[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>

15 files changed, 196 insertions, 100 deletions

diff --git a/src/bluetooth/bluez/bluez5_helper.cpp b/src/bluetooth/bluez/bluez5_helper.cpp
index 28b5c12d..384b9979 100644
--- a/src/bluetooth/bluez/bluez5_helper.cpp
+++ b/src/bluetooth/bluez/bluez5_helper.cpp
@@ -302,9 +302,14 @@ QString findAdapterForAddress(const QBluetoothAddress &wantedAddress, bool *ok =
     typedef QPair<QString, QBluetoothAddress> AddressForPathType;
     QList<AddressForPathType> localAdapters;
 
-    foreach (const QDBusObjectPath &path, reply.value().keys()) {
-        const InterfaceList ifaceList = reply.value().value(path);
-        foreach (const QString &iface, ifaceList.keys()) {
+    ManagedObjectList managedObjectList = reply.value();
+    for (ManagedObjectList::const_iterator it = managedObjectList.constBegin(); it != managedObjectList.constEnd(); ++it) {
+        const QDBusObjectPath &path = it.key();
+        const InterfaceList &ifaceList = it.value();
+
+        for (InterfaceList::const_iterator jt = ifaceList.constBegin(); jt != ifaceList.constEnd(); ++jt) {
+            const QString &iface = jt.key();
+
             if (iface == QStringLiteral("org.bluez.Adapter1")) {
                 AddressForPathType pair;
                 pair.first = path.path();
diff --git a/src/bluetooth/qbluetoothdevicediscoveryagent_bluez.cpp b/src/bluetooth/qbluetoothdevicediscoveryagent_bluez.cpp
index 7f477a02..b0fd88d5 100644
--- a/src/bluetooth/qbluetoothdevicediscoveryagent_bluez.cpp
+++ b/src/bluetooth/qbluetoothdevicediscoveryagent_bluez.cpp
@@ -239,9 +239,14 @@ void QBluetoothDeviceDiscoveryAgentPrivate::startBluez5()
     QDBusPendingReply<ManagedObjectList> reply = managerBluez5->GetManagedObjects();
     reply.waitForFinished();
     if (!reply.isError()) {
-        foreach (const QDBusObjectPath &path, reply.value().keys()) {
-            const InterfaceList ifaceList = reply.value().value(path);
-            foreach (const QString &iface, ifaceList.keys()) {
+        ManagedObjectList managedObjectList = reply.value();
+        for (ManagedObjectList::const_iterator it = managedObjectList.constBegin(); it != managedObjectList.constEnd(); ++it) {
+            const QDBusObjectPath &path = it.key();
+            const InterfaceList &ifaceList = it.value();
+
+            for (InterfaceList::const_iterator jt = ifaceList.constBegin(); jt != ifaceList.constEnd(); ++jt) {
+                const QString &iface = jt.key();
+
                 if (iface == QStringLiteral("org.bluez.Device1")) {
 
                     if (path.path().indexOf(adapterBluez5->path()) != 0)
diff --git a/src/bluetooth/qbluetoothlocaldevice_bluez.cpp b/src/bluetooth/qbluetoothlocaldevice_bluez.cpp
index cae21e1b..d2ec70b9 100644
--- a/src/bluetooth/qbluetoothlocaldevice_bluez.cpp
+++ b/src/bluetooth/qbluetoothlocaldevice_bluez.cpp
@@ -213,17 +213,22 @@ QList<QBluetoothHostInfo> QBluetoothLocalDevice::allDevices()
         if (reply.isError())
             return localDevices;
 
