demotool/c-filewatcher.cc

258 lines
6.7 KiB
C++

#include "externals.hh"
#include "c-filewatcher.hh"
//#define INTRUSIVE_TRACES
/*= T_FilesWatcher ===========================================================*/
T_FilesWatcher::T_FilesWatcher( )
: fd( inotify_init1( O_NONBLOCK ) )
{ }
T_FilesWatcher::~T_FilesWatcher( )
{
if ( fd ) {
close( fd );
}
for ( T_WatchSet_* wf : watched_ ) {
wf->watcher = nullptr;
}
}
void T_FilesWatcher::check( )
{
// Reset triggered status
for ( T_WatchSet_* wf : watched_ ) {
wf->triggered = false;
}
// Handle events from inotify
inotify_event ie;
while ( read( fd , &ie , sizeof( ie ) ) == sizeof( ie ) ) {
#ifdef INTRUSIVE_TRACES // {{{
printf( "inotify wd %d / evt %x\n" , ie.wd , ie.mask ); fflush( stdout );
#endif // INTRUSIVE_TRACES }}}
if ( ( ie.mask & ( IN_CLOSE_WRITE | IN_DELETE_SELF ) ) == 0 ) {
#ifdef INTRUSIVE_TRACES // {{{
printf( " -> skipping this event\n" );
#endif // INTRUSIVE_TRACES }}}
continue;
}
T_FSPath const* namePtr( inotify_.get( ie.wd ) );
if ( !namePtr ) {
#ifdef INTRUSIVE_TRACES // {{{
printf( " -> no matching file\n" ); fflush( stdout );
#endif // INTRUSIVE_TRACES }}}
continue;
}
const auto name( *namePtr );
#ifdef INTRUSIVE_TRACES // {{{
printf( " -> file '%s'\n" , name.toString( ).toOSString( ).data( ) );
#endif // INTRUSIVE_TRACES }}}
auto* const entry( fileWatchers_.get( name ) );
assert( entry );
const auto wd{ entry->wd };
entry->trigger( );
if ( ( ie.mask & IN_DELETE_SELF ) != 0 ) {
#ifdef INTRUSIVE_TRACES // {{{
printf( " -> %s deleted, added as missing\n" ,
name.toString( ).toOSString( ).data( ) );
fflush( stdout );
#endif // INTRUSIVE_TRACES }}}
inotify_rm_watch( fd , wd );
missing_.add( name );
inotify_.remove( wd );
// We need to fetch the correct entry back, as the callback
// might have changed the underlying data.
auto* const nEntry{ fileWatchers_.get( name ) };
assert( nEntry );
nEntry->wd = -2;
}
}
// Handle missing/deleted files
for ( auto it = missing_.begin( ) ; it < missing_.end( ) ; ++it ) {
auto const& path( *it );
#ifdef INTRUSIVE_TRACES // {{{
printf( "Checking missing file '%s'\n" , path.toString( ).toOSString( ).data( ) ); fflush( stdout );
#endif // INTRUSIVE_TRACES }}}
auto* const p( fileWatchers_.get( path ) );
#ifdef INTRUSIVE_TRACES // {{{
printf( " -> found? %c\n" , p ? 'Y' : 'N' );
#endif // INTRUSIVE_TRACES }}}
assert( p );
#ifdef INTRUSIVE_TRACES // {{{
printf( " -> wd = %d\n" , p->wd );
#endif // INTRUSIVE_TRACES }}}
assert( p->wd < 0 );
auto& we( *p );
const auto nwd( inotify_add_watch( fd ,
(char*) path.toString( ).toOSString( ).data( ) ,
IN_CLOSE_WRITE | IN_DELETE_SELF ) );
#ifdef INTRUSIVE_TRACES // {{{
printf( " -> inotify add watch %d\n" , nwd ); fflush( stdout );
#endif // INTRUSIVE_TRACES }}}
if ( nwd < 0 ) {
#ifdef INTRUSIVE_TRACES // {{{
printf( " -> still missing\n" ); fflush( stdout );
#endif // INTRUSIVE_TRACES }}}
we.wd = -1;
continue;
}
// Trigger if this was really a missing file
if ( we.wd == -1 ) {
#ifdef INTRUSIVE_TRACES // {{{
printf( " -> triggering\n" ); fflush( stdout );
#endif // INTRUSIVE_TRACES }}}
we.trigger( );
}
// Update cache
we.wd = nwd;
inotify_.add( nwd , path );
missing_.remove( it.pos( ) );
it --;
}
}
/*----------------------------------------------------------------------------*/
void T_FilesWatcher::T_File_::trigger( )
