task.hpp

#pragma once

#include "graph.hpp"

namespace tf {

// ----------------------------------------------------------------------------
// Task
// ----------------------------------------------------------------------------

class Task {

  friend class FlowBuilder;
  friend class Taskflow;
  friend class TaskView;
  
  public:

    Task() = default;

    Task(const Task& other);
    
    Task& operator = (const Task&);
    
    Task& operator = (std::nullptr_t);

    bool operator == (const Task& rhs) const;

    bool operator != (const Task& rhs) const;
    
    const std::string& name() const;
    
    size_t num_successors() const;

    size_t num_dependents() const;
    
    size_t num_strong_dependents() const;

    size_t num_weak_dependents() const;
    
    Task& name(const std::string& name);

    template <typename C>
    Task& work(C&& callable);
    
    template <typename... Ts>
    Task& precede(Ts&&... tasks);
    
    template <typename... Ts>
    Task& succeed(Ts&&... tasks);
    
    Task& reset();

    bool empty() const;

    bool has_work() const;
    
    template <typename V>
    void for_each_successor(V&& visitor) const;
    
    template <typename V>
    void for_each_dependent(V&& visitor) const;
    
  private:
    
    Task(Node&);
    Task(Node*);

    Node* _node {nullptr};

    template <typename S>
    void _gather(S&);

    template <typename S>
    void _precede(S&);
    
    template <typename S>
    void _succeed(S&);
};

// Constructor
inline Task::Task(Node& node) : _node {&node} {
}

// Constructor
inline Task::Task(Node* node) : _node {node} {
}

// Constructor
inline Task::Task(const Task& rhs) : _node {rhs._node} {
}

// Function: precede
template <typename... Ts>
Task& Task::precede(Ts&&... tgts) {
  (_node->_precede(tgts._node), ...);
  return *this;
}

// Function: succeed
template <typename... Bs>
Task& Task::succeed(Bs&&... tgts) {
  (tgts._node->_precede(_node), ...);
  return *this;
}

// Operator =
inline Task& Task::operator = (const Task& rhs) {
  _node = rhs._node;
  return *this;
}

// Operator =
inline Task& Task::operator = (std::nullptr_t ptr) {
  _node = ptr;
  return *this;
}

// Operator ==
inline bool Task::operator == (const Task& rhs) const {
  return _node == rhs._node;
}

// Operator !=
inline bool Task::operator != (const Task& rhs) const {
  return _node != rhs._node;
}

// Function: name
inline Task& Task::name(const std::string& name) {
  _node->_name = name;
  return *this;
}

// Procedure: reset
inline Task& Task::reset() {
  _node = nullptr;
  return *this;
}

// Function: name
inline const std::string& Task::name() const {
  return _node->_name;
}

// Function: num_dependents
inline size_t Task::num_dependents() const {
  return _node->num_dependents();
}

// Function: num_strong_dependents
inline size_t Task::num_strong_dependents() const {
  return _node->num_strong_dependents();
}

// Function: num_weak_dependents
inline size_t Task::num_weak_dependents() const {
  return _node->num_weak_dependents();
}

// Function: num_successors
inline size_t Task::num_successors() const {
  return _node->num_successors();
}

// Function: empty
inline bool Task::empty() const {
  return _node == nullptr;
}

// Function: has_work
inline bool Task::has_work() const {
  return _node ? _node->_work.index() != 0 : false;
}

// Function: for_each_successor
template <typename V>
void Task::for_each_successor(V&& visitor) const {
  for(size_t i=0; i<_node->_successors.size(); ++i) {
    visitor(Task(_node->_successors[i]));
  }
}

// Function: for_each_dependent
template <typename V>
void Task::for_each_dependent(V&& visitor) const {
  for(size_t i=0; i<_node->_dependents.size(); ++i) {
    visitor(Task(_node->_dependents[i]));
  }
}

// ----------------------------------------------------------------------------

class TaskView {
  
  friend class Executor;

  public:

    TaskView() = default;

    TaskView(const Task& task);
    
    TaskView(const TaskView& other);
    
    TaskView& operator = (const TaskView& other);
    
    TaskView& operator = (const Task& other);
    
    TaskView& operator = (std::nullptr_t);

    bool operator == (const TaskView&) const;
    
    bool operator != (const TaskView&) const;
    
    const std::string& name() const;
    
    size_t num_successors() const;

    size_t num_dependents() const;
    
    size_t num_strong_dependents() const;

    size_t num_weak_dependents() const;

    void reset();

    bool empty() const;
    
    template <typename V>
    void for_each_successor(V&& visitor) const;
    
    template <typename V>
    void for_each_dependent(V&& visitor) const;
    
  private:
    
    TaskView(Node*);

    Node* _node {nullptr};
};

// Constructor
inline TaskView::TaskView(Node* node) : _node {node} {
}

// Constructor
inline TaskView::TaskView(const TaskView& rhs) : _node {rhs._node} {
}

// Constructor
inline TaskView::TaskView(const Task& task) : _node {task._node} {
}

// Operator =
inline TaskView& TaskView::operator = (const TaskView& rhs) {
  _node = rhs._node;
  return *this;
}

// Operator =
inline TaskView& TaskView::operator = (const Task& rhs) {
  _node = rhs._node;
  return *this;
}

// Operator =
inline TaskView& TaskView::operator = (std::nullptr_t ptr) {
  _node = ptr;
  return *this;
}

// Function: name
inline const std::string& TaskView::name() const {
  return _node->_name;
}

// Function: num_dependents
inline size_t TaskView::num_dependents() const {
  return _node->num_dependents();
}

// Function: num_strong_dependents
inline size_t TaskView::num_strong_dependents() const {
  return _node->num_strong_dependents();
}

// Function: num_weak_dependents
inline size_t TaskView::num_weak_dependents() const {
  return _node->num_weak_dependents();
}

// Function: num_successors
inline size_t TaskView::num_successors() const {
  return _node->num_successors();
}

// Function: reset
inline void TaskView::reset() {
  _node = nullptr;
}

// Function: empty
inline bool TaskView::empty() const {
  return _node == nullptr;
}

// Operator ==
inline bool TaskView::operator == (const TaskView& rhs) const {
  return _node == rhs._node;
}

// Operator !=
inline bool TaskView::operator != (const TaskView& rhs) const {
  return _node != rhs._node;
}

// Function: for_each_successor
template <typename V>
void TaskView::for_each_successor(V&& visitor) const {
  for(size_t i=0; i<_node->_successors.size(); ++i) {
    visitor(TaskView(_node->_successors[i]));
  }
}

// Function: for_each_dependent
template <typename V>
void TaskView::for_each_dependent(V&& visitor) const {
  for(size_t i=0; i<_node->_dependents.size(); ++i) {
    visitor(TaskView(_node->_dependents[i]));
  }
}

}  // end of namespace tf. ---------------------------------------------------