dovecot: If we can do initial sync from .log file by reading les...

[dovecot at dovecot.org]

details:   http://hg.dovecot.org/dovecot/rev/fb91e7d729d1
changeset: 5851:fb91e7d729d1
user:      Timo Sirainen <tss at iki.fi>
date:      Sun Jul 01 01:40:25 2007 +0300
description:
If we can do initial sync from .log file by reading less than 2k, do it
instead of opening main index file.

diffstat:

1 file changed, 14 insertions(+), 3 deletions(-)
src/lib-index/mail-index-sync-update.c |   17 ++++++++++++++---

diffs (36 lines):

diff -r f8caf3c6a5a7 -r fb91e7d729d1 src/lib-index/mail-index-sync-update.c
--- a/src/lib-index/mail-index-sync-update.c	Sun Jul 01 01:05:40 2007 +0300
+++ b/src/lib-index/mail-index-sync-update.c	Sun Jul 01 01:40:25 2007 +0300
@@ -8,6 +8,10 @@
 #include "mail-index-sync-private.h"
 #include "mail-transaction-log.h"
 #include "mail-transaction-log-private.h"
+
+/* If we have less than this many bytes to sync from log file, don't bother
+   reading the main index */
+#define MAIL_INDEX_SYNC_MIN_READ_INDEX_SIZE 2048
 
 static void
 mail_index_sync_update_log_offset(struct mail_index_sync_map_ctx *ctx,
@@ -706,11 +710,18 @@ int mail_index_sync_map(struct mail_inde
 		   syncing the current map from the transaction log */
 		uoff_t log_size, index_size;
 
-		if (index->log->head == NULL || index->fd == -1)
+		if (index->log->head == NULL)
 			return 0;
 
-		index_size = map->hdr.header_size +
-			map->records_count * map->hdr.record_size;
+		if (index->fd == -1 &&
+		    index->log->head->hdr.prev_file_seq != 0) {
+			/* we don't know the index's size, so use the
+			   smallest index size we're willing to read */
+			index_size = MAIL_INDEX_SYNC_MIN_READ_INDEX_SIZE;
+		} else {
+			index_size = map->hdr.header_size +
+				map->records_count * map->hdr.record_size;
+		}
 
 		/* this isn't necessary correct currently, but it should be
 		   close enough */