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/* This file is part of the Zebra server.
Copyright (C) Index Data
Zebra is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
Software Foundation; either version 2, or (at your option) any later
version.
Zebra is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#if HAVE_CONFIG_H
#include <config.h>
#endif
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <assert.h>
#include "dict-p.h"
static void dict_del_subtree(Dict dict, Dict_ptr ptr,
void *client,
int (*f)(const char *, void *))
{
void *p = 0;
short *indxp;
int i, hi;
if (!ptr)
return;
dict_bf_readp(dict->dbf, ptr, &p);
indxp = (short*) ((char*) p+DICT_bsize(p)-sizeof(short));
hi = DICT_nodir(p)-1;
for (i = 0; i <= hi; i++)
{
if (indxp[-i] > 0)
{
/* string (Dict_char *) DICT_EOS terminated */
/* unsigned char length of information */
/* char * information */
char *info = (char*)p + indxp[-i];
if (f)
(*f)(info + (dict_strlen((Dict_char*) info)+1)
*sizeof(Dict_char), client);
}
else
{
Dict_ptr subptr;
/* Dict_ptr subptr */
/* Dict_char sub char */
/* unsigned char length of information */
/* char * information */
char *info = (char*)p - indxp[-i];
memcpy(&subptr, info, sizeof(Dict_ptr));
if (info[sizeof(Dict_ptr)+sizeof(Dict_char)])
{
if (f)
(*f)(info+sizeof(Dict_ptr)+sizeof(Dict_char), client);
}
if (subptr)
{
dict_del_subtree(dict, subptr, client, f);
/* page may be gone. reread it .. */
dict_bf_readp(dict->dbf, ptr, &p);
indxp = (short*) ((char*) p+DICT_bsize(p)-sizeof(short));
}
}
}
DICT_backptr(p) = dict->head.freelist;
dict->head.freelist = ptr;
dict_bf_touch(dict->dbf, ptr);
}
static int dict_del_string(Dict dict, const Dict_char *str, Dict_ptr ptr,
int sub_flag, void *client,
int (*f)(const char *, void *))
{
int mid, lo, hi;
int cmp;
void *p;
short *indxp;
char *info;
int r = 0;
Dict_ptr subptr = 0;
if (!ptr)
return 0;
dict_bf_readp(dict->dbf, ptr, &p);
mid = lo = 0;
hi = DICT_nodir(p)-1;
indxp = (short*) ((char*) p+DICT_bsize(p)-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 (sub_flag)
{
/* determine if prefix match */
if (!dict_strncmp(str, (Dict_char*) info, dict_strlen(str)))
{
if (f)
(*f)(info + (dict_strlen((Dict_char*) info)+1)
*sizeof(Dict_char), client);
hi = DICT_nodir(p)-1;
while (mid < hi)
{
indxp[-mid] = indxp[-mid-1];
mid++;
}
DICT_type(p) = 1;
(DICT_nodir(p))--;
dict_bf_touch(dict->dbf, ptr);
--hi;
mid = lo = 0;
r = 1; /* signal deleted */
/* start again (may not be the most efficient way to go)*/
continue;
}
}
else
{
/* normal delete: delete if equal */
if (!cmp)
{
hi = DICT_nodir(p)-1;
while (mid < hi)
{
indxp[-mid] = indxp[-mid-1];
mid++;
}
DICT_type(p) = 1;
(DICT_nodir(p))--;
dict_bf_touch(dict->dbf, ptr);
r = 1;
break;
}
}
}
else
{
Dict_char dc;
/* 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)])
{
/* entry does exist. Wipe it out */
info[sizeof(Dict_ptr)+sizeof(Dict_char)] = 0;
DICT_type(p) = 1;
dict_bf_touch(dict->dbf, ptr);
if (f)
(*f)(info+sizeof(Dict_ptr)+sizeof(Dict_char),
client);
r = 1;
}
if (sub_flag)
{
/* must delete all suffixes (subtrees) as well */
hi = DICT_nodir(p)-1;
while (mid < hi)
{
indxp[-mid] = indxp[-mid-1];
mid++;
}
(DICT_nodir(p))--;
DICT_type(p) = 1;
dict_bf_touch(dict->dbf, ptr);
}
}
else
{
/* subptr may be 0 */
r = dict_del_string(dict, str, subptr, sub_flag, client, f);
/* recover */
dict_bf_readp(dict->dbf, ptr, &p);
indxp = (short*)
((char*) p+DICT_bsize(p)-sizeof(short));
info = (char*)p - indxp[-mid];
subptr = 0; /* avoid dict_del_subtree (end of function)*/
if (r == 2)
{ /* subptr page became empty and is removed */
/* see if this entry is a real one or if it just
serves as pointer to subptr */
if (info[sizeof(Dict_ptr)+sizeof(Dict_char)])
{
/* this entry do exist, set subptr to 0 */
memcpy(info, &subptr, sizeof(subptr));
}
else
{
/* this entry ONLY points to subptr. remove it */
hi = DICT_nodir(p)-1;
while (mid < hi)
{
indxp[-mid] = indxp[-mid-1];
mid++;
}
(DICT_nodir(p))--;
}
dict_bf_touch(dict->dbf, ptr);
r = 1;
}
}
break;
}
}
if (cmp < 0)
lo = mid+1;
else
hi = mid-1;
}
if (DICT_nodir(p) == 0 && ptr != dict->head.root)
{
DICT_backptr(p) = dict->head.freelist;
dict->head.freelist = ptr;
dict_bf_touch(dict->dbf, ptr);
r = 2;
}
if (subptr && sub_flag)
dict_del_subtree(dict, subptr, client, f);
return r;
}
int dict_delete(Dict dict, const char *p)
{
return dict_del_string(dict, (const Dict_char*) p, dict->head.root, 0,
0, 0);
}
int dict_delete_subtree(Dict dict, const char *p, void *client,
int (*f)(const char *info, void *client))
{
return dict_del_string(dict, (const Dict_char*) p, dict->head.root, 1,
client, f);
}
/*
* Local variables:
* c-basic-offset: 4
* c-file-style: "Stroustrup"
* indent-tabs-mode: nil
* End:
* vim: shiftwidth=4 tabstop=8 expandtab
*/
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