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[disorder] / server / play.c

/*
 * This file is part of DisOrder.
 * Copyright (C) 2004-2009 Richard Kettlewell
 *
 * This program 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.
 *
 * 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 General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
/** @file server/play.c
 * @brief Playing tracks
 */

#include "disorder-server.h"
#include <ao/ao.h>

#define SPEAKER "disorder-speaker"

/** @brief The current playing track or NULL */
struct queue_entry *playing;

/** @brief Set when paused */
int paused;

static void finished(ev_source *ev);

/** @brief File descriptor of our end of the socket to the speaker */
static int speaker_fd = -1;

/** @brief Mapping of track IDs to associated decoder process IDs */
static hash *player_pids;

/** @brief Set when shutting down */
static int shutting_down;

/** @brief Remember a player's PID */
static void store_player_pid(const char *id, pid_t pid) {
  if(!player_pids) player_pids = hash_new(sizeof (pid_t));
  hash_add(player_pids, id, &pid, HASH_INSERT_OR_REPLACE);
}

/** @brief Find a player's PID */
static pid_t find_player_pid(const char *id) {
  pid_t *pidp;

  if(player_pids && (pidp = hash_find(player_pids, id))) return *pidp;
  return -1;
}

/** @brief Discard a player's ID->PID mappin
 *
 * Used when the player terminates.
 */
static void forget_player_pid(const char *id) {
  if(player_pids) hash_remove(player_pids, id);
}

/** @brief Called when speaker process terminates
 *
 * Currently kills of DisOrder completely.  A future version could terminate
 * the speaker when nothing was going on, or recover from failures, though any
 * tracks with decoders already started would need to have them restarted.
 */
static int speaker_terminated(ev_source attribute((unused)) *ev,
			      pid_t attribute((unused)) pid,
			      int attribute((unused)) status,
			      const struct rusage attribute((unused)) *rusage,
			      void attribute((unused)) *u) {
  fatal(0, "speaker subprocess %s",
	wstat(status));
}

/** @brief Called when we get a message from the speaker process */
static int speaker_readable(ev_source *ev, int fd,
			    void attribute((unused)) *u) {
  struct speaker_message sm;
  int ret = speaker_recv(fd, &sm);
  
  if(ret < 0) return 0;			/* EAGAIN */
  if(!ret) {				/* EOF */
    ev_fd_cancel(ev, ev_read, fd);
    return 0;
  }
  switch(sm.type) {
  case SM_PAUSED:
    /* track ID is paused, DATA seconds played */
    D(("SM_PAUSED %s %ld", sm.id, sm.data));
    playing->sofar = sm.data;
    break;
  case SM_FINISHED:			/* scratched the playing track */
  case SM_STILLBORN:			/* scratched too early */
  case SM_UNKNOWN:			/* scratched WAY too early */
    if(playing && !strcmp(sm.id, playing->id))
      finished(ev);
    break;
  case SM_PLAYING:
    /* track ID is playing, DATA seconds played */
    D(("SM_PLAYING %s %ld", sm.id, sm.data));
    playing->sofar = sm.data;
    break;
  default:
    error(0, "unknown speaker message type %d", sm.type);
  }
  return 0;
}

/** @brief Initialize the speaker process */
void speaker_setup(ev_source *ev) {
  int sp[2];
  pid_t pid;
  struct speaker_message sm;