-        foreach (const QDBusObjectPath &path, reply.value().keys()) {
-            const InterfaceList ifaceList = reply.value().value(path);
-            foreach (const QString &iface, ifaceList.keys()) {
+        ManagedObjectList managedObjectList = reply.value();
+        for (ManagedObjectList::const_iterator it = managedObjectList.constBegin(); it != managedObjectList.constEnd(); ++it) {
+            const InterfaceList &ifaceList = it.value();
+
+            for (InterfaceList::const_iterator jt = ifaceList.constBegin(); jt != ifaceList.constEnd(); ++jt) {
+                const QString &iface = jt.key();
+                const QVariantMap &ifaceValues = jt.value();
+
                 if (iface == QStringLiteral("org.bluez.Adapter1")) {
                     QBluetoothHostInfo hostInfo;
-                    const QString temp = ifaceList.value(iface).value(QStringLiteral("Address")).toString();
+                    const QString temp = ifaceValues.value(QStringLiteral("Address")).toString();
 
                     hostInfo.setAddress(QBluetoothAddress(temp));
                     if (hostInfo.address().isNull())
                         continue;
-                    hostInfo.setName(ifaceList.value(iface).value(QStringLiteral("Name")).toString());
+                    hostInfo.setName(ifaceValues.value(QStringLiteral("Name")).toString());
                     localDevices.append(hostInfo);
                 }
             }
@@ -447,10 +452,13 @@ void QBluetoothLocalDevicePrivate::requestPairingBluez5(const QBluetoothAddress
         return;
     }
 
+    ManagedObjectList managedObjectList = reply.value();
+    for (ManagedObjectList::const_iterator it = managedObjectList.constBegin(); it != managedObjectList.constEnd(); ++it) {
+        const QDBusObjectPath &path = it.key();
+        const InterfaceList &ifaceList = it.value();
 
-    foreach (const QDBusObjectPath &path, reply.value().keys()) {
-        const InterfaceList ifaceList = reply.value().value(path);
-        foreach (const QString &iface, ifaceList.keys()) {
+        for (InterfaceList::const_iterator jt = ifaceList.constBegin(); jt != ifaceList.constEnd(); ++jt) {
+            const QString &iface = jt.key();
 
             if (iface == QStringLiteral("org.bluez.Device1")) {
 
@@ -603,9 +611,13 @@ QBluetoothLocalDevice::Pairing QBluetoothLocalDevice::pairingStatus(
         if (reply.isError())
             return Unpaired;
 
-        foreach (const QDBusObjectPath &path, reply.value().keys()) {
-            const InterfaceList ifaceList = reply.value().value(path);
-            foreach (const QString &iface, ifaceList.keys()) {
+        ManagedObjectList managedObjectList = reply.value();
+        for (ManagedObjectList::const_iterator it = managedObjectList.constBegin(); it != managedObjectList.constEnd(); ++it) {
+            const QDBusObjectPath &path = it.key();
+            const InterfaceList &ifaceList = it.value();
+
+            for (InterfaceList::const_iterator jt = ifaceList.constBegin(); jt != ifaceList.constEnd(); ++jt) {
+                const QString &iface = jt.key();
 
                 if (iface == QStringLiteral("org.bluez.Device1")) {
 
@@ -670,9 +682,16 @@ void QBluetoothLocalDevicePrivate::connectDeviceChanges()
             return;
 
         OrgFreedesktopDBusPropertiesInterface *monitor = 0;
-        foreach (const QDBusObjectPath &path, reply.value().keys()) {
-            const InterfaceList ifaceList = reply.value().value(path);
-            foreach (const QString &iface, ifaceList.keys()) {
+
+        ManagedObjectList managedObjectList = reply.value();
+        for (ManagedObjectList::const_iterator it = managedObjectList.constBegin(); it != managedObjectList.constEnd(); ++it) {
+            const QDBusObjectPath &path = it.key();
+            const InterfaceList &ifaceList = it.value();
+
+            for (InterfaceList::const_iterator jt = ifaceList.constBegin(); jt != ifaceList.constEnd(); ++jt) {
+                const QString &iface = jt.key();
+                const QVariantMap &ifaceValues = jt.value();
+
                 if (iface == QStringLiteral("org.bluez.Device1")) {
                     monitor = new OrgFreedesktopDBusPropertiesInterface(QStringLiteral("org.bluez"),
                                                                         path.path(),
@@ -681,7 +700,6 @@ void QBluetoothLocalDevicePrivate::connectDeviceChanges()
                             SLOT(PropertiesChanged(QString,QVariantMap,QStringList)));
                     deviceChangeMonitors.insert(path.path(), monitor);
 
