| | 1 | /* $Id: man_hash.c,v 1.25 2011/07/24 18:15:14 kristaps Exp $ */ |
| | 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> |
| | 26 | #include <stdlib.h> |
| | 27 | #include <string.h> |
| | 28 | |
| | 29 | #include "man.h" |
| | 30 | #include "mandoc.h" |
| | 31 | #include "libman.h" |
| | 32 | |
| | 33 | #define HASH_DEPTH 6 |
| | 34 | |
| | 35 | #define HASH_ROW(x) do { \ |
| | 36 | if (isupper((unsigned char)(x))) \ |
| | 37 | (x) -= 65; \ |
| | 38 | else \ |
| | 39 | (x) -= 97; \ |
| | 40 | (x) *= HASH_DEPTH; \ |
| | 41 | } while (/* CONSTCOND */ 0) |
| | 42 | |
| | 43 | /* |
| | 44 | * Lookup table is indexed first by lower-case first letter (plus one |
| | 45 | * for the period, which is stored in the last row), then by lower or |
| | 46 | * uppercase second letter. Buckets correspond to the index of the |
| | 47 | * macro (the integer value of the enum stored as a char to save a bit |
| | 48 | * of space). |
| | 49 | */ |
| | 50 | static unsigned char table[26 * HASH_DEPTH]; |
| | 51 | |
| | 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 | */ |
| | 56 | void |
| | 57 | man_hash_init(void) |
| | 58 | { |
| | 59 | int i, j, x; |
| | 60 | |
| | 61 | memset(table, UCHAR_MAX, sizeof(table)); |
| | 62 | |
| | 63 | assert(/* LINTED */ |
| | 64 | MAN_MAX < UCHAR_MAX); |
| | 65 | |
| | 66 | for (i = 0; i < (int)MAN_MAX; i++) { |
| | 67 | x = man_macronames[i][0]; |
| | 68 | |
| | 69 | assert(isalpha((unsigned char)x)); |
| | 70 | |
| | 71 | HASH_ROW(x); |
| | 72 | |
| | 73 | for (j = 0; j < HASH_DEPTH; j++) |
| | 74 | if (UCHAR_MAX == table[x + j]) { |
| | 75 | table[x + j] = (unsigned char)i; |
| | 76 | break; |
| | 77 | } |
| | 78 | |
| | 79 | assert(j < HASH_DEPTH); |
| | 80 | } |
| | 81 | } |
| | 82 | |
| | 83 | |
| | 84 | enum mant |
| | 85 | man_hash_find(const char *tmp) |
| | 86 | { |
| | 87 | int x, y, i; |
| | 88 | enum mant tok; |
| | 89 | |
| | 90 | if ('\0' == (x = tmp[0])) |
| | 91 | return(MAN_MAX); |
| | 92 | if ( ! (isalpha((unsigned char)x))) |
| | 93 | return(MAN_MAX); |
| | 94 | |
| | 95 | HASH_ROW(x); |
| | 96 | |
| | 97 | for (i = 0; i < HASH_DEPTH; i++) { |
| | 98 | if (UCHAR_MAX == (y = table[x + i])) |
| | 99 | return(MAN_MAX); |
| | 100 | |
| | 101 | tok = (enum mant)y; |
| | 102 | if (0 == strcmp(tmp, man_macronames[tok])) |
| | 103 | return(tok); |
| | 104 | } |
| | 105 | |
| | 106 | return(MAN_MAX); |
| | 107 | } |
projects / dragonfly.git / blame_incremental