  if(socketpair(PF_UNIX, SOCK_DGRAM, 0, sp) < 0)
    fatal(errno, "error calling socketpair");
  if(!(pid = xfork())) {
    exitfn = _exit;
    ev_signal_atfork(ev);
    xdup2(sp[0], 0);
    xdup2(sp[0], 1);
    xclose(sp[0]);
    xclose(sp[1]);
    signal(SIGPIPE, SIG_DFL);
#if 0
    execlp("valgrind", "valgrind", SPEAKER, "--config", configfile,
	   debugging ? "--debug" : "--no-debug",
	   log_default == &log_syslog ? "--syslog" : "--no-syslog",
	   (char *)0);
#else
    execlp(SPEAKER, SPEAKER, "--config", configfile,
	   debugging ? "--debug" : "--no-debug",
	   log_default == &log_syslog ? "--syslog" : "--no-syslog",
	   (char *)0);
#endif
    fatal(errno, "error invoking %s", SPEAKER);
  }
  ev_child(ev, pid, 0, speaker_terminated, 0);
  speaker_fd = sp[1];
  xclose(sp[0]);
  cloexec(speaker_fd);
  /* Wait for the speaker to be ready */
  speaker_recv(speaker_fd, &sm);
  nonblock(speaker_fd);
  if(ev_fd(ev, ev_read, speaker_fd, speaker_readable, 0, "speaker read") < 0)
    fatal(0, "error registering speaker socket fd");
}

/** @brief Tell the speaker to reload its configuration */
void speaker_reload(void) {
  struct speaker_message sm;

  memset(&sm, 0, sizeof sm);
  sm.type = SM_RELOAD;
  speaker_send(speaker_fd, &sm);
}

/** @brief Called when the currently playing track finishes playing
 * @param ev Event loop or NULL
 *
 * There are three places this is called from:
 * 
 * 1) speaker_readable(), when the speaker tells us the playing track finished.
 * (Technically the speaker lies a little to arrange for gapless play.)
 *
 * 2) player_finished(), when the player for a non-raw track (i.e. one that
 * does not use the speaker) finishes.
 *
 * 3) quitting(), after signalling the decoder or player but possible before it
 * has actually terminated.  In this case @p ev is NULL, inhibiting any further
 * attempt to play anything.
 */
static void finished(ev_source *ev) {
  D(("finished playing=%p", (void *)playing));
  if(!playing)
    return;
  if(playing->state != playing_scratched)
    notify_not_scratched(playing->track, playing->submitter);
  switch(playing->state) {
  case playing_ok:
    eventlog("completed", playing->track, (char *)0);
    break;
  case playing_scratched:
    eventlog("scratched", playing->track, playing->scratched, (char *)0);
    break;
  case playing_failed:
    eventlog("failed", playing->track, wstat(playing->wstat), (char *)0);
    break;
  default:
    break;
  }
  queue_played(playing);
  recent_write();
  forget_player_pid(playing->id);
  playing = 0;
  /* Try to play something else */
  /* TODO re-support config->gap? */
  if(ev)
    play(ev);
}

/** @brief Called when a player or decoder process terminates
 *
 * This is called when a decoder process terminates (which might actually be
 * some time before the speaker reports it as finished) or when a non-raw
 * (i.e. non-speaker) player terminates.  In the latter case it's imaginable
 * that the OS has buffered the last few samples.
 * 
 */
static int player_finished(ev_source *ev,
			   pid_t pid,
			   int status,
			   const struct rusage attribute((unused)) *rusage,
			   void *u) {
  struct queue_entry *q = u;

  D(("player_finished pid=%lu status=%#x",
     (unsigned long)pid, (unsigned)status));
  /* Record that this PID is dead.  If we killed the track we might know this
   * already, but also it might have exited or crashed.  Either way we don't
   * want to end up signalling it. */
  if(pid == find_player_pid(q->id))
    forget_player_pid(q->id);
  switch(q->state) {
  case playing_unplayed:
  case playing_random:
    /* If this was a pre-prepared track then either it failed or we
     * deliberately stopped it: it might have been removed from the queue, or
     * moved down the queue, or the speaker might be on a break.  So we leave
     * it state alone for future use.
     */
    break;
  default:
    /* We actually started playing this track. */
    if(status) {
      /* Don't override 'scratched' with 'failed'. */
      if(q->state != playing_scratched)
	q->state = playing_failed;
    } else 
      q->state = playing_ok;
    break;
  }
  /* Regardless we always report and record the status and do cleanup for
   * prefork calls. */
  if(status)
    error(0, "player for %s %s", q->track, wstat(status));
  if(q->type & DISORDER_PLAYER_PREFORK)
    play_cleanup(q->pl, q->data);
  q->wstat = status;
  /* If this actually was the current track, and does not use the speaker
   * process, then it must have finished.  For raw-output players we will get a
   * separate notification from the speaker process. */
  if(q == playing
     && (q->type & DISORDER_PLAYER_TYPEMASK) != DISORDER_PLAYER_RAW)
    finished(ev);
  return 0;
}

