dynarmic/src/common/intrusive_list.h

378 lines
11 KiB
C++

/* This file is part of the dynarmic project.
* Copyright (c) 2016 MerryMage
* This software may be used and distributed according to the terms of the GNU
* General Public License version 2 or any later version.
*/
#pragma once
#include <cstddef>
#include <iterator>
#include <memory>
#include <type_traits>
#include "common/assert.h"
namespace Dynarmic {
namespace Common {
template <typename T> class IntrusiveList;
template <typename T> class IntrusiveListIterator;
template <typename T>
class IntrusiveListNode {
public:
bool IsSentinel() const {
return is_sentinel;
}
protected:
IntrusiveListNode* next = nullptr;
IntrusiveListNode* prev = nullptr;
bool is_sentinel = false;
friend class IntrusiveList<T>;
friend class IntrusiveListIterator<T>;
friend class IntrusiveListIterator<const T>;
};
template <typename T>
class IntrusiveListSentinel final : public IntrusiveListNode<T>
{
using IntrusiveListNode<T>::next;
using IntrusiveListNode<T>::prev;
using IntrusiveListNode<T>::is_sentinel;
public:
IntrusiveListSentinel() {
next = this;
prev = this;
is_sentinel = true;
}
};
template <typename T>
class IntrusiveListIterator {
public:
using iterator_category = std::bidirectional_iterator_tag;
using difference_type = std::ptrdiff_t;
using value_type = T;
using pointer = value_type*;
using const_pointer = const value_type*;
using reference = value_type&;
using const_reference = const value_type&;
// If value_type is const, we want "const IntrusiveListNode<value_type>", not "const IntrusiveListNode<const value_type>"
using node_type = std::conditional_t<std::is_const<value_type>::value,
const IntrusiveListNode<std::remove_const_t<value_type>>,
IntrusiveListNode<value_type>>;
using node_pointer = node_type*;
using node_reference = node_type&;
IntrusiveListIterator() = default;
IntrusiveListIterator(const IntrusiveListIterator& other) = default;
IntrusiveListIterator& operator=(const IntrusiveListIterator& other) = default;
explicit IntrusiveListIterator(node_pointer list_node) : node(list_node) {
}
explicit IntrusiveListIterator(pointer data) : node(data) {
}
explicit IntrusiveListIterator(reference data) : node(&data) {
}
IntrusiveListIterator& operator++() {
node = node->next;
return *this;
}
IntrusiveListIterator& operator--() {
node = node->prev;
return *this;
}
IntrusiveListIterator operator++(int) {
IntrusiveListIterator it(*this);
++*this;
return it;
}
IntrusiveListIterator operator--(int) {
IntrusiveListIterator it(*this);
--*this;
return it;
}
bool operator==(const IntrusiveListIterator& other) const {
return node == other.node;
}
bool operator!=(const IntrusiveListIterator& other) const {
return !operator==(other);
}
reference operator*() const {
DEBUG_ASSERT(!node->IsSentinel());
return static_cast<reference>(*node);
}
pointer operator->() const {
return std::addressof(operator*());
}
node_pointer AsNodePointer() const {
return node;
}
private:
friend class IntrusiveList<T>;
node_pointer node = nullptr;
};
template <typename T>
class IntrusiveList {
public:
using difference_type = std::ptrdiff_t;
using size_type = std::size_t;
using value_type = T;
using pointer = value_type*;
using const_pointer = const value_type*;
using reference = value_type&;
using const_reference = const value_type&;
using iterator = IntrusiveListIterator<value_type>;
using const_iterator = IntrusiveListIterator<const value_type>;
using reverse_iterator = std::reverse_iterator<iterator>;
using const_reverse_iterator = std::reverse_iterator<const_iterator>;
/**
* Inserts a node at the given location indicated by an iterator.
*
* @param location The location to insert the node.
* @param new_node The node to add.
*/
iterator insert(iterator location, pointer new_node) {
return insert_before(location, new_node);
}
/**
* Inserts a node at the given location, moving the previous
* node occupant ahead of the one inserted.
*
* @param location The location to insert the new node.
* @param new_node The node to insert into the list.
*/
iterator insert_before(iterator location, pointer new_node) {
auto existing_node = location.AsNodePointer();
new_node->next = existing_node;
new_node->prev = existing_node->prev;
existing_node->prev->next = new_node;
existing_node->prev = new_node;
return iterator(new_node);
}
/**
* Inserts a new node into the list ahead of the position indicated.
*
* @param position Location to insert the node in front of.
* @param new_node The node to be inserted into the list.
