PeakCAN: Use new device enumeration method from PCAN-Basic 4.4.0

So far only available for Windows, where the new code is much
faster. On my system, it takes 115 ms to enumerate both channels
of a PCAN USB Pro FD, instead of 901 ms withthe old method.
If no PCAN device is connected at all, it returns in 10 ms.
(Measured on Windows 7 Pro x64 in VirtualBox with Linux host).

On Linux, it has already been blazing fast with the old
enumeration code.

[ChangeLog][PeakCAN] QCanBusDevice::availableDevices() uses
PCAN_ATTACHED_CHANNELS on Windows now and gained a massive
speedup. The required PCAN-Basic-API is now 4.4.0 therefore.

Fixes: QTBUG-82115
Change-Id: Ic95b2f632110b0b1374b6eaa402cd228f278cdf2
Reviewed-by: Alex Blasche <alexander.blasche@qt.io>

4 files changed, 86 insertions, 3 deletions

diff --git a/src/plugins/canbus/peakcan/peakcan_symbols_p.h b/src/plugins/canbus/peakcan/peakcan_symbols_p.h
index 3618365..9031592 100644
--- a/src/plugins/canbus/peakcan/peakcan_symbols_p.h
+++ b/src/plugins/canbus/peakcan/peakcan_symbols_p.h
@@ -1,6 +1,7 @@
 /****************************************************************************
 **
 ** Copyright (C) 2017 Denis Shienkov <denis.shienkov@gmail.com>
+** Copyright (c) 2020 Andre Hartmann <aha_1980@gmx.de>
 ** Copyright (C) 2017 The Qt Company Ltd.
 ** Contact: http://www.qt.io/licensing/
 **
@@ -197,6 +198,8 @@
 #define PCAN_BUSSPEED_DATA       0x1BU  // Configured CAN data speed as Bits per seconds
 #define PCAN_IP_ADDRESS          0x1CU  // Remote address of a LAN channel as string in IPv4 format
 #define PCAN_LAN_SERVICE_STATUS  0x1DU  // Status of the Virtual PCAN-Gateway Service
+#define PCAN_ATTACHED_CHANNELS_COUNT  0x2AU  // Get the amount of PCAN channels attached to a system
+#define PCAN_ATTACHED_CHANNELS        0x2BU  // Get information about PCAN channels attached to a system
 
 #define FEATURE_FD_CAPABLE       0x01U  // Device supports flexible data-rate (CAN-FD)
 
@@ -225,6 +228,10 @@
 #define TRACE_FILE_TIME          0x04U  // Includes the start time into the name of the trace file
 #define TRACE_FILE_OVERWRITE     0x80U  // Causes the overwriting of available traces (same name)
 
+// Other constants
+#define MAX_LENGTH_HARDWARE_NAME      33     // Maximum length of the name of a device: 32 characters + terminator
+#define MAX_LENGTH_VERSION_STRING     18     // Maximum length of a version string: 17 characters + terminator
+
 // PCAN message types
 #define PCAN_MESSAGE_STANDARD    0x00U  // The PCAN message is a CAN Standard Frame (11-bit identifier)
 #define PCAN_MESSAGE_RTR         0x01U  // The PCAN message is a CAN Remote-Transfer-Request Frame
@@ -312,6 +319,18 @@ typedef struct tagTPCANMsgFD
     quint8            DATA[64]; // Data of the message (DATA[0]..DATA[63])
 } TPCANMsgFD;
 
+// Describes an available PCAN channel
+typedef struct tagTPCANChannelInformation
+{
+    TPCANHandle channel_handle;                 // PCAN channel handle
+    TPCANDevice device_type;                    // Kind of PCAN device
+    quint8 controller_number;                   // CAN-Controller number
+    quint32 device_features;                    // Device capabilities flag (see FEATURE_*)
+    char device_name[MAX_LENGTH_HARDWARE_NAME]; // Device name
+    quint32 device_id;                          // Device number
+    quint32 channel_condition;                  // Availability status of a PCAN-Channel
+} TPCANChannelInformation;
+
 #define GENERATE_SYMBOL_VARIABLE(returnType, symbolName, ...) \
     typedef returnType (DRV_CALLBACK_TYPE *fp_##symbolName)(__VA_ARGS__); \
     static fp_##symbolName symbolName;
diff --git a/src/plugins/canbus/peakcan/peakcanbackend.cpp b/src/plugins/canbus/peakcan/peakcanbackend.cpp
index 8154157..82177af 100644
--- a/src/plugins/canbus/peakcan/peakcanbackend.cpp
+++ b/src/plugins/canbus/peakcan/peakcanbackend.cpp
@@ -1,6 +1,7 @@
 /****************************************************************************
 **
 ** Copyright (C) 2017 Denis Shienkov <denis.shienkov@gmail.com>
+** Copyright (c) 2020 Andre Hartmann <aha_1980@gmx.de>
 ** Copyright (C) 2017 The Qt Company Ltd.
 ** Contact: http://www.qt.io/licensing/
 **
@@ -44,8 +45,10 @@
 #include <QtCore/qtimer.h>
 #include <QtCore/qcoreevent.h>
 #include <QtCore/qloggingcategory.h>
+#include <QtCore/qscopeguard.h>
 
