Import mdocml-1.13.1
[dragonfly.git] / contrib / mdocml / man_hash.c
CommitLineData
070c62a6 1/* $Id: man_hash.c,v 1.27 2014/04/20 16:46:04 schwarze Exp $ */
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2/*
3 * Copyright (c) 2008, 2009, 2010 Kristaps Dzonsons <kristaps@bsd.lv>
4 *
5 * Permission to use, copy, modify, and distribute this software for any
6 * purpose with or without fee is hereby granted, provided that the above
7 * copyright notice and this permission notice appear in all copies.
8 *
9 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16 */
17#ifdef HAVE_CONFIG_H
18#include "config.h"
19#endif
20
21#include <sys/types.h>
22
23#include <assert.h>
24#include <ctype.h>
25#include <limits.h>
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26#include <string.h>
27
60e1e752 28#include "man.h"
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29#include "mandoc.h"
30#include "libman.h"
31
32#define HASH_DEPTH 6
33
34#define HASH_ROW(x) do { \
36342e81 35 if (isupper((unsigned char)(x))) \
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36 (x) -= 65; \
37 else \
38 (x) -= 97; \
39 (x) *= HASH_DEPTH; \
40 } while (/* CONSTCOND */ 0)
41
42/*
43 * Lookup table is indexed first by lower-case first letter (plus one
44 * for the period, which is stored in the last row), then by lower or
45 * uppercase second letter. Buckets correspond to the index of the
46 * macro (the integer value of the enum stored as a char to save a bit
47 * of space).
48 */
36342e81 49static unsigned char table[26 * HASH_DEPTH];
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070c62a6 51
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52/*
53 * XXX - this hash has global scope, so if intended for use as a library
54 * with multiple callers, it will need re-invocation protection.
55 */
56void
57man_hash_init(void)
58{
59 int i, j, x;
60
61 memset(table, UCHAR_MAX, sizeof(table));
62
070c62a6 63 assert(MAN_MAX < UCHAR_MAX);
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64
65 for (i = 0; i < (int)MAN_MAX; i++) {
66 x = man_macronames[i][0];
67
36342e81 68 assert(isalpha((unsigned char)x));
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69
70 HASH_ROW(x);
71
72 for (j = 0; j < HASH_DEPTH; j++)
73 if (UCHAR_MAX == table[x + j]) {
36342e81 74 table[x + j] = (unsigned char)i;
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75 break;
76 }
77
78 assert(j < HASH_DEPTH);
79 }
80}
81
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82enum mant
83man_hash_find(const char *tmp)
84{
85 int x, y, i;
86 enum mant tok;
87
88 if ('\0' == (x = tmp[0]))
89 return(MAN_MAX);
36342e81 90 if ( ! (isalpha((unsigned char)x)))
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91 return(MAN_MAX);
92
93 HASH_ROW(x);
94
95 for (i = 0; i < HASH_DEPTH; i++) {
96 if (UCHAR_MAX == (y = table[x + i]))
97 return(MAN_MAX);
98
99 tok = (enum mant)y;
100 if (0 == strcmp(tmp, man_macronames[tok]))
101 return(tok);
102 }
103
104 return(MAN_MAX);
105}