[disorder] / server / choose.c

/*
 * This file is part of DisOrder 
 * Copyright (C) 2008 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 2 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, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
 * USA
 */
/** @file choose.c
 * @brief Random track chooser
 *
 * Picks a track at random and writes it to standard output.  If for
 * any reason no track can be picked - even a trivial reason like a
 * deadlock - it just exits and expects the server to try again.
 */

#include <config.h>
#include "types.h"

#include <getopt.h>
#include <stdio.h>
#include <stdlib.h>
#include <db.h>
#include <locale.h>
#include <errno.h>
#include <sys/types.h>
#include <unistd.h>
#include <pcre.h>
#include <string.h>
#include <fcntl.h>
#include <syslog.h>
#include <time.h>

#include "configuration.h"
#include "log.h"
#include "defs.h"
#include "mem.h"
#include "kvp.h"
#include "syscalls.h"
#include "printf.h"
#include "trackdb.h"
#include "trackdb-int.h"
#include "version.h"
#include "trackname.h"
#include "queue.h"
#include "server-queue.h"

static DB_TXN *global_tid;

static const struct option options[] = {
  { "help", no_argument, 0, 'h' },
  { "version", no_argument, 0, 'V' },
  { "config", required_argument, 0, 'c' },
  { "debug", no_argument, 0, 'd' },
  { "no-debug", no_argument, 0, 'D' },
  { "syslog", no_argument, 0, 's' },
  { "no-syslog", no_argument, 0, 'S' },
  { 0, 0, 0, 0 }
};

/* display usage message and terminate */
static void help(void) {
  xprintf("Usage:\n"
	  "  disorder-choose [OPTIONS]\n"
	  "Options:\n"
	  "  --help, -h              Display usage message\n"
	  "  --version, -V           Display version number\n"
	  "  --config PATH, -c PATH  Set configuration file\n"
	  "  --debug, -d             Turn on debugging\n"
          "  --[no-]syslog           Enable/disable logging to syslog\n"
          "\n"
          "Track choose for DisOrder.  Not intended to be run\n"
          "directly.\n");
  xfclose(stdout);
  exit(0);
}

/** @brief Weighted track record */
struct weighted_track {
  /** @brief Next track in the list */
  struct weighted_track *next;
  /** @brief Track name */
  const char *track;
  /** @brief Weight for this track (always positive) */
  unsigned long weight;
};

/** @brief List of tracks with nonzero weight */
static struct weighted_track *tracks;

/** @brief Sum of all weights */
static unsigned long long total_weight;

/** @brief Count of tracks */
static long ntracks;

static char **required_tags;
static char **prohibited_tags;

static int queue_contains(const struct queue_entry *head,
                          const char *track) {
  const struct queue_entry *q;

  for(q = head->next; q != head; q = q->next)
    if(!strcmp(q->track, track))
      return 1;
  return 0;
}

/** @brief Compute the weight of a track
 * @param track Track name (UTF-8)
 * @param data Track data
 * @param prefs Track preferences
 * @return Track weight (non-negative)
 *
 * Tracks to be excluded entirely are given a weight of 0.
 */
static unsigned long compute_weight(const char *track,
                                    struct kvp *data,
                                    struct kvp *prefs) {
  const char *s;
  char **track_tags;
  time_t last, now;

  /* Reject tracks not in any collection (race between edit config and
   * rescan) */
  if(!find_track_root(track)) {
    info("found track not in any collection: %s", track);
    return 0;
  }

  /* Reject aliases to avoid giving aliased tracks extra weight */
  if(kvp_get(data, "_alias_for"))
    return 0;
  
  /* Reject tracks with random play disabled */
  if((s = kvp_get(prefs, "pick_at_random"))
     && !strcmp(s, "0"))
    return 0;

  /* Reject tracks played within the last 8 hours */
  if((s = kvp_get(prefs, "played_time"))) {
    last = atoll(s);
    now = time(0);
    if(now < last + config->replay_min)
      return 0;
  }

  /* Reject tracks currently in the queue or in the recent list */
  if(queue_contains(&qhead, track)
     || queue_contains(&phead, track))
    return 0;

  /* We'll need tags for a number of things */
  track_tags = parsetags(kvp_get(prefs, "tags"));

  /* Reject tracks with prohibited tags */
  if(prohibited_tags && tag_intersection(track_tags, prohibited_tags))
    return 0;