{
for ( T_WatchSet_* const wf : watchers ) {
if ( !wf->triggered ) {
wf->triggered = true;
wf->callback( );
}
}
}
void T_FilesWatcher::watchFile(
T_FSPath const& path ,
T_WatchSet_* const watcher )
{
#ifdef INTRUSIVE_TRACES // {{{
printf( "creating watch on '%s' for watcher %p\n" , path.toString( ).toOSString( ).data( ) , watcher ); fflush( stdout );
#endif // INTRUSIVE_TRACES }}}
auto* const exFilePos( fileWatchers_.get( path ) );
if ( exFilePos ) {
#ifdef INTRUSIVE_TRACES // {{{
printf( " -> existing\n" ); fflush( stdout );
#endif // INTRUSIVE_TRACES }}}
auto& wl( exFilePos->watchers );
if ( !wl.contains( watcher ) ) {
wl.add( watcher );
}
} else {
T_File_ f;
const auto fstr{ path.toString( ).toOSString( ) };
f.wd = inotify_add_watch( fd , (char*) fstr.data( ) ,
IN_CLOSE_WRITE | IN_DELETE_SELF );
#ifdef INTRUSIVE_TRACES // {{{
printf( " -> inotify wd %d\n" , f.wd ); fflush( stdout );
#endif // INTRUSIVE_TRACES }}}
if ( f.wd == -1 ) {
missing_.add( path );
#ifdef INTRUSIVE_TRACES // {{{
printf( " -> missing\n" ); fflush( stdout );
#endif // INTRUSIVE_TRACES }}}
} else {
inotify_.add( f.wd , path );
#ifdef INTRUSIVE_TRACES // {{{
printf( " -> found\n" ); fflush( stdout );
#endif // INTRUSIVE_TRACES }}}
const int32_t idx{ missing_.indexOf( path ) };
if ( idx >= 0 ) {
missing_.removeSwap( idx );
#ifdef INTRUSIVE_TRACES // {{{
printf( " -> removing from missing files (index %d)\n" , idx ); fflush( stdout );
#endif // INTRUSIVE_TRACES }}}
}
}
f.watchers.add( watcher );
fileWatchers_.add( path , std::move( f ) );
}
}
void T_FilesWatcher::unwatchAll(
T_WatchSet_* const watcher )
{
for ( auto i = 0u ; i < fileWatchers_.size( ) ; ) {
auto const& path( fileWatchers_.keys( )[ i ] );
auto& fw( *fileWatchers_.get( path ) );
auto& wl( fw.watchers );
const auto pos( wl.indexOf( watcher ) );
if ( pos == -1 ) {
i ++;
continue;
}
wl.remove( pos );
if ( wl.empty( ) ) {
const auto wd( fw.wd );
if ( wd < 0 ) {
auto const pos( missing_.indexOf( path ) );
assert( pos != -1 );
missing_.remove( pos );
} else {
inotify_rm_watch( fd , wd );
inotify_.remove( wd );
}
fileWatchers_.remove( path );
} else {
i ++;
}
}
}
/*----------------------------------------------------------------------------*/
T_FilesWatcher::T_WatchSet_::T_WatchSet_( T_FilesWatcher* watcher ,
F_OnFileChanges callback ) noexcept
: watcher( watcher ) , callback( std::move( callback ) ) ,
triggered( false )
{
watcher->watched_.add( this );
}
T_FilesWatcher::T_WatchSet_::~T_WatchSet_( )
{
if ( watcher ) {
watcher->unwatchAll( this );
watcher->watched_.remove( watcher->watched_.indexOf( this ) );
}
}
/*= T_WatchedFiles ===========================================================*/
T_WatchedFiles::T_WatchedFiles( T_WatchedFiles&& other ) noexcept
: watchSet_( std::move( other.watchSet_ ) )
{ }
T_WatchedFiles::T_WatchedFiles(
T_FilesWatcher& watcher ,
F_OnFileChanges callback )
: watchSet_( NewOwned< T_FilesWatcher::T_WatchSet_ >( &watcher , std::move( callback ) ) )
{ }
void T_WatchedFiles::clear( )
{
if ( watchSet_->watcher ) {
watchSet_->watcher->unwatchAll( watchSet_.get( ) );
}
}
bool T_WatchedFiles::watch(
T_FSPath const& file )
{
if ( !watchSet_->watcher || !file.isValid( ) ) {
return false;
}
watchSet_->watcher->watchFile( file , watchSet_.get( ) );
return true;
}