add template for plugin system

sources/queued/QueuedConfig.h.in

@@ -84,6 +84,17 @@ const char LIB_INSTALL_DIR[] = "@LIB_INSTALL_DIR@";
  * @brief the same as CMAKE_INSTALL_PREFIX
  */
 const char ROOT_INSTALL_DIR[] = "@CMAKE_INSTALL_PREFIX@";
+// application specific
+/**
+ * @def HOME_PATH
+ * path to queued home directory
+ */
+const char HOME_PATH[] = "queued";
+/**
+ * @def PLUGIN_PATH
+ * path to plugins inside @ref HOME_PATH
+ */
+const char PLUGIN_PATH[] = "plugins";
 
 // internal configuration
 /**

sources/queued/include/queued/Queued.h

@@ -36,6 +36,9 @@
 #include "QueuedEnums.h"
 #include "QueuedExceptions.h"
 #include "QueuedLimits.h"
+#include "QueuedPluginInterface.h"
+#include "QueuedPluginManager.h"
+#include "QueuedPluginManagerInterface.h"
 #include "QueuedProcess.h"
 #include "QueuedProcessManager.h"
 #include "QueuedReportManager.h"

sources/queued/include/queued/QueuedPluginInterface.h

@@ -0,0 +1,62 @@
+/*
+ * Copyright (c) 2016 Evgeniy Alekseev
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ *
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ */
+/**
+ * @file QueuedPluginInterface.h
+ * Header of Queued library
+ * @author Evgeniy Alekseev
+ * @copyright MIT
+ * @bug https://github.com/arcan1s/queued/issues
+ */
+
+
+#ifndef QUEUEDPLUGININTERFACE_H
+#define QUEUEDPLUGININTERFACE_H
+
+#include <QtPlugin>
+
+#include "QueuedConfig.h"
+
+
+class QueuedPluginManagerInterface;
+
+/**
+ * @brief plugin interface for queued
+ */
+class QueuedPluginInterface
+{
+public:
+    /**
+     * @brief QueuedPluginInterface class destructor
+     */
+    virtual ~QueuedPluginInterface(){};
+    /**
+     * @brief will be emitted to map interface signals to plugin slots
+     * @param _manager
+     * pointer to manager interface object
+     */
+    virtual void connect(const QueuedPluginManagerInterface *_manager) = 0;
+    /**
+     * @brief plugin initialization method
+     * @param _settings
+     * plugin settings structure from database
+     * @remark plugin settings will be stored as "plugin.name.Key"
+     */
+    virtual void init(const QVariantHash &_settings) = 0;
+};
+
+Q_DECLARE_INTERFACE(QueuedPluginInterface, PLUGIN_INTERFACE_NAME)
+
+
+#endif /* QUEUEDPLUGININTERFACE_H */

sources/queued/include/queued/QueuedPluginManager.h

@@ -0,0 +1,97 @@
+/*
+ * Copyright (c) 2016 Evgeniy Alekseev
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ *
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ */
+/**
+ * @file QueuedPluginManager.h
+ * Header of Queued library
+ * @author Evgeniy Alekseev
+ * @copyright MIT
+ * @bug https://github.com/arcan1s/queued/issues
+ */
+
+
+#ifndef QUEUEDPLUGINMANAGER_H
+#define QUEUEDPLUGINMANAGER_H
+
+#include <QHash>
+#include <QObject>
+
+
+class QueuedPluginInterface;
+class QueuedPluginManagerInterface;
+
+/**
+ * @brief report manager for queued
+ */
+class QueuedPluginManager : public QObject
+{
+    Q_OBJECT
+
+public:
+    /**
+     * @typedef QueuedPluginMap
+     * map of names to QueuedPluginInterface pointers
+     */
+    typedef QHash<QString, QueuedPluginInterface *> QueuedPluginMap;
+
+    /**
+     * @brief QueuedPluginManager class constructor
+     * @param parent
+     * pointer to parent item
+     */
+    explicit QueuedPluginManager(QObject *parent);
+    /**
+     * @brief QueuedPluginManager class destructor
+     */
+    virtual ~QueuedPluginManager();
+    /**
+     * @brief plugin manager interface
+     * @return pointer to plugin manager interface
+     */
+    QueuedPluginManagerInterface *interface();
+    /**
+     * @brief load plugin
+     * @param _name
+     * plugin name
+     * @param _settings
+     * plugin settings
+     * @return true on success load otherwise return false
+     */
+    bool loadPlugin(const QString &_name, const QVariantHash &_settings);
+    /**
+     * @brief path to plugin location
+     * @return full path to plugin location
+     */
+    QStringList pluginLocations() const;
+    /**
+     * @brief unload plugin
+     * @param _name
+     * plugin name
+     * @return true on success unload otherwise return false
+     */
+    bool unloadPlugin(const QString &_name);
+
+private:
+    /**
+     * @brief loaded plugins
+     */
+    QueuedPluginMap m_plugins;
+    /**
+     * @brief pointer to database object
+     */
+    QueuedPluginManagerInterface *m_interface = nullptr;
+};
+
+
+#endif /* QUEUEDPLUGINMANAGER_H */

