path: root/kmymoney2/mymoney/storage/mymoneymap.h

#include <stdint.h>
#include <qmap.h>
#include <qptrstack.h>
#include <kmymoney/mymoneyexception.h>

#ifndef MYMONEYMAP_H
#define MYMONEYMAP_H

#define MY_OWN_DEBUG 0

/**
  * @author Thomas Baumgart
  *
  * This template class adds transaction security to the QMap<> class.
  * The interface is very simple. Before you perform any changes,
  * you have to call the startTransaction() method. Then you can use
  * the insert(), modify() and remove() methods to modify the map.
  * Changes are recorded and if you are finished, use the
  * commitTransaction() to finish the transaction. If you want to go
  * back before you have committed the transaction, use
  * rollbackTransaction() to set the container to the state it was
  * in before you called startTransaction().
  *
  * The implementation is based on the command pattern, in case
  * someone is interested.
  */
template <class Key, class T>
class MyMoneyMap : protected QMap<Key, T>
{
public:
  // typedef QMapConstIterator<Key, T> const_iterator;

  MyMoneyMap() : QMap<Key, T>() {}
  virtual ~MyMoneyMap() {}

  void startTransaction(unsigned long* id = 0)
  {
    m_stack.push(new MyMoneyMapStart(this, id));
  }

  void rollbackTransaction(void)
  {
    if(m_stack.count() == 0)
      throw new MYMONEYEXCEPTION("No transaction started to rollback changes");

    // undo all actions
    MyMoneyMapAction* action;
    while(m_stack.count()) {
      action = m_stack.pop();
      action->undo();
      delete action;
    }
  }

  bool commitTransaction(void)
  {
    if(m_stack.count() == 0)
      throw new MYMONEYEXCEPTION("No transaction started to commit changes");

    bool rc = m_stack.count() > 1;
    m_stack.setAutoDelete(true);
    m_stack.clear();
    return rc;
  }

  void insert(const Key& key, const T& obj)
  {
    if(m_stack.count() == 0)
      throw new MYMONEYEXCEPTION("No transaction started to insert new element into container");

    // store object in
    m_stack.push(new MyMoneyMapInsert(this, key, obj));
  }

  void modify(const Key& key, const T& obj)
  {
    if(m_stack.count() == 0)
      throw new MYMONEYEXCEPTION("No transaction started to modify element in container");

#if 0
    // had to take this out, because we use QPair in one instance as key
    if(key.isEmpty())
      throw new MYMONEYEXCEPTION("No key to update object");
#endif

    m_stack.push(new MyMoneyMapModify(this, key, obj));
  }

  void remove(const Key& key)
  {
    if(m_stack.count() == 0)
      throw new MYMONEYEXCEPTION("No transaction started to remove element from container");

#if 0
    // had to take this out, because we use QPair in one instance as key
    if(key.isEmpty())
      throw new MYMONEYEXCEPTION("No key to remove object");
#endif

    m_stack.push(new MyMoneyMapRemove(this, key));
  }

  MyMoneyMap<Key, T>& operator= (const QMap<Key, T>& m)
  {
    if(m_stack.count() != 0) {
      throw new MYMONEYEXCEPTION("Cannot assign whole container during transaction");
    }
    QMap<Key, T>::operator=(m);
    return *this;
  }


  inline QValueList<T> values(void) const
  {
    return QMap<Key,T>::values();
  }

  inline QValueList<Key> keys(void) const
  {
    return QMap<Key,T>::keys();
  }

  const T& operator[] ( const Key& k ) const
        { QT_CHECK_INVALID_MAP_ELEMENT; return QMap<Key,T>::operator[](k); }

  inline Q_TYPENAME QMap<Key, T>::const_iterator find(const Key& k) const
  {
    return QMap<Key,T>::find(k);
  }

  inline Q_TYPENAME QMap<Key, T>::const_iterator begin(void) const
  {
    return QMap<Key,T>::begin();
  }

  inline Q_TYPENAME QMap<Key, T>::const_iterator end(void) const
  {
    return QMap<Key,T>::end();
  }

  inline bool contains(const Key& k) const
  {
    return find(k) != end();
  }

  inline void map(QMap<Key, T>& that) const
  {
    //QMap<Key, T>* ptr = dynamic_cast<QMap<Key, T>* >(this);
    //that = *ptr;
    that = *(dynamic_cast<QMap<Key, T>* >(const_cast<MyMoneyMap<Key, T>* >(this)));
  }

  inline size_t count(void) const
  {
    return QMap<Key, T>::count();
  }

#if MY_OWN_DEBUG
  void dump(void) const
  {
    printf("Container dump\n");
    printf(" items in container = %d\n", count());
    printf(" items on stack     = %d\n", m_stack.count());

    const_iterator it;
    for(it = begin(); it != end(); ++it) {
      printf("  %s \n", it.key().data());
    }
  }
#endif

private:
  class MyMoneyMapAction
  {
    public:
      MyMoneyMapAction(QMap<Key, T>* container) :
        m_container(container) {}