  /* Reject tracks that lack required tags */
  if(*required_tags && !tag_intersection(track_tags, required_tags))
    return 0;

  /* Use the configured weight if available */
  if((s = kvp_get(prefs, "weight"))) {
    long n;
    errno = 0;

    n = strtol(s, 0, 10);
    if((errno == 0 || errno == ERANGE) && n >= 0)
      return n;
  }
  
  return 90000;
}

/** @brief Called for each track */
static int collect_tracks_callback(const char *track,
				   struct kvp *data,
                                   struct kvp *prefs,
				   void attribute((unused)) *u,
				   DB_TXN attribute((unused)) *tid) {
  unsigned long weight = compute_weight(track, data, prefs);

  if(weight) {
    struct weighted_track *const t = xmalloc(sizeof *t);

    /* Clamp weight so that we can fit in billions of tracks when we do
     * arithmetic in long long */
    if(weight > 0x7fffffff)
      weight = 0x7fffffff;
    t->next = tracks;
    t->track = track;
    t->weight = weight;
    tracks = t;
    total_weight += weight;
    ++ntracks;
  }
  return 0;
}

/** @brief Pick a random integer uniformly from [0, limit) */
static unsigned long long pick_weight(unsigned long long limit) {
  unsigned long long n;
  static int fd = -1;
  int r;

  if(fd < 0) {
    if((fd = open("/dev/urandom", O_RDONLY)) < 0)
      fatal(errno, "opening /dev/urandom");
  }
  if((r = read(fd, &n, sizeof n)) < 0)
    fatal(errno, "reading /dev/urandom");
  if((size_t)r < sizeof n)
    fatal(0, "short read from /dev/urandom");
  return n % limit;
}

/** @brief Pick a track at random and write it to stdout */
static void pick_track(void) {
  long long w;
  struct weighted_track *t;

  w = pick_weight(total_weight);
  t = tracks;
  while(t && w >= t->weight) {
    w -= t->weight;
    t = t->next;
  }
  if(!t)
    fatal(0, "ran out of tracks but %lld weighting left", w);
  xprintf("%s", t->track);
}

int main(int argc, char **argv) {
  int n, logsyslog = !isatty(2), err;
  const char *tags;
  
  set_progname(argv);
  mem_init();
  if(!setlocale(LC_CTYPE, "")) fatal(errno, "error calling setlocale");
  while((n = getopt_long(argc, argv, "hVc:dDSs", options, 0)) >= 0) {
    switch(n) {
    case 'h': help();
    case 'V': version("disorder-choose");
    case 'c': configfile = optarg; break;
    case 'd': debugging = 1; break;
    case 'D': debugging = 0; break;
    case 'S': logsyslog = 0; break;
    case 's': logsyslog = 1; break;
    default: fatal(0, "invalid option");
    }
  }
  if(logsyslog) {
    openlog(progname, LOG_PID, LOG_DAEMON);
    log_default = &log_syslog;
  }
  if(config_read(0)) fatal(0, "cannot read configuration");
  /* Find out current queue/recent list */
  queue_read();
  recent_read();
  /* Generate the candidate track list */
  trackdb_init(TRACKDB_NO_RECOVER);
  trackdb_open(TRACKDB_NO_UPGRADE|TRACKDB_READ_ONLY);
  global_tid = trackdb_begin_transaction();
  if((err = trackdb_get_global_tid("required-tags", global_tid, &tags)))
    fatal(0, "error getting required-tags: %s", db_strerror(err));
  required_tags = parsetags(tags);
  if((err = trackdb_get_global_tid("prohibited-tags", global_tid, &tags)))
    fatal(0, "error getting prohibited-tags: %s", db_strerror(err));
  prohibited_tags = parsetags(tags);
  if(trackdb_scan(0, collect_tracks_callback, 0, global_tid))
    exit(1);
  trackdb_commit_transaction(global_tid);
  trackdb_close();
  trackdb_deinit();
  //info("ntracks=%ld total_weight=%lld", ntracks, total_weight);
  if(!total_weight)
    fatal(0, "no tracks match random choice criteria");
  /* Pick a track */
  pick_track();
  xfclose(stdout);
  return 0;
}

