[dovecot-cvs] dovecot/src/lib-index mail-index.c,1.82,1.83 mail-index.h,1.64,1.65 mail-modifylog.c,1.39,1.40

[cras at procontrol.fi]

Update of /home/cvs/dovecot/src/lib-index
In directory danu:/tmp/cvs-serv6886

Modified Files:
	mail-index.c mail-index.h mail-modifylog.c 
Log Message:
Modify log used to test if there were other users for every changed flag or
expunged message, causing two fcntl() syscalls every time -> SLOW. Now we
check it only once after exclusively locking the index.



Index: mail-index.c
===================================================================
RCS file: /home/cvs/dovecot/src/lib-index/mail-index.c,v
retrieving revision 1.82
retrieving revision 1.83
diff -u -d -r1.82 -r1.83
--- mail-index.c	11 Jan 2003 19:55:56 -0000	1.82
+++ mail-index.c	22 Jan 2003 19:52:17 -0000	1.83
@@ -391,6 +391,7 @@
 		/* while holding exclusive lock, keep the FSCK flag on.
 		   when the lock is released, the FSCK flag will also be
 		   removed. */
+		index->excl_lock_counter++;
 		index->header->flags |= MAIL_INDEX_FLAG_FSCK;
 		if (!mail_index_fmdatasync(index,
 					   sizeof(struct mail_index_header))) {
@@ -421,6 +422,7 @@
 	}
 
 	if (index->lock_type == MAIL_LOCK_EXCLUSIVE) {
+		index->excl_lock_counter++;
 		if (index->modifylog != NULL)
 			mail_modifylog_notify_lock_drop(index->modifylog);
 

Index: mail-index.h
===================================================================
RCS file: /home/cvs/dovecot/src/lib-index/mail-index.h,v
retrieving revision 1.64
retrieving revision 1.65
diff -u -d -r1.64 -r1.65
--- mail-index.h	11 Jan 2003 19:55:56 -0000	1.64
+++ mail-index.h	22 Jan 2003 19:52:17 -0000	1.65
@@ -362,6 +362,9 @@
 	unsigned int indexid;
 	unsigned int sync_id;
 
+        /* updated whenever exclusive lock is set/unset */
+	unsigned int excl_lock_counter;
+
 	int mbox_fd;
 	struct istream *mbox_stream;
 	enum mail_lock_type mbox_lock_type;
@@ -421,7 +424,7 @@
 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, \
 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, \
 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, \
-	0
+	0, 0
 #endif
 
 /* defaults - same as above but prefixed with mail_index_. */

Index: mail-modifylog.c
===================================================================
RCS file: /home/cvs/dovecot/src/lib-index/mail-modifylog.c,v
retrieving revision 1.39
retrieving revision 1.40
diff -u -d -r1.39 -r1.40
--- mail-modifylog.c	9 Jan 2003 12:35:16 -0000	1.39
+++ mail-modifylog.c	22 Jan 2003 19:52:17 -0000	1.40
@@ -60,6 +60,9 @@
 
 	struct modify_log_file file1, file2;
 	struct modify_log_file *head, *tail;
+
+	int cache_have_others;
+	unsigned int cache_lock_counter;
 };
 
 static const struct modify_log_expunge no_expunges = { 0, 0, 0 };
@@ -707,16 +710,32 @@
 	i_assert((*rec)->seq1 != 0);
 	i_assert((*rec)->uid1 != 0);
 
-	if (!external_change) {
+	if (!external_change &&
+	    file->log->cache_lock_counter !=
+	    file->log->index->excl_lock_counter) {
 		switch (modifylog_have_other_users(file->log, FALSE)) {
 		case 0:
 			/* we're the only one having this log open,
 			   no need for modify log. */
+			file->log->cache_have_others = FALSE;
+			file->log->cache_lock_counter =
+				file->log->index->excl_lock_counter;
+
 			*rec = NULL;
 			return TRUE;
 		case -1:
 			return FALSE;
+		default:
+			file->log->cache_have_others = TRUE;
+			file->log->cache_lock_counter =
+				file->log->index->excl_lock_counter;
+			break;
 		}
+	}
+
+	if (!file->log->cache_have_others) {
+		*rec = NULL;
+		return FALSE;
 	}
 
 	if (file->mmap_used_length == file->mmap_full_length) {