-/*
- * uid.c -- UIDL handling for POP3 servers without LAST
+/**
+ * \file uid.c -- UIDL handling for POP3 servers without LAST
*
* For license terms, see the file COPYING in this directory.
*/
#include "fetchmail.h"
#include "i18n.h"
+#include "sdump.h"
/*
* Machinery for handling UID lists live here. This is mainly to support
* be picked up by the next run. If there are no un-expunged
* messages, the file is deleted.
*
+ * 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!
*/
-/* UIDs associated with un-queried hosts */
-static struct idlist *scratchlist;
+int dofastuidl = 0;
#ifdef POP3_ENABLE
+/** UIDs associated with un-queried hosts */
+static struct idlist *scratchlist;
+
+/** Read saved IDs from \a idfile and attach to each host in \a hostlist. */
void initialize_saved_lists(struct query *hostlist, const char *idfile)
-/* read file of saved IDs and attach to each host */
{
struct stat statbuf;
FILE *tmpfp;
if (lstat(idfile, &statbuf) < 0) {
if (errno == ENOTDIR)
{
- report(stderr, GT_("lstat: %s: %s\n"), idfile, strerror(errno));
+ report(stderr, "lstat: %s: %s\n", idfile, strerror(errno));
exit(PS_IOERR);
}
}
* the rightmost '@'. This is not correct, as InterMail puts an
* '@' in the UIDL.
*/
-
+
/* first, skip leading spaces */
user = buf + strspn(buf, " \t");
* 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.
+ * host will follow with the ' ' separator with the id.
+ *
+ * XXX FIXME: There is a case this code cannot handle:
+ * the user name cannot have blanks after a '@'.
*/
if ((delimp1 = strchr(user, '@')) != NULL &&
(id = strchr(delimp1,' ')) != NULL)
id = id + strspn(id, " ");
delimp1++; /* but what if there is only white space ?!? */
- saveddelim1 = *delimp1; /* save char after token */
+ /* we have at least one @, else we are not in this branch */
+ saveddelim1 = *delimp1; /* save char after token */
*delimp1 = '\0'; /* delimit token with \0 */
- if (id != NULL)
- {
- /* now remove trailing white space chars from id */
- if ((delimp2 = strpbrk(id, " \t\n")) != NULL ) {
- saveddelim2 = *delimp2;
- *delimp2 = '\0';
- }
- atsign = strrchr(user, '@');
- if (atsign) {
- *atsign = '\0';
- host = atsign + 1;
- }
- for (ctl = hostlist; ctl; ctl = ctl->next) {
- if (strcasecmp(host, ctl->server.queryname) == 0
+ /* now remove trailing white space chars from id */
+ if ((delimp2 = strpbrk(id, " \t\n")) != NULL ) {
+ saveddelim2 = *delimp2;
+ *delimp2 = '\0';
+ }
+
+ atsign = strrchr(user, '@');
+ /* we have at least one @, else we are not in this branch */
+ *atsign = '\0';
+ host = atsign + 1;
+
+ /* find proper list and save it */
+ for (ctl = hostlist; ctl; ctl = ctl->next) {
+ if (strcasecmp(host, ctl->server.queryname) == 0
&& strcasecmp(user, ctl->remotename) == 0) {
-
- save_str(&ctl->oldsaved, id, UID_SEEN);
- break;
- }
+ save_str(&ctl->oldsaved, id, UID_SEEN);
+ break;
}
- /*
- * If it's not in a host we're querying,
- * save it anyway. Otherwise we'd lose UIDL
- * information any time we queried an explicit
- * subset of hosts.
- */
- if (ctl == (struct query *)NULL) {
- /* restore string */
- *delimp1 = saveddelim1;
- *atsign = '@';
- if (delimp2 != NULL) {
- *delimp2 = saveddelim2;
- }
- save_str(&scratchlist, buf, UID_SEEN);
+ }
+ /*
+ * If it's not in a host we're querying,
+ * save it anyway. Otherwise we'd lose UIDL
+ * information any time we queried an explicit
+ * subset of hosts.