/*
Local Variables:
c-basic-offset:2
comment-column:40
fill-column:79
indent-tabs-mode:nil
End:
*/
Commit	Line	Data
bea6f6d5 RK	1	/*
	2	* This file is part of DisOrder
	3	* Copyright (C) 2008 Richard Kettlewell
	4	*
	5	* This program is free software; you can redistribute it and/or modify
	6	* it under the terms of the GNU General Public License as published by
	7	* the Free Software Foundation; either version 2 of the License, or
	8	* (at your option) any later version.
	9	*
	10	* This program is distributed in the hope that it will be useful, but
	11	* WITHOUT ANY WARRANTY; without even the implied warranty of
	12	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	13	* General Public License for more details.
	14	*
	15	* You should have received a copy of the GNU General Public License
	16	* along with this program; if not, write to the Free Software
	17	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
	18	* USA
	19	*/
	20	/** @file choose.c
	21	* @brief Random track chooser
	22	*
	23	* Picks a track at random and writes it to standard output. If for
	24	* any reason no track can be picked - even a trivial reason like a
	25	* deadlock - it just exits and expects the server to try again.
	26	*/
	27
	28	#include <config.h>
	29	#include "types.h"
	30
	31	#include <getopt.h>
	32	#include <stdio.h>
	33	#include <stdlib.h>
	34	#include <db.h>
	35	#include <locale.h>
	36	#include <errno.h>
	37	#include <sys/types.h>
	38	#include <unistd.h>
	39	#include <pcre.h>
	40	#include <string.h>
	41	#include <fcntl.h>
	42	#include <syslog.h>
91c9324a	43	#include <time.h>
bea6f6d5 RK	44
	45	#include "configuration.h"
	46	#include "log.h"
	47	#include "defs.h"
	48	#include "mem.h"
	49	#include "kvp.h"
	50	#include "syscalls.h"
	51	#include "printf.h"
	52	#include "trackdb.h"
	53	#include "trackdb-int.h"
	54	#include "version.h"
91c9324a	55	#include "trackname.h"
28dc2d22 RK	56	#include "queue.h"
28dc2d22 RK	57	#include "server-queue.h"
bea6f6d5 RK	58
	59	static DB_TXN *global_tid;
	60
	61	static const struct option options[] = {
	62	{ "help", no_argument, 0, 'h' },
	63	{ "version", no_argument, 0, 'V' },
	64	{ "config", required_argument, 0, 'c' },
	65	{ "debug", no_argument, 0, 'd' },
	66	{ "no-debug", no_argument, 0, 'D' },
	67	{ "syslog", no_argument, 0, 's' },
	68	{ "no-syslog", no_argument, 0, 'S' },
	69	{ 0, 0, 0, 0 }
	70	};
	71
	72	/* display usage message and terminate */
	73	static void help(void) {
	74	xprintf("Usage:\n"
	75	" disorder-choose [OPTIONS]\n"
	76	"Options:\n"
	77	" --help, -h Display usage message\n"
	78	" --version, -V Display version number\n"
	79	" --config PATH, -c PATH Set configuration file\n"
	80	" --debug, -d Turn on debugging\n"
	81	" --[no-]syslog Enable/disable logging to syslog\n"
	82	"\n"
	83	"Track choose for DisOrder. Not intended to be run\n"
	84	"directly.\n");
	85	xfclose(stdout);
	86	exit(0);
	87	}
	88
	89	/** @brief Weighted track record */
	90	struct weighted_track {
	91	/** @brief Next track in the list */
	92	struct weighted_track *next;
	93	/** @brief Track name */
	94	const char *track;
	95	/** @brief Weight for this track (always positive) */
	96	unsigned long weight;
	97	};
	98
	99	/** @brief List of tracks with nonzero weight */
	100	static struct weighted_track *tracks;
	101
	102	/** @brief Sum of all weights */
	103	static unsigned long long total_weight;
	104
	105	/** @brief Count of tracks */
	106	static long ntracks;
	107
91c9324a RK	108	static char **required_tags;
	109	static char **prohibited_tags;
	110
28dc2d22 RK	111	static int queue_contains(const struct queue_entry *head,
	112	const char *track) {
	113	const struct queue_entry *q;
	114
	115	for(q = head->next; q != head; q = q->next)
	116	if(!strcmp(q->track, track))
	117	return 1;
	118	return 0;
	119	}