/** @brief Find the player for @p q */
static int find_player(const struct queue_entry *q) {
  int n;
  
  for(n = 0; n < config->player.n; ++n)
    if(fnmatch(config->player.s[n].s[0], q->track, 0) == 0)
      break;
  if(n >= config->player.n)
    return -1;
  else
    return n;
}

/* Return values from start() */
#define START_OK 0	   /**< @brief Succeeded. */
#define START_HARDFAIL 1   /**< @brief Track is broken. */
#define START_SOFTFAIL 2   /**< @brief Track OK, system (temporarily?) broken */

/** @brief Play or prepare @p q
 * @param ev Event loop
 * @param q Track to play/prepare
 * @param prepare_only If true, only prepares track
 * @return @ref START_OK, @ref START_HARDFAIL or @ref START_SOFTFAIL
 *
 * TODO: probably ought to be split up into separate prepare() and start()
 * operations, the latter calling the former if necessary and perhaps the two
 * sharing some subprocess creation logic.
 *
 * "Preparing" a track means starting a background decoder and connecting it to
 * the speaker process.  Obviously this only applies to raw-format
 * (i.e. speaker-using) players.
 */
static int start(ev_source *ev,
		 struct queue_entry *q,
		 int prepare_only) {
  int n, lfd;
  const char *p;
  int np[2], sfd;
  struct speaker_message sm;
  char buffer[64];
  int optc;
  ao_sample_format format;
  ao_device *device;
  int retries;
  struct timespec ts;
  const char *waitdevice = 0;
  const char *const *optv;
  pid_t pid, npid;
  struct sockaddr_un addr;
  uint32_t l;

