collect1.h

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/*_############################################################################
  _## 
  _##  collect1.h  
  _##
  _##  SNMP++v3.2.15
  _##  -----------------------------------------------
  _##  Copyright (c) 2001-2004 Jochen Katz, Frank Fock
  _##
  _##  This software is based on SNMP++2.6 from Hewlett Packard:
  _##  
  _##    Copyright (c) 1996
  _##    Hewlett-Packard Company
  _##  
  _##  ATTENTION: USE OF THIS SOFTWARE IS SUBJECT TO THE FOLLOWING TERMS.
  _##  Permission to use, copy, modify, distribute and/or sell this software 
  _##  and/or its documentation is hereby granted without fee. User agrees 
  _##  to display the above copyright notice and this license notice in all 
  _##  copies of the software and any documentation of the software. User 
  _##  agrees to assume all liability for the use of the software; 
  _##  Hewlett-Packard and Jochen Katz make no representations about the 
  _##  suitability of this software for any purpose. It is provided 
  _##  "AS-IS" without warranty of any kind, either express or implied. User 
  _##  hereby grants a royalty-free license to any and all derivatives based
  _##  upon this software code base. 
  _##  
  _##  Stuttgart, Germany, Tue Jan  4 21:42:42 CET 2005 
  _##  
  _##########################################################################*/
// $Id: collect1.h,v 1.5 2004/09/05 18:59:48 katz Exp $
#ifdef SNMP_PP_NAMESPACE
namespace Snmp_pp {
#endif

template <class T> class SnmpCollection
{
  class cBlock
  {
    public:
     cBlock(cBlock *p, cBlock *n) : prev(p), next(n) {};
     T *item[MAXT];
     cBlock *prev;
     cBlock *next;
  };

 public:

  /**
   * Create an empty collection.
   */
  SnmpCollection()
    : count(0), data(0,0) {};

  /**
   * Create a collection using a single template object.
   */
  SnmpCollection(const T &t)
    : count(1), data(0, 0)
  {
    data.item[0] = (T*) (t.clone());
  };

  /**
   * Create a collection with another collection (copy constructor).
   */
  SnmpCollection(const SnmpCollection<T> &c)
    : count(0), data(0, 0)
  {
    if (c.count == 0) return;

    // load up the new collection
    cBlock *current = &data;
    cBlock *nextBlock;
    int cn = 0;

    while (count < c.count)
    {
      if (cn >= MAXT)
      {
        nextBlock = new cBlock(current, 0);
        current->next = nextBlock;
        current = nextBlock;
        cn=0;
      }
      T *tmp;
      c.get_element(tmp, count);
      current->item[cn] = (T*) (tmp->clone());
      count++;
      cn++;
    }
  };

  /**
   * Destroy the collection.
   */
  ~SnmpCollection()
  {
    clear();  // just delete the data
  };

  /**
   * Get the size of the collection.
   */
  int size() const
  {
    return count;
  };

  /**
   * Append an item to the collection.
   */
  SnmpCollection& operator +=(const T &i)
  {
    cBlock *current = &data;
    int cn = (int) count % MAXT;
    while (current->next)
      current = current->next;
    if ((count > 0) && ((count % MAXT) == 0))
    {
      cBlock *add = new cBlock(current, 0);
      if (!add) return *this;
      current->next = add;
      add->item[0] = (T*) (i.clone());
    }
    else
    {
      current->item[cn] = (T*) (i.clone());
    }
    count++;

    return *this;
  };

  /**
   * Assign one collection to another.
   */
  SnmpCollection &operator =(const SnmpCollection<T> &c)
  {
    if (this == &c) return *this;  // check for self assignment

    clear(); // delete the data

    if (c.count == 0) return *this;

