source: trunk/nv/library.hh @ 256

// Copyright (C) 2012-2013 ChaosForge / Kornel Kisielewicz
// http://chaosforge.org/
//
// This file is part of NV Libraries.
// For conditions of distribution and use, see copyright notice in nv.hh

/**
 * @file library.hh
 * @author Kornel Kisielewicz
 * @brief Implements a dynamic library class
 */

#ifndef NV_LIBRARY_HH
#define NV_LIBRARY_HH

#include <nv/exception.hh>
#include <nv/string.hh>

namespace nv
{
        /**
         * library
         * @brief Class representing a dynamically loaded library
         */
        class library 
        {
        public:

                /**
                 * Library constructor
                 */
                library();

                /**
                 * Opens the library
                 *
                 * Throws library_error on failure
                 */
                void open( const string& name );

                /**
                 * Tries to open the library
                 *
                 * returns true if succeeded, false otherwise
                 */
                bool try_open( const string& name );

                /**
                 * Returns true if the library is open, false otherwise
                 */
                bool is_open() const;

                /**
                 * Returns library name
                 */
                const string& get_name() const;

                /**
                 * Get symbol from library
                 *
                 * Throws on symbol not found
                 */
                void* get( const string& symbol );

                /**
                 * Get symbol from library
                 *
                 * Returns null if symbol not found
                 */
                void* try_get( const string& symbol );

                /**
                 * Destructor
                 *
                 * Closes the library if open.
                 */
                ~library();

                /**
                 * Returns library loading error if present
                 *
                 * Exact implementation depends on platform/compiler.
                 */
                static string get_error();

        protected:
                /**
                 * Opens the library
                 *
                 * Opens the library and prepares it for getting symbols.
                 * Needs to be done before any get call.
                 *
                 * returns true on success, false otherwise
                 */
                bool open();

                /**
                 * @brief Closes the library
                 *
                 * Closes the library. Any further get calls or operations on
                 * received symbols are invalid!
                 */
                void close();

                /// Library handle
                void* m_handle;

                /// Library name
                string m_name;

        };  // class Library

        class library_error : public runtime_error
        {
                /// Library name
                string m_name;
        public:
                /**
                 * Constructor
                 */
                library_error( const string& message, const string& name )
                        : runtime_error( "Library (" + name + ") : " + message + " [ " + library::get_error() + " ]"), m_name( name )
                {
                }

                /**
                 * Destructor.
                 *
                 * It must not throw any exceptions because of the inheritance
                 */
                ~library_error() throw() {}

                /**
                 * Returns library name
                 */
                const string& get_name()
                {
                        return m_name;
                }
        };

} // namespace nv

#endif // NV_LIBRARY_HH