  memset(&sm, 0, sizeof sm);
  D(("start %s %d", q->id, prepare_only));
  if(q->prepared) {
    /* The track is already prepared */
    if(!prepare_only) {
      /* We want to run it, since it's prepared the answer is to tell the
       * speaker to set it off */
      strcpy(sm.id, q->id);
      sm.type = SM_PLAY;
      speaker_send(speaker_fd, &sm);
      D(("sent SM_PLAY for %s", sm.id));
    }
    return START_OK;
  }
  /* Find the player plugin. */
  if((n = find_player(q)) < 0) return START_HARDFAIL;
  if(!(q->pl = open_plugin(config->player.s[n].s[1], 0)))
    return START_HARDFAIL;
  q->type = play_get_type(q->pl);
  /* Can't prepare non-raw tracks. */
  if(prepare_only
     && (q->type & DISORDER_PLAYER_TYPEMASK) != DISORDER_PLAYER_RAW)
    return START_OK;
  /* Call the prefork function in the player module.  None of the built-in
   * modules use this so it's not well tested, unfortunately. */
  p = trackdb_rawpath(q->track);
  if(q->type & DISORDER_PLAYER_PREFORK)
    if(!(q->data = play_prefork(q->pl, p))) {
      error(0, "prefork function for %s failed", q->track);
      return START_HARDFAIL;
    }
  /* Capture the player/decoder's stderr and feed it into our logs.
   *
   * Use the second arg as the tag if available (it's probably a command name),
   * otherwise the module name. */
  if(!isatty(2))
    lfd = logfd(ev, (config->player.s[n].s[2]
		     ? config->player.s[n].s[2] : config->player.s[n].s[1]));
  else
    lfd = -1;
  /* Parse player arguments */
  optc = config->player.s[n].n - 2;
  optv = (void *)&config->player.s[n].s[2];
  while(optc > 0 && optv[0][0] == '-') {
    if(!strcmp(optv[0], "--")) {
      ++optv;
      --optc;
      break;
    }
    if(!strcmp(optv[0], "--wait-for-device")
       || !strncmp(optv[0], "--wait-for-device=", 18)) {
      if((waitdevice = strchr(optv[0], '='))) {
	++waitdevice;
      } else
	waitdevice = "";		/* use default */
      ++optv;
      --optc;
    } else {
      error(0, "unknown option %s", optv[0]);
      return START_HARDFAIL;
    }
  }
  /* Create the subprocess */
  switch(pid = fork()) {
  case 0:
    /* Child of disorderd */
    exitfn = _exit;
    progname = "disorderd-fork";
    ev_signal_atfork(ev);
    signal(SIGPIPE, SIG_DFL);
    /* Send our log output to DisOrder's logs */
    if(lfd != -1) {
      xdup2(lfd, 1);
      xdup2(lfd, 2);
      xclose(lfd);			/* tidy up */
    }
    /* Create a new process group, ID = child PID */
    setpgid(0, 0);
    if((q->type & DISORDER_PLAYER_TYPEMASK) == DISORDER_PLAYER_RAW) {
      /* "Raw" format players always have their output send down a pipe
       * to the disorder-normalize process.  This will connect to the
       * speaker process to actually play the audio data.
       */
      /* np will be the pipe to disorder-normalize */
      if(socketpair(PF_UNIX, SOCK_STREAM, 0, np) < 0)
	fatal(errno, "error calling socketpair");
      /* Beware of the Leopard!  On OS X 10.5.x, the order of the shutdown
       * calls here DOES MATTER.  If you do the SHUT_WR first then the SHUT_RD
       * fails with "Socket is not connected".  I think this is a bug but
       * provided implementors either don't care about the order or all agree
       * about the order, choosing the reliable order is an adequate
       * workaround.  */
      xshutdown(np[1], SHUT_RD);	/* decoder writes to np[1] */
      xshutdown(np[0], SHUT_WR);	/* normalize reads from np[0] */
      blocking(np[0]);
      blocking(np[1]);
      /* Start disorder-normalize.  We double-fork so that nothing has to wait
       * for disorder-normalize. */
      if(!(npid = xfork())) {
        /* Grandchild of disorderd */
	if(!xfork()) {
          /* Great-grandchild of disorderd */
	  /* Connect to the speaker process */
	  memset(&addr, 0, sizeof addr);
	  addr.sun_family = AF_UNIX;
	  snprintf(addr.sun_path, sizeof addr.sun_path,
		   "%s/speaker/socket", config->home);
	  sfd = xsocket(PF_UNIX, SOCK_STREAM, 0);
	  if(connect(sfd, (const struct sockaddr *)&addr, sizeof addr) < 0)
	    fatal(errno, "connecting to %s", addr.sun_path);
          /* Send the ID, with a NATIVE-ENDIAN 32 bit length */
	  l = strlen(q->id);
