QSpdyProtocolHandler: don't create QLists of key and value just to iterate over

Just iterate over the QMultiMap directly. Also, now that we use
iterators, the remove operation becomes amortized O(1) instead
of O(logN). The loop could be even O(N) (clean, not amortized)
if QMap had range-erase.

Change-Id: I0cf3511adc3a558e551ddd91e47dabcab376001a
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

1 files changed, 7 insertions, 12 deletions

diff --git a/src/network/access/qspdyprotocolhandler.cpp b/src/network/access/qspdyprotocolhandler.cpp
index 7430ca029d..7d2c0dfef2 100644
--- a/src/network/access/qspdyprotocolhandler.cpp
+++ b/src/network/access/qspdyprotocolhandler.cpp
@@ -288,16 +288,14 @@ bool QSpdyProtocolHandler::sendRequest()
 
     m_channel->state = QHttpNetworkConnectionChannel::WritingState;
 
-    // requests will be ordered by priority (see QMultiMap doc)
-    QList<HttpMessagePair> requests = m_channel->spdyRequestsToSend.values();
-    QList<int> priorities = m_channel->spdyRequestsToSend.keys();
-
-    int requestsToSend = qMin(requests.count(), maxPossibleRequests);
+    int requestsToSend = qMin(m_channel->spdyRequestsToSend.size(), maxPossibleRequests);
 
+    QMultiMap<int, HttpMessagePair>::iterator it = m_channel->spdyRequestsToSend.begin();
+    // requests will be ordered by priority (see QMultiMap doc)
     for (int a = 0; a < requestsToSend; ++a) {
-        HttpMessagePair currentPair = requests.at(a);
-        QHttpNetworkRequest currentRequest = requests.at(a).first;
-        QHttpNetworkReply *currentReply = requests.at(a).second;
+        HttpMessagePair currentPair = *it;
+        QHttpNetworkRequest currentRequest = currentPair.first;
+        QHttpNetworkReply *currentReply = currentPair.second;
 
         currentReply->setSpdyWasUsed(true);
         qint32 streamID = generateNextStreamID();
@@ -310,10 +308,7 @@ bool QSpdyProtocolHandler::sendRequest()
         connect(currentReply, SIGNAL(destroyed(QObject*)), this, SLOT(_q_replyDestroyed(QObject*)));
 
         sendSYN_STREAM(currentPair, streamID, /* associatedToStreamID = */ 0);
-        int requestsRemoved = m_channel->spdyRequestsToSend.remove(
-                    priorities.at(a), currentPair);
-        Q_ASSERT(requestsRemoved == 1);
-        Q_UNUSED(requestsRemoved); // silence -Wunused-variable
+        m_channel->spdyRequestsToSend.erase(it++);
     }
     m_channel->state = QHttpNetworkConnectionChannel::IdleState;
     return true;