release/src/router/transmission/daemon/watch.c

   1 /*
   2  * This file Copyright (C) 2009-2014 Mnemosyne LLC
   3  *
   4  * It may be used under the GNU GPL versions 2 or 3
   5  * or any future license endorsed by Mnemosyne LLC.
   6  *
   7  * $Id: watch.c 14241 2014-01-21 03:10:30Z jordan $
   8  */
   9
  10 #ifdef WITH_INOTIFY
  11   #include <sys/inotify.h>
  12   #include <sys/select.h>
  13   #include <unistd.h> /* close */
  14 #else
  15   #include <sys/types.h> /* stat */
  16   #include <sys/stat.h> /* stat */
  17   #include <event2/buffer.h> /* evbuffer */
  18 #endif
  19
  20 #include <errno.h>
  21 #include <string.h> /* strlen () */
  22 #include <stdio.h> /* perror () */
  23
  24 #include <dirent.h> /* readdir */
  25
  26 #include <libtransmission/transmission.h>
  27 #include <libtransmission/log.h>
  28 #include <libtransmission/utils.h> /* tr_buildPath (), tr_logAddInfo () */
  29 #include "watch.h"
  30
  31 struct dtr_watchdir
  32 {
  33     tr_session * session;
  34     char * dir;
  35     dtr_watchdir_callback * callback;
  36 #ifdef WITH_INOTIFY
  37     int inotify_fd;
  38 #else /* readdir implementation */
  39     time_t lastTimeChecked;
  40     struct evbuffer * lastFiles;
  41 #endif
  42 };
  43
  44 /***
  45 ****  INOTIFY IMPLEMENTATION
  46 ***/
  47
  48 #if defined (WITH_INOTIFY)
  49
  50 /* how many inotify events to try to batch into a single read */
  51 #define EVENT_BATCH_COUNT 50
  52 /* size of the event structure, not counting name */
  53 #define EVENT_SIZE (sizeof (struct inotify_event))
  54 /* reasonable guess as to size of 50 events */
  55 #define BUF_LEN (EVENT_BATCH_COUNT * (EVENT_SIZE + 16) + 2048)
  56
  57 #define DTR_INOTIFY_MASK (IN_CLOSE_WRITE|IN_MOVED_TO|IN_CREATE|IN_ONLYDIR)
  58
  59 static void
  60 watchdir_new_impl (dtr_watchdir * w)
  61 {
  62     int i;
  63     DIR * odir;
  64     w->inotify_fd = inotify_init ();
  65
  66     if (w->inotify_fd < 0)
  67     {
  68         i = -1;
  69     }
  70     else
  71     {
  72         tr_logAddInfo ("Using inotify to watch directory \"%s\"", w->dir);
  73         i = inotify_add_watch (w->inotify_fd, w->dir, DTR_INOTIFY_MASK);
  74     }
  75
  76     if (i < 0)
  77     {
  78         tr_logAddError ("Unable to watch \"%s\": %s", w->dir, tr_strerror (errno));
  79     }
  80     else if ((odir = opendir (w->dir)))
  81     {
  82         struct dirent * d;
  83
  84         while ((d = readdir (odir)))
  85         {
  86             const char * name = d->d_name;
  87
  88             if (!tr_str_has_suffix (name, ".torrent")) /* skip non-torrents */
  89                 continue;
  90
  91             tr_logAddInfo ("Found new .torrent file \"%s\" in watchdir \"%s\"", name, w->dir);
  92             w->callback (w->session, w->dir, name);
  93         }
  94
  95         closedir (odir);
  96     }
  97
  98 }
  99 static void
 100 watchdir_free_impl (dtr_watchdir * w)
 101 {
 102     if (w->inotify_fd >= 0)
 103     {
 104         inotify_rm_watch (w->inotify_fd, DTR_INOTIFY_MASK);
 105
 106         close (w->inotify_fd);
 107     }
 108 }
 109 static void
 110 watchdir_update_impl (dtr_watchdir * w)
 111 {
 112     int ret;
 113     fd_set rfds;
 114     struct timeval time;
 115     const int fd = w->inotify_fd;
 116
 117     /* timeout after one second */
 118     time.tv_sec = 1;
 119     time.tv_usec = 0;
 120
 121     /* make the fd_set hold the inotify fd */
 122     FD_ZERO (&rfds);
 123     FD_SET (fd, &rfds);
 124
 125     /* check for added files */
 126     ret = select (fd+1, &rfds, NULL, NULL, &time);
 127     if (ret < 0) {
 128         perror ("select");
 129     } else if (!ret) {
 130         /* timed out! */
 131     } else if (FD_ISSET (fd, &rfds)) {
 132         int i = 0;
 133         char buf[BUF_LEN];
 134         int len = read (fd, buf, sizeof (buf));
 135         while (i < len) {
 136             struct inotify_event * event = (struct inotify_event *) &buf[i];