	  if(write(sfd, &l, sizeof l) < 0
	     || write(sfd, q->id, l) < 0)
	    fatal(errno, "writing to %s", addr.sun_path);
	  /* Await the ack */
	  if (read(sfd, &l, 1) < 0) 
		fatal(errno, "reading ack from %s", addr.sun_path);
	  /* Plumbing */
	  xdup2(np[0], 0);
	  xdup2(sfd, 1);
	  xclose(np[0]);
	  xclose(np[1]);
	  xclose(sfd);
	  /* Ask the speaker to actually start playing the track; we do it here
	   * so it's definitely after ack.
           *
           * This is actually insufficient.  If the track is prepared and then
           * very shortly afterwards played, then the race we're trying to
           * avoid here will still exist.  So either the speaker must cope with
           * SM_PLAY before connection has arrived (in which case we might as
           * well move the SM_PLAY somewhere saner) or we must do more work
           * here to avoid the race.
           *
           * In fact the current speaker can indeed cope with SM_PLAY before
           * the connection arrives.  So this code can probably be moved
           * somewhere saner in due course.  TODO!
           */
	  if(!prepare_only) {
	    strcpy(sm.id, q->id);
	    sm.type = SM_PLAY;
	    speaker_send(speaker_fd, &sm);
	    D(("sent SM_PLAY for %s", sm.id));
	  }
	  /* TODO stderr shouldn't be redirected for disorder-normalize
	   * (but it should be for play_track() */
	  execlp("disorder-normalize", "disorder-normalize",
		 log_default == &log_syslog ? "--syslog" : "--no-syslog",
		 "--config", configfile,
		 (char *)0);
	  fatal(errno, "executing disorder-normalize");
	  /* End of the great-grandchild of disorderd */
	}
        /* Back in the grandchild of disorderd */
	_exit(0);
        /* End of the grandchild of disorderd */
      }
      /* Back in the child of disorderd */
      /* Wait for the grandchild of disordered to finish */
      while(waitpid(npid, &n, 0) < 0 && errno == EINTR)
	;
      /* Pass the file descriptor to the driver in an environment
       * variable. */
      snprintf(buffer, sizeof buffer, "DISORDER_RAW_FD=%d", np[1]);
      if(putenv(buffer) < 0)
	fatal(errno, "error calling putenv");
      /* Close all the FDs we don't need */
      xclose(np[0]);
    }
    /* Wait for a device to clear.  This ugliness is now deprecated and will
     * eventually be removed. */
    if(waitdevice) {
      ao_initialize();
      if(*waitdevice) {
	n = ao_driver_id(waitdevice);
	if(n == -1)
	  fatal(0, "invalid libao driver: %s", optv[0]);
	} else
	  n = ao_default_driver_id();
      /* Make up a format. */
      memset(&format, 0, sizeof format);
      format.bits = 8;
      format.rate = 44100;
      format.channels = 1;
      format.byte_format = AO_FMT_NATIVE;
      retries = 20;
      ts.tv_sec = 0;
      ts.tv_nsec = 100000000;	/* 0.1s */
      while((device = ao_open_live(n, &format, 0)) == 0 && retries-- > 0)
	  nanosleep(&ts, 0);
      if(device)
	ao_close(device);
    }
    play_track(q->pl,
	       optv, optc,
	       p,
	       q->track);
    /* End of child of disorderd */
    _exit(0);
  case -1:
    /* Back in disorderd (child could not be created) */
    error(errno, "error calling fork");
    if(q->type & DISORDER_PLAYER_PREFORK)
      play_cleanup(q->pl, q->data);	/* else would leak */
    if(lfd != -1)
      xclose(lfd);
    return START_SOFTFAIL;
  }
  /* Back in disorderd (child was created) */
  /* Remmber the PID */
  store_player_pid(q->id, pid);
  /* This track is prepared.  (Non-raw tracks are by implication prepared as
   * soon as they are playing, but really the question doesn't make much sense
   * for them.) */
  q->prepared = 1;
  if(lfd != -1)
    xclose(lfd);
  /* Set the child's process group ID.
   *
   * But wait, didn't we already set it in the child?  Yes, but it's possible
   * that we'll need to address it by process group ID before it gets that far,
   * so we set it here too.  One or the other may fail but as long as one
   * succeeds that's fine.
   */
  setpgid(pid, pid);
  /* Ask the event loop to tell us when the child terminates */
  ev_child(ev, pid, 0, player_finished, q);
  D(("player subprocess ID %lu", (unsigned long)pid));
  return START_OK;
}

