LiteLoaderBDS-1.16.40/LiteLoader/third-party/include/entt/graph/flow.hpp
2023-03-03 10:18:21 -08:00

328 lines
10 KiB
C++

#ifndef ENTT_GRAPH_FLOW_HPP
#define ENTT_GRAPH_FLOW_HPP
#include <algorithm>
#include <cstddef>
#include <functional>
#include <iterator>
#include <memory>
#include <type_traits>
#include <utility>
#include <vector>
#include "../config/config.h"
#include "../container/dense_map.hpp"
#include "../container/dense_set.hpp"
#include "../core/compressed_pair.hpp"
#include "../core/fwd.hpp"
#include "../core/iterator.hpp"
#include "../core/utility.hpp"
#include "adjacency_matrix.hpp"
#include "fwd.hpp"
namespace entt {
/**
* @brief Utility class for creating task graphs.
* @tparam Allocator Type of allocator used to manage memory and elements.
*/
template<typename Allocator>
class basic_flow {
using alloc_traits = std::allocator_traits<Allocator>;
static_assert(std::is_same_v<typename alloc_traits::value_type, id_type>, "Invalid value type");
using task_container_type = dense_set<id_type, identity, std::equal_to<id_type>, typename alloc_traits::template rebind_alloc<id_type>>;
using ro_rw_container_type = std::vector<std::pair<std::size_t, bool>, typename alloc_traits::template rebind_alloc<std::pair<std::size_t, bool>>>;
using deps_container_type = dense_map<id_type, ro_rw_container_type, identity, std::equal_to<id_type>, typename alloc_traits::template rebind_alloc<std::pair<const id_type, ro_rw_container_type>>>;
void emplace(const id_type res, const bool is_rw) {
ENTT_ASSERT(index.first() < vertices.size(), "Invalid node");
if(!deps.contains(res) && sync_on != vertices.size()) {
deps[res].emplace_back(sync_on, true);
}
deps[res].emplace_back(index.first(), is_rw);
}
public:
/*! @brief Allocator type. */
using allocator_type = Allocator;
/*! @brief Unsigned integer type. */
using size_type = std::size_t;
/*! @brief Iterable task list. */
using iterable = iterable_adaptor<typename task_container_type::const_iterator>;
/*! @brief Default constructor. */
basic_flow()
: basic_flow{allocator_type{}} {}
/**
* @brief Constructs a flow builder with a given allocator.
* @param allocator The allocator to use.
*/
explicit basic_flow(const allocator_type &allocator)
: index{0u, allocator},
vertices{},
deps{},
sync_on{} {}
/*! @brief Default copy constructor. */
basic_flow(const basic_flow &) = default;
/**
* @brief Allocator-extended copy constructor.
* @param other The instance to copy from.
* @param allocator The allocator to use.
*/
basic_flow(const basic_flow &other, const allocator_type &allocator)
: index{other.index.first(), allocator},
vertices{other.vertices, allocator},
deps{other.deps, allocator},
sync_on{other.sync_on} {}
/*! @brief Default move constructor. */
basic_flow(basic_flow &&) noexcept = default;
/**
* @brief Allocator-extended move constructor.
* @param other The instance to move from.
* @param allocator The allocator to use.
*/
basic_flow(basic_flow &&other, const allocator_type &allocator)
: index{other.index.first(), allocator},
vertices{std::move(other.vertices), allocator},
deps{std::move(other.deps), allocator},
sync_on{other.sync_on} {}
/**
* @brief Default copy assignment operator.
* @return This flow builder.
*/
basic_flow &operator=(const basic_flow &) = default;
/**
* @brief Default move assignment operator.
* @return This flow builder.
*/
basic_flow &operator=(basic_flow &&) noexcept = default;
/**
* @brief Returns the associated allocator.
* @return The associated allocator.
*/
[[nodiscard]] constexpr allocator_type get_allocator() const noexcept {
return allocator_type{index.second()};
}
/**
* @brief Returns the identifier at specified location.
* @param pos Position of the identifier to return.
* @return The requested identifier.
*/
[[nodiscard]] id_type operator[](const size_type pos) const {
return vertices.cbegin()[pos];
}
/*! @brief Clears the flow builder. */
void clear() noexcept {
index.first() = sync_on = {};
vertices.clear();
deps.clear();
}
/**
* @brief Exchanges the contents with those of a given flow builder.
* @param other Flow builder to exchange the content with.
*/
void swap(basic_flow &other) {
using std::swap;
std::swap(index, other.index);
std::swap(vertices, other.vertices);
std::swap(deps, other.deps);
std::swap(sync_on, other.sync_on);
}
/**
* @brief Returns the number of tasks.
