Rewrite OFileNotification to use the upcoming inotify (kernel 2.6) interface instead of the deprecated dnotify

2 files changed, 139 insertions, 226 deletions

diff --git a/libopie2/opiecore/ofilenotify.cpp b/libopie2/opiecore/ofilenotify.cpp
index 2a9bb8c..c221e58 100644
--- a/libopie2/opiecore/ofilenotify.cpp
+++ b/libopie2/opiecore/ofilenotify.cpp
@@ -1,322 +1,228 @@
 /*
                             This file is part of the Opie Project
-             =.             Copyright (C) 2004 Michael 'Mickey' Lauer <mickey@Vanille.de>
+             =.             Copyright (C) 2004-2005 Michael 'Mickey' Lauer <mickey@Vanille.de>
            .=l.             Copyright (C) The Opie Team <opie-devel@handhelds.org>
           .>+-=
 _;:,     .>    :=|.         This program is free software; you can
 .> <`_,   >  .   <=         redistribute it and/or  modify it under
 :`=1 )Y*s>-.--   :          the terms of the GNU Library General Public
 .="- .-=="i,     .._        License as published by the Free Software
-- .   .-<_>     .<>         Foundation; either version 2 of the License,
-    ._= =}       :          or (at your option) any later version.
+- .   .-<_>     .<>         Foundation; version 2 of the License.
+    ._= =}       :
    .%`+i>       _;_.
    .i_,=:_.      -<s.       This program 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
 ..}^=.=       =       ;     Library General Public License for more
 ++=   -.     .`     .:      details.
 :     =  ...= . :.=-
 -.   .:....=;==+<;          You should have received a copy of the GNU
  -_. . .   )=.  =           Library General Public License along with
    --        :-=`           this library; see the file COPYING.LIB.
                             If not, write to the Free Software Foundation,
                             Inc., 59 Temple Place - Suite 330,
                             Boston, MA 02111-1307, USA.
 */
 
 #include "ofilenotify.h"
 using namespace Opie::Core;
 
 /* OPIE */
 
 /* QT */
 #include <qobject.h>
+#include <qsocketnotifier.h>
 #include <qsignal.h>
 #include <qintdict.h>
 #include <qdir.h>
 
 /* STD */
 #include <sys/types.h>
 #include <sys/stat.h>
-#include <assert.h>
+#include <sys/ioctl.h>
 #include <fcntl.h>
+#include <assert.h>
 #include <string.h>
 #include <errno.h>
 #include <unistd.h>
 
 static QIntDict<OFileNotification> notification_list;
 
+QSocketNotifier* OFileNotification::_sn;
+int OFileNotification::_fd = -1;
+
+#define INOTIFY_DEVICE "/dev/inotify"
+
 namespace Opie {
 namespace Core {
 
 OFileNotification::OFileNotification( QObject* parent, const char* name )
-                  :QObject( parent, name ), _active( false )
+                  :QObject( parent, name ), _active( false ), _multi( true )
 {
     qDebug( "OFileNotification::OFileNotification()" );
 }
 
 
 OFileNotification::~OFileNotification()
 {
+    stop();
     qDebug( "OFileNotification::~OFileNotification()" );
 }
 
