/*
* Machinery for handling UID lists live here. This is mainly to support
- * RFC1725-conformant POP3 servers without a LAST command, but may also be
- * useful for making the IMAP4 querying logic UID-oriented, if a future
+ * RFC1725/RFC1939-conformant POP3 servers without a LAST command, but may also
+ * be useful for making the IMAP4 querying logic UID-oriented, if a future
* revision of IMAP forces me to.
*
* These functions are also used by the rest of the code to maintain
* This list is initially set up by initialize_saved_list() from the
* .fetchids file.
*
- * Early in the query, during the execution of the protocol-specific
+ * Early in the query, during the execution of the protocol-specific
* getrange code, the driver expects that the host's `newsaved' member
* will be filled with a list of UIDs and message numbers representing
* the mailbox state. If this list is empty, the server did
* be picked up by the next run. If there are no un-expunged
* messages, the file is deleted.
*
- * Note: some comparisons (those used for DNS address lists) are caseblind!
+ * One disadvantage of UIDL is that all the UIDs have to be downloaded
+ * before a search for new messages can be done. Typically, new messages
+ * are appended to mailboxes. Hence, downloading all UIDs just to download
+ * a few new mails is a waste of bandwidth. If new messages are always at
+ * the end of the mailbox, fast UIDL will decrease the time required to
+ * download new mails.
+ *
+ * During fast UIDL, the UIDs of all messages are not downloaded! The first
+ * unseen message is searched for by using a binary search on UIDs. UIDs
+ * after the first unseen message are downloaded as and when needed.
+ *
+ * The advantages of fast UIDL are (this is noticeable only when the
+ * mailbox has too many mails):
+ *
+ * - There is no need to download the UIDs of all mails right at the start.
+ * - There is no need to save all the UIDs in memory separately in
+ * `newsaved' list.
+ * - There is no need to download the UIDs of seen mail (except for the
+ * first binary search).
+ * - The first new mail is downloaded considerably faster.
+ *
+ * The disadvantages are:
+ *
+ * - Since all UIDs are not downloaded, it is not possible to swap old and
+ * new list. The current state of the mailbox is essentially a merged state
+ * of old and new mails.
+ * - If an intermediate mail has been temporarily refused (say, due to 4xx
+ * code from the smtp server), this mail may not get downloaded.
+ * - If 'flush' is used, such intermediate mails will also get deleted.
+ *
+ * The first two disadvantages can be overcome by doing a linear search
+ * once in a while (say, every 10th poll). Also, with flush, fast UIDL
+ * should be disabled.
+ *
+ * Note: some comparisons (those used for DNS address lists) are caseblind!
*/
+int dofastuidl = 0;
+
/* UIDs associated with un-queried hosts */
static struct idlist *scratchlist;
struct query *ctl;
/* make sure lists are initially empty */
- for (ctl = hostlist; ctl; ctl = ctl->next)
- ctl->skipped = ctl->oldsaved = ctl->newsaved = (struct idlist *)NULL;
+ for (ctl = hostlist; ctl; ctl = ctl->next) {
+ ctl->skipped = (struct idlist *)NULL;
+ ctl->oldsaved = (struct idlist *)NULL;
+ ctl->newsaved = (struct idlist *)NULL;
+ ctl->oldsavedend = &ctl->oldsaved;
+ }
errno = 0;
* that all implementations of lstat() will return ENOTDIR
* rather than plain ENOENT in this case...
*/
- if (lstat(idfile, &statbuf) < 0) {
- if (errno == ENOTDIR)
- {
- report(stderr, GT_("lstat: %s: %s\n"), idfile, strerror(errno));
- exit(PS_IOERR);
+ if (lstat(idfile, &statbuf) < 0) {
+ if (errno == ENOTDIR)
+ {
+ report(stderr, "lstat: %s: %s\n", idfile, strerror(errno));
+ exit(PS_IOERR);
+ }
}
- }
/* let's get stored message UIDs from previous queries */
if ((tmpfp = fopen(idfile, "r")) != (FILE *)NULL)
* espescially if the POP server returns an X-UIDL header
* instead of a Message-ID, as GMX's (www.gmx.net) POP3
* StreamProxy V1.0 does.