sources/queued/include/queued/QueuedPluginManagerInterface.h

@@ -0,0 +1,54 @@
+/*
+ * Copyright (c) 2016 Evgeniy Alekseev
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ *
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ */
+/**
+ * @file QueuedPluginManagerInterface.h
+ * Header of Queued library
+ * @author Evgeniy Alekseev
+ * @copyright MIT
+ * @bug https://github.com/arcan1s/queued/issues
+ */
+
+
+#ifndef QUEUEDPLUGINMANAGERINTERFACE_H
+#define QUEUEDPLUGINMANAGERINTERFACE_H
+
+#include <QObject>
+
+
+/**
+ * @brief signal interface for plugin manager
+ */
+class QueuedPluginManagerInterface : public QObject
+{
+    Q_OBJECT
+
+public:
+    /**
+     * @brief QueuedPluginManagerInterface class constructor
+     * @param parent
+     * pointer to parent object
+     */
+    explicit QueuedPluginManagerInterface(QObject *parent)
+        : QObject(parent){};
+    /**
+     * @brief QueuedPluginManagerInterface class destructor
+     */
+    virtual ~QueuedPluginManagerInterface(){};
+
+signals:
+};
+
+
+#endif /* QUEUEDPLUGINMANAGERINTERFACE_H */

sources/queued/src/QueuedPluginManager.cpp

@@ -0,0 +1,142 @@
+/*
+ * Copyright (c) 2016 Evgeniy Alekseev
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ *
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ */
+/**
+ * @file QueuedPluginManager.cpp
+ * Source code of queued library
+ * @author Evgeniy Alekseev
+ * @copyright GPLv3
+ * @bug https://github.com/arcan1s/queued/issues
+ */
+
+
+#include "queued/Queued.h"
+
+#include <QDir>
+#include <QPluginLoader>
+#include <QStandardPaths>
+
+
+/**
+ * @class QueuedPluginManager
+ */
+/**
+ * @fn QueuedPluginManager
+ */
+QueuedPluginManager::QueuedPluginManager(QObject *parent)
+    : QObject(parent)
+{
+    qCDebug(LOG_PL) << __PRETTY_FUNCTION__;
+
+    m_interface = new QueuedPluginManagerInterface(this);
+}
+
+
+/**
+ * @fn ~QueuedPluginManager
+ */
+QueuedPluginManager::~QueuedPluginManager()
+{
+    qCDebug(LOG_PL) << __PRETTY_FUNCTION__;
+
+    QStringList plugins = m_plugins.keys();
+    for (auto &plugin : plugins)
+        unloadPlugin(plugin);
+
+    delete m_interface;
+}
+
+
+/**
+ * @fn interface
+ */
+QueuedPluginManagerInterface *QueuedPluginManager::interface()
+{
+    return m_interface;
+}
+
+
+/**
+ * @fn loadPlugin
+ */
+bool QueuedPluginManager::loadPlugin(const QString &_name,
+                                     const QVariantHash &_settings)
+{
+    qCDebug(LOG_PL) << "Load plugin" << _name << "with settings" << _settings;
+
+    QString libraryName = QString("lib%2.so").arg(_name);
+
+    for (auto &dir : pluginLocations()) {
+        if (!QDir(dir).entryList(QDir::Files).contains(libraryName))
+            continue;
+        // build plugin loader
+        QPluginLoader loader(QString("%1/%2").arg(dir).arg(libraryName), this);
+        qCInfo(LOG_PL) << "Loading" << loader.fileName();
+        // load plugin
+        QObject *plugin = loader.instance();
+        QueuedPluginInterface *item = nullptr;
+        if (loader.isLoaded())
+            item = qobject_cast<QueuedPluginInterface *>(plugin);
+        else
+            qCCritical(LOG_PL) << "Could not load the library for" << _name
+                               << "error" << loader.errorString();
+        if (item) {
+            m_plugins[_name] = item;
+            item->init(_settings);
+            item->connect(interface());
+        } else {
+            qCCritical(LOG_PL) << "Could not cast plugin" << _name;
+        }
+        // do not try to load it from other paths
+        break;
+    }
+
+    return m_plugins.contains(_name);
+}
+
+
+/**
+ * @fn pluginLocations
+ */
+QStringList QueuedPluginManager::pluginLocations() const
+{
+    QStringList locations = QStandardPaths::standardLocations(
+        QStandardPaths::GenericDataLocation);
+    for (auto &loc : locations)
+        loc = QString("%1/%2/%3")
+                  .arg(loc)
+                  .arg(QueuedConfig::HOME_PATH)
+                  .arg(QueuedConfig::PLUGIN_PATH);
+
+    return locations;
+}
+
+
+/**
+ * @fn unloadPlugin
+ */
+bool QueuedPluginManager::unloadPlugin(const QString &_name)
+{
+    qCDebug(LOG_PL) << "Unload plugin" << _name;
+
+    if (!m_plugins.contains(_name)) {
+        qCWarning(LOG_LIB) << "Could not find plugin" << _name;
+        return false;
+    }
+
+    auto plugin = m_plugins.take(_name);
+    delete plugin;
+
+    return true;
+}