+ */
+ if (ctl == (struct query *)NULL) {
+ /* restore string */
+ *delimp1 = saveddelim1;
+ *atsign = '@';
+ if (delimp2 != NULL) {
+ *delimp2 = saveddelim2;
}
+ save_str(&scratchlist, buf, UID_SEEN);
}
}
}
if (outlevel >= O_DEBUG)
{
struct idlist *idp;
- int uidlcount = 0;
for (ctl = hostlist; ctl; ctl = ctl->next)
- if (ctl->server.uidl)
{
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);
+ idp = ctl->oldsaved;
if (!idp)
report_build(stdout, GT_(" <empty>"));
+ else for (idp = ctl->oldsaved; idp; idp = idp->next) {
+ char *t = sdump(idp->id, strlen(idp->id)-1);
+ report_build(stdout, " %s\n", t);
+ free(t);
+ }
report_complete(stdout, "\n");
- uidlcount++;
}
- if (uidlcount)
- {
- report_build(stdout, GT_("Scratch list of UIDs:"));
- for (idp = scratchlist; idp; idp = idp->next)
- report_build(stdout, " %s", idp->id);
- if (!idp)
+ report_build(stdout, GT_("Scratch list of UIDs:"));
+ if (!scratchlist)
report_build(stdout, GT_(" <empty>"));
- report_complete(stdout, "\n");
+ else for (idp = scratchlist; idp; idp = idp->next) {
+ char *t = sdump(idp->id, strlen(idp->id)-1);
+ report_build(stdout, " %s\n", t);
+ free(t);
}
+ report_complete(stdout, "\n");
}
}
-#endif /* POP3_ENABLE */
-
-/* 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@*/ 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;
-
- /* do it nonrecursively so the list is in the right order */
- for (end = idl; *end; end = &(*end)->next)
- continue;
-
- *end = (struct idlist *)xmalloc(sizeof(struct idlist));
- (*end)->val.status.mark = status;
- (*end)->id = (unsigned char *)str;
- (*end)->next = NULL;
-
- 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;
-
- free_str_list(&(*idl)->next);
- free ((*idl)->id);
- free(*idl);
- *idl = (struct idlist *)NULL;
-}
-
-void save_str_pair(struct idlist **idl, const char *str1, const char *str2)
-/* save an ID pair on the given list */
-{
- struct idlist **end;
-
- /* do it nonrecursively so the list is in the right order */
- for (end = idl; *end; end = &(*end)->next)
- continue;
-
- *end = (struct idlist *)xmalloc(sizeof(struct idlist));
- (*end)->id = str1 ? xstrdup(str1) : (char *)NULL;
- if (str2)
- (*end)->val.id2 = xstrdup(str2);
- else
- (*end)->val.id2 = (char *)NULL;
- (*end)->next = (struct idlist *)NULL;
-}
-
-#ifdef __UNUSED__
-void free_str_pair_list(struct idlist **idl)
-/* free the given ID pair list */
-{
- if (*idl == (struct idlist *)NULL)
- return;
-
- free_idpair_list(&(*idl)->next);
- free ((*idl)->id);
- free ((*idl)->val.id2);
- free(*idl);
- *idl = (struct idlist *)NULL;
-}
-#endif
-
-int str_in_list(struct idlist **idl, const char *str, const flag caseblind)
-/* is a given ID in the given list? (comparison may be caseblind) */
-{
- struct idlist *walk;
- if (caseblind) {
- for( walk = *idl; walk; walk = walk->next )
- if( strcasecmp( str, (char *)walk->id) == 0 )
- return 1;
- } else {
- for( walk = *idl; walk; walk = walk->next )
- if( strcmp( str, (char *)walk->id) == 0 )
- return 1;
- }
- return 0;
-}
-
-int str_nr_in_list( struct idlist **idl, const char *str )
- /* return the position of str in idl */
-{
- int nr;
- struct idlist *walk;
- if ( !str )
- return -1;
- for( walk = *idl, nr = 0; walk; nr ++, walk = walk->next )
- if( strcmp( str, walk->id) == 0 )
- return nr;
- return -1;
-}
-
-int str_nr_last_in_list( struct idlist **idl, const char *str)
