Merge lp:~jonas-drange/ubuntu-ui-extras/dedupe-requests into lp:~phablet-team/ubuntu-ui-extras/printer-components

[Jonas G. Drange]

guards against excessive loading of printers and drivers

guards against excessive loading of printers and drivers

[Andrew Hayzen (ahayzen)]

Looks good, one inline comment.

1) As there is only ever going to be one instance of each printerName in the list, can this not be a QSet ?

review: Needs Information

[lp:~jonas-drange/ubuntu-ui-extras/dedupe-requests]

135. By Jonas G. Drange on 2017-02-24

qlist->qset

[Andrew Hayzen (ahayzen)]

LGTM, prevents multiple threads loading the same printer :-)

review: Approve

=== modified file 'modules/Ubuntu/Components/Extras/Printers/backend/backend_cups.cpp'
--- modules/Ubuntu/Components/Extras/Printers/backend/backend_cups.cpp	2017-02-23 14:04:26 +0000
+++ modules/Ubuntu/Components/Extras/Printers/backend/backend_cups.cpp	2017-02-24 12:53:52 +0000
@@ -613,6 +613,10 @@
 
 void PrinterCupsBackend::requestPrinter(const QString &printerName)
 {
+    if (m_activeRequests.contains(printerName)) {
+        return;
+    }
+
     auto thread = new QThread;
     auto loader = new PrinterLoader(printerName, m_client, m_notifier);
     loader->moveToThread(thread);
@@ -621,8 +625,12 @@
     connect(loader, SIGNAL(finished()), loader, SLOT(deleteLater()));
     connect(loader, SIGNAL(loaded(QSharedPointer<Printer>)),
             this, SIGNAL(printerLoaded(QSharedPointer<Printer>)));
+    connect(loader, SIGNAL(loaded(QSharedPointer<Printer>)),
+            this, SLOT(onPrinterLoaded(QSharedPointer<Printer>)));
     connect(thread, SIGNAL(finished()), thread, SLOT(deleteLater()));
     thread->start();
+
+    m_activeRequests << printerName;
 }
 
 void PrinterCupsBackend::requestPrinterDrivers()
@@ -707,3 +715,8 @@
         return m_ppds[name];
     }
 }
+
+void PrinterCupsBackend::onPrinterLoaded(QSharedPointer<Printer> printer)
+{
+    m_activeRequests.remove(printer->name());
+}

=== modified file 'modules/Ubuntu/Components/Extras/Printers/backend/backend_cups.h'
--- modules/Ubuntu/Components/Extras/Printers/backend/backend_cups.h	2017-02-23 14:04:26 +0000
+++ modules/Ubuntu/Components/Extras/Printers/backend/backend_cups.h	2017-02-24 12:53:52 +0000
@@ -24,6 +24,7 @@
 #include <cups/cups.h>
 
 #include <QPrinterInfo>
+#include <QSet>
 
 class PRINTERS_DECL_EXPORT PrinterCupsBackend : public PrinterBackend
 {
@@ -126,6 +127,10 @@
     int m_cupsSubscriptionId;
     mutable QMap<QString, cups_dest_t*> m_dests; // Printer name, dest.
     mutable QMap<QString, ppd_file_t*> m_ppds; // Printer name, ppd.
+    QSet<QString> m_activeRequests;
+
+private Q_SLOTS:
+    void onPrinterLoaded(QSharedPointer<Printer> printer);
 };
 
 #endif // USC_PRINTERS_CUPS_BACKEND_H

=== modified file 'modules/Ubuntu/Components/Extras/Printers/printers/printers.cpp'
--- modules/Ubuntu/Components/Extras/Printers/printers/printers.cpp	2017-02-23 14:04:26 +0000
+++ modules/Ubuntu/Components/Extras/Printers/printers/printers.cpp	2017-02-24 12:53:52 +0000
@@ -159,7 +159,9 @@
 
 void Printers::prepareToAddPrinter()
 {
-    m_drivers.load();
+    if (m_drivers.rowCount() == 0) {
+        m_drivers.load();
+    }
 }
 
 bool Printers::addPrinter(const QString &name, const QString &ppd,