 #include <algorithm>
+#include <vector>
 
 #ifdef Q_OS_WIN32
 #   include <QtCore/qwineventnotifier.h>
@@ -126,7 +129,7 @@ static const PcanChannel pcanChannels[] = {
     { "none",  PCAN_NONEBUS  }
 };
 
-QList<QCanBusDeviceInfo> PeakCanBackend::interfaces()
+QList<QCanBusDeviceInfo> PeakCanBackend::interfacesByChannelCondition()
 {
     QList<QCanBusDeviceInfo> result;
 
@@ -168,6 +171,65 @@ QList<QCanBusDeviceInfo> PeakCanBackend::interfaces()
     return result;
 }
 
+QList<QCanBusDeviceInfo> PeakCanBackend::interfacesByAttachedChannels(bool *ok)
+{
+    *ok = true;
+    quint32 count = 0;
+    const TPCANStatus countStat = ::CAN_GetValue(0, PCAN_ATTACHED_CHANNELS_COUNT,
+                                                 &count, sizeof(count));
+    if (Q_UNLIKELY(countStat != PCAN_ERROR_OK)) {
+        qCWarning(QT_CANBUS_PLUGINS_PEAKCAN, "Cannot query PCAN_ATTACHED_CHANNELS_COUNT.");
+        *ok = false;
+        return {};
+    }
+    if (count == 0)
+        return {};
+
+    std::vector<TPCANChannelInformation> infos(count);
+    const TPCANStatus infosStat = ::CAN_GetValue(0, PCAN_ATTACHED_CHANNELS, infos.data(),
+                                                 infos.size() * sizeof(TPCANChannelInformation));
+    if (Q_UNLIKELY(infosStat != PCAN_ERROR_OK)) {
+        qCWarning(QT_CANBUS_PLUGINS_PEAKCAN, "Cannot query PCAN_ATTACHED_CHANNELS.");
+        *ok = false;
+        return {};
+    }
+
+    QList<QCanBusDeviceInfo> result;
+    for (quint32 i = 0; i < count; ++i) {
+        auto info = infos[i];
+        if (info.channel_condition & PCAN_CHANNEL_AVAILABLE) {
+            const quint32 deviceId = info.channel_handle;
+            const auto pcanChannel = std::find_if(std::begin(pcanChannels), std::end(pcanChannels),
+                                                  [deviceId](PcanChannel channel) {
+                return channel.index == deviceId;
+            });
+            const QString name = pcanChannel->name;
+            const QString description = info.device_name;
+            const QString alias = QString::number(info.device_id);
+            const int channel = info.controller_number;
+            const bool isCanFd = (info.device_features & FEATURE_FD_CAPABLE);
+
+            result.append(std::move(createDeviceInfo(name, QString(), description, alias,
+                                                     channel, false, isCanFd)));
+        }
+    }
+
+    return result;
+}
+
+QList<QCanBusDeviceInfo> PeakCanBackend::interfaces()
+{
+#ifdef Q_OS_WIN
+    bool ok = false;
+    const QList<QCanBusDeviceInfo> attachedChannelsResult = interfacesByAttachedChannels(&ok);
+    if (ok)
+        return attachedChannelsResult;
+#endif
+
+    const QList<QCanBusDeviceInfo> result = interfacesByChannelCondition();
+    return result;
+}
+
 #if defined(Q_OS_WIN32)
 class PeakCanReadNotifier : public QWinEventNotifier
 {
diff --git a/src/plugins/canbus/peakcan/peakcanbackend.h b/src/plugins/canbus/peakcan/peakcanbackend.h
index a9e108e..0ee74c3 100644
--- a/src/plugins/canbus/peakcan/peakcanbackend.h
+++ b/src/plugins/canbus/peakcan/peakcanbackend.h
@@ -69,6 +69,8 @@ public:
     QString interpretErrorFrame(const QCanBusFrame &errorFrame) override;
 
     static bool canCreate(QString *errorReason);
+    static QList<QCanBusDeviceInfo> interfacesByChannelCondition();
+    static QList<QCanBusDeviceInfo> interfacesByAttachedChannels(bool *ok);
     static QList<QCanBusDeviceInfo> interfaces();
 
 private:
diff --git a/src/serialbus/doc/src/peakcan.qdoc b/src/serialbus/doc/src/peakcan.qdoc
index 8189c90..c10263b 100644
--- a/src/serialbus/doc/src/peakcan.qdoc
+++ b/src/serialbus/doc/src/peakcan.qdoc
@@ -34,8 +34,8 @@
     \l{http://www.peak-system.com/}{PEAK-System} CAN adapters.
 
     This plugin requires the PCAN device drivers and the PCAN-Basic library
-    version 4.0.0 or higher on Windows (pcanbasic.dll) and Linux (libpcanbasic.so).
-    On macOS the plugin requires the PCBUSB library from
+    version 4.4.0 or higher on Windows (pcanbasic.dll) resp. 4.0.0 on Linux
+    (libpcanbasic.so). On macOS the plugin requires the PCBUSB library from
     \l{http://www.mac-can.com}{UV Software}.
 
     \note QCanBusDeviceInfo::alias() is only supported on Windows and with