 
 bool OFileNotification::isActive() const
 {
     return _active;
 }
 
 
-int OFileNotification::start( const QString& path, bool sshot, OFileNotificationType type )
+int OFileNotification::watch( const QString& path, bool sshot, OFileNotificationType type )
 {
-    _path = QString::null;
-    _fd = 0;
-    if ( _active ) stop();
-    QString dirpath;
-
-    // check if path exists and whether it is a file or a directory, if it exists at all
-    int result = ::stat( (const char*) path, &_stat );
-    if ( !(type & Create) && result == -1 )
-    {
-        qWarning( "OFileNotification::start(): Can't stat '%s': %s.", (const char*) path, strerror( errno ) );
-        return -1;
-    }
-
-    // if it is not a directory, we need to find out in which directory the file is
-    bool isDirectory = S_ISDIR( _stat.st_mode );
-    if ( !isDirectory )
-    {
-        int slashpos;
-        slashpos = path.findRev( '/' );
-        if ( slashpos > 0 )
-        {
-            _path = path;
-            dirpath = path.left( slashpos );
-        }
-    }
-    else /* isDirectory */
-    {
-        qWarning( "FIXME FIXME FIXME = Directory Notification Not Yet Implemented!" );
-        _path = path;
-        dirpath = path;
-        assert( 0 );
-    }
-
-    int fd = ::open( (const char*) dirpath, O_RDONLY );
-    if ( fd != -1 )
+    if ( QFile::exists( path ) )
     {
         if ( notification_list.isEmpty() )
         {
-            OFileNotification::registerSignalHandler();
+            OFileNotification::registerEventHandler();
         }
 
-        result = ::fcntl( fd, F_SETSIG, SIGRTMIN );
-        if ( result == -1 )
-        {
-            qWarning( "OFileNotification::start(): Can't subscribe to '%s': %s.", (const char*) dirpath, strerror( errno ) );
-            return -1;
-        }
-        if ( !sshot ) type = static_cast<OFileNotificationType>( (int) type | (int) Multi );
-        result = ::fcntl( fd, F_NOTIFY, type );
-        if ( result == -1 )
+        struct inotify_watch_request iwr;
+        ::memset( &iwr, 0, sizeof iwr );
+        iwr.name = const_cast<char*>( (const char*) path );
+        iwr.mask = type;
+
+        _wd = ::ioctl( OFileNotification::_fd, INOTIFY_WATCH, &iwr );
+
+        if ( _wd < 0 )
         {
-            qWarning( "OFileNotification::start(): Can't subscribe to '%s': %s.", (const char*) dirpath, strerror( errno ) );
+            qWarning( "OFileNotification::watch(): inotify can't watch '%s': %s.", (const char*) path, strerror( errno ) );
             return -1;
         }
-        qDebug( "OFileNotification::start(): Subscribed for changes to %s (fd = %d, mask = 0x%0x)", (const char*) dirpath, fd, type );
-        notification_list.insert( fd, this );
+
+        notification_list.insert( _wd, this );
+        _multi = !sshot;
         _type = type;
-        _fd = fd;
         _active = true;
-        ::memset( &_stat, 0, sizeof _stat );
-        ::stat( _path, &_stat );
-        return fd;
+        qDebug( "OFileNotification::watch(): watching '%s' [wd=%d].", (const char*) path, _wd );
+        return _wd;
     }
     else
     {
-        qWarning( "OFileNotification::start(): Error with path '%s': %s.", (const char*) dirpath, strerror( errno ) );
+        qWarning( "OFileNotification::watch(): Can't watch '%s': %s.", (const char*) path, strerror( errno ) );
         return -1;
     }
 }
 
 
 void OFileNotification::stop()
 {
-    if ( !_active ) return;
-
-    int result = ::fcntl( _fd, F_NOTIFY, 0 );
-    if ( result == -1 )
-    {
-        qWarning( "OFileNotification::stop(): Can't remove subscription to '%s': %s.", (const char*) _path, strerror( errno ) );
-    }
-    else
+    notification_list.remove( _wd );
+    _path = QString::null;
+    _wd = 0;
+    _active = false;
+    if ( notification_list.isEmpty() )
     {
-        ::close( _fd );
-        _type = Single;
-        _path = QString::null;
-        _fd = 0;
-        _active = false;
+        OFileNotification::unregisterEventHandler();
     }
 }
 
 
 OFileNotificationType OFileNotification::type() const
 {
     return _type;
 }
 
 
 QString OFileNotification::path() const
 {
     return _path;
 }
 
 
-int OFileNotification::fileno() const
+bool OFileNotification::activate()
 {
-    return _fd;
+    emit triggered();
+    _signal.activate();
+    if ( !_multi ) stop();
+    return true;
 }
 
