ACE/apps/gperf/src/Hash_Table.h

   1 // -*- C++ -*-
   2
   3 /**
   4  * Copyright (C) 1989 Free Software Foundation, Inc.
   5  * written by Douglas C. Schmidt (d.schmidt@vanderbilt.edu)
   6  *
   7  * This file is part of GNU GPERF.
   8  *
   9  * This program is free software; you can redistribute it and/or
  10  * modify it under the terms of the GNU General Public License
  11  * as published by the Free Software Foundation; either version 2
  12  * of the License, or (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; if not, write to the Free Software
  21  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  22  */
  23
  24 #ifndef HASH_TABLE_H
  25 #define HASH_TABLE_H
  26
  27 #include "ace/config-all.h"
  28
  29 #if !defined (ACE_LACKS_PRAGMA_ONCE)
  30 # pragma once
  31 #endif /* ACE_LACKS_PRAGMA_ONCE */
  32
  33 #include "Options.h"
  34 #include "List_Node.h"
  35 #include "ace/Copy_Disabled.h"
  36
  37 /**
  38  * Hash table used to check for duplicate keyword entries.
  39  *
  40  * This implementation uses "double hashing."
  41  *
  42  * @todo This class should be replaced by something in ACE, e.g.,
  43  * ACE_Hash_Map_Manager.  Perhaps we should implement a new
  44  * ACE_Hash_Map that uses double hashing, however!
  45  */
  46 class Hash_Table : private ACE_Copy_Disabled
  47 {
  48 public:
  49   /// Constructor
  50   Hash_Table (size_t s);
  51
  52   /// Destructor
  53   ~Hash_Table ();
  54
  55   List_Node *find (List_Node *item, int ignore_length);
  56
  57 private:
  58   /// Vector of pointers to linked lists of List_Node's.
  59   List_Node **table_;
  60
  61   /// Size of the vector.
  62   size_t size_;
  63
  64   /// Find out how well our double hashing is working!
  65   int collisions_;
  66 };
  67
  68 #endif /* HASH_TABLE_H */