QNetworkReplyHttpImpl: convert some QDateTime::currentDateTime() to currentDateTimeUtc()

The latter is much faster as it doesn't have to deal with
time zones.

This change is safe, because the QDateTime is only used to
compare against a copy of itself, adjusted by some seconds,
which doen't care which TZ the date-time is in, to get a
time_t, which is much faster done from a UTC time, and
to calculate the seconds to expirationTime, which, from a
quick glance around, seem to be mostly, if not exclusively,
in UTC. secsTo() works across time zones, but the comparison
between UTC date-times is fastest.

Credits to Milian Wolff, from whose QtWS15 talk this advice is
taken.

Change-Id: I22aa5350b29493f01fb503ef5ec68a964ca95cf3
Reviewed-by: Lars Knoll <lars.knoll@theqtcompany.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/src/network/access/qnetworkreplyhttpimpl.cpp b/src/network/access/qnetworkreplyhttpimpl.cpp
index 63fca2bda2..c29b132217 100644
--- a/src/network/access/qnetworkreplyhttpimpl.cpp
+++ b/src/network/access/qnetworkreplyhttpimpl.cpp
@@ -512,7 +512,7 @@ bool QNetworkReplyHttpImplPrivate::loadFromCacheIfAllowed(QHttpNetworkRequest &h
             return false;
     }
 
-    QDateTime currentDateTime = QDateTime::currentDateTime();
+    QDateTime currentDateTime = QDateTime::currentDateTimeUtc();
     QDateTime expirationDate = metaData.expirationDate();
 
     bool response_is_fresh;
@@ -545,7 +545,7 @@ bool QNetworkReplyHttpImplPrivate::loadFromCacheIfAllowed(QHttpNetworkRequest &h
             date_value = dateHeader.toTime_t();
         }
 
-        int now = currentDateTime.toUTC().toTime_t();
+        int now = currentDateTime.toTime_t();
         int request_time = now;
         int response_time = now;