+ *
+ * this is one other trick. The userhost part
+ * may contain ' ' in the user part, at least in
+ * the lotus notes case.
+ * So we start looking for the '@' after which the
+ * host will follow with the ' ' seperator finaly id.
*/
- if ((id = strchr(user, ' ')) != NULL )
+ if ((delimp1 = strchr(user, '@')) != NULL &&
+ (id = strchr(delimp1,' ')) != NULL)
{
-
- /*
- * this is one other trick. The userhost part
- * may contain ' ' in the user part, at least in
- * the lotus notes case.
- * So we start looking for the '@' after which the
- * host will follow with the ' ' seperator finaly id.
- */
- delimp1 = strchr(user, '@');
- id = strchr(delimp1,' ');
for (delimp1 = id; delimp1 >= user; delimp1--)
if ((*delimp1 != ' ') && (*delimp1 != '\t'))
break;
report_build(stdout, GT_("Old UID list from %s:"),
ctl->server.pollname);
for (idp = ctl->oldsaved; idp; idp = idp->next)
- report_build(stdout, " %s", idp->id);
+ report_build(stdout, " %s", (char *)idp->id);
if (!idp)
report_build(stdout, GT_(" <empty>"));
report_complete(stdout, "\n");
{
report_build(stdout, GT_("Scratch list of UIDs:"));
for (idp = scratchlist; idp; idp = idp->next)
- report_build(stdout, " %s", idp->id);
+ report_build(stdout, " %s", (char *)idp->id);
if (!idp)
report_build(stdout, GT_(" <empty>"));
report_complete(stdout, "\n");
}
#endif /* POP3_ENABLE */
-struct idlist *save_str(struct idlist **idl, const char *str, flag status)
+/* return a pointer to the last element of the list to help the quick,
+ * constant-time addition to the list, NOTE: this function does not dup
+ * the string, the caller must do that. */
+/*@shared@*/ static struct idlist **save_str_quick(/*@shared@*/ struct idlist **idl,
+ /*@only@*/ char *str, flag status)
/* save a number/UID pair on the given UID list */
{
struct idlist **end;
continue;
*end = (struct idlist *)xmalloc(sizeof(struct idlist));
+ (*end)->id = (unsigned char *)str;
(*end)->val.status.mark = status;
- (*end)->id = str ? xstrdup(str) : (char *)NULL;
+ (*end)->val.status.num = 0;
(*end)->next = NULL;
- return(*end);
+ return end;
+}
+
+/* return the end list element for direct modification */
+struct idlist *save_str(struct idlist **idl, const char *str, flag st)
+{
+ return *save_str_quick(idl, str ? xstrdup(str) : NULL, st);
}
void free_str_list(struct idlist **idl)
/* free the given UID list */
{
- if (*idl == (struct idlist *)NULL)
- return;
+ struct idlist *i = *idl;
- free_str_list(&(*idl)->next);
- free ((*idl)->id);
- free(*idl);
- *idl = (struct idlist *)NULL;
+ while(i) {
+ struct idlist *t = i->next;
+ free(i->id);
+ free(i);
+ i = t;
+ }
+ *idl = 0;
}
void save_str_pair(struct idlist **idl, const char *str1, const char *str2)
}
#endif
-int str_in_list(struct idlist **idl, const char *str, const flag caseblind)
+struct idlist *str_in_list(struct idlist **idl, const char *str, const flag caseblind)
/* is a given ID in the given list? (comparison may be caseblind) */
{
- if (*idl == (struct idlist *)NULL || str == (char *) NULL)
- return(0);
- else if (!caseblind && strcmp(str, (*idl)->id) == 0)
- return(1);