 
-bool OFileNotification::activate()
+void OFileNotification::singleShot( const QString& path, QObject* receiver, const char* member, OFileNotificationType type )
 {
-    if ( hasChanged() )
-    {
-        emit triggered();
-        _signal.activate();
-        return true;
-    }
-    else
-        return false;
+    OFileNotification* ofn = new OFileNotification();
+    ofn->_signal.connect( receiver, member );
+    ofn->watch( path, true, type );
 }
 
 
-bool OFileNotification::hasChanged()
+void OFileNotification::inotifyEventHandler()
 {
-    bool c = false;
+    qWarning( "OFileNotification::__eventHandler(): reached." );
 
-    struct stat newstat;
-    ::memset( &newstat, 0, sizeof newstat );
-    int result = ::stat( _path, &newstat ); // may fail if file has been renamed or deleted. that doesn't matter :)
+    char buffer[16384];
+    size_t buffer_i;
+    struct inotify_event *pevent, *event;
+    ssize_t r;
+    size_t event_size;
+    int count = 0;
 
-    qDebug( "result of newstat call is %d (%s=%d)", result, result == -1 ? strerror( errno ) : "success", errno );
-    qDebug( "stat.atime = %0lx, newstat.atime = %0lx", (long)_stat.st_atime, (long)newstat.st_atime );
-    qDebug( "stat.mtime = %0lx, newstat.mtime = %0lx", (long)_stat.st_mtime, (long)newstat.st_mtime );
-    qDebug( "stat.ctime = %0lx, newstat.ctime = %0lx", (long)_stat.st_ctime, (long)newstat.st_ctime );
+    r = ::read(_fd, buffer, 16384);
 
-    if ( !c && (_type & Create) &&
-        (long)_stat.st_atime == 0 && (long)_stat.st_mtime == 0 && (long)_stat.st_ctime == 0 &&
-        (long)newstat.st_atime > 0 && (long)newstat.st_mtime > 0 && (long)newstat.st_ctime > 0)
-    {
-        qDebug( "OFileNotification::hasChanged(): file has been created" );
-        c = true;
-    }
-    if ( !c && (_type & (Delete|Rename)) && (long)newstat.st_atime == 0 && (long)newstat.st_mtime == 0 && (long)newstat.st_ctime == 0)
-    {
-        qDebug( "OFileNotification::hasChanged(): file has been deleted or renamed" );
-        c = true;
-    }
-    if ( !c && (_type & Access) && (long)_stat.st_atime < (long)newstat.st_atime )
-    {
-        qDebug( "OFileNotification::hasChanged(): atime changed" );
-        c = true;
-    }
-    if ( !c && (_type & Modify) && (long)_stat.st_mtime < (long)newstat.st_mtime )
-    {
-        qDebug( "OFileNotification::hasChanged(): mtime changed" );
-        c = true;
-    }
-    if ( !c && (_type & Attrib) && (long)_stat.st_ctime < (long)newstat.st_ctime )
+    if ( r <= 0 )
+        return;
+
+    buffer_i = 0;
+    while ( buffer_i < r )
     {
-        qDebug( "OFileNotification::hasChanged(): ctime changed" );
-        c = true;
-    }
+            /* Parse events and queue them ! */
+            pevent = (struct inotify_event *)&buffer[buffer_i];
+            event_size = sizeof(struct inotify_event) + pevent->len;
+            qDebug( "pevent->len = %d\n", pevent->len);
 
-    return c;
-}
+            OFileNotification* fn = notification_list[ pevent->wd ];
+            if ( fn )
+                fn->activate();
+            else
+                assert( false );
 
+            //event = malloc(event_size);
+            //memmove(event, pevent, event_size);
+            //queue_enqueue(event, q);
+            buffer_i += event_size;
+            count++;
+    }
 
-void OFileNotification::singleShot( const QString& path, QObject* receiver, const char* member, OFileNotificationType type )
-{
-    OFileNotification* ofn = new OFileNotification();
-    ofn->_signal.connect( receiver, member );
-    ofn->start( path, true, type );
+    qDebug( "received %d events...", count );
+    return;
 }
 
