OPeNDAP Hyrax Back End Server (BES)
Updated for version 3.8.3
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00001 // BESPlugin.h 00002 00003 // This file is part of bes, A C++ back-end server implementation framework 00004 // for the OPeNDAP Data Access Protocol. 00005 00006 // Copyright (c) 2004-2009 University Corporation for Atmospheric Research 00007 // Author: Patrick West <pwest@ucar.edu> and Jose Garcia <jgarcia@ucar.edu> 00008 // and James Gallagher <jgallagher@gso.uri.edu> 00009 // 00010 // This library is free software; you can redistribute it and/or 00011 // modify it under the terms of the GNU Lesser General Public 00012 // License as published by the Free Software Foundation; either 00013 // version 2.1 of the License, or (at your option) any later version. 00014 // 00015 // This library is distributed in the hope that it will be useful, 00016 // but WITHOUT ANY WARRANTY; without even the implied warranty of 00017 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 00018 // Lesser General Public License for more details. 00019 // 00020 // You should have received a copy of the GNU Lesser General Public 00021 // License along with this library; if not, write to the Free Software 00022 // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 00023 // 00024 // You can contact University Corporation for Atmospheric Research at 00025 // 3080 Center Green Drive, Boulder, CO 80301 00026 00027 // (c) COPYRIGHT University Corporation for Atmospheric Research 2004-2005 00028 // Please read the full copyright statement in the file COPYRIGHT_UCAR. 00029 // 00030 // Authors: 00031 // pwest Patrick West <pwest@ucar.edu> 00032 // jgarcia Jose Garcia <jgarcia@ucar.edu> 00033 // jimg James Gallagher <jgallagher@gso.uri.edu> 00034 00035 #ifndef T_BESPlugin_h 00036 #define T_BESPlugin_h 00037 00038 #include <dlfcn.h> 00039 #include <string> 00040 #include <iostream> 00041 00042 #include "BESObj.h" 00043 #include "BESInternalFatalError.h" 00044 #include "BESInternalError.h" 00045 00046 using std::string; 00047 using std::cerr; 00048 using std::endl; 00049 00053 class NoSuchLibrary : public BESInternalFatalError 00054 { 00055 public: 00056 NoSuchLibrary( const string &msg, const string &file, int line ) 00057 : BESInternalFatalError( msg, file, line ) {} 00058 }; 00059 00063 class NoSuchObject : public BESInternalFatalError 00064 { 00065 public: 00066 NoSuchObject( const string &msg, const string &file, int line ) 00067 : BESInternalFatalError( msg, file, line ) {} 00068 }; 00069 00090 template<typename M> 00091 class BESPlugin : public BESObj 00092 { 00093 private: 00094 string d_filename; // Library filename 00095 void *d_lib; // Open library handle 00096 00099 BESPlugin() throw(BESInternalError) 00100 { 00101 throw BESInternalError( "Unimplemented method", __FILE__, __LINE__ ); 00102 } 00103 00108 BESPlugin(const BESPlugin &p) throw(BESInternalError) 00109 { 00110 throw BESInternalError( "Unimplemented method.", __FILE__, __LINE__ ); 00111 } 00112 00116 BESPlugin &operator=(const BESPlugin &p) throw(BESInternalError) 00117 { 00118 throw BESInternalError( "Unimplemented method.", __FILE__, __LINE__ ); 00119 } 00120 00121 void *get_lib() throw(NoSuchLibrary) { 00122 if (!d_lib) { 00123 d_lib = dlopen(d_filename.c_str(), RTLD_NOW|RTLD_LOCAL); 00124 if (d_lib == NULL) { 00125 throw NoSuchLibrary( string( dlerror() ), __FILE__, __LINE__ ) ; 00126 } 00127 } 00128 00129 return d_lib; 00130 } 00131 00132 public: 00137 BESPlugin(const string &filename) : d_filename(filename), d_lib(0) {} 00138 00141 virtual ~BESPlugin() { 00142 if (d_lib) 00143 dlclose(d_lib); 00144 } 00145 00152 M* instantiate() throw(NoSuchLibrary, NoSuchObject) { 00153 void *maker = dlsym(get_lib(), "maker"); 00154 if (!maker) { 00155 throw NoSuchObject( string( dlerror() ), __FILE__, __LINE__ ) ; 00156 } 00157 00158 typedef M *(*maker_func_ptr)(); 00159 maker_func_ptr my_maker = *reinterpret_cast<maker_func_ptr*>(&maker); 00160 M *my_M = (my_maker)(); 00161 00162 return my_M; 00163 } 00164 00165 virtual void dump( ostream &strm ) const 00166 { 00167 strm << "BESPlugin::dump - (" << (void *)this << ")" << endl ; 00168 strm << " plugin name: " << d_filename << endl ; 00169 strm << " library handle: " << (void *)d_lib << endl ; 00170 } 00171 }; 00172 00173 #endif // T_BESPlugin_h 00174