Performance|Network|libcore: Keep local IP addresses cached

On some platforms it takes a while to query the IP addresses of all the
available network interfaces. Now this query is done in the background and
the results are cached for quick access.

doomsday/sdk/libcore/src/net/address.cpp

@@ -19,9 +19,9 @@
 
 #include "de/Address"
 #include "de/String"
+#include "networkinterfaces.h"
 
 #include <QHostInfo>
-#include <QNetworkInterface>
 #include <QRegularExpression>
 
 namespace de {
@@ -171,9 +171,9 @@ bool Address::isHostLocal(QHostAddress const &host) // static
     if (host.isLoopback()) return true;
 
     QHostAddress const hostv6(host.toIPv6Address());
-    foreach (QHostAddress addr, QNetworkInterface::allAddresses())
+    foreach (QHostAddress addr, internal::NetworkInterfaces::get().allAddresses())
     {
-        if (QHostAddress(addr.toIPv6Address()) == hostv6)
+        if (addr == hostv6)
             return true;
     }
     return false;

doomsday/sdk/libcore/src/net/beacon.cpp

@@ -22,7 +22,6 @@
 #include "de/LogBuffer"
 #include <QUdpSocket>
 #include <QHostInfo>
-#include <QNetworkInterface>
 #include <QTimer>
 #include <QMap>
 

doomsday/sdk/libcore/src/net/networkinterfaces.cpp

@@ -0,0 +1,97 @@
+/** @file networkinterfaces.cpp  Information about network interfaces.
+ *
+ * @authors Copyright (c) 2017 Jaakko Keränen <jaakko.keranen@iki.fi>
+ *
+ * @par License
+ * LGPL: http://www.gnu.org/licenses/lgpl.html
+ *
+ * <small>This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or (at your
+ * option) any later version. This program is distributed in the hope that it
+ * will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser
+ * General Public License for more details. You should have received a copy of
+ * the GNU Lesser General Public License along with this program; if not, see:
+ * http://www.gnu.org/licenses</small>
+ */
+
+#include "networkinterfaces.h"
+#include "de/Task"
+#include "de/TaskPool"
+
+#include <QNetworkInterface>
+#include <QTimer>
+
+namespace de {
+namespace internal {
+
+DENG2_PIMPL(NetworkInterfaces), public Lockable
+{
+    struct AddressQueryTask : public Task
+    {
+        NetworkInterfaces::Impl *d;
+
+        AddressQueryTask(NetworkInterfaces::Impl *d) : d(d) {}
+
+        void runTask() override
+        {
+            QList<QHostAddress> ipv6;
+            foreach (QHostAddress addr, QNetworkInterface::allAddresses())
+            {
+                ipv6 << QHostAddress(addr.toIPv6Address());
+            }
+
+            // Submit the updated information.
+            {
+                DENG2_GUARD(d);
+                d->addresses = ipv6;
+                d->gotAddresses = true;
+            }
+
+            qDebug() << "Local IP addresses:" << ipv6;
+        }
+    };
+
+    QList<QHostAddress> addresses; // lock before access
+    TaskPool tasks;
+    QTimer updateTimer;
+    bool gotAddresses = false;
+
+    Impl(Public *i) : Base(i)
+    {
+        updateTimer.setInterval(1000 * 60 * 1);
+        updateTimer.setSingleShot(false);
+        QObject::connect(&updateTimer, &QTimer::timeout, [this] ()
+        {
+            tasks.start(new AddressQueryTask(this));
+        });
+        updateTimer.start();
+        tasks.start(new AddressQueryTask(this));
+    }
+};
+
+NetworkInterfaces::NetworkInterfaces()
+    : d(new Impl(this))
+{}
+
+QList<QHostAddress> NetworkInterfaces::allAddresses() const
+{
+    if (!d->gotAddresses)
+    {
+        // Too early...
+        d->tasks.waitForDone();
+    }
+
+    DENG2_GUARD(d);
+    return d->addresses;
+}
+
+NetworkInterfaces &NetworkInterfaces::get() // static
+{
+    static NetworkInterfaces nif;
+    return nif;
+}
+
+} // namespace internal
+} // namespace de

doomsday/sdk/libcore/src/net/networkinterfaces.h

@@ -0,0 +1,57 @@
+/** @file networkinterfaces.h  Information about network interfaces.
+ *
+ * @authors Copyright (c) 2017 Jaakko Keränen <jaakko.keranen@iki.fi>
+ *
+ * @par License
+ * LGPL: http://www.gnu.org/licenses/lgpl.html
+ *
+ * <small>This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or (at your
+ * option) any later version. This program is distributed in the hope that it
+ * will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser
+ * General Public License for more details. You should have received a copy of
+ * the GNU Lesser General Public License along with this program; if not, see:
+ * http://www.gnu.org/licenses</small>
+ */
+
+#ifndef LIBDENG2_NETWORKINTERFACES_H
+#define LIBDENG2_NETWORKINTERFACES_H
+
+#include "de/libcore.h"
+#include <QList>
+#include <QHostAddress>
+
+namespace de {
+namespace internal {
+
+/**
+ * Information abuot network interfaces.
+ *
+ * Maintains a quickly-accessible copy of the network interface data.
+ */
+class NetworkInterfaces
+{
+public:
+    static NetworkInterfaces &get();
+
+public:
+    NetworkInterfaces();
+
+    /**
+     * Returns a cached copy of the list of network addresses for all of the currently
+     * available network interfaces. Updated periodically in the background.
+     *
+     * @return Network interface addresses, in IPv6 format.
+     */
+    QList<QHostAddress> allAddresses() const;
+
+private:
+    DENG2_PRIVATE(d)
+};
+
+} // namespace internal
+} // namespace de
+
+#endif // LIBDENG2_NETWORKINTERFACES_H