-                    const QVariantMap ifaceValues = ifaceList.value(QStringLiteral("org.bluez.Device1"));
                     if (ifaceValues.value(QStringLiteral("Connected"), false).toBool()) {
                         QBluetoothAddress address(ifaceValues.value(QStringLiteral("Address")).toString());
                         connectedDevicesSet.insert(address);
diff --git a/src/bluetooth/qbluetoothservicediscoveryagent_bluez.cpp b/src/bluetooth/qbluetoothservicediscoveryagent_bluez.cpp
index de12e6f2..ae51d681 100644
--- a/src/bluetooth/qbluetoothservicediscoveryagent_bluez.cpp
+++ b/src/bluetooth/qbluetoothservicediscoveryagent_bluez.cpp
@@ -652,14 +652,18 @@ void QBluetoothServiceDiscoveryAgentPrivate::performMinimalServiceDiscovery(cons
     }
 
     QStringList uuidStrings;
-    foreach (const QDBusObjectPath &path, reply.value().keys()) {
-        const InterfaceList ifaceList = reply.value().value(path);
-        foreach (const QString &iface, ifaceList.keys()) {
+
+    ManagedObjectList managedObjectList = reply.value();
+    for (ManagedObjectList::const_iterator it = managedObjectList.constBegin(); it != managedObjectList.constEnd(); ++it) {
+        const InterfaceList &ifaceList = it.value();
+
+        for (InterfaceList::const_iterator jt = ifaceList.constBegin(); jt != ifaceList.constEnd(); ++jt) {
+            const QString &iface = jt.key();
+            const QVariantMap &ifaceValues = jt.value();
+
             if (iface == QStringLiteral("org.bluez.Device1")) {
-                const QVariantMap details = ifaceList.value(iface);
-                if (deviceAddress.toString()
-                        == details.value(QStringLiteral("Address")).toString()) {
-                    uuidStrings = details.value(QStringLiteral("UUIDs")).toStringList();
+                if (deviceAddress.toString() == ifaceValues.value(QStringLiteral("Address")).toString()) {
+                    uuidStrings = ifaceValues.value(QStringLiteral("UUIDs")).toStringList();
                     break;
                 }
             }
diff --git a/src/bluetooth/qbluetoothserviceinfo.cpp b/src/bluetooth/qbluetoothserviceinfo.cpp
index d6cc633b..fefb2549 100644
--- a/src/bluetooth/qbluetoothserviceinfo.cpp
+++ b/src/bluetooth/qbluetoothserviceinfo.cpp
@@ -375,7 +375,7 @@ bool QBluetoothServiceInfo::isValid() const
 */
 bool QBluetoothServiceInfo::isComplete() const
 {
-    return d_ptr->attributes.keys().contains(ProtocolDescriptorList);
+    return d_ptr->attributes.contains(ProtocolDescriptorList);
 }
 
 /*!
diff --git a/src/bluetooth/qbluetoothserviceinfo_osx.mm b/src/bluetooth/qbluetoothserviceinfo_osx.mm
index 743fb377..d79156e2 100644
--- a/src/bluetooth/qbluetoothserviceinfo_osx.mm
+++ b/src/bluetooth/qbluetoothserviceinfo_osx.mm
@@ -309,7 +309,7 @@ bool QBluetoothServiceInfo::isValid() const
 
 bool QBluetoothServiceInfo::isComplete() const
 {
-    return d_ptr->attributes.keys().contains(ProtocolDescriptorList);
+    return d_ptr->attributes.contains(ProtocolDescriptorList);
 }
 
 QBluetoothDeviceInfo QBluetoothServiceInfo::device() const
diff --git a/src/bluetooth/qbluetoothsocket_bluez.cpp b/src/bluetooth/qbluetoothsocket_bluez.cpp
index 6947e9d0..71f26296 100644
--- a/src/bluetooth/qbluetoothsocket_bluez.cpp
+++ b/src/bluetooth/qbluetoothsocket_bluez.cpp
@@ -384,13 +384,17 @@ QString QBluetoothSocketPrivate::peerName() const
         if (reply.isError())
             return QString();
 
