transmission/daemon/watch.c

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/*
2010-01-04 21:00:47 +00:00
* This file Copyright (C) 2009-2010 Mnemosyne LLC
*
* This file is licensed by the GPL version 2. Works owned by the
* Transmission project are granted a special exemption to clause 2(b)
* so that the bulk of its code can remain under the MIT license.
* This exemption does not extend to derived works not owned by
* the Transmission project.
*
* $Id$
*/
#ifdef WITH_INOTIFY
#include <sys/inotify.h>
#include <sys/select.h>
#include <unistd.h> /* close */
#else
#include <sys/types.h> /* stat */
#include <sys/stat.h> /* stat */
#include <dirent.h> /* readdir */
#include <event.h> /* evbuffer */
#endif
#include <errno.h>
#include <string.h> /* strstr */
#include <libtransmission/transmission.h>
#include <libtransmission/utils.h> /* tr_buildPath(), tr_inf() */
#include "watch.h"
struct dtr_watchdir
{
tr_session * session;
char * dir;
dtr_watchdir_callback * callback;
#ifdef WITH_INOTIFY
int inotify_fd;
#else /* readdir implementation */
time_t lastTimeChecked;
struct evbuffer * lastFiles;
#endif
};
/***
**** INOTIFY IMPLEMENTATION
***/
#if defined(WITH_INOTIFY)
/* how many inotify events to try to batch into a single read */
#define EVENT_BATCH_COUNT 50
/* size of the event structure, not counting name */
#define EVENT_SIZE (sizeof (struct inotify_event))
/* reasonable guess as to size of 50 events */
#define BUF_LEN (EVENT_BATCH_COUNT * (EVENT_SIZE + 16) + 2048)
#define DTR_INOTIFY_MASK (IN_CREATE|IN_CLOSE_WRITE|IN_MOVED_TO)
static void
watchdir_new_impl( dtr_watchdir * w )
{
int i;
w->inotify_fd = inotify_init( );
tr_inf( "Using inotify to watch directory \"%s\"", w->dir );
i = inotify_add_watch( w->inotify_fd, w->dir, DTR_INOTIFY_MASK );
if( i < 0 )
tr_err( "Unable to watch \"%s\": %s", w->dir, strerror (errno) );
}
static void
watchdir_free_impl( dtr_watchdir * w )
{
inotify_rm_watch( w->inotify_fd, DTR_INOTIFY_MASK );
close( w->inotify_fd );
}
static void
watchdir_update_impl( dtr_watchdir * w )
{
int ret;
fd_set rfds;
struct timeval time;
const int fd = w->inotify_fd;
/* timeout after one second */
time.tv_sec = 1;
time.tv_usec = 0;
/* make the fd_set hold the inotify fd */
FD_ZERO( &rfds );
FD_SET( fd, &rfds );
/* check for added files */
ret = select( fd+1, &rfds, NULL, NULL, &time );
if( ret < 0 ) {
perror( "select" );
} else if( !ret ) {
/* timed out! */
} else if( FD_ISSET( fd, &rfds ) ) {
int i = 0;
char buf[BUF_LEN];
int len = read( fd, buf, sizeof( buf ) );
while (i < len) {
struct inotify_event * event = (struct inotify_event *) &buf[i];
tr_inf( "Found new .torrent file \"%s\" in watchdir \"%s\"", event->name, w->dir );
w->callback( w->session, w->dir, event->name );
i += EVENT_SIZE + event->len;
}
}
}
#else /* WITH_INOTIFY */
/***
**** READDIR IMPLEMENTATION
***/
#define WATCHDIR_POLL_INTERVAL_SECS 10
#define FILE_DELIMITER '\0'
static void
watchdir_new_impl( dtr_watchdir * w UNUSED )
{
tr_inf( "Using readdir to watch directory \"%s\"", w->dir );
w->lastFiles = evbuffer_new( );
}
static void
watchdir_free_impl( dtr_watchdir * w )
{
evbuffer_free( w->lastFiles );
}
static void
add_file_to_list( struct evbuffer * buf, const char * filename, size_t len )
{
const char delimiter = FILE_DELIMITER;
evbuffer_add( buf, &delimiter, 1 );
evbuffer_add( buf, filename, len );
evbuffer_add( buf, &delimiter, 1 );
}
static tr_bool
is_file_in_list( struct evbuffer * buf, const char * filename, size_t len )
{
tr_bool in_list;
struct evbuffer * test = evbuffer_new( );
add_file_to_list( test, filename, len );
in_list = evbuffer_find( buf, EVBUFFER_DATA( test ), EVBUFFER_LENGTH( test ) ) != NULL;
evbuffer_free( test );
return in_list;
}
static void
watchdir_update_impl( dtr_watchdir * w )
{
struct stat sb;
DIR * odir;
const time_t oldTime = w->lastTimeChecked;
const char * dirname = w->dir;
struct evbuffer * curFiles = evbuffer_new( );
if ( ( oldTime + WATCHDIR_POLL_INTERVAL_SECS < time( NULL ) )
&& !stat( dirname, &sb )
&& S_ISDIR( sb.st_mode )
&& (( odir = opendir( dirname ))) )
{
struct dirent * d;
for( d = readdir( odir ); d != NULL; d = readdir( odir ) )
{
size_t len;
if( !d->d_name || *d->d_name=='.' ) /* skip dotfiles */
continue;
if( !strstr( d->d_name, ".torrent" ) ) /* skip non-torrents */
continue;
len = strlen( d->d_name );
add_file_to_list( curFiles, d->d_name, len );
/* if this file wasn't here last time, try adding it */
if( !is_file_in_list( w->lastFiles, d->d_name, len ) ) {
tr_inf( "Found new .torrent file \"%s\" in watchdir \"%s\"", d->d_name, w->dir );
w->callback( w->session, w->dir, d->d_name );
}
}
closedir( odir );
w->lastTimeChecked = time( NULL );
evbuffer_free( w->lastFiles );
w->lastFiles = curFiles;
}
}
#endif
/***
****
***/
dtr_watchdir*
dtr_watchdir_new( tr_session * session, const char * dir, dtr_watchdir_callback * callback )
{
dtr_watchdir * w = tr_new0( dtr_watchdir, 1 );
w->session = session;
w->dir = tr_strdup( dir );
w->callback = callback;
watchdir_new_impl( w );
return w;
}
void
dtr_watchdir_update( dtr_watchdir * w )
{
if( w != NULL )
watchdir_update_impl( w );
}
void
dtr_watchdir_free( dtr_watchdir * w )
{
if( w != NULL )
{
watchdir_free_impl( w );
tr_free( w->dir );
tr_free( w );
}
}