refs #442 Add CPluginManager class

src/blackcore/context_simulator_impl.cpp

@@ -13,6 +13,7 @@
 #include "context_settings.h"
 #include "context_application.h"
 #include "context_network_impl.h"
+#include "plugin_manager.h"
 #include "context_runtime.h"
 #include "blackcore/blackcorefreefunctions.h"
 #include "blackmisc/propertyindexvariantmap.h"
@@ -53,21 +54,12 @@ namespace BlackCore
 
         if (!plugin->factory)
         {
-            QPluginLoader loader(plugin->fileName);
-            QObject *instance = loader.instance();
-            if (instance)
+            CPluginManager *pm = CPluginManager::getInstance();
+            ISimulatorFactory *factory = qobject_cast<ISimulatorFactory *>(pm->getPluginById(plugin->identifier));
+            if (factory)
             {
-                ISimulatorFactory *factory = qobject_cast<ISimulatorFactory *>(instance);
-                if (factory)
-                {
-                    plugin->factory = factory;
-                    CLogMessage(this).info("Loaded driver: %1") << plugin->info.toQString();
-                }
-            }
-            else
-            {
-                QString errorMsg = loader.errorString().append(" ").append("Also check if required dll/libs of plugin exists");
-                CLogMessage(this).error(errorMsg);
+                plugin->factory = factory;
+                CLogMessage(this).info("Loaded driver: %1") << plugin->info.toQString();
             }
         }
 
@@ -692,39 +684,25 @@ namespace BlackCore
 
     void CContextSimulator::findSimulatorPlugins()
     {
-        const QString path = qApp->applicationDirPath().append("/plugins/simulator");
-        m_pluginsDir = QDir(path);
-        if (!m_pluginsDir.exists())
-        {
-            CLogMessage(this).error("No plugin directory: %1") << m_pluginsDir.currentPath();
-            return;
-        }
+        CPluginManager *pm = CPluginManager::getInstance();
+        auto plugins = pm->plugins("org.swift-project.blackcore.simulatorinterface");
 
-        QStringList fileNames = m_pluginsDir.entryList(QDir::Files);
-        fileNames.sort(Qt::CaseInsensitive); // give a certain order, rather than random file order
-        for (const auto &fileName : fileNames)
+        std::for_each(plugins.begin(), plugins.end(), [this](const QJsonObject &json)
         {
-            if (!QLibrary::isLibrary(fileName))
+            QString identifier = json.value("MetaData").toObject().value("identifier").toString();
+            Q_ASSERT(!identifier.isEmpty());
+            CSimulatorPluginInfo info;
+            info.convertFromJson(json);
+            if (info.isValid())
             {
-                continue;
-            }
-
-            CLogMessage(this).debug() << "Try to load plugin: " << fileName;
-            QString pluginPath = m_pluginsDir.absoluteFilePath(fileName);
-            QPluginLoader loader(pluginPath);
-            QJsonObject json = loader.metaData();
-            CSimulatorPluginInfo simulatorPluginInfo;
-            simulatorPluginInfo.convertFromJson(json);
-            if (simulatorPluginInfo.isValid())
-            {
-                m_simulatorPlugins << PluginData { simulatorPluginInfo, nullptr, nullptr, nullptr, pluginPath};
-                CLogMessage(this).debug() << "Found simulator driver: " << simulatorPluginInfo.toQString();
+                m_simulatorPlugins << PluginData { info, nullptr, nullptr, nullptr, identifier };
+                CLogMessage(this).debug() << "Found simulator driver: " << info.toQString();
             }
             else
             {
-                CLogMessage(this).warning("Simulator driver in %1 is invalid") << pluginPath;
+                CLogMessage(this).warning("Simulator driver in %1 is invalid") << identifier;
             }
-        }
+        });
     }
 
     void CContextSimulator::stopSimulatorListeners()

src/blackcore/context_simulator_impl.h

@@ -182,14 +182,14 @@ namespace BlackCore
         //! \todo Would we want to use m_member style here?
         struct PluginData
         {
-            PluginData(const BlackMisc::Simulation::CSimulatorPluginInfo &info, ISimulatorFactory *factory, ISimulatorListener *listener, ISimulator *simulator, const QString &fileName) :
-                info(info), factory(factory), listener(listener), simulator(simulator), fileName(fileName) {}
+            PluginData(const BlackMisc::Simulation::CSimulatorPluginInfo &info, ISimulatorFactory *factory, ISimulatorListener *listener, ISimulator *simulator, const QString &identifier) :
+                info(info), factory(factory), listener(listener), simulator(simulator), identifier(identifier) {}
 
             BlackMisc::Simulation::CSimulatorPluginInfo info;
             ISimulatorFactory *factory = nullptr;   //!< Lazy-loaded, nullptr by default
             ISimulatorListener *listener = nullptr; //!< Listener instance, nullptr by default
             ISimulator *simulator = nullptr;        //!< The simulator itself (always nullptr unless it is the currently working one)
-            QString fileName;                       //!< Plugin file name (relative to plugins/simulator)
+            QString identifier = QString();         //!< The plugin identifier
             QHash<QString, BlackMisc::CVariant> m_storage; //!< Permanent plugin storage - data stored here will be kept even when plugin is unloaded
         };
 