 137             const char * name = event->name;
 138             if (tr_str_has_suffix (name, ".torrent"))
 139             {
 140                 tr_logAddInfo ("Found new .torrent file \"%s\" in watchdir \"%s\"", name, w->dir);
 141                 w->callback (w->session, w->dir, name);
 142             }
 143             i += EVENT_SIZE +  event->len;
 144         }
 145     }
 146 }
 147
 148 #else /* WITH_INOTIFY */
 149
 150 /***
 151 ****  READDIR IMPLEMENTATION
 152 ***/
 153
 154 #define WATCHDIR_POLL_INTERVAL_SECS 10
 155
 156 #define FILE_DELIMITER '\t'
 157
 158 static void
 159 watchdir_new_impl (dtr_watchdir * w UNUSED)
 160 {
 161     tr_logAddInfo ("Using readdir to watch directory \"%s\"", w->dir);
 162     w->lastFiles = evbuffer_new ();
 163 }
 164 static void
 165 watchdir_free_impl (dtr_watchdir * w)
 166 {
 167     evbuffer_free (w->lastFiles);
 168 }
 169
 170 static char*
 171 get_key_from_file (const char * filename, const size_t len)
 172 {
 173     return tr_strdup_printf ("%c%*.*s%d", FILE_DELIMITER, (int)len, (int)len, filename, FILE_DELIMITER);
 174 }
 175
 176 static void
 177 add_file_to_list (struct evbuffer * buf, const char * filename, size_t len)
 178 {
 179     char * key = get_key_from_file (filename, len);
 180     evbuffer_add (buf, key, strlen (key));
 181     tr_free (key);
 182 }
 183 static bool
 184 is_file_in_list (struct evbuffer * buf, const char * filename, size_t len)
 185 {
 186     bool in_list;
 187     struct evbuffer_ptr ptr;
 188     char * key = get_key_from_file (filename, len);
 189
 190     ptr = evbuffer_search (buf, key, strlen (key), NULL);
 191     in_list = ptr.pos != -1;
 192
 193     tr_free (key);
 194     return in_list;
 195 }
 196 static void
 197 watchdir_update_impl (dtr_watchdir * w)
 198 {
 199     struct stat sb;
 200     DIR * odir;
 201     const time_t oldTime = w->lastTimeChecked;
 202     const char * dirname = w->dir;
 203     struct evbuffer * curFiles = evbuffer_new ();
 204
 205     if ((oldTime + WATCHDIR_POLL_INTERVAL_SECS < time (NULL))
 206          && !stat (dirname, &sb)
 207          && S_ISDIR (sb.st_mode)
 208          && ((odir = opendir (dirname))))
 209     {
 210         struct dirent * d;
 211
 212         for (d = readdir (odir); d != NULL; d = readdir (odir))
 213         {
 214             size_t len;
 215             const char * name = d->d_name;
 216
 217             if (!name || *name=='.') /* skip dotfiles */
 218                 continue;
 219             if (!tr_str_has_suffix (name, ".torrent")) /* skip non-torrents */
 220                 continue;
 221
 222             len = strlen (name);
 223             add_file_to_list (curFiles, name, len);
 224
 225             /* if this file wasn't here last time, try adding it */
 226             if (!is_file_in_list (w->lastFiles, name, len)) {
 227                 tr_logAddInfo ("Found new .torrent file \"%s\" in watchdir \"%s\"", name, w->dir);
 228                 w->callback (w->session, w->dir, name);
 229             }
 230         }
 231
 232         closedir (odir);
 233         w->lastTimeChecked = time (NULL);
 234         evbuffer_free (w->lastFiles);
 235         w->lastFiles = curFiles;
 236     }
 237 }
 238
 239 #endif
 240
 241 /***
 242 ****
 243 ***/
 244
 245 dtr_watchdir*
 246 dtr_watchdir_new (tr_session * session, const char * dir, dtr_watchdir_callback * callback)
 247 {
 248     dtr_watchdir * w = tr_new0 (dtr_watchdir, 1);
 249
 250     w->session = session;
 251     w->dir = tr_strdup (dir);
 252     w->callback = callback;
 253
 254     watchdir_new_impl (w);
 255
 256     return w;
 257 }
 258
 259 void
 260 dtr_watchdir_update (dtr_watchdir * w)
 261 {
 262     if (w != NULL)
 263         watchdir_update_impl (w);
 264 }
 265
 266 void
 267 dtr_watchdir_free (dtr_watchdir * w)
 268 {
 269     if (w != NULL)
 270     {
 271         watchdir_free_impl (w);
 272         tr_free (w->dir);
 273         tr_free (w);
 274     }
 275 }