memory_manager.hpp

#ifndef SASS_MEMORY_MANAGER_H
#define SASS_MEMORY_MANAGER_H

#include <vector>
#include <iostream>

namespace Sass {
  using namespace std;
  /////////////////////////////////////////////////////////////////////////////
  // A class for tracking allocations of AST_Node objects. The intended usage
  // is something like: Some_Node* n = new (mem_mgr) Some_Node(...);
  // Then, at the end of the program, the memory manager will delete all of the
  // allocated nodes that have been passed to it.
  // In the future, this class may implement a custom allocator.
  /////////////////////////////////////////////////////////////////////////////
  template <typename T>
  class Memory_Manager {
    vector<T*> nodes;

  public:
    Memory_Manager(size_t size = 0) : nodes(vector<T*>())
    { nodes.reserve(size); }

    ~Memory_Manager()
    {
      for (size_t i = 0, S = nodes.size(); i < S; ++i) {
        // cout << "deleting " << typeid(*nodes[i]).name() << endl;
        delete nodes[i];
      }
    }

    T* operator()(T* np)
    {
      nodes.push_back(np);
      // cout << "registering " << typeid(*np).name() << endl;
      return np;
    }

    void remove(T* np)
    {
      nodes.erase(find(nodes.begin(), nodes.end(), np));
    }
  };
}

template <typename T>
inline void* operator new(size_t size, Sass::Memory_Manager<T>& mem_mgr)
{ return mem_mgr(static_cast<T*>(operator new(size))); }

template <typename T>
inline void operator delete(void *np, Sass::Memory_Manager<T>& mem_mgr)
{
  mem_mgr.remove(reinterpret_cast<T*>(np));
  operator delete(np);
}

#endif