[Bluetooth] Optimize loops

Decrease complexity from O(N+N*logN) to just O(N) for cases like

foreach (Key key, map.keys())
    Value value = map.value(key);

, by rewriting with use of iterators.

Change-Id: I81f1334797f16b624293fcebdee885b2be3c89f1
Reviewed-by: Alex Blasche <alexander.blasche@theqtcompany.com>

1 files changed, 7 insertions, 3 deletions

diff --git a/src/bluetooth/qlowenergyservice.cpp b/src/bluetooth/qlowenergyservice.cpp
index 67bd7c77..9fb8e47c 100644
--- a/src/bluetooth/qlowenergyservice.cpp
+++ b/src/bluetooth/qlowenergyservice.cpp
@@ -454,9 +454,13 @@ QLowEnergyService::ServiceTypes QLowEnergyService::type() const
 */
 QLowEnergyCharacteristic QLowEnergyService::characteristic(const QBluetoothUuid &uuid) const
 {
-    foreach (const QLowEnergyHandle handle, d_ptr->characteristicList.keys()) {
-        if (d_ptr->characteristicList[handle].uuid == uuid)
-            return QLowEnergyCharacteristic(d_ptr, handle);
+    CharacteristicDataMap::const_iterator charIt = d_ptr->characteristicList.constBegin();
+    for ( ; charIt != d_ptr->characteristicList.constEnd(); ++charIt) {
+        const QLowEnergyHandle charHandle = charIt.key();
+        const QLowEnergyServicePrivate::CharData &charDetails = charIt.value();
+
+        if (charDetails.uuid == uuid)
+            return QLowEnergyCharacteristic(d_ptr, charHandle);
     }
 
     return QLowEnergyCharacteristic();