Tesseract  3.02
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closed.cpp
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1 /* -*-C-*-
2  ********************************************************************************
3  *
4  * File: closed.c (Formerly closed.c)
5  * Description: Hash table for closed search states.
6  * Author: Mark Seaman, OCR Technology
7  * Created: Fri Oct 16 14:37:00 1987
8  * Modified: Fri May 25 11:31:16 1990 (Mark Seaman) marks@hpgrlt
9  * Language: C
10  * Package: N/A
11  * Status: Reusable Software Component
12  *
13  * (c) Copyright 1987, Hewlett-Packard Company.
14  ** Licensed under the Apache License, Version 2.0 (the "License");
15  ** you may not use this file except in compliance with the License.
16  ** You may obtain a copy of the License at
17  ** http://www.apache.org/licenses/LICENSE-2.0
18  ** Unless required by applicable law or agreed to in writing, software
19  ** distributed under the License is distributed on an "AS IS" BASIS,
20  ** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
21  ** See the License for the specific language governing permissions and
22  ** limitations under the License.
23  *
24  *********************************************************************************/
25 /*----------------------------------------------------------------------
26  I n c l u d e s
27 ----------------------------------------------------------------------*/
28 #include "freelist.h"
29 #include "closed.h"
30 #include "cutil.h"
31 #include "callcpp.h"
32 #ifdef __UNIX__
33 #include <assert.h>
34 #endif
35 
36 /*----------------------------------------------------------------------
37  V a r i a b l e s
38 ----------------------------------------------------------------------*/
39 #define TABLE_SIZE 2000
40 
41 /*----------------------------------------------------------------------
42  F u n c t i o n s
43 ----------------------------------------------------------------------*/
50 int hash_add(HASH_TABLE state_table, STATE *state) {
51  int x;
52  int i = 0;
53  int table_limit = TABLE_SIZE;
54 
55  x = state->part2 % table_limit;
56  while (i < table_limit) {
57  assert (0 <= x && x < table_limit);
58  /* Found it */
59  if ((state_table[x].part2 == state->part2) &&
60  (state_table[x].part1 == state->part1)) {
61  return (FALSE);
62  }
63  /* Not in table */
64  else if (state_table[x].part1 == NO_STATE) {
65  state_table[x].part2 = state->part2;
66  state_table[x].part1 = state->part1;
67  return (TRUE);
68  }
69  i++;
70  if (++x >= table_limit)
71  x = 0;
72  }
73  cprintf("warning: hash table is full");
74 
75  abort();
76  return 0;
77 }
78 
79 
86 int hash_lookup(HASH_TABLE state_table, STATE *state) {
87  int x;
88  int i = 0;
89  int table_limit = TABLE_SIZE;
90 
91  x = state->part2 % table_limit;
92  while (i < table_limit) {
93  assert (0 <= x && x < table_limit);
94  /* Found it */
95  if ((state_table[x].part2 == state->part2) &&
96  (state_table[x].part1 == state->part1)) {
97  return (TRUE);
98  }
99  /* Not in table */
100  else if (state_table[x].part1 == NO_STATE) {
101  return (FALSE);
102  }
103 
104  i++;
105  if (++x >= table_limit)
106  x = 0;
107  }
108  cprintf ("warning: fell off end of hash table (%x) %x\n",
109  state->part2, state->part2 % table_limit);
110  abort();
111  return 0;
112 }
113 
114 
121  HASH_TABLE ht;
122  int x;
123 
124  ht = (HASH_TABLE) memalloc (TABLE_SIZE * sizeof (STATE));
125  for (x = 0; x < TABLE_SIZE; x++) {
126  ht[x].part1 = NO_STATE;
127  ht[x].part2 = NO_STATE;
128  }
129  return (ht);
130 }