-        foreach (const QDBusObjectPath &path, reply.value().keys()) {
-            const InterfaceList ifaceList = reply.value().value(path);
-            foreach (const QString &iface, ifaceList.keys()) {
+        ManagedObjectList managedObjectList = reply.value();
+        for (ManagedObjectList::const_iterator it = managedObjectList.constBegin(); it != managedObjectList.constEnd(); ++it) {
+            const InterfaceList &ifaceList = it.value();
+
+            for (InterfaceList::const_iterator jt = ifaceList.constBegin(); jt != ifaceList.constEnd(); ++jt) {
+                const QString &iface = jt.key();
+                const QVariantMap &ifaceValues = jt.value();
+
                 if (iface == QStringLiteral("org.bluez.Device1")) {
-                    if (ifaceList.value(iface).value(QStringLiteral("Address")).toString()
-                            == peerAddress)
-                        return ifaceList.value(iface).value(QStringLiteral("Alias")).toString();
+                    if (ifaceValues.value(QStringLiteral("Address")).toString() == peerAddress)
+                        return ifaceValues.value(QStringLiteral("Alias")).toString();
                 }
             }
         }
diff --git a/src/bluetooth/qlowenergycharacteristic.cpp b/src/bluetooth/qlowenergycharacteristic.cpp
index aba4a66b..885b1337 100644
--- a/src/bluetooth/qlowenergycharacteristic.cpp
+++ b/src/bluetooth/qlowenergycharacteristic.cpp
@@ -338,11 +338,18 @@ QLowEnergyDescriptor QLowEnergyCharacteristic::descriptor(const QBluetoothUuid &
     if (d_ptr.isNull() || !data)
         return QLowEnergyDescriptor();
 
-    QList<QLowEnergyHandle> descriptorKeys = d_ptr->characteristicList[data->handle].
-                                                    descriptorList.keys();
-    foreach (const QLowEnergyHandle descHandle, descriptorKeys) {
-        if (uuid == d_ptr->characteristicList[data->handle].descriptorList[descHandle].uuid)
-            return QLowEnergyDescriptor(d_ptr, data->handle, descHandle);
+    CharacteristicDataMap::const_iterator charIt = d_ptr->characteristicList.constFind(data->handle);
+    if (charIt != d_ptr->characteristicList.constEnd()) {
+        const QLowEnergyServicePrivate::CharData &charDetails = charIt.value();
+
+        DescriptorDataMap::const_iterator descIt = charDetails.descriptorList.constBegin();
+        for ( ; descIt != charDetails.descriptorList.constEnd(); ++descIt) {
+            const QLowEnergyHandle descHandle = descIt.key();
+            const QLowEnergyServicePrivate::DescData &descDetails = descIt.value();
+
+            if (descDetails.uuid == uuid)
+                return QLowEnergyDescriptor(d_ptr, data->handle, descHandle);
+        }
     }
 
     return QLowEnergyDescriptor();
diff --git a/src/bluetooth/qlowenergycontroller.cpp b/src/bluetooth/qlowenergycontroller.cpp
index 44b6a6da..99a3724e 100644
--- a/src/bluetooth/qlowenergycontroller.cpp
+++ b/src/bluetooth/qlowenergycontroller.cpp
@@ -339,13 +339,18 @@ quint16 QLowEnergyControllerPrivate::updateValueOfCharacteristic(
         QLowEnergyHandle charHandle,const QByteArray &value, bool appendValue)
 {
     QSharedPointer<QLowEnergyServicePrivate> service = serviceForHandle(charHandle);
-    if (!service.isNull() && service->characteristicList.contains(charHandle)) {
-        if (appendValue)
-            service->characteristicList[charHandle].value += value;
-        else
-            service->characteristicList[charHandle].value = value;
+    if (!service.isNull()) {
+        CharacteristicDataMap::iterator charIt = service->characteristicList.find(charHandle);
+        if (charIt != service->characteristicList.end()) {
+            QLowEnergyServicePrivate::CharData &charDetails = charIt.value();
 
