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Diffstat (limited to 'libdb/db_delete.c')
| -rw-r--r-- | libdb/db_delete.c | 146 |
1 files changed, 146 insertions, 0 deletions
diff --git a/libdb/db_delete.c b/libdb/db_delete.c new file mode 100644 index 0000000..6d8870f --- /dev/null +++ b/libdb/db_delete.c @@ -0,0 +1,146 @@ +/* + * 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 "error.h" +#include "gl_list.h" +#include "xalloc.h" + +#include "gettext.h" +#define _(String) gettext (String) + +#include "manconfig.h" + +#include "appendstr.h" +#include "debug.h" +#include "filenames.h" +#include "glcontainers.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 */ + gl_list_t refs; + struct name_ext this_ref, *ref; + size_t this_index; + char *multi_content = NULL; + datum multi_key; + + /* Extract all of the extensions associated with + this key */ + + refs = list_extensions (MYDBM_DPTR (cont) + 1); + + this_ref.name = name; + this_ref.ext = info->ext; + this_index = gl_list_indexof (refs, &this_ref); + + if (this_index == (size_t) -1) { + gl_list_free (refs); + MYDBM_FREE_DPTR (cont); + MYDBM_FREE_DPTR (key); + return NO_ENTRY; + } + + multi_key = make_multi_key (name, info->ext); + if (!MYDBM_EXISTS (dbf, multi_key)) { + error (0, 0, + _( "multi key %s does not exist"), + MYDBM_DPTR (multi_key)); + gripe_corrupt_data (dbf); + } + MYDBM_DELETE (dbf, multi_key); + MYDBM_FREE_DPTR (multi_key); + gl_list_remove_at (refs, this_index); + + /* If all manual pages with this name have been deleted, + we'll have to remove the key too. */ + + if (!gl_list_size (refs)) { + gl_list_free (refs); + MYDBM_FREE_DPTR (cont); + MYDBM_DELETE (dbf, key); + MYDBM_FREE_DPTR (key); + return 0; + } + + /* create our new multi content */ + multi_content = xstrdup (""); + GL_LIST_FOREACH (refs, ref) + multi_content = appendstr (multi_content, + "\t", ref->name, + "\t", ref->ext, + (void *) 0); + + MYDBM_FREE_DPTR (cont); + MYDBM_SET (cont, multi_content); + if (MYDBM_REPLACE (dbf, key, cont)) + gripe_replace_key (dbf, MYDBM_DPTR (key)); + + gl_list_free (refs); + } + + MYDBM_FREE_DPTR (key); + return 0; +} |