/** @brief Prepare a track for later play
 *
 * Only applies to raw-format (speaker-using) players.
 */
int prepare(ev_source *ev,
	    struct queue_entry *q) {
  int n;

  /* Find the player plugin */
  if(find_player_pid(q->id) > 0) return 0; /* Already going. */
  if((n = find_player(q)) < 0) return -1; /* No player */
  q->pl = open_plugin(config->player.s[n].s[1], 0); /* No player */
  q->type = play_get_type(q->pl);
  if((q->type & DISORDER_PLAYER_TYPEMASK) != DISORDER_PLAYER_RAW)
    return 0;				/* Not a raw player */
  return start(ev, q, 1/*prepare_only*/); /* Prepare it */
}

/** @brief Abandon a queue entry
 *
 * Called from c_remove() (but NOT when scratching a track).  Only does
 * anything to raw-format tracks.  Terminates the background decoder and tells
 * the speaker process to cancel the track.
 */
void abandon(ev_source attribute((unused)) *ev,
	     struct queue_entry *q) {
  struct speaker_message sm;
  pid_t pid = find_player_pid(q->id);

  if(pid < 0) return;			/* Not prepared. */
  if((q->type & DISORDER_PLAYER_TYPEMASK) != DISORDER_PLAYER_RAW)
    return;				/* Not a raw player. */
  /* Terminate the player. */
  kill(-pid, config->signal);
  forget_player_pid(q->id);
  /* Cancel the track. */
  memset(&sm, 0, sizeof sm);
  sm.type = SM_CANCEL;
  strcpy(sm.id, q->id);
  speaker_send(speaker_fd, &sm);
}

/** @brief Called with a new random track
 * @param ev Event loop
 * @param track Track name
 */
static void chosen_random_track(ev_source *ev,
				const char *track) {
  struct queue_entry *q;

  if(!track)
    return;
  /* Add the track to the queue */
  q = queue_add(track, 0, WHERE_END, origin_random);
  D(("picked %p (%s) at random", (void *)q, q->track));
  queue_write();
  /* Maybe a track can now be played */
  play(ev);
}

/** @brief Maybe add a randomly chosen track
 * @param ev Event loop
 *
 * Picking can take some time so the track will only be added after this
 * function has returned.
 */
void add_random_track(ev_source *ev) {
  struct queue_entry *q;
  long qlen = 0;

  /* If random play is not enabled then do nothing. */
  if(shutting_down || !random_is_enabled())
    return;
  /* Count how big the queue is */
  for(q = qhead.next; q != &qhead; q = q->next)
    ++qlen;
  /* If it's smaller than the desired size then add a track */
  if(qlen < config->queue_pad)
    trackdb_request_random(ev, chosen_random_track);
}

/** @brief Attempt to play something
 *
 * This is called from numerous locations - whenever it might conceivably have
 * become possible to play something.
 */
void play(ev_source *ev) {
  struct queue_entry *q;
  int random_enabled = random_is_enabled();