-        return service->characteristicList[charHandle].value.size();
+            if (appendValue)
+                charDetails.value += value;
+            else
+                charDetails.value = value;
+
+            return charDetails.value.size();
+        }
     }
 
     return 0;
@@ -359,18 +364,26 @@ quint16 QLowEnergyControllerPrivate::updateValueOfDescriptor(
         const QByteArray &value, bool appendValue)
 {
     QSharedPointer<QLowEnergyServicePrivate> service = serviceForHandle(charHandle);
-    if (service.isNull() || !service->characteristicList.contains(charHandle))
-        return 0;
-
-    if (!service->characteristicList[charHandle].descriptorList.contains(descriptorHandle))
-        return 0;
-
-    if (appendValue)
-        service->characteristicList[charHandle].descriptorList[descriptorHandle].value += value;
-    else
-        service->characteristicList[charHandle].descriptorList[descriptorHandle].value = value;
+    if (!service.isNull()) {
+        CharacteristicDataMap::iterator charIt = service->characteristicList.find(charHandle);
+        if (charIt != service->characteristicList.end()) {
+            QLowEnergyServicePrivate::CharData &charDetails = charIt.value();
+
+            DescriptorDataMap::iterator descIt = charDetails.descriptorList.find(descriptorHandle);
+            if (descIt != charDetails.descriptorList.end()) {
+                QLowEnergyServicePrivate::DescData &descDetails = descIt.value();
+
+                if (appendValue)
+                    descDetails.value += value;
+                else
+                    descDetails.value = value;
+
+                return descDetails.value.size();
+            }
+        }
+    }
 
-    return service->characteristicList[charHandle].descriptorList[descriptorHandle].value.size();
+    return 0;
 }
 
 /*!
@@ -641,11 +654,15 @@ QLowEnergyService *QLowEnergyController::createServiceObject(
         const QBluetoothUuid &serviceUuid, QObject *parent)
 {
     Q_D(QLowEnergyController);
-    if (!d->serviceList.contains(serviceUuid))
-        return 0;
 
-    QLowEnergyService *service = new QLowEnergyService(
-                d->serviceList.value(serviceUuid), parent);
+    QLowEnergyService *service = Q_NULLPTR;
+
+    ServiceDataMap::const_iterator it = d->serviceList.constFind(serviceUuid);
+    if (it != d->serviceList.constEnd()) {
+        const QSharedPointer<QLowEnergyServicePrivate> &serviceData = it.value();
+
+        service = new QLowEnergyService(serviceData, parent);
+    }
 
     return service;
 }
diff --git a/src/bluetooth/qlowenergycontroller_android.cpp b/src/bluetooth/qlowenergycontroller_android.cpp
index f48c0e85..b04ddedd 100644
--- a/src/bluetooth/qlowenergycontroller_android.cpp
+++ b/src/bluetooth/qlowenergycontroller_android.cpp
@@ -453,9 +453,11 @@ void QLowEnergyControllerPrivate::descriptorRead(
             serviceList.value(serviceUuid);
 
     bool entryUpdated = false;
-    foreach (QLowEnergyHandle charHandle, service->characteristicList.keys()) {
-        QLowEnergyServicePrivate::CharData &charDetails =
-                service->characteristicList[charHandle];
+
+    CharacteristicDataMap::iterator charIt = service->characteristicList.begin();
+    for ( ; charIt != service->characteristicList.end(); ++charIt) {
+        QLowEnergyServicePrivate::CharData &charDetails = charIt.value();
+
         if (charDetails.uuid != charUuid)
             continue;
 
diff --git a/src/bluetooth/qlowenergycontroller_bluez.cpp b/src/bluetooth/qlowenergycontroller_bluez.cpp
index 8906eb06..a7b2e794 100644
--- a/src/bluetooth/qlowenergycontroller_bluez.cpp
+++ b/src/bluetooth/qlowenergycontroller_bluez.cpp
@@ -1151,12 +1151,11 @@ void QLowEnergyControllerPrivate::readServiceValues(
 
     // Create list of attribute handles which need to be read
     QList<QPair<QLowEnergyHandle, quint32> > targetHandles;
-    const QList<QLowEnergyHandle> keys = service->characteristicList.keys();
-    for (int i = 0; i < keys.count(); i++) {
-        const QLowEnergyHandle charHandle = keys[i];
-        const QLowEnergyServicePrivate::CharData &charDetails =
-                service->characteristicList[charHandle];
 