 
-void OFileNotification::__signalHandler( int sig, siginfo_t *si, void *data )
+bool OFileNotification::registerEventHandler()
 {
-    Q_UNUSED( sig )
-    Q_UNUSED( data )
-    qWarning( "OFileNotification::__signalHandler(): reached." );
-    int fd = si->si_fd;
-    OFileNotification* fn = notification_list[fd];
-    if ( fn )
-    {
-        // check if it really was the file (dnotify triggers on directory granularity, not file granularity)
-        if ( !fn->activate() )
-        {
-            qDebug( "OFileNotification::__signalHandler(): false alarm ;) Restarting the trigger (if it was single)..." );
-            if ( !(fn->type() & Multi ) )
-            {
-                int result = ::fcntl( fn->fileno(), F_NOTIFY, fn->type() );
-                if ( result == -1 )
-                {
-                    qWarning( "OFileNotification::__signalHandler(): Can't restart the trigger: %s.", strerror( errno ) );
-                }
-            }
-            return;
-        }
-        #if 1
-        if ( !(fn->type() & Multi) )
-        {
-            qDebug( "OFileNotification::__signalHandler(): '%d' was singleShot. Removing from list.", fd );
-            notification_list.remove( fd );
-            if ( notification_list.isEmpty() )
-            {
-                OFileNotification::unregisterSignalHandler();
-            }
-        }
-        #endif
-    }
-    else
+    OFileNotification::_fd = ::open( INOTIFY_DEVICE, O_RDONLY );
+    if ( OFileNotification::_fd < 0 )
     {
-        qWarning( "OFileNotification::__signalHandler(): D'oh! Called without fd in notification_list. Race condition?" );
+        qWarning( "OFileNotification::registerEventHandler(): couldn't register event handler: %s", strerror( errno ) );
+        return false;
     }
-}
 
+    OFileNotification::_sn = new QSocketNotifier( _fd, QSocketNotifier::Read, this, "inotify event" );
+    connect( OFileNotification::_sn, SIGNAL( activated(int) ), this, SLOT( inotifyEventHandler() ) );
 
-bool OFileNotification::registerSignalHandler()
-{
-    struct sigaction act;
-    act.sa_sigaction = OFileNotification::__signalHandler;
-    ::sigemptyset( &act.sa_mask );
-    act.sa_flags = SA_SIGINFO;
-    if ( ::sigaction( SIGRTMIN, &act, NULL ) == -1 )
-    {
-        qWarning( "OFileNotification::registerSignalHandler(): couldn't register signal handler: %s", strerror( errno ) );
-        return false;
-    }
-    qDebug( "OFileNotification::registerSignalHandler(): done" );
+    qDebug( "OFileNotification::registerEventHandler(): done" );
     return true;
 }
 
 
-void OFileNotification::unregisterSignalHandler()
+void OFileNotification::unregisterEventHandler()
 {
-    struct sigaction act;
-    act.sa_sigaction = ( void (*)(int, siginfo_t*, void*) ) SIG_DFL;
-    ::sigemptyset( &act.sa_mask );
-    if ( ::sigaction( SIGRTMIN, &act, NULL ) == -1 )
-    {
-        qWarning( "OFileNotification::unregisterSignalHandler(): couldn't deregister signal handler: %s", strerror( errno ) );
-    }
-    qDebug( "OFileNotification::unregisterSignalHandler(): done" );
+    if ( OFileNotification::_fd )
+    ::close( OFileNotification::_fd );
+    qDebug( "OFileNotification::unregisterEventHandler(): done" );
 }
 