  D(("play playing=%p", (void *)playing));
  /* If we're shutting down, or there's something playing, or playing is not
   * enabled, give up now */
  if(shutting_down || playing || !playing_is_enabled()) return;
  /* See if there's anything to play */
  if(qhead.next == &qhead) {
    /* Queue is empty.  We could just wait around since there are periodic
     * attempts to add a random track anyway.  However they are rarer than
     * attempts to force a track so we initiate one now. */
    add_random_track(ev);
    /* chosen_random_track() will call play() when a new random track has been
     * added to the queue. */
    return;
  }
  /* There must be at least one track in the queue. */
  q = qhead.next;
  /* If random play is disabled but the track is a non-adopted random one
   * then don't play it.  play() will be called again when random play is
   * re-enabled. */
  if(!random_enabled && q->origin == origin_random)
    return;
  D(("taken %p (%s) from queue", (void *)q, q->track));
  /* Try to start playing. */
  switch(start(ev, q, 0/*!prepare_only*/)) {
  case START_HARDFAIL:
    if(q == qhead.next) {
      queue_remove(q, 0);		/* Abandon this track. */
      queue_played(q);
      recent_write();
    }
    /* Oh well, try the next one */
    play(ev);
    break;
  case START_SOFTFAIL:
    /* We'll try the same track again shortly. */
    break;
  case START_OK:
    /* Remove from the queue */
    if(q == qhead.next) {
      queue_remove(q, 0);
      queue_write();
    }
    /* It's become the playing track */
    playing = q;
    time(&playing->played);
    playing->state = playing_started;
    notify_play(playing->track, playing->submitter);
    eventlog("playing", playing->track,
	     playing->submitter ? playing->submitter : (const char *)0,
	     (const char *)0);
    /* Maybe add a random track. */
    add_random_track(ev);
    /* If there is another track in the queue prepare it now.  This could
     * potentially be a just-added random track. */
    if(qhead.next != &qhead)
      prepare(ev, qhead.next);
    break;
  }
}

/** @brief Return true if play is enabled */
int playing_is_enabled(void) {
  const char *s = trackdb_get_global("playing");

  return !s || !strcmp(s, "yes");
}

/** @brief Enable play */
void enable_playing(const char *who, ev_source *ev) {
  trackdb_set_global("playing", "yes", who);
  /* Add a random track if necessary. */
  add_random_track(ev);
  play(ev);
}

/** @brief Disable play */
void disable_playing(const char *who) {
  trackdb_set_global("playing", "no", who);
}

/** @brief Return true if random play is enabled */
int random_is_enabled(void) {
  const char *s = trackdb_get_global("random-play");

  return !s || !strcmp(s, "yes");
}

/** @brief Enable random play */
void enable_random(const char *who, ev_source *ev) {
  trackdb_set_global("random-play", "yes", who);
  add_random_track(ev);
  play(ev);
}

/** @brief Disable random play */
void disable_random(const char *who) {
  trackdb_set_global("random-play", "no", who);
}

/** @brief Scratch a track
 * @param User responsible (or NULL)
 * @param Track ID (or NULL for current)
 */
void scratch(const char *who, const char *id) {
  struct queue_entry *q;
  struct speaker_message sm;
  pid_t pid;

  D(("scratch playing=%p state=%d id=%s playing->id=%s",
     (void *)playing,
     playing ? playing->state : 0,
     id ? id : "(none)",
     playing ? playing->id : "(none)"));
  /* There must be a playing track; it must be in a scratchable state; if a
   * specific ID was mentioned it must be that track. */
  if(playing
     && (playing->state == playing_started
	 || playing->state == playing_paused)
     && (!id
	 || !strcmp(id, playing->id))) {
    /* Update state (for the benefit of the 'recent' list) */
    playing->state = playing_scratched;
    playing->scratched = who ? xstrdup(who) : 0;
    /* Find the player and kill the whole process group */
    if((pid = find_player_pid(playing->id)) > 0) {
      D(("kill -%d -%lu", config->signal, (unsigned long)pid));
      kill(-pid, config->signal);
      forget_player_pid(playing->id);
    } else {
      /* TODO if the background decoder finished and the speaker is working
       * through buffered data this will produce a bogus log message. */
      error(0, "could not find PID for %s", playing->id);
    }
    /* Tell the speaker, if we think it'll care */
    if((playing->type & DISORDER_PLAYER_TYPEMASK) == DISORDER_PLAYER_RAW) {
      memset(&sm, 0, sizeof sm);
      sm.type = SM_CANCEL;
      strcpy(sm.id, playing->id);
      speaker_send(speaker_fd, &sm);
      D(("sending SM_CANCEL for %s", playing->id));
    }
    /* put a scratch track onto the front of the queue (but don't
     * bother if playing is disabled) */
    if(playing_is_enabled() && config->scratch.n) {
      int r = rand() * (double)config->scratch.n / (RAND_MAX + 1.0);
      q = queue_add(config->scratch.s[r], who, WHERE_START, origin_scratch);
    }
    notify_scratch(playing->track, playing->submitter, who,
		   time(0) - playing->played);
  }
}