src/blackcore/plugin_manager.cpp

@@ -0,0 +1,131 @@
+/* Copyright (C) 2013
+ * swift Project Community / Contributors
+ *
+ * This file is part of swift project. It is subject to the license terms in the LICENSE file found in the top-level
+ * directory of this distribution and at http://www.swift-project.org/license.html. No part of swift project,
+ * including this file, may be copied, modified, propagated, or distributed except according to the terms
+ * contained in the LICENSE file.
+ */
+
+#include "plugin_manager.h"
+#include "blackmisc/logmessage.h"
+#include "blackmisc/loghandler.h"
+#include <QCoreApplication>
+#include <QDir>
+#include <QDirIterator>
+#include <QLibrary>
+
+using namespace BlackMisc;
+
+namespace BlackCore {
+
+    BlackMisc::CSequence<QJsonObject> CPluginManager::plugins(const QString &iid) const
+    {
+        return m_metadatas.values(iid);
+    }
+
+    QObject *CPluginManager::getPluginById(const QString &identifier)
+    {
+        if (m_instances.contains(identifier))
+        {
+            return m_instances.value(identifier);
+        }
+
+        if (!m_paths.contains(identifier))
+        {
+            CLogMessage(this).warning("Plugin with id %1 does not exist") << identifier;
+            return nullptr;
+        }
+
+        QString path = m_paths.value(identifier);
+        QPluginLoader loader(path);
+        QObject *instance = loader.instance();
+        if (instance)
+        {
+            m_instances.insert(identifier, instance);
+            return instance;
+        }
+        else
+        {
+            CLogMessage(this).error(loader.errorString());
+            return nullptr;
+        }
+    }
+
+    CPluginManager *CPluginManager::getInstance()
+    {
+        static CPluginManager *instance = nullptr;
+        if (!instance)
+        {
+            instance = new CPluginManager();
+        }
+        return instance;
+    }
+
+    CPluginManager::CPluginManager(QObject *parent) : QObject(parent)
+    {
+        collectPlugins();
+
+        connect(qApp, &QCoreApplication::aboutToQuit, this, &CPluginManager::deleteLater);
+    }
+
+    void CPluginManager::collectPlugins()
+    {
+        QDir pluginDir(qApp->applicationDirPath().append("/plugins"));
+        if (!pluginDir.exists())
+        {
+            CLogMessage(this).warning("No plugins directory: %1") << pluginDir.path();
+            return;
+        }
+
+        QDirIterator it(pluginDir, QDirIterator::Subdirectories);
+        while (it.hasNext())
+        {
+            if (!QLibrary::isLibrary(it.next()))
+            {
+                continue;
+            }
+
+            CLogMessage(this).debug() << "Loading plugin: " << it.filePath();
+            QPluginLoader loader(it.filePath());
+            QJsonObject json = loader.metaData();
+            QString identifier = pluginIdentifier(json);
+            if (identifier.isEmpty())
+            {
+                CLogMessage(this).warning("Plugin %1 invalid, not loading it") << it.filePath();
+                continue;
+            }
+
+            m_paths.insert(identifier, it.filePath());
+            m_metadatas.insert(json["IID"].toString(), json);
+        }
+    }
+
+    QString CPluginManager::pluginIdentifier(const QJsonObject &metadata)
+    {
+        if (!metadata.contains("IID") || !metadata["IID"].isString())
+        {
+            return QString();
+        }
+
+        if (!metadata["MetaData"].isObject())
+        {
+            return QString();
+        }
+
+        QJsonObject data = metadata["MetaData"].toObject();
+        if (!data.contains("identifier"))
+        {
+            return QString();
+        }
+
+        QJsonValue identifier = data["identifier"];
+        if (!identifier.isString())
+        {
+            return QString();
+        }
+
+        return identifier.toString();
+    }
+
+} // namespace

src/blackcore/plugin_manager.h

@@ -0,0 +1,65 @@
+/* Copyright (C) 2013
+ * swift Project Community / Contributors
+ *
+ * This file is part of swift project. It is subject to the license terms in the LICENSE file found in the top-level
+ * directory of this distribution and at http://www.swift-project.org/license.html. No part of swift project,
+ * including this file, may be copied, modified, propagated, or distributed except according to the terms
+ * contained in the LICENSE file.
+ */
+
+//! \file
+
+#ifndef CPLUGINMANAGER_H
+#define CPLUGINMANAGER_H
+
+#include "blackmisc/sequence.h"
+#include <QObject>
+#include <QMultiMap>
+#include <QJsonObject>
+
+namespace BlackCore
+{
+
+    /*!
+     * \brief Manages all installed plugins, provides easy access to all of them.
+     * Plugin loading works as follows:
+     *  1. Collect all interesting plugins by their IID (\ref plugins());
+     *      all plugins are guaranteed to be valid, i.e. they have valid IID and identifier.
+     *  2. Load specified plugin (\ref getPluginById()).
+     */
+    class CPluginManager : public QObject
+    {
+        Q_OBJECT
+
+    public:
+        //! Retrieves plugin metadata list for the given IID.
+        //! If no implementations are found, the empty list is returned.
+        BlackMisc::CSequence<QJsonObject> plugins(const QString &iid) const;
+
+        //! Loads the given plugin (if necessary) and returns its instance.
+        //! Returns _nullptr_ on failure.
+        QObject *getPluginById(const QString &identifier);
+
+        //! Gets the singleton
+        static CPluginManager *getInstance();
+
+    protected:
+        //! Constructor
+        explicit CPluginManager(QObject *parent = nullptr);
+
+    private:
+        //! Looks (recursively) for all installed plugins
+        void collectPlugins();
+
+        //! Checks whether the provided metadata is valid
+        //! \return The plugin identifier
+        QString pluginIdentifier(const QJsonObject &metadata);
+
+        QMultiMap<QString, QJsonObject> m_metadatas; //!< IID <-> metadata pairs
+        QMap<QString, QString> m_paths; //!< identifier <-> file path pairs
+        QMap<QString, QObject*> m_instances; //!< identifier <-> instance pairs
+
+    };
+}
+
+#endif // CPLUGINMANAGER_H