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Annotation of src/usr.bin/mandoc/man_hash.c, Revision 1.8

1.8     ! schwarze    1: /*     $Id: man_hash.c,v 1.7 2009/10/19 10:20:24 schwarze Exp $ */
1.1       kristaps    2: /*
1.2       schwarze    3:  * Copyright (c) 2008, 2009 Kristaps Dzonsons <kristaps@kth.se>
1.1       kristaps    4:  *
                      5:  * Permission to use, copy, modify, and distribute this software for any
1.2       schwarze    6:  * purpose with or without fee is hereby granted, provided that the above
                      7:  * copyright notice and this permission notice appear in all copies.
1.1       kristaps    8:  *
1.2       schwarze    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.
1.1       kristaps   16:  */
1.7       schwarze   17: #include <sys/types.h>
                     18:
1.1       kristaps   19: #include <assert.h>
1.8     ! schwarze   20: #include <ctype.h>
1.6       schwarze   21: #include <limits.h>
1.1       kristaps   22: #include <stdlib.h>
                     23: #include <string.h>
                     24:
                     25: #include "libman.h"
                     26:
1.8     ! schwarze   27: #define        HASH_DEPTH       6
        !            28:
        !            29: #define        HASH_ROW(x) do { \
        !            30:                if ('.' == (x)) \
        !            31:                        (x) = 26; \
        !            32:                else if (isupper((u_char)(x))) \
        !            33:                        (x) -= 65; \
        !            34:                else \
        !            35:                        (x) -= 97; \
        !            36:                (x) *= HASH_DEPTH; \
        !            37:        } while (/* CONSTCOND */ 0)
        !            38:
        !            39: /*
        !            40:  * Lookup table is indexed first by lower-case first letter (plus one
        !            41:  * for the period, which is stored in the last row), then by lower or
        !            42:  * uppercase second letter.  Buckets correspond to the index of the
        !            43:  * macro (the integer value of the enum stored as a char to save a bit
        !            44:  * of space).
        !            45:  */
        !            46: static u_char           table[27 * HASH_DEPTH];
1.1       kristaps   47:
1.6       schwarze   48: /*
                     49:  * XXX - this hash has global scope, so if intended for use as a library
                     50:  * with multiple callers, it will need re-invocation protection.
                     51:  */
1.1       kristaps   52: void
1.6       schwarze   53: man_hash_init(void)
1.1       kristaps   54: {
                     55:        int              i, j, x;
                     56:
1.6       schwarze   57:        memset(table, UCHAR_MAX, sizeof(table));
1.1       kristaps   58:
1.8     ! schwarze   59:        assert(/* CONSTCOND */ MAN_MAX < UCHAR_MAX);
        !            60:
1.3       schwarze   61:        for (i = 0; i < MAN_MAX; i++) {
1.1       kristaps   62:                x = man_macronames[i][0];
                     63:
1.8     ! schwarze   64:                assert(isalpha((u_char)x) || '.' == x);
1.1       kristaps   65:
1.8     ! schwarze   66:                HASH_ROW(x);
        !            67:
        !            68:                for (j = 0; j < HASH_DEPTH; j++)
1.6       schwarze   69:                        if (UCHAR_MAX == table[x + j]) {
                     70:                                table[x + j] = (u_char)i;
1.1       kristaps   71:                                break;
                     72:                        }
1.8     ! schwarze   73:
        !            74:                assert(j < HASH_DEPTH);
1.1       kristaps   75:        }
                     76: }
                     77:
1.8     ! schwarze   78:
        !            79: enum mant
1.6       schwarze   80: man_hash_find(const char *tmp)
1.1       kristaps   81: {
1.8     ! schwarze   82:        int              x, y, i;
        !            83:        enum mant        tok;
1.1       kristaps   84:
1.8     ! schwarze   85:        if ('\0' == (x = tmp[0]))
1.1       kristaps   86:                return(MAN_MAX);
1.8     ! schwarze   87:        if ( ! (isalpha((u_char)x) || '.' == x))
1.1       kristaps   88:                return(MAN_MAX);
                     89:
1.8     ! schwarze   90:        HASH_ROW(x);
1.1       kristaps   91:
1.8     ! schwarze   92:        for (i = 0; i < HASH_DEPTH; i++) {
        !            93:                if (UCHAR_MAX == (y = table[x + i]))
1.1       kristaps   94:                        return(MAN_MAX);
1.8     ! schwarze   95:
        !            96:                tok = (enum mant)y;
1.1       kristaps   97:                if (0 == strcmp(tmp, man_macronames[tok]))
                     98:                        return(tok);
                     99:        }
                    100:
                    101:        return(MAN_MAX);
                    102: }