl->slot(m_impl->m_size)) T(value);
++m_impl->m_size;
}
void append(T&& value)
{
ensure_capacity(size() + 1);
new (m_impl->slot(m_impl->m_size)) T(move(value));
++m_impl->m_size;
}
void append(const T& value)
{
ensure_capacity(size() + 1);
new (m_impl->slot(m_impl->m_size)) T(value);
++m_impl->m_size;
}
void append(const T* values, int count)
{
if (!count)
return;
ensure_capacity(size() + count);
for (int i = 0; i < count; ++i)
new (m_impl->slot(m_impl->m_size + i)) T(values[i]);
m_impl->m_size += count;
}
void ensure_capacity(int neededCapacity)
{
if (capacity() >= neededCapacity)
return;
int new_capacity = padded_capacity(neededCapacity);
auto new_impl = VectorImpl<T>::create(new_capacity);
if (m_impl) {
new_impl->m_size = m_impl->m_size;
for (int i = 0; i < size(); ++i) {
new (new_impl->slot(i)) T(move(m_impl->at(i)));
m_impl->at(i).~T();
}
}
m_impl = move(new_impl);
}
void resize(int new_size)
{
if (new_size == size())
return;
if (!new_size) {
clear();
return;
}
if (new_size > size()) {
ensure_capacity(new_size);
for (int i = size(); i < new_size; ++i)
new (m_impl->slot(i)) T;
} else {
for (int i = new_size; i < size(); ++i)
m_impl->at(i).~T();
}
m_impl->m_size = new_size;
}
class Iterator {
public:
bool operator!=(const Iterator& other) { return m_index != other.m_index; }
bool operator==(const Iterator& other) { return m_index == other.m_index; }
bool operator<(const Iterator& other) { return m_index < other.m_index; }
Iterator& operator++() { ++m_index; return *this; }
Iterator operator-(int value) { return { m_vector, m_index - value }; }
Iterator operator+(int value) { return { m_vector, m_index + value }; }
T& operator*() { return m_vector[m_index]; }
private:
friend class Vector;
Iterator(Vector& vector, int index) : m_vector(vector), m_index(index) { }
Vector& m_vector;
int 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; }
bool operator==(const ConstIterator& other) { return m_index == other.m_index; }
bool operator<(const ConstIterator& other) { return m_index < other.m_index; }
ConstIterator& operator++() { ++m_index; return *this; }
ConstIterator operator-(int value) { return { m_vector, m_index - value }; }
ConstIterator operator+(int value) { return { m_vector, m_index + value }; }
const T& operator*() const { return m_vector[m_index]; }
private:
friend class Vector;
ConstIterator(const Vector& vector, const int index) : m_vector(vector), m_index(index) { }
const Vector& m_vector;
int m_index { 0 };
};
ConstIterator begin() const { return ConstIterator(*this, 0); }
ConstIterator end() const { return ConstIterator(*this, size()); }
private:
static int padded_capacity(int capacity)
{
return max(int(4), capacity + (capacity / 4) + 4);
}
OwnPtr<VectorImpl<T>> m_impl;
};
}
using AK::Vector;