+    CharacteristicDataMap::const_iterator charIt = service->characteristicList.constBegin();
+    for ( ; charIt != service->characteristicList.constEnd(); ++charIt) {
+        const QLowEnergyHandle charHandle = charIt.key();
+        const QLowEnergyServicePrivate::CharData &charDetails = charIt.value();
 
         if (readCharacteristics) {
             // Collect handles of all characteristic value attributes
@@ -1171,7 +1170,10 @@ void QLowEnergyControllerPrivate::readServiceValues(
 
         } else {
             // Collect handles of all descriptor attributes
-            foreach (QLowEnergyHandle descriptorHandle, charDetails.descriptorList.keys()) {
+            DescriptorDataMap::const_iterator descIt = charDetails.descriptorList.constBegin();
+            for ( ; descIt != charDetails.descriptorList.constEnd(); ++descIt) {
+                const QLowEnergyHandle descriptorHandle = descIt.key();
+
                 pair.first = descriptorHandle;
                 pair.second = (charHandle | (descriptorHandle << 16));
                 targetHandles.append(pair);
@@ -1270,15 +1272,15 @@ void QLowEnergyControllerPrivate::discoverServiceDescriptors(
     qCDebug(QT_BT_BLUEZ) << "Discovering descriptor values for"
                          << serviceUuid.toString();
     QSharedPointer<QLowEnergyServicePrivate> service = serviceList.value(serviceUuid);
-    // start handle of all known characteristics
-    QList<QLowEnergyHandle> keys = service->characteristicList.keys();
 
-    if (keys.isEmpty()) { // service has no characteristics
+    if (service->characteristicList.isEmpty()) { // service has no characteristics
         // implies that characteristic & descriptor discovery can be skipped
         service->setState(QLowEnergyService::ServiceDiscovered);
         return;
     }
 
+    // start handle of all known characteristics
+    QList<QLowEnergyHandle> keys = service->characteristicList.keys();
     std::sort(keys.begin(), keys.end());
 
     discoverNextDescriptor(service, keys, keys[0]);
diff --git a/src/bluetooth/qlowenergycontroller_osx.mm b/src/bluetooth/qlowenergycontroller_osx.mm
index c4628069..d0d65248 100644
--- a/src/bluetooth/qlowenergycontroller_osx.mm
+++ b/src/bluetooth/qlowenergycontroller_osx.mm
@@ -277,7 +277,9 @@ void QLowEnergyControllerPrivateOSX::serviceDiscoveryFinished(LEServices service
         qCDebug(QT_BT_OSX) << Q_FUNC_INFO << "no services found";
     }
 
-    foreach (const QBluetoothUuid &uuid, discoveredServices.keys()) {
+    for (ServiceMap::const_iterator it = discoveredServices.constBegin(); it != discoveredServices.constEnd(); ++it) {
+        const QBluetoothUuid &uuid = it.key();
+
         QMetaObject::invokeMethod(q_ptr, "serviceDiscovered", Qt::QueuedConnection,
                                  Q_ARG(QBluetoothUuid, uuid));
     }
@@ -642,13 +644,18 @@ quint16 QLowEnergyControllerPrivateOSX::updateValueOfCharacteristic(QLowEnergyHa
                                                                     bool appendValue)
 {
     QSharedPointer<QLowEnergyServicePrivate> service = serviceForHandle(charHandle);
-    if (!service.isNull() && service->characteristicList.contains(charHandle)) {
-        if (appendValue)
-            service->characteristicList[charHandle].value += value;
-        else
-            service->characteristicList[charHandle].value = value;
+    if (!service.isNull()) {
+        CharacteristicDataMap::iterator charIt = service->characteristicList.find(charHandle);
+        if (charIt != service->characteristicList.end()) {
+            QLowEnergyServicePrivate::CharData &charData = charIt.value();
+
+            if (appendValue)
+                charData.value += value;
+            else
+                charData.value = value;
 
