class_loader.h

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/*
 * Copyright (c) 2009, Willow Garage, Inc.
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 * 
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in the
 *       documentation and/or other materials provided with the distribution.
 *     * Neither the name of the Willow Garage, Inc. nor the names of its
 *       contributors may be used to endorse or promote products derived from
 *       this software without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */
#ifndef PLUGINLIB_CLASS_LOADER_H
#define PLUGINLIB_CLASS_LOADER_H

#include "ros/console.h"

#include "pluginlib/class_desc.h"

#include "Poco/ClassLoader.h"
#include "ros/package.h"
#include "tinyxml.h"
#include <vector>
#include <map>


#include "boost/algorithm/string.hpp"
#include "pluginlib/boost_fs_wrapper.h"

namespace pluginlib
{
  class PluginlibException: public std::runtime_error
  {
    public:
      PluginlibException(const std::string error_desc) : std::runtime_error(error_desc) {}
  };

  class LibraryLoadException: public PluginlibException
  {
    public:
      LibraryLoadException(const std::string error_desc) : PluginlibException(error_desc) {}
  };

  class LibraryUnloadException: public PluginlibException
  {
    public:
      LibraryUnloadException(const std::string error_desc) : PluginlibException(error_desc) {}
  };

  class CreateClassException: public PluginlibException
  {
    public:
      CreateClassException(const std::string error_desc) : PluginlibException(error_desc) {}
  };

  class ClassLoaderBase
  {
    public:
      virtual ~ClassLoaderBase() {}

      virtual std::vector<std::string> getDeclaredClasses() = 0;

      virtual void refreshDeclaredClasses() = 0;

      virtual std::string getName(const std::string& lookup_name) = 0;

      virtual bool isClassAvailable(const std::string& lookup_name) = 0;

      virtual std::string getClassType(const std::string& lookup_name) = 0;

      virtual std::string getClassDescription(const std::string& lookup_name) = 0;

      virtual std::string getBaseClassType() const = 0;

      virtual std::string getClassPackage(const std::string& lookup_name) = 0;

      virtual std::string getPluginManifestPath(const std::string& lookup_name) = 0;

      virtual bool isClassLoaded(const std::string& lookup_name) = 0;

      virtual void loadLibraryForClass(const std::string & lookup_name) = 0;

      virtual int unloadLibraryForClass(const std::string& lookup_name) = 0;

      virtual std::vector<std::string> getRegisteredLibraries() = 0;

      virtual std::string getClassLibraryPath(const std::string& lookup_name) = 0;
  };

  template <class T>
    class ClassLoader: public ClassLoaderBase
    {
      private:
        typedef std::map<std::string, unsigned int> LibraryCountMap;

      public:
        typedef typename std::map<std::string, ClassDesc>::iterator ClassMapIterator;

      public:
        ClassLoader(std::string package, std::string base_class, std::string attrib_name = std::string("plugin"));

        ~ClassLoader();

        std::vector<std::string> getDeclaredClasses();

        void refreshDeclaredClasses();

        std::string getName(const std::string& lookup_name);

        bool isClassAvailable(const std::string& lookup_name);

        std::string getClassType(const std::string& lookup_name);

        std::string getClassDescription(const std::string& lookup_name);

        std::string getBaseClassType() const;

        std::string getClassPackage(const std::string& lookup_name);

        std::string getPluginManifestPath(const std::string& lookup_name);

        __attribute__((deprecated)) T* createClassInstance(const std::string& lookup_name, bool auto_load = true);
        
        boost::shared_ptr<T> createInstance(const std::string& lookup_name);
        
        T* createUnmanagedInstance(const std::string& lookup_name);

        bool isClassLoaded(const std::string& lookup_name);

        void loadLibraryForClass(const std::string & lookup_name);

        int unloadLibraryForClass(const std::string& lookup_name);

        std::vector<std::string> getRegisteredLibraries();

        std::string getClassLibraryPath(const std::string& lookup_name);

      private:
        void garbageInstance(T* p, const std::string& lookup_name);

        bool unloadClassLibrary(const std::string& library_path);

        bool loadClassLibrary(const std::string& library_path);

        std::vector<std::string> getClassesInLibrary(const std::string & library_path);

        std::vector<std::string> getLoadedLibraries();

        void loadClassLibraryInternal(const std::string& library_path, const std::string& list_name_arg = std::string(""));

        int unloadClassLibraryInternal(const std::string& library_path);

        std::map<std::string, ClassDesc> determineAvailableClasses();

        std::string getErrorStringForUnknownClass(const std::string& lookup_name);

        //used for proper unloading of automatically loaded libraries
        LibraryCountMap loaded_libraries_;

        // map from library to class's descriptions  
        // This is all available classes found in xml
        std::map<std::string, ClassDesc> classes_available_;
        std::string package_;
        std::string base_class_;
        std::string attrib_name_;

        Poco::ClassLoader<T> poco_class_loader_;  
    };

};

#include "class_loader_imp.h"

#endif //PLUGINLIB_CLASS_LOADER_H