1/* This may look like C code, but it is really -*- C++ -*- */
2
3/* Hash table used to check for duplicate keyword entries.
4
5 Copyright (C) 1989-1998, 2000, 2002 Free Software Foundation, Inc.
6 Written by Douglas C. Schmidt <schmidt@ics.uci.edu>
7 and Bruno Haible <bruno@clisp.org>.
8
9 This file is part of GNU GPERF.
10
11 This program is free software: you can redistribute it and/or modify
12 it under the terms of the GNU General Public License as published by
13 the Free Software Foundation; either version 3 of the License, or
14 (at your option) any later version.
15
16 This program is distributed in the hope that it will be useful,
17 but WITHOUT ANY WARRANTY; without even the implied warranty of
18 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 GNU General Public License for more details.
20
21 You should have received a copy of the GNU General Public License
22 along with this program. If not, see <http://www.gnu.org/licenses/>. */
23
24#ifndef hash_table_h
25#define hash_table_h 1
26
27#include "keyword.h"
28
29/* Hash table of KeywordExt* entries.
30 Two entries are considered equal if their _selchars are the same and
31 - if !ignore_length - if their _allchars_length are the same. */
32
33class Hash_Table
34{
35public:
36 /* Constructor.
37 size is the maximum number of entries.
38 ignore_length determines a detail in the comparison function. */
39 Hash_Table (unsigned int size, bool ignore_length);
40 /* Destructor. */
41 ~Hash_Table ();
42 /* Attempts to insert ITEM in the table. If there is already an equal
43 entry in it, returns it. Otherwise inserts ITEM and returns NULL. */
44 KeywordExt * insert (KeywordExt *item);
45 /* Print the table's contents. */
46 void dump () const;
47
48private:
49 /* Vector of entries. */
50 KeywordExt ** _table;
51 /* Size of the vector. */
52 unsigned int _size;
53 /* log2(_size). */
54 unsigned int _log_size;
55 /* A detail of the comparison function. */
56 bool const _ignore_length;
57 /* Statistics: Number of collisions so far. */
58 unsigned int _collisions;
59
60 /* Compares two items. */
61 bool equal (KeywordExt *item1, KeywordExt *item2) const;
62};
63
64#endif
65