      MyMoneyMapAction(QMap<Key, T>* container, const Key& key, const T& obj) :
        m_container(container),
        m_obj(obj),
        m_key(key) {}

      virtual ~MyMoneyMapAction() {}
      virtual void undo(void) = 0;

    protected:
      QMap<Key, T>* m_container;
      T m_obj;
      Key m_key;
  };

  class MyMoneyMapStart : public MyMoneyMapAction
  {
    public:
      MyMoneyMapStart(QMap<Key, T>* container, unsigned long* id) :
        MyMoneyMapAction(container),
        m_idPtr(id)
      {
        if(id != 0)
          m_id = *id;
      }
      virtual ~MyMoneyMapStart() {}
      void undo(void)
      {
        if(m_idPtr != 0)
          *m_idPtr = m_id;
      }

    private:
      unsigned long* m_idPtr;
      unsigned long  m_id;
  };

  class MyMoneyMapInsert : public MyMoneyMapAction
  {
    public:
      MyMoneyMapInsert(QMap<Key, T>* container, const Key& key, const T& obj) :
        MyMoneyMapAction(container, key, obj)
      {
        (*container)[key] = obj;
      }

      virtual ~MyMoneyMapInsert() {}
      void undo(void)
      {
        // m_container->remove(m_key) does not work on GCC 4.0.2
        // using this-> to access those member does the trick
        this->m_container->remove(this->m_key);
      }
  };

  class MyMoneyMapRemove : public MyMoneyMapAction
  {
    public:
      MyMoneyMapRemove(QMap<Key, T>* container, const Key& key) :
        MyMoneyMapAction(container, key, (*container)[key])
      {
        container->remove(key);
      }

      virtual ~MyMoneyMapRemove() {}
      void undo(void)
      {
        (*(this->m_container))[this->m_key] = this->m_obj;
      }
  };

  class MyMoneyMapModify : public MyMoneyMapAction
  {
    public:
      MyMoneyMapModify(QMap<Key, T>* container, const Key& key, const T& obj) :
        MyMoneyMapAction(container, key, (*container)[key])
      {
        (*container)[key] = obj;
      }

      virtual ~MyMoneyMapModify() {}
      void undo(void)
      {
        (*(this->m_container))[this->m_key] = this->m_obj;
      }
  };

protected:
  QPtrStack<MyMoneyMapAction> m_stack;
};

#if MY_OWN_DEBUG
#include <kmymoney/mymoneyaccount.h>
#include <kmymoney/mymoneytransaction.h>
main()
{
  MyMoneyMap<QString, MyMoneyAccount> container;
  MyMoneyMap<QString, MyMoneyTransaction> ct;

  MyMoneyAccount acc;
  acc.setName("Test");
  // this should not be possible
  // container["a"] = acc;

  QValueList<MyMoneyAccount> list;
  list = container.values();

  MyMoneyAccount b;
  b.setName("Thomas");

  try {
    container.startTransaction();
    container.insert("001", acc);
    container.dump();
    container.commitTransaction();
    acc.setName("123");
    container.startTransaction();
    container.modify("001", acc);
    container.dump();
    container.rollbackTransaction();
    container.dump();

    container.startTransaction();
    container.remove(QString("001"));
    container.dump();
    container.rollbackTransaction();
    container.dump();

    b = container["001"];
    printf("b.name() = %s\n", b.name().data());

    QMap<QString, MyMoneyAccount>::ConstIterator it;
    it = container.find("001");
    it = container.begin();

  } catch(MyMoneyException *e) {
    printf("Caught exception: %s\n", e->what().data());
    delete e;
  }

  QMap<QString, MyMoneyAccount> map;
  map["005"] = b;
  container = map;

  printf("b.name() = %s\n", container["001"].name().data());
  printf("b.name() = %s\n", container["005"].name().data());
}

#endif

#endif