fileMonitor.H

Go to the documentation of this file.

/*---------------------------------------------------------------------------*\
  =========                 |
  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
   \\    /   O peration     | Website:  https://openfoam.org
    \\  /    A nd           | Copyright (C) 2011-2022 OpenFOAM Foundation
     \\/     M anipulation  |
-------------------------------------------------------------------------------
License
    This file is part of OpenFOAM.
 
    OpenFOAM is free software: you can redistribute it and/or modify it
    under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.
 
    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
    for more details.
 
    You should have received a copy of the GNU General Public License
    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
 
Class
    Foam::fileMonitor
 
Description
    Checking for changes to files.
 
    Note:
        The default is to use stat to get the timestamp.
 
        Compile with FOAM_USE_INOTIFY to use the inotify (Linux specific, since
        2.6.13) framework. The problem is that inotify does not work on nfs3
        mounted directories!!
 
SourceFiles
    fileMonitor.C
 
\*---------------------------------------------------------------------------*/
 
#ifndef fileMonitor_H
#define fileMonitor_H
 
#include <sys/types.h>
#include "NamedEnum.H"
#include "className.H"
#include "DynamicList.H"
 
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
namespace Foam
{
 
class fileMonitor;
class fileMonitorWatcher;
 
/*---------------------------------------------------------------------------*\
                         Class fileMonitor Declaration
\*---------------------------------------------------------------------------*/
 
class fileMonitor
{
 
public:
 
    // Public data types
 
        //- Enumeration defining the file state.
        enum fileState
        {
            UNMODIFIED = 0,
            MODIFIED = 1,
            DELETED = 2
        };
 
        static const NamedEnum<fileState, 3> fileStateNames_;
 
 
private:
 
    // Private Data
 
        //- Whether to use inotify (requires -DFOAM_USE_INOTIFY, see above)
        const bool useInotify_;
 
        //- State for all watchFds based on local files
        mutable DynamicList<fileState> localState_;
 
        //- State for all watchFds - synchronised
        mutable DynamicList<fileState> state_;
 
        //- Filename for all watchFds
        DynamicList<fileName> watchFile_;
 
        //- Free watchFds
        DynamicList<label> freeWatchFds_;
 
        //- Watch mechanism (stat or inotify)
        mutable autoPtr<fileMonitorWatcher> watcher_;
 
 
    // Private Member Functions
 
        //- Update localState_ from any events.
        void checkFiles() const;
 
 
public:
 
    // Declare name of the class and its debug switch
    ClassName("fileMonitor");
 
    // Constructors
 
        //- Construct null
        fileMonitor(const bool useInotify);
 
        //- Disallow default bitwise copy construction
        fileMonitor(const fileMonitor&) = delete;
 
 
    //- Destructor
    ~fileMonitor();
 
 
    // Member Functions
 
        //- Add file to watch. Return watch descriptor
        label addWatch(const fileName&);
 
        //- Remove file to watch. Return true if successful
        bool removeWatch(const label watchFd);
 
        //- Get name of file being watched
        const fileName& getFile(const label watchFd) const;
 
        //- Check state using handle
        fileState getState(const label watchFd) const;
 
        //- Check state of all files. Updates state_.
        void updateStates
        (
            const bool masterOnly,
            const bool syncPar
        ) const;
 
        //- Reset state (e.g. after having read it) using handle
        void setUnmodified(const label watchFd);
 
 
    // Member Operators
 
        //- Disallow default bitwise assignment
        void operator=(const fileMonitor&) = delete;
};
 
 
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
} // End namespace Foam
 
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
#endif
 
// ************************************************************************* //