- else if (caseblind && strcasecmp(str, (*idl)->id) == 0)
- return(1);
- else
- return(str_in_list(&(*idl)->next, str, caseblind));
+ struct idlist *walk;
+ if (caseblind) {
+ for( walk = *idl; walk; walk = walk->next )
+ if( strcasecmp( str, (char *)walk->id) == 0 )
+ return walk;
+ } else {
+ for( walk = *idl; walk; walk = walk->next )
+ if( strcmp( str, (char *)walk->id) == 0 )
+ return walk;
+ }
+ return NULL;
}
int str_nr_in_list( struct idlist **idl, const char *str )
return 1 + count_list( &(*idl)->next );
}
-char *str_from_nr_list(struct idlist **idl, int number)
+/*@null@*/ char *str_from_nr_list(struct idlist **idl, long number)
/* return the number'th string in idl */
{
if( !*idl || number < 0)
return str_from_nr_list(&(*idl)->next, number-1);
}
-
-char *str_find(struct idlist **idl, int number)
+
+char *str_find(struct idlist **idl, long number)
/* return the id of the given number in the given list. */
{
if (*idl == (struct idlist *) 0)
return(str_find(&(*idl)->next, number));
}
+struct idlist *id_find(struct idlist **idl, long number)
+/* return the id of the given number in the given list. */
+{
+ struct idlist *idp;
+ for (idp = *idl; idp; idp = idp->next)
+ if (idp->val.status.num == number)
+ return(idp);
+ return(0);
+}
+
char *idpair_find(struct idlist **idl, const char *id)
/* return the id of the given id in the given list (caseblind comparison) */
{
return(idpair_find(&(*idl)->next, id));
}
-int delete_str(struct idlist **idl, int num)
+int delete_str(struct idlist **idl, long num)
/* delete given message from given list */
{
struct idlist *idp;
{
struct idlist *idl;
- for (idl = ctl->newsaved; idl; idl = idl->next)
+ for (idl = dofastuidl ? ctl->oldsaved : ctl->newsaved; idl; idl = idl->next)
if (idl->val.status.mark == UID_DELETED)
idl->val.status.mark = UID_EXPUNGED;
}
{
struct idlist *idp;
- report_build(stdout, GT_("New UID list from %s:"), ctl->server.pollname);
- for (idp = ctl->newsaved; idp; idp = idp->next)
- report_build(stdout, " %s = %d", idp->id, idp->val.status.mark);
+ if (dofastuidl)
+ report_build(stdout, GT_("Merged UID list from %s:"), ctl->server.pollname);
+ else
+ report_build(stdout, GT_("New UID list from %s:"), ctl->server.pollname);
+ for (idp = dofastuidl ? ctl->oldsaved : ctl->newsaved; idp; idp = idp->next)
+ report_build(stdout, " %s = %d", (char *)idp->id, idp->val.status.mark);
if (!idp)
report_build(stdout, GT_(" <empty>"));
report_complete(stdout, "\n");
if (ctl->newsaved)
{
/* old state of mailbox may now be irrelevant */
+ struct idlist *temp = ctl->oldsaved;
if (outlevel >= O_DEBUG)
report(stdout, GT_("swapping UID lists\n"));
- free_str_list(&ctl->oldsaved);
ctl->oldsaved = ctl->newsaved;
ctl->newsaved = (struct idlist *) NULL;
+ free_str_list(&temp);
}
- else if (outlevel >= O_DEBUG)
+ /* in fast uidl, there is no need to swap lists: the old state of
+ * mailbox cannot be discarded! */
+ else if (outlevel >= O_DEBUG && !dofastuidl)
report(stdout, GT_("not swapping UID lists, no UIDs seen this query\n"));
}
+void uid_discard_new_list(struct query *ctl)
+/* finish a query which had errors */
+{
+ /* debugging code */
