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Diffstat (limited to 'libdb/db_delete.c')
| -rw-r--r-- | libdb/db_delete.c | 148 |
1 files changed, 148 insertions, 0 deletions
diff --git a/libdb/db_delete.c b/libdb/db_delete.c new file mode 100644 index 0000000..4ac6401 --- /dev/null +++ b/libdb/db_delete.c @@ -0,0 +1,148 @@ +/* + * db_delete.c: dbdelete(), database delete routine. + * + * Copyright (C) 1994, 1995 Graeme W. Wilford. (Wilf.) + * Copyright (C) 2001, 2002 Colin Watson. + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Library General Public + * License as published by the Free Software Foundation; either + * version 2 of the License, or (at your option) any later version. + * + * This library 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 + * Library General Public License for more details. + * + * You should have received a copy of the GNU Library General Public + * License along with this library; if not, write to the Free Software + * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA + * + * Mon Aug 8 20:35:30 BST 1994 Wilf. (G.Wilford@ee.surrey.ac.uk) + */ + +#ifdef HAVE_CONFIG_H +#include "config.h" +#endif /* HAVE_CONFIG_H */ + +#include <stdio.h> +#include <string.h> +#include <stdlib.h> +#include <unistd.h> + +#include "gettext.h" +#define _(String) gettext (String) + +#include "manconfig.h" + +#include "error.h" + +#include "mydbm.h" +#include "db_storage.h" + +/* Delete an entry for a page. + Again, 3 possibilities: + + 1) page is singular reference, just delete it :) + 2) page has 2+ companions. Delete page and alter multi entry to not + point to it anymore. + 3) page has 1 companion. Could do as (2), but we'd waste an entry in + the db. Should delete page, extract friend and reinsert as singular, + overwriting the old multi entry. +*/ + +#define NO_ENTRY 1; + +int dbdelete (MYDBM_FILE dbf, const char *name, struct mandata *info) +{ + datum key, cont; + + memset (&key, 0, sizeof key); + memset (&cont, 0, sizeof cont); + + /* get entry for info */ + + debug ("Attempting delete of %s(%s) entry.\n", name, info->ext); + + MYDBM_SET (key, name_to_key (name)); + cont = MYDBM_FETCH (dbf, key); + + if (!MYDBM_DPTR (cont)) { /* 0 entries */ + MYDBM_FREE_DPTR (key); + return NO_ENTRY; + } else if (*MYDBM_DPTR (cont) != '\t') { /* 1 entry */ + MYDBM_DELETE (dbf, key); + MYDBM_FREE_DPTR (cont); + } else { /* 2+ entries */ + char **names, **ext; + char *multi_content = NULL; + datum multi_key; + int refs, i, j; + + /* Extract all of the extensions associated with + this key */ + + refs = list_extensions (MYDBM_DPTR (cont) + 1, &names, &ext); + + for (i = 0; i < refs; ++i) + if (STREQ (names[i], name) && + STREQ (ext[i], info->ext)) + break; + + if (i >= refs) { + free (names); + free (ext); + MYDBM_FREE_DPTR (cont); + MYDBM_FREE_DPTR (key); + return NO_ENTRY; + } + + multi_key = make_multi_key (names[i], ext[i]); + if (!MYDBM_EXISTS (dbf, multi_key)) { + error (0, 0, + _( "multi key %s does not exist"), + MYDBM_DPTR (multi_key)); + gripe_corrupt_data (); + } + MYDBM_DELETE (dbf, multi_key); + MYDBM_FREE_DPTR (multi_key); + + /* refs *may* be 1 if all manual pages with this name + have been deleted. In this case, we'll have to remove + the key too */ + + if (refs == 1) { + free (names); + free (ext); + MYDBM_FREE_DPTR (cont); + MYDBM_DELETE (dbf, key); + MYDBM_FREE_DPTR (key); + return 0; + } + + /* create our new multi content */ + for (j = 0; j < refs; ++j) + if (i != j) + multi_content = appendstr (multi_content, + "\t", names[j], + "\t", ext[j], + (void *) 0); + + MYDBM_FREE_DPTR (cont); + + /* if refs = 2 do something else. Doesn't really matter as + the gdbm db file does not shrink any after a deletion + anyway */ + + MYDBM_SET (cont, multi_content); + + if (MYDBM_REPLACE (dbf, key, cont)) + gripe_replace_key (MYDBM_DPTR (key)); + + free (names); + free (ext); + } + + MYDBM_FREE_DPTR (key); + return 0; +} |