2 * uid.c -- UIDL handling for POP3 servers without LAST
4 * For license terms, see the file COPYING in this directory.
11 #if defined(STDC_HEADERS)
16 #if defined(HAVE_UNISTD_H)
20 #include "fetchmail.h"
23 * Machinery for handling UID lists live here. This is mainly to support
24 * RFC1725-conformant POP3 servers without a LAST command, but may also be
25 * useful for making the IMAP4 querying logic UID-oriented, if a future
26 * revision of IMAP forces me to. (This would be bad. Server-side
27 * seen bits are better than UIDs, because they track messages seen by
32 * At start of a query, we have a (possibly empty) list of UIDs to be
33 * considered seen in `oldsaved'. These are messages that were left in
34 * the mailbox and *not deleted* on previous queries (we don't need to
35 * remember the UIDs of deleted messages because ... well, they're gone!)
36 * This list is initially set up by initialized_saved_list() from the
39 * Early in the query, during the execution of the protocol-specific
40 * getrange code, the driver expects that the host's `newsaved' member
41 * will be filled with a list of UIDs and message numbers representing
42 * the mailbox state. If this list is empty, the server did
43 * not respond to the request for a UID listing.
45 * Each time a message is fetched, we can check its UID against the
46 * `oldsaved' list to see if it is old. If not, it should be downloaded
47 * (and possibly deleted). It should be downloaded anyway if --all
48 * is on. It should not be deleted if --keep is on.
50 * Each time a message is deleted, we remove its id from the `newsaved'
53 * At the end of the query, whatever remains in the `newsaved' member
54 * (because it was not deleted) becomes the `oldsaved' list. The old
55 * `oldsaved' list is freed.
57 * At the end of the fetchmail run, all current `oldsaved' lists are
58 * flushed out to the .fetchids file to be picked up by the next run.
59 * If there are no such messages, the file is deleted.
62 /* UIDs associated with un-queried hosts */
63 static struct idlist *scratchlist;
65 void initialize_saved_lists(struct query *hostlist, char *idfile)
66 /* read file of saved IDs and attach to each host */
72 /* make sure lists are initially empty */
73 for (hostp = hostlist; hostp; hostp = hostp->next)
74 hostp->oldsaved = hostp->newsaved = (struct idlist *)NULL;
76 /* let's get stored message UIDs from previous queries */
77 if ((tmpfp = fopen(idfile, "r")) != (FILE *)NULL) {
78 char buf[POPBUFSIZE+1], host[HOSTLEN+1], id[IDLEN+1];
80 while (fgets(buf, POPBUFSIZE, tmpfp) != (char *)NULL)
82 if ((st = sscanf(buf, "%s %s\n", host, id)) == 2)
84 for (hostp = hostlist; hostp; hostp = hostp->next)
86 if (strcmp(host, hostp->servername) == 0)
88 save_uid(&hostp->oldsaved, -1, id);
93 /* if it's not in a host we're querying, save it anyway */
94 if (hostp == (struct query *)NULL)
95 save_uid(&scratchlist, -1, buf);
102 struct idlist *save_uid(struct idlist **idl, int num, char *str)
103 /* save a number/UID pair on the given UID list */
107 new = (struct idlist *)xmalloc(sizeof(struct idlist));
109 new->id = xstrdup(str);
116 void free_uid_list(struct idlist **idl)
117 /* free the given UID list */
119 if (*idl == (struct idlist *)NULL)
122 free_uid_list(&(*idl)->next);
125 *idl = (struct idlist *)NULL;
128 void save_id_pair(struct idlist **idl, char *str1, char *str2)
129 /* save an ID pair on the given list */
133 new = (struct idlist *)xmalloc(sizeof(struct idlist));
134 new->id = xstrdup(str1);
136 new->val.id2 = xstrdup(str2);
138 new->val.id2 = (char *)NULL;
144 void free_idpair_list(struct idlist **idl)
145 /* free the given ID pair list */
147 if (*idl == (struct idlist *)NULL)
150 free_idpair_list(&(*idl)->next);
152 free ((*idl)->val.id2);
154 *idl = (struct idlist *)NULL;
158 int uid_in_list(struct idlist **idl, char *str)
159 /* is a given ID in the given list? */
161 if (*idl == (struct idlist *)NULL || str == (char *) NULL)
163 else if (strcmp(str, (*idl)->id) == 0)
166 return(uid_in_list(&(*idl)->next, str));
169 char *uid_find(struct idlist **idl, int number)
170 /* return the id of the given number in the given list. */
172 if (*idl == (struct idlist *) 0)
174 else if (number == (*idl)->val.num)
177 return(uid_find(&(*idl)->next, number));
180 char *idpair_find(struct idlist **idl, char *id)
181 /* return the id of the given number in the given list. */
183 if (*idl == (struct idlist *) 0)
185 else if (strcmp(id, (*idl)->id) == 0)
186 return((*idl)->val.id2 ? (*idl)->val.id2 : (*idl)->id);
188 return(idpair_find(&(*idl)->next, id));
191 int delete_uid(struct idlist **idl, int num)
192 /* delete given message from given list */
194 if (*idl == (struct idlist *)NULL)
196 else if ((*idl)->val.num == num)
198 struct idlist *next = (*idl)->next;
206 return(delete_uid(&(*idl)->next, num));
210 void append_uid_list(struct idlist **idl, struct idlist **nidl)
211 /* append nidl to idl (does not copy *) */
213 if ((*idl) == (struct idlist *)NULL)
215 else if ((*idl)->next == (struct idlist *)NULL)
216 (*idl)->next = *nidl;
218 append_uid_list(&(*idl)->next, nidl);
221 void update_uid_lists(struct query *hostp)
222 /* perform end-of-query actions on UID lists */
224 free_uid_list(&hostp->oldsaved);
225 hostp->oldsaved = hostp->newsaved;
226 hostp->newsaved = (struct idlist *) NULL;
229 void write_saved_lists(struct query *hostlist, char *idfile)
230 /* perform end-of-run write of seen-messages list */
237 /* if all lists are empty, nuke the file */
239 for (hostp = hostlist; hostp; hostp = hostp->next) {
244 /* either nuke the file or write updated last-seen IDs */
248 if ((tmpfp = fopen(idfile, "w")) != (FILE *)NULL) {
249 for (hostp = hostlist; hostp; hostp = hostp->next) {
250 for (idp = hostp->oldsaved; idp; idp = idp->next)
251 fprintf(tmpfp, "%s %s\n", hostp->servername, idp->id);
253 for (idp = scratchlist; idp; idp = idp->next)
254 fputs(idp->id, tmpfp);
259 /* uid.c ends here */