dovecot-2.1: maildir: Avoid refreshing uidlist unnecessarily.

[dovecot at dovecot.org]

details:   http://hg.dovecot.org/dovecot-2.1/rev/4124c28db2a4
changeset: 13401:4124c28db2a4
user:      Timo Sirainen <tss at iki.fi>
date:      Mon Sep 05 12:46:49 2011 +0300
description:
maildir: Avoid refreshing uidlist unnecessarily.
Even if the uidlist itself wasn't read, it was still stat()ed.

diffstat:

 src/lib-storage/index/maildir/maildir-storage.h |   1 +
 src/lib-storage/index/maildir/maildir-sync.c    |  36 +++++++++++++-----------
 2 files changed, 20 insertions(+), 17 deletions(-)

diffs (67 lines):

diff -r ae7a7282af83 -r 4124c28db2a4 src/lib-storage/index/maildir/maildir-storage.h
--- a/src/lib-storage/index/maildir/maildir-storage.h	Mon Sep 05 11:48:11 2011 +0300
+++ b/src/lib-storage/index/maildir/maildir-storage.h	Mon Sep 05 12:46:49 2011 +0300
@@ -93,6 +93,7 @@
 	unsigned int private_flags_mask_set:1;
 	unsigned int backend_readonly:1;
 	unsigned int backend_readonly_set:1;
+	unsigned int sync_uidlist_refreshed:1;
 };
 
 extern struct mail_vfuncs maildir_mail_vfuncs;
diff -r ae7a7282af83 -r 4124c28db2a4 src/lib-storage/index/maildir/maildir-sync.c
--- a/src/lib-storage/index/maildir/maildir-sync.c	Mon Sep 05 11:48:11 2011 +0300
+++ b/src/lib-storage/index/maildir/maildir-sync.c	Mon Sep 05 12:46:49 2011 +0300
@@ -942,26 +942,27 @@
 	int ret;
 
 	ret = maildir_uidlist_lookup(mbox->uidlist, uid, flags_r, fname_r);
-	if (ret <= 0) {
-		if (ret < 0)
+	if (ret != 0)
+		return ret;
+
+	if (maildir_uidlist_is_open(mbox->uidlist)) {
+		/* refresh uidlist and check again in case it was added
+		   after the last mailbox sync */
+		if (mbox->sync_uidlist_refreshed) {
+			/* we've already refreshed it, don't bother again */
+			return ret;
+		}
+		mbox->sync_uidlist_refreshed = TRUE;
+		if (maildir_uidlist_refresh(mbox->uidlist) < 0)
 			return -1;
-		if (maildir_uidlist_is_open(mbox->uidlist)) {
-			/* refresh uidlist and check again in case it was added
-			   after the last mailbox sync */
-			if (maildir_uidlist_refresh(mbox->uidlist) < 0)
-				return -1;
-		} else {
-			/* the uidlist doesn't exist. */
-			if (maildir_storage_sync_force(mbox, uid) < 0)
-				return -1;
-		}
-
-		/* try again */
-		ret = maildir_uidlist_lookup(mbox->uidlist, uid,
-					     flags_r, fname_r);
+	} else {
+		/* the uidlist doesn't exist. */
+		if (maildir_storage_sync_force(mbox, uid) < 0)
+			return -1;
 	}
 
-	return ret;
+	/* try again */
+	return maildir_uidlist_lookup(mbox->uidlist, uid, flags_r, fname_r);
 }
 
 int maildir_storage_sync_force(struct maildir_mailbox *mbox, uint32_t uid)
@@ -1046,6 +1047,7 @@
 		maildir_uidlist_set_all_nonsynced(mbox->uidlist);
 	}
 	mbox->synced = TRUE;
+	mbox->sync_uidlist_refreshed = FALSE;
 	return index_mailbox_sync_init(box, flags, ret < 0);
 }