/*
- * Copyright (C) 1994, Index Data I/S
+ * Copyright (C) 1994-1998, Index Data I/S
* All rights reserved.
* Sebastian Hammer, Adam Dickmeiss
*
* $Log: lookup.c,v $
- * Revision 1.1 1994-08-16 16:26:48 adam
+ * Revision 1.8 1998-03-05 08:17:24 adam
+ * Added a few comments - no code changed.
+ *
+ * Revision 1.7 1996/02/02 13:43:51 adam
+ * The public functions simply use char instead of Dict_char to represent
+ * search strings. Dict_char is used internally only.
+ *
+ * Revision 1.6 1995/12/11 09:04:50 adam
+ * Bug fix: the lookup/scan/lookgrep didn't handle empty dictionary.
+ *
+ * Revision 1.5 1995/09/04 09:09:15 adam
+ * String arg in lookup is const.
+ *
+ * Revision 1.4 1994/10/05 12:16:51 adam
+ * Pagesize is a resource now.
+ *
+ * Revision 1.3 1994/09/26 10:17:25 adam
+ * Minor changes.
+ *
+ * Revision 1.2 1994/09/16 15:39:14 adam
+ * Initial code of lookup - not tested yet.
+ *
+ * Revision 1.1 1994/08/16 16:26:48 adam
* Added dict.
*
*/
#include <dict.h>
-int dict_lookup (Dict dict, Dict_char *p)
+static char *dict_look (Dict dict, const Dict_char *str)
+{
+ Dict_ptr ptr = 1;
+ int mid, lo, hi;
+ int cmp;
+ void *p;
+ short *indxp;
+ char *info;
+
+ dict_bf_readp (dict->dbf, ptr, &p);
+ mid = lo = 0;
+ hi = DICT_nodir(p)-1;
+ indxp = (short*) ((char*) p+DICT_pagesize(dict)-sizeof(short));
+ while (lo <= hi)
+ {
+ mid = (lo+hi)/2;
+ if (indxp[-mid] > 0)
+ {
+ /* string (Dict_char *) DICT_EOS terminated */
+ /* unsigned char length of information */
+ /* char * information */
+ info = (char*)p + indxp[-mid];
+ cmp = dict_strcmp((Dict_char*) info, str);
+ if (!cmp)
+ return info+(dict_strlen ((Dict_char*) info)+1)
+ *sizeof(Dict_char);
+ }
+ else
+ {
+ Dict_char dc;
+ Dict_ptr subptr;
+
+ /* Dict_ptr subptr */
+ /* Dict_char sub char */
+ /* unsigned char length of information */
+ /* char * information */
+ info = (char*)p - indxp[-mid];
+ memcpy (&dc, info+sizeof(Dict_ptr), sizeof(Dict_char));
+ cmp = dc- *str;
+ if (!cmp)
+ {
+ memcpy (&subptr, info, sizeof(Dict_ptr));
+ if (*++str == DICT_EOS)
+ {
+ if (info[sizeof(Dict_ptr)+sizeof(Dict_char)])
+ return info+sizeof(Dict_ptr)+sizeof(Dict_char);
+ return NULL;
+ }
+ else
+ {
+ if (subptr == 0)
+ return NULL;
+ ptr = subptr;
+ dict_bf_readp (dict->dbf, ptr, &p);
+ mid = lo = 0;
+ hi = DICT_nodir(p)-1;
+ indxp = (short*) ((char*) p+DICT_pagesize(dict)
+ -sizeof(short));
+ continue;
+ }
+ }
+ }
+ if (cmp < 0)
+ lo = mid+1;
+ else
+ hi = mid-1;
+ }
+ return NULL;
+}
+
+char *dict_lookup (Dict dict, const char *p)
{
- return 0;
+ if (dict->head.last <= 1)
+ return NULL;
+ return dict_look (dict, (const Dict_char *) p);
}