If no man.cgi `whatis' results are found, offer a quick link to the apropos

[mandoc.git] / man_hash.c

diff --git a/man_hash.c b/man_hash.c
index 647239169ca254d2bc761c397a677075b4a74905..86c5c40a199b8c62d8e166ccac3669fde1e42ed6 100644 (file)
--- a/man_hash.c
+++ b/man_hash.c
@@ -1,93 +1,107 @@
-/* $Id: man_hash.c,v 1.6 2009/04/05 16:34:22 kristaps Exp $ */
+/*     $Id: man_hash.c,v 1.25 2011/07/24 18:15:14 kristaps Exp $ */
 /*
- * Copyright (c) 2008, 2009 Kristaps Dzonsons <kristaps@openbsd.org>
+ * Copyright (c) 2008, 2009, 2010 Kristaps Dzonsons <kristaps@bsd.lv>
  *
  * Permission to use, copy, modify, and distribute this software for any
- * purpose with or without fee is hereby granted, provided that the
- * above copyright notice and this permission notice appear in all
- * copies.
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
  *
- * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL
- * WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED
- * WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE
- * AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
- * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
- * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
- * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
- * PERFORMANCE OF THIS SOFTWARE.
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <sys/types.h>
+
 #include <assert.h>
+#include <ctype.h>
+#include <limits.h>
 #include <stdlib.h>
 #include <string.h>
 
+#include "man.h"
+#include "mandoc.h"
 #include "libman.h"
 
+#define        HASH_DEPTH       6
 
-/* ARGUSED */
-void
-man_hash_free(void *htab)
-{
-
-       free(htab);
-}
+#define        HASH_ROW(x) do { \
+               if (isupper((unsigned char)(x))) \
+                       (x) -= 65; \
+               else \
+                       (x) -= 97; \
+               (x) *= HASH_DEPTH; \
+       } while (/* CONSTCOND */ 0)
 
+/*
+ * Lookup table is indexed first by lower-case first letter (plus one
+ * for the period, which is stored in the last row), then by lower or
+ * uppercase second letter.  Buckets correspond to the index of the
+ * macro (the integer value of the enum stored as a char to save a bit
+ * of space).
+ */
+static unsigned char    table[26 * HASH_DEPTH];
 
-/* ARGUSED */
-void *
-man_hash_alloc(void)
+/*
+ * XXX - this hash has global scope, so if intended for use as a library
+ * with multiple callers, it will need re-invocation protection.
+ */
+void
+man_hash_init(void)
 {
-       int             *htab;
        int              i, j, x;
 
-       htab = calloc(26 * 5, sizeof(int));
-       if (NULL == htab)
-               return(NULL);
+       memset(table, UCHAR_MAX, sizeof(table));
+
+       assert(/* LINTED */ 
+                       MAN_MAX < UCHAR_MAX);
 
-       for (i = 1; i < MAN_MAX; i++) {
+       for (i = 0; i < (int)MAN_MAX; i++) {
                x = man_macronames[i][0];
 
-               assert((x >= 65 && x <= 90) ||
-                               (x >= 97 && x <= 122));
+               assert(isalpha((unsigned char)x));
 
-               x -= (x <= 90) ? 65 : 97;
-               x *= 5;
+               HASH_ROW(x);
 
-               for (j = 0; j < 5; j++)
-                       if (0 == htab[x + j]) {
-                               htab[x + j] = i;
+               for (j = 0; j < HASH_DEPTH; j++)
+                       if (UCHAR_MAX == table[x + j]) {
+                               table[x + j] = (unsigned char)i;
                                break;
                        }
 
-               assert(j < 5);
+               assert(j < HASH_DEPTH);
        }
-
-       return((void *)htab);
 }
 
 
-int
-man_hash_find(const void *arg, const char *tmp)
+enum mant
+man_hash_find(const char *tmp)
 {
-       int              x, i, tok;
-       const int       *htab;
-
-       htab = (const int *)arg;
+       int              x, y, i;
+       enum mant        tok;
 
-       if (0 == (x = tmp[0]))
+       if ('\0' == (x = tmp[0]))
                return(MAN_MAX);
-       if ( ! ((x >= 65 && x <= 90) || (x >= 97 && x <= 122)))
+       if ( ! (isalpha((unsigned char)x)))
                return(MAN_MAX);
 
-       x -= (x <= 90) ? 65 : 97;
-       x *= 5;
+       HASH_ROW(x);
 
-       for (i = 0; i < 5; i++) {
-               if (0 == (tok = htab[x + i]))
+       for (i = 0; i < HASH_DEPTH; i++) {
+               if (UCHAR_MAX == (y = table[x + i]))
                        return(MAN_MAX);
+
+               tok = (enum mant)y;
                if (0 == strcmp(tmp, man_macronames[tok]))
                        return(tok);
        }
 
        return(MAN_MAX);
 }
-