ENH: added fileMonitor class (uses inotify)

src/OSspecific/POSIX/fileMonitor.H

@@ -0,0 +1,159 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | Copyright (C) 2010-2010 OpenCFD Ltd.
+     \\/     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
+    fileMonitor
+
+Description
+    Checking for changes to files.
+
+!!!!!!!NOTE:
+    Default is to use inotify (Linux specific, since 2.6.13)
+
+    Compile with FOAM_USE_STAT to use the stat function call.
+
+
+    - works fine except for if file gets deleted and recreated
+    it stops monitoring the file!
+    (does work though if the file gets moved)
+
+SourceFiles
+    fileMonitor.C
+
+\*---------------------------------------------------------------------------*/
+
+#ifndef fileMonitor_H
+#define fileMonitor_H
+
+#include <sys/types.h>
+#include "Map.H"
+#include "NamedEnum.H"
+#include "labelList.H"
+#include "className.H"
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+namespace Foam
+{
+
+class fileMonitor;
+
+/*---------------------------------------------------------------------------*\
+                           Class fileMonitor Declaration
+\*---------------------------------------------------------------------------*/
+
+class fileMonitor
+{
+
+public:
+
+    // Public data types
+
+        //- Enumeration defining the file state.
+        enum fileState
+        {
+            UNMODIFIED = 0,
+            DELETED = 1,
+            MODIFIED = 2
+        };
+
+        static const NamedEnum<fileState, 3> fileStateNames_;
+
+private:
+    // Private data
+
+        //- State for all watchFds
+        mutable Map<fileState> state_;
+        
+        //- From watch descriptor to filename
+        HashTable<fileName, label> watchFile_;
+
+#ifdef FOAM_USE_STAT
+
+        //- From watch descriptor to modified time
+        mutable HashTable<label, time_t> lastModified_;
+#else
+        //- File descriptor for the inotify instance
+        int inotifyFd_;
+
+        //- Pre-allocated structure containing file descriptors
+        mutable fd_set watchSet_;
+
+#endif
+        //- Update state_ from any events.
+        void checkFiles() const;
+
+        //- Disallow default bitwise copy construct
+        fileMonitor(const fileMonitor&);
+
+        //- Disallow default bitwise assignment
+        void operator=(const fileMonitor&);
+
+
+public:
+
+    // Declare name of the class and its debug switch
+    ClassName("fileMonitor");
+
+    // Constructors
+
+        //- Construct null
+        fileMonitor();
+
+
+    // Destructor
+
+        ~fileMonitor();
+
+
+    // Member Functions
+
+        //- Add file to watch. Returns 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 syncPar) const;
+
+        //- Reset state (e.g. after having read it) using handle
+        void setUnmodified(const label watchFd);
+};
+
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+} // End namespace Foam
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+#endif
+
+// ************************************************************************* //