 
 }
 }
diff --git a/libopie2/opiecore/ofilenotify.h b/libopie2/opiecore/ofilenotify.h
index d820f7c..e3621cf 100644
--- a/libopie2/opiecore/ofilenotify.h
+++ b/libopie2/opiecore/ofilenotify.h
@@ -1,190 +1,197 @@
 /*
                             This file is part of the Opie Project
-             =.             Copyright (C) 2004 Michael 'Mickey' Lauer <mickey@Vanille.de>
+             =.             Copyright (C) 2004-2005 Michael 'Mickey' Lauer <mickey@Vanille.de>
            .=l.             Copyright (C) The Opie Team <opie-devel@handhelds.org>
           .>+-=
 _;:,     .>    :=|.         This program is free software; you can
 .> <`_,   >  .   <=         redistribute it and/or  modify it under
 :`=1 )Y*s>-.--   :          the terms of the GNU Library General Public
 .="- .-=="i,     .._        License as published by the Free Software
-- .   .-<_>     .<>         Foundation; either version 2 of the License,
-    ._= =}       :          or (at your option) any later version.
+- .   .-<_>     .<>         Foundation; version 2 of the License.
+    ._= =}       :
    .%`+i>       _;_.
    .i_,=:_.      -<s.       This program 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
 ..}^=.=       =       ;     Library General Public License for more
 ++=   -.     .`     .:      details.
 :     =  ...= . :.=-
 -.   .:....=;==+<;          You should have received a copy of the GNU
  -_. . .   )=.  =           Library General Public License along with
    --        :-=`           this library; see the file COPYING.LIB.
                             If not, write to the Free Software Foundation,
                             Inc., 59 Temple Place - Suite 330,
                             Boston, MA 02111-1307, USA.
 */
 
 #ifndef OFILENOTIFY_H
 #define OFILENOTIFY_H
 #if defined (__GNUC__) && (__GNUC__ < 3)
 #define _GNU_SOURCE
 #endif
 
 /* QT */
-#include <qobject.h>
+#include <qsocketnotifier.h>
 #include <qsignal.h>
 #include <qstring.h>
 
 /* STD */
-#include <signal.h>
-#include <fcntl.h>
+#include "inotify.h"
 
 namespace Opie {
 namespace Core {
 
 /*======================================================================================
  * OFileNotificationType
  *======================================================================================*/
 
 /**
  * @brief An enumerate for the different types of file notifications
  *
  * This enumerate provides a means to specify the type of events that you are interest in.
  * Valid values are:
  * <ul>
  *    <li>Access: The file was accessed (read)
  *    <li>Modify The file was modified (write,truncate)
- *    <li>Create = The file was created in the directory
- *    <li>Delete = The file was unlinked from directory
- *    <li>Rename = The file was renamed
  *    <li>Attrib = The file had its attributes changed (chmod,chown,chgrp)
+ *    <li>CloseWrite = Writable file was closed
+ *    <li>CloseNoWrite = Unwritable file was closed
+ *    <li>Open = File was opened
+ *    <li>MovedFrom = File was moved from X
+ *    <li>MovedTo = File was moved to Y
+ *    <li>DeleteSubdir = Subdir was deleted
+ *    <li>DeleteFile = Subfile was deleted
+ *    <li>CreateSubdir = Subdir was created
+ *    <li>CreateFile = Subfile was created
+ *    <li>DeleteSelf = Self was deleted
+ *    <li>Unmount = The backing filesystem was unmounted
  * </ul>
  *
  **/
 
-enum OFileNotificationType { Single = 0x0000000,
-                             Multi  = DN_MULTISHOT,
-                             Access = DN_ACCESS,
-                             Modify = DN_MODIFY,
-                             Create = DN_CREATE,
-                             Delete = DN_DELETE,
-                             Rename = DN_RENAME,
-                             Attrib = DN_ATTRIB };
+enum OFileNotificationType
+{
+    Access          =   IN_ACCESS,
+    Modify          =   IN_MODIFY,
+    Attrib          =   IN_ATTRIB,
+    CloseWrite      =   IN_CLOSE_WRITE,
+    CloseNoWrite    =   IN_CLOSE_NOWRITE,
+    Open            =   IN_OPEN,
+    MovedFrom       =   IN_MOVED_FROM,
+    MovedTo         =   IN_MOVED_TO,
+    DeleteSubdir    =   IN_DELETE_SUBDIR,
+    DeleteFile      =   IN_DELETE_FILE,
+    CreateSubdir    =   IN_CREATE_SUBDIR,
+    CreateFile      =   IN_CREATE_FILE,
+    DeleteSelf      =   IN_DELETE_SELF,
+    Unmount         =   IN_UNMOUNT,
+    _QueueOverflow  =   IN_Q_OVERFLOW,  /* Internal, don't use this in client code */
+    _Ignored        =   IN_IGNORED,     /* Internal, don't use this in client code */
+};
 
