CFileSystemWatcher.h

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/* +---------------------------------------------------------------------------+
   |                     Mobile Robot Programming Toolkit (MRPT)               |
   |                          http://www.mrpt.org/                             |
   |                                                                           |
   | Copyright (c) 2005-2017, Individual contributors, see AUTHORS file        |
   | See: http://www.mrpt.org/Authors - All rights reserved.                   |
   | Released under BSD License. See details in http://www.mrpt.org/License    |
   +---------------------------------------------------------------------------+ */
#ifndef  CFileSystemWatcher_H
#define  CFileSystemWatcher_H

#include <mrpt/utils/utils_defs.h>
#include <mrpt/system/os.h>
#include <mrpt/system/threads.h>
#include <mrpt/utils/CThreadSafeQueue.h>

namespace mrpt
{
        namespace system
        {
                /** This class subscribes to notifications of file system changes, thus it can be used to efficiently stay informed about changes in a directory tree.
                  *  - Windows: Requires Windows 2000 or newer.
                  *  - Linux: Requires kernel 2.6.13 or newer.
                  *  Using this class in an old Linux or other unsoported system (Unix,etc...) has no effect, i.e. no notification will be ever received.
                  *  \sa CDirectoryExplorer
                 * \ingroup mrpt_base_grp
                  */
                class BASE_IMPEXP CFileSystemWatcher
                {
                public:
                        /** Each of the changes detected by utils::CFileSystemWatcher
                          */
                        struct BASE_IMPEXP TFileSystemChange
                        {
                                TFileSystemChange() : 
                                        path(), isDir(false),
                                        eventModified(false), eventCloseWrite(false),
                                        eventDeleted(false), eventMovedTo(false),
                                        eventMovedFrom(false), eventCreated(false),
                                        eventAccessed(false) {}

                                std::string path;                               //!< Complete path of the file/directory that has changed.
                                bool            isDir;                          //!< Whether the event happened to a file or a directory.
                                bool            eventModified;
                                bool            eventCloseWrite;
                                bool            eventDeleted;
                                bool            eventMovedTo;
                                bool            eventMovedFrom;
                                bool            eventCreated;
                                bool            eventAccessed;
                        };

                        typedef std::deque<TFileSystemChange>   TFileSystemChangeList;

                        /** Creates the subscription to a specified path.
                          * \param path The file or directory to watch.
                          */
                        CFileSystemWatcher(     const std::string &path );

                        /** Destructor
                          */
                        virtual ~CFileSystemWatcher();

                        /** Call this method sometimes to get the list of changes in the watched directory.
                          *  \sa processChange
                          */
                        void getChanges( TFileSystemChangeList &out_list );

                private:
                        std::string             m_watchedDirectory; //!< Ended in "/"
        #ifdef MRPT_OS_WINDOWS
                        void    *m_hNotif;
                        mrpt::system::TThreadHandle     m_watchThread;
                        void thread_win32_watch(); //!< Watch thread; only needed in win32
                        mrpt::utils::CThreadSafeQueue<TFileSystemChange>  m_queue_events_win32;

        #endif

        #if defined(MRPT_OS_LINUX) || defined(MRPT_OS_APPLE)
                        int     m_fd;  //!< The fd returned by inotify_init.
                        int     m_wd;  //!< The fd of the watch.
        #endif

                }; // End of class def.

        } // End of namespace
} // End of namespace

#endif