*/
iterator insert_after(iterator position, pointer new_node) {
if (empty())
return insert(begin(), new_node);
return insert(++position, new_node);
}
/**
* Add an entry to the start of the list.
* @param node Node to add to the list.
*/
void push_front(pointer node) {
insert(begin(), node);
}
/**
* Add an entry to the end of the list
* @param node Node to add to the list.
*/
void push_back(pointer node) {
insert(end(), node);
}
/**
* Erases the node at the front of the list.
* @note Must not be called on an empty list.
*/
void pop_front() {
DEBUG_ASSERT(!empty());
erase(begin());
}
/**
* Erases the node at the back of the list.
* @note Must not be called on an empty list.
*/
void pop_back() {
DEBUG_ASSERT(!empty());
erase(--end());
}
/**
* Removes a node from this list
* @param it An iterator that points to the node to remove from list.
*/
pointer remove(iterator& it) {
DEBUG_ASSERT(it != end());
pointer node = &*it++;
node->prev->next = node->next;
node->next->prev = node->prev;
#if !defined(NDEBUG)
node->next = nullptr;
node->prev = nullptr;
#endif
return node;
}
/**
* Removes a node from this list
* @param it A constant iterator that points to the node to remove from list.
*/
pointer remove(const iterator& it) {
iterator copy = it;
return remove(copy);
}
/**
* Removes a node from this list.
* @param node A pointer to the node to remove.
*/
pointer remove(pointer node) {
return remove(iterator(node));
}
/**
* Removes a node from this list.
* @param node A reference to the node to remove.
*/
pointer remove(reference node) {
return remove(iterator(node));
}
/**
* Is this list empty?
* @returns true if there are no nodes in this list.
*/
bool empty() const {
return root->next == root.get();
}
/**
* Gets the total number of elements within this list.
* @return the number of elements in this list.
*/
size_type size() const {
return static_cast<size_type>(std::distance(begin(), end()));
}
/**
* Retrieves a reference to the node at the front of the list.
* @note Must not be called on an empty list.
*/
reference front() {
DEBUG_ASSERT(!empty());
return *begin();
}
/**
* Retrieves a constant reference to the node at the front of the list.
* @note Must not be called on an empty list.
*/
const_reference front() const {
DEBUG_ASSERT(!empty());
return *begin();
}
/**
* Retrieves a reference to the node at the back of the list.
* @note Must not be called on an empty list.
*/
reference back() {
DEBUG_ASSERT(!empty());
return *--end();
}
/**
* Retrieves a constant reference to the node at the back of the list.
* @note Must not be called on an empty list.
*/
const_reference back() const {
DEBUG_ASSERT(!empty());
return *--end();
}
// Iterator interface
iterator begin() { return iterator(root->next); }
const_iterator begin() const { return const_iterator(root->next); }
const_iterator cbegin() const { return begin(); }
iterator end() { return iterator(root.get()); }
const_iterator end() const { return const_iterator(root.get()); }
const_iterator cend() const { return end(); }
reverse_iterator rbegin() { return reverse_iterator(end()); }
const_reverse_iterator rbegin() const { return const_reverse_iterator(end()); }
const_reverse_iterator crbegin() const { return rbegin(); }
reverse_iterator rend() { return reverse_iterator(begin()); }
const_reverse_iterator rend() const { return const_reverse_iterator(begin()); }
const_reverse_iterator crend() const { return rend(); }
/**
* Erases a node from the list, indicated by an iterator.
* @param it The iterator that points to the node to erase.
*/
iterator erase(iterator it) {
remove(it);
return it;
}
/**
* Erases a node from this list.
* @param node A pointer to the node to erase from this list.
*/
iterator erase(pointer node) {
return erase(iterator(node));
}
/**
* Erases a node from this list.
* @param node A reference to the node to erase from this list.
*/
iterator erase(reference node) {
return erase(iterator(node));
}
/**
* Exchanges contents of this list with another list instance.
* @param other The other list to swap with.
*/
void swap(IntrusiveList& other) noexcept {
root.swap(other.root);
}
private:
std::shared_ptr<IntrusiveListNode<T>> root = std::make_shared<IntrusiveListSentinel<T>>();
};
/**
* Exchanges contents of an intrusive list with another intrusive list.
* @tparam T The type of data being kept track of by the lists.
* @param lhs The first list.
* @param rhs The second list.
*/
template <typename T>
void swap(IntrusiveList<T>& lhs, IntrusiveList<T>& rhs) noexcept {
lhs.swap(rhs);
}
} // namespace Common
} // namespace Dynarmic