* @return The number of tasks.
*/
[[nodiscard]] size_type size() const noexcept {
return vertices.size();
}
/**
* @brief Binds a task to a flow builder.
* @param value Task identifier.
* @return This flow builder.
*/
basic_flow &bind(const id_type value) {
sync_on += (sync_on == vertices.size());
const auto it = vertices.emplace(value).first;
index.first() = size_type(it - vertices.begin());
return *this;
}
/**
* @brief Turns the current task into a sync point.
* @return This flow builder.
*/
basic_flow &sync() {
ENTT_ASSERT(index.first() < vertices.size(), "Invalid node");
sync_on = index.first();
for(const auto &elem: deps) {
elem.second.emplace_back(sync_on, true);
}
return *this;
}
/**
* @brief Assigns a resource to the current task with a given access mode.
* @param res Resource identifier.
* @param is_rw Access mode.
* @return This flow builder.
*/
basic_flow &set(const id_type res, bool is_rw = false) {
emplace(res, is_rw);
return *this;
}
/**
* @brief Assigns a read-only resource to the current task.
* @param res Resource identifier.
* @return This flow builder.
*/
basic_flow &ro(const id_type res) {
emplace(res, false);
return *this;
}
/**
* @brief Assigns a range of read-only resources to the current task.
* @tparam It Type of input iterator.
* @param first An iterator to the first element of the range of elements.
* @param last An iterator past the last element of the range of elements.
* @return This flow builder.
*/
template<typename It>
std::enable_if_t<std::is_same_v<std::remove_const_t<typename std::iterator_traits<It>::value_type>, id_type>, basic_flow &>
ro(It first, It last) {
for(; first != last; ++first) {
emplace(*first, false);
}
return *this;
}
/**
* @brief Assigns a writable resource to the current task.
* @param res Resource identifier.
* @return This flow builder.
*/
basic_flow &rw(const id_type res) {
emplace(res, true);
return *this;
}
/**
* @brief Assigns a range of writable resources to the current task.
* @tparam It Type of input iterator.
* @param first An iterator to the first element of the range of elements.
* @param last An iterator past the last element of the range of elements.
* @return This flow builder.
*/
template<typename It>
std::enable_if_t<std::is_same_v<std::remove_const_t<typename std::iterator_traits<It>::value_type>, id_type>, basic_flow &>
rw(It first, It last) {
for(; first != last; ++first) {
emplace(*first, true);
}
return *this;
}
/**
* @brief Generates a task graph for the current content.
* @return The adjacency matrix of the task graph.
*/
[[nodiscard]] adjacency_matrix<directed_tag> graph() const {
const auto length = vertices.size();
adjacency_matrix<directed_tag> matrix{length};
// creates the adjacency matrix
for(const auto &elem: deps) {
const auto last = elem.second.cend();
auto it = elem.second.cbegin();
while(it != last) {
if(it->second) {
// rw item
if(auto curr = it++; it != last) {
if(it->second) {
matrix.insert(curr->first, it->first);
} else if(const auto next = std::find_if(it, last, [](const auto &value) { return value.second; }); next != last) {
for(; it != next; ++it) {
matrix.insert(curr->first, it->first);
matrix.insert(it->first, next->first);
}
} else {
for(; it != next; ++it) {
matrix.insert(curr->first, it->first);
}
}
}
} else {
// ro item (first iteration only)
if(const auto next = std::find_if(it, last, [](const auto &value) { return value.second; }); next != last) {
for(; it != next; ++it) {
matrix.insert(it->first, next->first);
}
} else {
it = last;
}
}
}
}
// computes the transitive closure
for(std::size_t vk{}; vk < length; ++vk) {
for(std::size_t vi{}; vi < length; ++vi) {
for(std::size_t vj{}; vj < length; ++vj) {
if(matrix.contains(vi, vk) && matrix.contains(vk, vj)) {
matrix.insert(vi, vj);
}
}
}
}
// applies the transitive reduction
for(std::size_t vert{}; vert < length; ++vert) {
matrix.erase(vert, vert);
}
for(std::size_t vj{}; vj < length; ++vj) {
for(std::size_t vi{}; vi < length; ++vi) {
if(matrix.contains(vi, vj)) {
for(std::size_t vk{}; vk < length; ++vk) {
if(matrix.contains(vj, vk)) {
matrix.erase(vi, vk);
}
}
}
}
}
return matrix;
}
private:
compressed_pair<size_type, allocator_type> index;
task_container_type vertices;
deps_container_type deps;
size_type sync_on;
};
} // namespace entt
#endif