X-Git-Url: http://git.indexdata.com/?p=idzebra-moved-to-github.git;a=blobdiff_plain;f=dict%2Fdelete.c;h=d81c384666c361457f04e557feddc0e276ffdc55;hp=cb9d64dd901825cbc63d35caccbda140ba6ba284;hb=3bb2fd863b1664f1ff71dadb540313f301ca234f;hpb=b31a8654c5b7a597dd4a351f452ac91e5ef60798 diff --git a/dict/delete.c b/dict/delete.c index cb9d64d..d81c384 100644 --- a/dict/delete.c +++ b/dict/delete.c @@ -1,45 +1,107 @@ -/* - * Copyright (C) 1994, Index Data I/S - * All rights reserved. - * Sebastian Hammer, Adam Dickmeiss - * - * $Log: delete.c,v $ - * Revision 1.4 1996-02-02 13:43:50 adam - * The public functions simply use char instead of Dict_char to represent - * search strings. Dict_char is used internally only. - * - * Revision 1.3 1995/12/07 11:48:55 adam - * Insert operation obeys DICT_type = 1 (slack in page). - * Function dict_open exists if page size or magic aren't right. - * - * Revision 1.2 1995/12/06 17:48:30 adam - * Bug fix: delete didn't work. - * - * Revision 1.1 1995/12/06 14:52:21 adam - * New function: dict_delete. - * - */ +/* This file is part of the Zebra server. + Copyright (C) 1994-2011 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 +#endif #include #include #include #include -#include +#include "dict-p.h" -static int dict_del (Dict dict, const Dict_char *str) +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 *)) { - Dict_ptr ptr = 1; int mid, lo, hi; int cmp; void *p; short *indxp; char *info; + int r = 0; + Dict_ptr subptr = 0; - dict_bf_readp (dict->dbf, ptr, &p); + if (!ptr) + return 0; + dict_bf_readp(dict->dbf, ptr, &p); mid = lo = 0; hi = DICT_nodir(p)-1; - indxp = (short*) ((char*) p+DICT_pagesize(dict)-sizeof(short)); + indxp = (short*) ((char*) p+DICT_bsize(p)-sizeof(short)); while (lo <= hi) { mid = (lo+hi)/2; @@ -49,59 +111,132 @@ static int dict_del (Dict dict, const Dict_char *str) /* unsigned char length of information */ /* char * information */ info = (char*)p + indxp[-mid]; - cmp = dict_strcmp((Dict_char*) info, str); - 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); - return 1; - } + + 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_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)); + memcpy(&dc, info+sizeof(Dict_ptr), sizeof(Dict_char)); cmp = dc- *str; if (!cmp) { - memcpy (&subptr, info, sizeof(Dict_ptr)); + 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); - return 1; + dict_bf_touch(dict->dbf, ptr); + + if (f) + (*f)(info+sizeof(Dict_ptr)+sizeof(Dict_char), + client); + r = 1; } - return 0; + 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 { - if (subptr == 0) - return 0; - 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; + /* 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) @@ -109,12 +244,37 @@ static int dict_del (Dict dict, const Dict_char *str) else hi = mid-1; } - return 0; + 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 (Dict dict, const char *p) +int dict_delete_subtree(Dict dict, const char *p, void *client, + int (*f)(const char *info, void *client)) { - if (dict->head.last == 1) - return 0; - return dict_del (dict, (const Dict_char*) p); + 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 + */ +