-/* return the last position of str in idl */
-{
- int nr, ret = -1;
- struct idlist *walk;
- if ( !str )
- return -1;
- for( walk = *idl, nr = 0; walk; nr ++, walk = walk->next )
- if( strcmp( str, walk->id) == 0 )
- ret = nr;
- return ret;
-}
-void str_set_mark( struct idlist **idl, const char *str, const flag val)
-/* update the mark on an of an id to given value */
-{
- int nr;
- struct idlist *walk;
- if (!str)
- return;
- for(walk = *idl, nr = 0; walk; nr ++, walk = walk->next)
- if (strcmp(str, walk->id) == 0)
- walk->val.status.mark = val;
-}
-
-int count_list( struct idlist **idl)
-/* count the number of elements in the list */
-{
- if( !*idl )
- return 0;
- return 1 + count_list( &(*idl)->next );
-}
-
-/*@null@*/ char *str_from_nr_list(struct idlist **idl, long number)
-/* return the number'th string in idl */
-{
- if( !*idl || number < 0)
- return 0;
- if( number == 0 )
- return (*idl)->id;
- return str_from_nr_list(&(*idl)->next, number-1);
-}
-
-
-char *str_find(struct idlist **idl, long number)
-/* return the id of the given number in the given list. */
+/** Assert that all UIDs marked deleted in query \a ctl have actually been
+expunged. */
+void expunge_uids(struct query *ctl)
{
- if (*idl == (struct idlist *) 0)
- return((char *) 0);
- else if (number == (*idl)->val.status.num)
- return((*idl)->id);
- else
- return(str_find(&(*idl)->next, number));
-}
+ struct idlist *idl;
-char *idpair_find(struct idlist **idl, const char *id)
-/* return the id of the given id in the given list (caseblind comparison) */
-{
- if (*idl == (struct idlist *) 0)
- return((char *) 0);
- else if (strcasecmp(id, (*idl)->id) == 0)
- return((*idl)->val.id2 ? (*idl)->val.id2 : (*idl)->id);
- else
- return(idpair_find(&(*idl)->next, id));
+ for (idl = dofastuidl ? ctl->oldsaved : ctl->newsaved; idl; idl = idl->next)
+ if (idl->val.status.mark == UID_DELETED)
+ idl->val.status.mark = UID_EXPUNGED;
}
-int delete_str(struct idlist **idl, long num)
-/* delete given message from given list */
+static const char *str_uidmark(int mark)
{
- struct idlist *idp;
-
- for (idp = *idl; idp; idp = idp->next)
- if (idp->val.status.num == num)
- {
- idp->val.status.mark = UID_DELETED;
- return(1);
+ static char buf[20];
+
+ switch(mark) {
+ case UID_UNSEEN:
+ return "UNSEEN";
+ case UID_SEEN:
+ return "SEEN";
+ case UID_EXPUNGED:
+ return "EXPUNGED";
+ case UID_DELETED:
+ return "DELETED";
+ default:
+ if (snprintf(buf, sizeof(buf), "MARK=%d", mark) < 0)
+ return "ERROR";
+ else
+ return buf;
}
- return(0);
-}
-
-struct idlist *copy_str_list(struct idlist *idl)
-/* copy the given UID list */
-{
- struct idlist *newnode ;
-
- if (idl == (struct idlist *)NULL)
- return(NULL);
- else
- {
- newnode = (struct idlist *)xmalloc(sizeof(struct idlist));
- memcpy(newnode, idl, sizeof(struct idlist));
- newnode->next = copy_str_list(idl->next);
- return(newnode);
- }
}
-void append_str_list(struct idlist **idl, struct idlist **nidl)
-/* append nidl to idl (does not copy *) */
-{
- if ((*nidl) == (struct idlist *)NULL || *nidl == *idl)
- return;
- else if ((*idl) == (struct idlist *)NULL)
- *idl = *nidl;
- else if ((*idl)->next == (struct idlist *)NULL)
- (*idl)->next = *nidl;
- else if ((*idl)->next != *nidl)
- append_str_list(&(*idl)->next, nidl);
-}
-
-#ifdef POP3_ENABLE
-void expunge_uids(struct query *ctl)
-/* assert that all UIDs marked deleted have actually been expunged */