 /*======================================================================================
  * OFileNotification
  *======================================================================================*/
 
 /**
  * @brief Represents a file notification
  *
  * This class allows to watch for events happening to files.
- * It uses the dnotify kernel interface which is a very efficient signalling interface.
+ * It uses the inotify kernel interface
  *
- * @see <file:///usr/src/linux/Documentation/dnotify.txt>
+ * @see http://www.kernel.org/pub/linux/kernel/people/rml/inotify/
  *
  * @author Michael 'Mickey' Lauer <mickey@vanille.de>
  *
  **/
 
 class OFileNotification : public QObject
 {
   Q_OBJECT
 
   public:
     OFileNotification( QObject* parent = 0, const char* name = 0 );
     ~OFileNotification();
     /**
      * This static function calls a slot when an event with @a type happens to file @a path.
      *
      *  It is very convenient to use this function because you do not need to
      *  bother with a timerEvent or to create a local QTimer object.
      *
      *  Example:
      *  <pre>
      *
      *     #include <opie2/oapplication.h>
-     *     #include <opie2/onitify.h>
+     *     #include <opie2/ofilenotify.h>
      *     using namespace Opie::Core;
      *
      *     int main( int argc, char **argv )
      *     {
      *         OApplication a( argc, argv, "File Notification Example" );
      *         OFileNotification::singleShot( "/tmp/quit", &a, SLOT(quit()), Create );
      *         ... // create and show your widgets
      *         return a.exec();
      *     }
      *  </pre>
      *
-     * This sample program automatically terminates when the file "/tmp/quite" has been created.
+     * This sample program automatically terminates when the file "/tmp/quit" has been created.
      *
      *
      * The @a receiver is the receiving object and the @a member is the slot.
      **/
     static void singleShot( const QString& path, QObject* receiver, const char* member, OFileNotificationType type = Modify );
     /**
      * Starts to watch for @a type changes to @a path. Set @a sshot to True if you want to be notified only once.
      * Note that in that case it may be more convenient to use @ref OFileNotification::singleShot() then.
      **/
-    int start( const QString& path, bool sshot = false, OFileNotificationType type = Modify );
+    int watch( const QString& path, bool sshot = false, OFileNotificationType type = Modify );
     /**
      * Stop watching for file events.
      **/
     void stop();
     /**
      * @returns the notification type as set by @ref start().
      **/
     OFileNotificationType type() const;
     /**
      * @returns the path to the file being watched by this instance.
      **/
     QString path() const;
     /**
-     * @returns the UNIX file descriptor for the file being watched.
-     **/
-    int fileno() const;
-    /**
      * @returns if a file is currently being watched.
      **/
     bool isActive() const;
 
   signals:
     /**
      * This signal is emitted if an event happens of the specified type happens to the file being watched.
      **/
     void triggered();
 
   protected:
     bool activate();
-    virtual bool hasChanged();
-    static bool registerSignalHandler();
-    static void unregisterSignalHandler();
-    static void __signalHandler( int sig, siginfo_t *si, void *data );
+
+  private slots:
+    void inotifyEventHandler();
 
   private:
+    bool registerEventHandler();
+    void unregisterEventHandler();
+
     QString _path;
     OFileNotificationType _type;
     QSignal _signal;
-    int _fd;
     bool _active;
-    struct stat _stat;
-};
-
-#if 0
-
-class ODirectoryNotification : public OFileNotification
-{
-
-  public:
-      virtual bool hasChanged() { return true; };
+    bool _multi;
+    static QSocketNotifier* _sn;
+    int _wd; // inotify watch descriptor
+    static int _fd; // inotify device descriptor
 };
 
-#endif
-
 }
 }
 
 #endif