From: Phil Carmody <phil@dovecot.fi>
Date: Mon, 2 Jun 2014 11:50:34 +0000 (+0300)
Subject: mail-index: Preparatory HACK - reverse the loop order in the expunge
X-Git-Tag: 2.2.14.rc1~446
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=aba9cc9bf97576c0ca653d4e218567e617061029;p=thirdparty%2Fdovecot%2Fcore.git

mail-index: Preparatory HACK - reverse the loop order in the expunge
This is the final step before the actual optimisation of the memmoves.

HACK, as it it de-optimises the moves so as much as possible gets moved
as many times as possible. It clears the path for a later patch which
optimises them far better.

Based on draft patch by Timo Sirainen.

Signed-off-by: Phil Carmody <phil@dovecot.fi>
---

diff --git a/src/lib-index/mail-index-sync-update.c b/src/lib-index/mail-index-sync-update.c
index 6b7b112e9d..5248cb2683 100644
--- a/src/lib-index/mail-index-sync-update.c
+++ b/src/lib-index/mail-index-sync-update.c
@@ -254,10 +254,10 @@ sync_expunge_range(struct mail_index_sync_map_ctx *ctx, const ARRAY_TYPE(seq_ran
 		}
 	}
 
-	/* do this in reverse so the memmove()s are smaller */
-	for (i = count; i > 0; i--) {
-		uint32_t seq1 = range[i-1].seq1;
-		uint32_t seq2 = range[i-1].seq2;
+	/* Preparatory HACK - do this in forward order so the memmove()s are pessimal! */
+	for (i = 0; i < count; i++) {
+		uint32_t seq1 = range[i].seq1;
+		uint32_t seq2 = range[i].seq2;
 		struct mail_index_record *rec;
 		uint32_t seq_count, seq;