include/ptlib/pluginmgr.h

   1 /*
   2  * pluginmgr.h
   3  *
   4  * Plugin Manager Class Declarations
   5  *
   6  * Portable Windows Library
   7  *
   8  * Contributor(s): Snark at GnomeMeeting
   9  *
  10  * $Log$
  11  * Revision 1.13  2004/05/19 06:54:11  csoutheren
  12  * Removed unused code
  13  *
  14  * Revision 1.12  2004/05/18 06:01:06  csoutheren
  15  * Deferred plugin loading until after main has executed by using abstract factory classes
  16  *
  17  * Revision 1.11  2004/05/17 06:05:20  csoutheren
  18  * Changed "make docs" to use doxygen
  19  * Added new config file and main page
  20  *
  21  * Revision 1.10  2004/04/22 11:43:47  csoutheren
  22  * Factored out functions useful for loading dynamic libraries
  23  *
  24  * Revision 1.9  2004/04/22 07:55:30  csoutheren
  25  * Fix problem with generic plugin manager having pure virtual. Thanks to Ben Lear
  26  *
  27  * Revision 1.8  2004/04/14 11:14:10  csoutheren
  28  * Final fix for generic plugin manager
  29  *
  30  * Revision 1.7  2004/04/14 10:57:38  csoutheren
  31  * Removed multiple definition of statc function in generic plugin functions
  32  *
  33  * Revision 1.6  2004/04/14 10:01:54  csoutheren
  34  * Fixed compile problem on Windows
  35  *
  36  * Revision 1.5  2004/04/14 08:12:02  csoutheren
  37  * Added support for generic plugin managers
  38  *
  39  * Revision 1.4  2004/03/23 04:43:42  csoutheren
  40  * Modified plugin manager to allow code modules to be notified when plugins
  41  * are loaded or unloaded
  42  *
  43  * Revision 1.3  2003/11/12 10:24:35  csoutheren
  44  * Changes to allow operation of static plugins under Windows
  45  *
  46  * Revision 1.2  2003/11/12 03:26:17  csoutheren
  47  * Initial version of plugin code from Snark of GnomeMeeting with changes
  48  *    by Craig Southeren os Post Increment
  49  *
  50  *
  51  */
  52
  53 #ifndef _PLUGINMGR_H
  54 #define _PLUGINMGR_H
  55
  56 #define DEFAULT_PLUGINDIR "/usr/lib/pwlib"
  57
  58 #include <ptlib/plugin.h>
  59
  60 template <class C>
  61 void PLoadPluginDirectory(C & obj, const PDirectory & directory)
  62 {
  63   PDirectory dir = directory;
  64   if (!dir.Open()) {
  65     PTRACE(4, "Cannot open plugin directory " << dir);
  66     return;
  67   }
  68   PTRACE(4, "Enumerating plugin directory " << dir);
  69   do {
  70     PString entry = dir + dir.GetEntryName();
  71     if (dir.IsSubDir())
  72       PLoadPluginDirectory<C>(obj, entry);
  73     else if (PFilePath(entry).GetType() *= PDynaLink::GetExtension())
  74       obj.LoadPlugin(entry);
  75   } while (dir.Next());
  76 }
  77
  78 //////////////////////////////////////////////////////
  79 //
  80 //  Manager for plugins
  81 //
  82
  83 class PPluginManager : public PObject
  84 {
  85   PCLASSINFO(PPluginManager, PObject);
  86
  87   public:
  88     PPluginManager ();
  89     ~PPluginManager ();
  90
  91     // functions to load/unload a dynamic plugin
  92     BOOL LoadPlugin (const PString & fileName);
  93     void LoadPluginDirectory (const PDirectory & dir)
  94     { PLoadPluginDirectory<PPluginManager>(*this, dir); }
  95
  96     // functions to access the plugins' services
  97     PStringList GetPluginTypes() const;
  98     PStringList GetPluginsProviding (const PString & serviceType) const;
  99     PPluginServiceDescriptor * GetServiceDescriptor (const PString & serviceName, const PString & serviceType);
 100
 101     // function to register a service (used by the plugins themselves)
 102     BOOL RegisterService (const PString & serviceName, const PString & serviceType, PPluginServiceDescriptor * descriptor);
 103
 104     // Get the list of plugin directories
 105     static PStringArray GetPluginDirs();
 106
 107     // static functions for accessing global instances of plugin managers
 108     static PPluginManager & GetPluginManager();
 109
 110     /**Add a notifier to the plugin manager.
 111        The call back function is executed just after loading, or
 112        just after unloading, a plugin.
 113
 114        To use define:
 115          PDECLARE_NOTIFIER(PDynaLink, YourClass, YourFunction);
 116        and
 117          void YourClass::YourFunction(PDynaLink & dll, INT code)
 118          {
 119            // code == 0 means loading
 120            // code == 1 means unloading
 121          }
 122        and to connect to the plugin manager:
 123          PPluginManager & mgr = PPluginManager::GetPluginManager();
 124          mgr->AddNotifier((PCREATE_NOTIFIER(YourFunction));
 125       */
 126
 127     void AddNotifier(
 128       const PNotifier & filterFunction,
 129       BOOL existing = FALSE
 130     );
 131
 132     void RemoveNotifier(
 133       const PNotifier & filterFunction
 134     );
 135
 136   protected:
 137     void CallNotifier(PDynaLink & dll, INT code);
 138
 139     PMutex pluginListMutex;
 140     PList<PDynaLink> pluginList;
 141
 142     PMutex serviceListMutex;
 143     PList<PPluginService> serviceList;
 144
 145     PMutex notifierMutex;
 146     PList<PNotifier> notifierList;
 147 };
 148
 149 //////////////////////////////////////////////////////
 150 //
 151 //  Manager for plugin modules
 152 //
 153
 154 class PPluginModuleManager : public PObject
 155 {
 156   public:
 157     typedef PDictionary<PString, PDynaLink> PluginListType;
 158
 159     PPluginModuleManager(const char * _signatureFunctionName, PPluginManager * pluginMgr = NULL);
 160
 161     BOOL LoadPlugin(const PString & fileName)
 162     { if (pluginMgr == NULL) return FALSE; else return pluginMgr->LoadPlugin(fileName); }
 163
 164     void LoadPluginDirectory(const PDirectory &directory)
 165     { if (pluginMgr != NULL) pluginMgr->LoadPluginDirectory(directory); }
 166
 167     virtual void OnLoadPlugin(PDynaLink & /*dll*/, INT /*code*/)
 168     { }
 169
 170     virtual PluginListType GetPluginList() const
 171     { return pluginList; }
 172
 173   protected:
 174     PluginListType pluginList;
 175     PDECLARE_NOTIFIER(PDynaLink, PPluginModuleManager, OnLoadModule);
 176
 177   protected:
 178     const char * signatureFunctionName;
 179     PPluginManager * pluginMgr;
 180 };
 181
 182 #endif // ifndef _PLUGINMGR_H