// @(#)root/base:$Id: TPluginManager.h 20877 2007-11-19 11:17:07Z rdm $ // Author: Fons Rademakers 26/1/2002 /************************************************************************* * Copyright (C) 1995-2002, Rene Brun and Fons Rademakers. * * All rights reserved. * * * * For the licensing terms see $ROOTSYS/LICENSE. * * For the list of contributors see $ROOTSYS/README/CREDITS. * *************************************************************************/ #ifndef ROOT_TPluginManager #define ROOT_TPluginManager ////////////////////////////////////////////////////////////////////////// // // // TPluginManager // // // // This class implements a plugin library manager. It keeps track of // // a list of plugin handlers. A plugin handler knows which plugin // // library to load to get a specific class that is used to extend the // // functionality of a specific base class and how to create an object // // of this class. For example, to extend the base class TFile to be // // able to read RFIO files one needs to load the plugin library // // libRFIO.so which defines the TRFIOFile class. This loading should // // be triggered when a given URI contains a regular expression defined // // by the handler. // // Plugin handlers can be defined via macros in a list of plugin // // directories. With $ROOTSYS/etc/plugins the default top plugin // // directory specified in $ROOTSYS/etc/system.rootrc. The macros must // // have names like /PX0_.C, e.g.: // // TFile/P10_TRFIOFile.C, TSQLServer/P20_TMySQLServer.C, etc. // // to allow easy sorting and grouping. If the BaseClass is in a // // namespace the directory must have the name NameSpace@@BaseClass as // // : is a reserved pathname character on some operating systems. // // Macros not beginning with 'P' and ending with ".C" are ignored. // // These macros typically look like: // // // // void P10_TDCacheFile() // // { // // gPluginMgr->AddHandler("TFile", "^dcache", "TDCacheFile", // // "DCache", "TDCacheFile(const char*,Option_t*)"); // // } // // // // Plugin handlers can also be defined via resources in the .rootrc // // file. Although now deprecated this method still works for backward // // compatibility, e.g.: // // // // Plugin.TFile: ^rfio: TRFIOFile RFIO "" // // Plugin.TSQLServer: ^mysql: TMySQLServer MySQL "" // // +Plugin.TSQLServer: ^pgsql: TPgSQLServer PgSQL "" // // Plugin.TVirtualFitter: * TFitter Minuit "TFitter(Int_t)" // // // // Where the + in front of Plugin.TSQLServer says that it extends the // // existing definition of TSQLServer, useful when there is more than // // one plugin that can extend the same base class. The "" // // should be the constructor or a static method that generates an // // instance of the specified class. Global methods should start with // // "::" in their name, like "::CreateFitter()". // // Instead of being a shared library a plugin can also be a CINT // // script, so instead of libDialog.so one can have Dialog.C. // // The * is a placeholder in case there is no need for a URI to // // differentiate between different plugins for the same base class. // // For the default plugins see $ROOTSYS/etc/system.rootrc. // // // // Plugin handlers can also be registered at run time, e.g.: // // // // gPluginMgr->AddHandler("TSQLServer", "^sapdb:", // // "TSapDBServer", "SapDB", // // "TSapDBServer(const char*,const char*, const char*)"); // // // // A list of currently defined handlers can be printed using: // // // // gPluginMgr->Print(); // use option="a" to see ctors // // // // The use of the plugin library manager removes all textual references // // to hard-coded class and library names and the resulting dependencies // // in the base classes. The plugin manager is used to extend a.o. // // TFile, TSQLServer, TGrid, etc. functionality. // // // ////////////////////////////////////////////////////////////////////////// #ifndef ROOT_TObject #include "TObject.h" #endif #ifndef ROOT_TString #include "TString.h" #endif class TEnv; class TList; class THashTable; class TFunction; class TMethodCall; class TPluginManager; class TPluginHandler : public TObject { friend class TPluginManager; private: TString fBase; // base class which will be extended by plugin TString fRegexp; // regular expression which must be matched in URI TString fClass; // class to be loaded from plugin library TString fPlugin; // plugin library which should contain fClass TString fCtor; // ctor used to instantiate object of fClass TString fOrigin; // origin of plugin handler definition TMethodCall *fCallEnv; //!ctor method call environment TFunction *fMethod; //!ctor method or global function Int_t fCanCall; //!if 1 fCallEnv is ok, -1 fCallEnv is not ok Bool_t fIsMacro; // plugin is a macro and not a library Bool_t fIsGlobal; // plugin ctor is a global function TPluginHandler() : fBase(), fRegexp(), fClass(), fPlugin(), fCtor(), fOrigin(), fCallEnv(0), fMethod(0), fCanCall(0), fIsMacro(kTRUE), fIsGlobal(kTRUE) { } TPluginHandler(const char *base, const char *regexp, const char *className, const char *pluginName, const char *ctor, const char *origin); TPluginHandler(const TPluginHandler&); // not implemented TPluginHandler& operator=(const TPluginHandler&); // not implemented ~TPluginHandler(); const char *GetBase() const { return fBase; } const char *GetRegexp() const { return fRegexp; } const char *GetPlugin() const { return fPlugin; } const char *GetCtor() const { return fCtor; } const char *GetOrigin() const { return fOrigin; } Bool_t CanHandle(const char *base, const char *uri); void SetupCallEnv(); public: const char *GetClass() const { return fClass; } Int_t CheckPlugin(); Int_t LoadPlugin(); Long_t ExecPlugin(Int_t nargs, ...); ClassDef(TPluginHandler,3) // Handler for plugin libraries }; class TPluginManager : public TObject { private: TList *fHandlers; // list of plugin handlers THashTable *fBasesLoaded; //! table of base classes already checked or loaded Bool_t fReadingDirs; //! true if we are running LoadHandlersFromPluginDirs TPluginManager(const TPluginManager& pm); // not implemented TPluginManager& operator=(const TPluginManager& pm); // not implemented void LoadHandlerMacros(const char *path); public: TPluginManager() : fHandlers(0), fBasesLoaded(0), fReadingDirs(kFALSE) { } ~TPluginManager(); void LoadHandlersFromEnv(TEnv *env); void LoadHandlersFromPluginDirs(const char *base = 0); void AddHandler(const char *base, const char *regexp, const char *className, const char *pluginName, const char *ctor = 0, const char *origin = 0); void RemoveHandler(const char *base, const char *regexp = 0); TPluginHandler *FindHandler(const char *base, const char *uri = 0); void Print(Option_t *opt = "") const; Int_t WritePluginMacros(const char *dir, const char *plugin = 0) const; ClassDef(TPluginManager,1) // Manager for plugin handlers }; R__EXTERN TPluginManager *gPluginMgr; #endif