+static void dump_list(const struct idlist *idp)
{
- struct idlist *idl;
-
- for (idl = ctl->newsaved; idl; idl = idl->next)
- if (idl->val.status.mark == UID_DELETED)
- idl->val.status.mark = UID_EXPUNGED;
+ if (!idp) {
+ report_build(stdout, GT_(" <empty>"));
+ } else while (idp) {
+ char *t = sdump(idp->id, strlen(idp->id));
+ report_build(stdout, " %s = %s%s", t, str_uidmark(idp->val.status.mark), idp->next ? "," : "");
+ free(t);
+ idp = idp->next;
+ }
}
-void uid_swap_lists(struct query *ctl)
/* finish a query */
+void uid_swap_lists(struct query *ctl)
{
/* debugging code */
- if (ctl->server.uidl && outlevel >= O_DEBUG)
+ if (outlevel >= O_DEBUG)
{
- 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 (!idp)
- report_build(stdout, GT_(" <empty>"));
+ if (dofastuidl) {
+ report_build(stdout, GT_("Merged UID list from %s:"), ctl->server.pollname);
+ dump_list(ctl->oldsaved);
+ } else {
+ report_build(stdout, GT_("New UID list from %s:"), ctl->server.pollname);
+ dump_list(ctl->newsaved);
+ }
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"));
}
+/* finish a query which had errors */
+void uid_discard_new_list(struct query *ctl)
+{
+ /* debugging code */
+ if (outlevel >= O_DEBUG)
+ {
+ /* 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);
+ dump_list(ctl->oldsaved);
+ 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;
+ }
+}
+
+/** Reset the number associated with each id */
+void uid_reset_num(struct query *ctl)
+{
+ struct idlist *idp;
+ for (idp = ctl->oldsaved; idp; idp = idp->next)
+ idp->val.status.num = 0;
+}
+
+/** Write list of seen messages, at end of run. */
void write_saved_lists(struct query *hostlist, const char *idfile)
-/* perform end-of-run write of seen-messages list */
{
long idcount;
FILE *tmpfp;
/* either nuke the file or write updated last-seen IDs */
if (!idcount && !scratchlist)
{
- if (outlevel >= O_DEBUG)
- report(stdout, GT_("Deleting fetchids file.\n"));
- unlink(idfile);
- }
- else
- {
+ if (outlevel >= O_DEBUG) {
+ if (access(idfile, F_OK) == 0)
+ report(stdout, GT_("Deleting fetchids file.\n"));
+ }
+ if (unlink(idfile) && errno != ENOENT)
+ report(stderr, GT_("Error deleting %s: %s\n"), idfile, strerror(errno));
+ } else {
+ char *newnam = (char *)xmalloc(strlen(idfile) + 2);
+ strcpy(newnam, idfile);
+ strcat(newnam, "_");
if (outlevel >= O_DEBUG)
report(stdout, GT_("Writing fetchids file.\n"));
- /* FIXME: do not overwrite the old idfile */
- if ((tmpfp = fopen(idfile, "w")) != (FILE *)NULL) {
+ (void)unlink(newnam); /* remove file/link first */
+ if ((tmpfp = fopen(newnam, "w")) != (FILE *)NULL) {
+ int errflg = 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)
- fprintf(tmpfp, "%s@%s %s\n",
- ctl->remotename, ctl->server.queryname, idp->id);
+ if (fprintf(tmpfp, "%s@%s %s\n",
+ ctl->remotename, ctl->server.queryname, idp->id) < 0) {
+ int e = errno;
+ report(stderr, GT_("Write error on fetchids file %s: %s\n"), newnam, strerror(e));
+ errflg = 1;
+ goto bailout;
+ }
}
for (idp = scratchlist; idp; idp = idp->next)
- fputs(idp->id, tmpfp);
+ if (EOF == fputs(idp->id, tmpfp)) {
+ int e = errno;
+ report(stderr, GT_("Write error on fetchids file %s: %s\n"), newnam, strerror(e));
+ errflg = 1;
+ goto bailout;
+ }
+
+bailout:
+ (void)fflush(tmpfp); /* return code ignored, we check ferror instead */
+ 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