+ if (ctl->server.uidl && outlevel >= O_DEBUG)
+ {
+ struct idlist *idp;
+
+ /* this is now a merged list! the mails which were seen in this
+ * poll are marked here. */
+ report_build(stdout, GT_("Merged UID list from %s:"), ctl->server.pollname);
+ for (idp = ctl->oldsaved; idp; idp = idp->next)
+ report_build(stdout, " %s = %d", (char *)idp->id, idp->val.status.mark);
+ if (!idp)
+ report_build(stdout, GT_(" <empty>"));
+ report_complete(stdout, "\n");
+ }
+
+ if (ctl->newsaved)
+ {
+ /* new state of mailbox is not reliable */
+ if (outlevel >= O_DEBUG)
+ report(stdout, GT_("discarding new UID list\n"));
+ free_str_list(&ctl->newsaved);
+ ctl->newsaved = (struct idlist *) NULL;
+ }
+}
+
+void uid_reset_num(struct query *ctl)
+/* reset the number associated with each id */
+{
+ struct idlist *idp;
+ for (idp = ctl->oldsaved; idp; idp = idp->next)
+ idp->val.status.num = 0;
+}
+
void write_saved_lists(struct query *hostlist, const char *idfile)
/* perform end-of-run write of seen-messages list */
{
- int idcount;
+ long idcount;
FILE *tmpfp;
struct query *ctl;
struct idlist *idp;
/* if all lists are empty, nuke the file */
idcount = 0;
for (ctl = hostlist; ctl; ctl = ctl->next) {
- for (idp = ctl->oldsaved; idp; idp = idp->next)
- if (idp->val.status.mark == UID_SEEN
- || idp->val.status.mark == UID_DELETED)
- idcount++;
+ for (idp = ctl->oldsaved; idp; idp = idp->next)
+ if (idp->val.status.mark == UID_SEEN
+ || idp->val.status.mark == UID_DELETED)
+ idcount++;
}
/* either nuke the file or write updated last-seen IDs */
{
if (outlevel >= O_DEBUG)
report(stdout, GT_("Deleting fetchids file.\n"));
- unlink(idfile);
- }
- else
- {
+ if (unlink(idfile) && errno != ENOENT)
+ report(stderr, GT_("Error deleting %s: %s\n"), idfile, strerror(errno));
+ } else {
+ char *newnam = xmalloc(strlen(idfile) + 2);
+ strcpy(newnam, idfile);
+ strcat(newnam, "_");
if (outlevel >= O_DEBUG)
report(stdout, GT_("Writing fetchids file.\n"));
- if ((tmpfp = fopen(idfile, "w")) != (FILE *)NULL) {
+ (void)unlink(newnam); /* remove file/link first */
+ if ((tmpfp = fopen(newnam, "w")) != (FILE *)NULL) {
+ int errflg;
for (ctl = hostlist; ctl; ctl = ctl->next) {
for (idp = ctl->oldsaved; idp; idp = idp->next)
if (idp->val.status.mark == UID_SEEN
|| idp->val.status.mark == UID_DELETED)
fprintf(tmpfp, "%s@%s %s\n",
- ctl->remotename, ctl->server.queryname, idp->id);
+ ctl->remotename, ctl->server.queryname, (char *)idp->id);
}
for (idp = scratchlist; idp; idp = idp->next)
fputs(idp->id, tmpfp);
+ fflush(tmpfp);
+ errflg = ferror(tmpfp);
fclose(tmpfp);
+ /* if we could write successfully, move into place;
+ * otherwise, drop */
+ if (errflg) {
+ report(stderr, GT_("Error writing to fetchids file %s, old file left in place.\n"), newnam);
+ unlink(newnam);
+ } else {
+ if (rename(newnam, idfile)) {
+ report(stderr, GT_("Cannot rename fetchids file %s to %s: %s\n"), newnam, idfile, strerror(errno));
+ }
+ }
+ } else {
+ report(stderr, GT_("Cannot open fetchids file %s for writing: %s\n"), newnam, strerror(errno));
}
+ free(newnam);
}
}
#endif /* POP3_ENABLE */
projects / ~andy / fetchmail / blobdiff