ACE/apps/drwho/Binary_Search.h

   1 /* -*- C++ -*- */
   2
   3 //=============================================================================
   4 /**
   5  *  @file    Binary_Search.h
   6  *
   7  *  Defines a binary search abstraction for friend records.
   8  *
   9  *  @author Douglas C. Schmidt
  10  */
  11 //=============================================================================
  12
  13
  14 #ifndef _BINARY_SEARCH_H
  15 #define _BINARY_SEARCH_H
  16
  17 #include "Search_Struct.h"
  18
  19 /**
  20  * @class Binary_Search
  21  *
  22  * @brief Defines a binary search abstraction for friend records.
  23  */
  24 class Binary_Search : public Search_Struct
  25 {
  26 public:
  27   /// Initialize the values for the iterators...
  28   Binary_Search ();
  29
  30   /// Destructor.
  31   virtual ~Binary_Search ();
  32
  33   /**
  34    * Returns the next friend in the sequence of sorted friends.  Note
  35    * that this function would be simplified if we expanded the
  36    * iterator interface to include an "initialize" and "next"
  37    * function!
  38    */
  39   virtual Protocol_Record *get_next_entry ();
  40
  41   /**
  42    * An iterator, similar to Binary_Search::get_next_friend, though in
  43    * this case the friend records are returned in the order they
  44    * appeared in the friend file, rather than in sorted order.  Also,
  45    * we skip over entries that don't have any hosts associated with
  46    * them.
  47    */
  48   virtual Protocol_Record *get_each_entry ();
  49
  50   /**
  51    * This function is used to merge the <key_name> from server
  52    * <host_name> into the sorted list of userids kept on the client's
  53    * side.
  54    */
  55   virtual Protocol_Record *insert (const char *key_name,
  56                                    int max_len = MAXUSERIDNAMELEN) = 0;
  57
  58   /// This function is passed to qsort to perform the comparison
  59   /// between login names for two friends.
  60   static int name_compare (const void *, const void *);
  61
  62 protected:
  63   Protocol_Record **current_ptr_;
  64   int current_index_;
  65
  66   Protocol_Record *protocol_record_;
  67   Protocol_Record **sorted_record_;
  68
  69   const char *buffer_;
  70   int buffer_size_;
  71 };
  72
  73 #endif /* _BINARY_SEARCH_H */