-        return service->characteristicList[charHandle].value.size();
+            return charData.value.size();
+        }
     }
 
     return 0;
@@ -693,19 +700,27 @@ void QLowEnergyControllerPrivateOSX::writeDescriptor(QSharedPointer<QLowEnergySe
 quint16 QLowEnergyControllerPrivateOSX::updateValueOfDescriptor(QLowEnergyHandle charHandle, QLowEnergyHandle descHandle,
                                                                 const QByteArray &value, bool appendValue)
 {
-    ServicePrivate service(serviceForHandle(charHandle));
-    if (service.isNull() || !service->characteristicList.contains(charHandle))
-        return 0;
+    QSharedPointer<QLowEnergyServicePrivate> service = serviceForHandle(charHandle);
+    if (!service.isNull()) {
+        CharacteristicDataMap::iterator charIt = service->characteristicList.find(charHandle);
+        if (charIt != service->characteristicList.end()) {
+            QLowEnergyServicePrivate::CharData &charData = charIt.value();
 
-    if (!service->characteristicList[charHandle].descriptorList.contains(descHandle))
-        return 0;
+            DescriptorDataMap::iterator descIt = charData.descriptorList.find(descHandle);
+            if (descIt != charData.descriptorList.end()) {
+                QLowEnergyServicePrivate::DescData &descDetails = descIt.value();
 
-    if (appendValue)
-        service->characteristicList[charHandle].descriptorList[descHandle].value += value;
-    else
-        service->characteristicList[charHandle].descriptorList[descHandle].value = value;
+                if (appendValue)
+                    descDetails.value += value;
+                else
+                    descDetails.value = value;
 
-    return service->characteristicList[charHandle].descriptorList[descHandle].value.size();
+                return descDetails.value.size();
+            }
+        }
+    }
+
+    return 0;
 }
 
 QSharedPointer<QLowEnergyServicePrivate> QLowEnergyControllerPrivateOSX::serviceForHandle(QLowEnergyHandle handle)
@@ -952,10 +967,16 @@ QLowEnergyService *QLowEnergyController::createServiceObject(const QBluetoothUui
 {
     OSX_D_PTR;
 
-    if (!osx_d_ptr->discoveredServices.contains(serviceUuid))
-        return Q_NULLPTR;
+    QLowEnergyService *service = Q_NULLPTR;
+
+    QLowEnergyControllerPrivateOSX::ServiceMap::const_iterator it = osx_d_ptr->discoveredServices.constFind(serviceUuid);
+    if (it != osx_d_ptr->discoveredServices.constEnd()) {
+        const QSharedPointer<QLowEnergyServicePrivate> &serviceData = it.value();
+
+        service = new QLowEnergyService(serviceData, parent);
+    }
 
-    return new QLowEnergyService(osx_d_ptr->discoveredServices.value(serviceUuid), parent);
+    return service;
 }
 
 QLowEnergyController::Error QLowEnergyController::error() const
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();
diff --git a/src/bluetooth/qlowenergyservice_osx.mm b/src/bluetooth/qlowenergyservice_osx.mm
index 78861dc1..da1636cb 100644
--- a/src/bluetooth/qlowenergyservice_osx.mm
+++ b/src/bluetooth/qlowenergyservice_osx.mm
@@ -104,9 +104,13 @@ QLowEnergyService::ServiceState QLowEnergyService::state() 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();
diff --git a/src/bluetooth/qlowenergyserviceprivate_p.h b/src/bluetooth/qlowenergyserviceprivate_p.h
index a020341f..0232b912 100644
--- a/src/bluetooth/qlowenergyserviceprivate_p.h
+++ b/src/bluetooth/qlowenergyserviceprivate_p.h
@@ -104,6 +104,9 @@ public:
     QPointer<QLowEnergyControllerPrivate> controller;
 };
 
+typedef QHash<QLowEnergyHandle, QLowEnergyServicePrivate::CharData> CharacteristicDataMap;
+typedef QHash<QLowEnergyHandle, QLowEnergyServicePrivate::DescData> DescriptorDataMap;
+
 QT_END_NAMESPACE
 
 Q_DECLARE_METATYPE(QSharedPointer<QLowEnergyServicePrivate>)