    // load up the new collection
    cBlock *current = &data;
    cBlock *nextBlock;
    int cn = 0;
    count = 0;
    while (count < c.count)
    {
      if (cn >= MAXT)
      {
        nextBlock = new cBlock(current, 0);
        current->next = nextBlock;
        current = nextBlock;
        cn=0;
      }
      T *tmp;
      c.get_element(tmp, count);
      current->item[cn] = (T*) (tmp->clone());
      count++;
      cn++;
    }

    return *this;
  };

  /**
   * Access an element in the collection.
   *
   * @return The requestet element or an empty element if out of bounds.
   */
  T operator[](const int p) const
  {
    if ((p < count) && (p >= 0))
    {
      cBlock const *current = &data;
      int bn = (int) (p / MAXT);
      int cn = (int) p % MAXT;
      for (int z=0; z<bn; z++)
        current = current->next;
      return *(current->item[cn]);
    }
    else
    {
      // return an instance of nothing!!
      T t;
      return t;
    }
  };

  /**
   * Set an element in the collection.
   *
   * @return 0 on success and -1 on failure.
   */
  int set_element( const T& i, const int p)
  {
    if ((p < 0) || (p > count)) return -1; // not found!

    cBlock *current = &data;
    int bn = (int) p / MAXT;
    int cn = (int) p % MAXT;
    for (int z=0; z<bn; z++)
      current = current->next;
    delete current->item[cn];
    current->item[cn] = (T*) (i.clone());
    return 0;
  };

  /**
   * Get an element in the collection.
   *
   * @return 0 on success and -1 on failure.
   */
  int get_element(T &t, const int p) const
  {
    if ((p < 0) || (p > count)) return -1; // not found!

    cBlock const *current = &data;
    int bn = (int) p / MAXT;
    int cn = (int) p % MAXT;
    for (int z=0; z<bn; z++)
      current = current->next;
    t = *(current->item[cn]);
    return 0;
  };

  /**
   * Get a pointer to an element in the collection.
   *
   * @return 0 on success and -1 on failure.
   */
  int get_element(T *&t, const int p) const
  {
    if ((p < 0) || (p > count)) return -1; // not found!

    cBlock const *current = &data;
    int bn = (int) p / MAXT;
    int cn = (int) p % MAXT;
    for (int z=0; z<bn; z++)
      current = current->next;
    t = current->item[cn];
    return 0;
  };

  /**
   * Apply an function to the entire collection, iterator.
   */
  void apply(void f(T&))
  {
    T temp;
    for ( int z=0; z<count; z++)
    {
      this->get_element(temp, z);
      f(temp);
    }
  };

  /**
   * Looks for an element in the collection.
   *
   * @return TRUE if found.
   */
  int find(const T& i, int &pos) const
  {
    T temp;
    for (int z=0; z<count; z++)
    {
      this->get_element(temp, z);
      if ( temp == i) {
        pos = z;
        return TRUE;
      }
    }
    return FALSE;
  };

  /**
   * Delete an element in the collection.
   */
  int remove(const T& i)
  {
    // first see if we have it
    int pos;
    if (find(i, pos))
    {
      SnmpCollection<T> newCollection;

      for (int z=0; z<count; z++)
      {
        if (z != pos)
        {
          T item;
          get_element(item, z);
          newCollection += item;
        }
      }

      // assign new collection to 'this'
      operator =(newCollection);

      return TRUE;
    }
    return FALSE;   // not found thus not removed
  };

  /**
   * Delete all elements within the collection.
   */
  void clear()
  {
    if (count == 0) return;

    cBlock *current = &data;
    int z=0;
    int cn=0;
    while ( z< count)
    {
      if (cn >= MAXT)
      {
        cn =0;
        current = current->next;
      }
      delete current->item[cn];
      cn++;
      z++;
    }

    // delete the blocks
    while (current->next)
      current = current->next;
    while (current->prev)
    {
      current = current->prev;
      delete current->next;
    }

    count = 0;
    data.next=0;
    data.prev=0;
  };

 private:
  int count;
  cBlock data;
};

#ifdef SNMP_PP_NAMESPACE
}; // end of namespace Snmp_pp
#endif 

---