/** @brief Called from quit() to tear down eveyrthing belonging to this file */
void quitting(ev_source *ev) {
  struct queue_entry *q;
  pid_t pid;

  /* Don't start anything new */
  shutting_down = 1;
  /* Shut down the current player */
  if(playing) {
    if((pid = find_player_pid(playing->id)) > 0) {
      kill(-pid, config->signal);
      forget_player_pid(playing->id);
    } else{
      /* TODO if the background decoder finished and the speaker is working
       * through buffered data this will produce a bogus log message. */
      error(0, "could not find PID for %s", playing->id);
    }
    playing->state = playing_quitting;
    finished(0);
  }
  /* Zap any other players */
  for(q = qhead.next; q != &qhead; q = q->next)
    if((pid = find_player_pid(q->id)) > 0) {
      D(("kill -%d %lu", config->signal, (unsigned long)pid));
      kill(-pid, config->signal);
      forget_player_pid(q->id);
    } else {
      /* TODO if we never started a background decoder then this will produce a
       * very bogus log message (see issue 32) */
      error(0, "could not find PID for %s", q->id);
    }
  /* Don't need the speaker any more */
  ev_fd_cancel(ev, ev_read, speaker_fd);
  xclose(speaker_fd);
}

/** @brief Pause the playing track */
int pause_playing(const char *who) {
  struct speaker_message sm;
  long played;
  
  /* Can't pause if already paused or if nothing playing. */
  if(!playing || paused) return 0;
  switch(playing->type & DISORDER_PLAYER_TYPEMASK) {
  case DISORDER_PLAYER_STANDALONE:
    if(!(playing->type & DISORDER_PLAYER_PAUSES)) {
    default:
      error(0,  "cannot pause because player is not powerful enough");
      return -1;
    }
    if(play_pause(playing->pl, &played, playing->data)) {
      error(0, "player indicates it cannot pause");
      return -1;
    }
    time(&playing->lastpaused);
    playing->uptopause = played;
    playing->lastresumed = 0;
    break;
  case DISORDER_PLAYER_RAW:
    memset(&sm, 0, sizeof sm);
    sm.type = SM_PAUSE;
    speaker_send(speaker_fd, &sm);
    break;
  }
  if(who) info("paused by %s", who);
  notify_pause(playing->track, who);
  paused = 1;
  if(playing->state == playing_started)
    playing->state = playing_paused;
  eventlog("state", "pause", (char *)0);
  return 0;
}

/** @brief Resume playing after a pause */
void resume_playing(const char *who) {
  struct speaker_message sm;

  if(!paused) return;
  paused = 0;
  if(!playing) return;
  switch(playing->type & DISORDER_PLAYER_TYPEMASK) {
  case DISORDER_PLAYER_STANDALONE:
    if(!playing->type & DISORDER_PLAYER_PAUSES) {
    default:
      /* Shouldn't happen */
      return;
    }
    play_resume(playing->pl, playing->data);
    time(&playing->lastresumed);
    break;
  case DISORDER_PLAYER_RAW:
    memset(&sm, 0, sizeof sm);
    sm.type = SM_RESUME;
    speaker_send(speaker_fd, &sm);
    break;
  }
  if(who) info("resumed by %s", who);
  notify_resume(playing->track, who);
  if(playing->state == playing_paused)
    playing->state = playing_started;
  eventlog("state", "resume", (char *)0);
}

/*
Local Variables:
c-basic-offset:2
comment-column:40
fill-column:79
indent-tabs-mode:nil
End:
*/