	120
bea6f6d5 RK	121	/** @brief Compute the weight of a track
	122	* @param track Track name (UTF-8)
	123	* @param data Track data
	124	* @param prefs Track preferences
	125	* @return Track weight (non-negative)
	126	*
	127	* Tracks to be excluded entirely are given a weight of 0.
	128	*/
91c9324a RK	129	static unsigned long compute_weight(const char *track,
91c9324a RK	130	struct kvp *data,
bea6f6d5 RK	131	struct kvp *prefs) {
bea6f6d5 RK	132	const char *s;
91c9324a RK	133	char **track_tags;
	134	time_t last, now;
	135
	136	/* Reject tracks not in any collection (race between edit config and
	137	* rescan) */
	138	if(!find_track_root(track)) {
	139	info("found track not in any collection: %s", track);
	140	return 0;
	141	}
bea6f6d5	142
91c9324a RK	143	/* Reject aliases to avoid giving aliased tracks extra weight */
	144	if(kvp_get(data, "_alias_for"))
	145	return 0;
	146
	147	/* Reject tracks with random play disabled */
bea6f6d5 RK	148	if((s = kvp_get(prefs, "pick_at_random"))
	149	&& !strcmp(s, "0"))
	150	return 0;
91c9324a RK	151
	152	/* Reject tracks played within the last 8 hours */
	153	if((s = kvp_get(prefs, "played_time"))) {
	154	last = atoll(s);
	155	now = time(0);
cebe3127	156	if(now < last + config->replay_min)
91c9324a RK	157	return 0;
	158	}
	159
28dc2d22 RK	160	/* Reject tracks currently in the queue or in the recent list */
	161	if(queue_contains(&qhead, track)
	162	\|\| queue_contains(&phead, track))
	163	return 0;
	164
91c9324a RK	165	/* We'll need tags for a number of things */
	166	track_tags = parsetags(kvp_get(prefs, "tags"));
	167
	168	/* Reject tracks with prohibited tags */
	169	if(prohibited_tags && tag_intersection(track_tags, prohibited_tags))
	170	return 0;
	171
	172	/* Reject tracks that lack required tags */
	173	if(*required_tags && !tag_intersection(track_tags, required_tags))
	174	return 0;
	175
36a1a882 RK	176	/* Use the configured weight if available */
	177	if((s = kvp_get(prefs, "weight"))) {
	178	long n;
	179	errno = 0;
	180
	181	n = strtol(s, 0, 10);
	182	if((errno == 0 \|\| errno == ERANGE) && n >= 0)
	183	return n;
	184	}
	185
bea6f6d5 RK	186	return 90000;
	187	}
	188
	189	/** @brief Called for each track */
	190	static int collect_tracks_callback(const char *track,
	191	struct kvp *data,
	192	struct kvp *prefs,
	193	void attribute((unused)) *u,
	194	DB_TXN attribute((unused)) *tid) {
36a1a882	195	unsigned long weight = compute_weight(track, data, prefs);
bea6f6d5 RK	196
	197	if(weight) {
	198	struct weighted_track const t = xmalloc(sizeof t);
	199
36a1a882 RK	200	/* Clamp weight so that we can fit in billions of tracks when we do
	201	* arithmetic in long long */
	202	if(weight > 0x7fffffff)
	203	weight = 0x7fffffff;
bea6f6d5 RK	204	t->next = tracks;
	205	t->track = track;
	206	t->weight = weight;
	207	tracks = t;
	208	total_weight += weight;
	209	++ntracks;
	210	}
	211	return 0;
	212	}
	213
	214	/** @brief Pick a random integer uniformly from [0, limit) */
	215	static unsigned long long pick_weight(unsigned long long limit) {
	216	unsigned long long n;
	217	static int fd = -1;
	218	int r;
	219
	220	if(fd < 0) {
	221	if((fd = open("/dev/urandom", O_RDONLY)) < 0)
	222	fatal(errno, "opening /dev/urandom");
	223	}
	224	if((r = read(fd, &n, sizeof n)) < 0)
	225	fatal(errno, "reading /dev/urandom");
	226	if((size_t)r < sizeof n)
	227	fatal(0, "short read from /dev/urandom");
	228	return n % limit;
	229	}
	230
	231	/** @brief Pick a track at random and write it to stdout */
	232	static void pick_track(void) {
	233	long long w;
	234	struct weighted_track *t;
	235
	236	w = pick_weight(total_weight);
	237	t = tracks;
	238	while(t && w >= t->weight) {
	239	w -= t->weight;
	240	t = t->next;
	241	}
	242	if(!t)
	243	fatal(0, "ran out of tracks but %lld weighting left", w);
	244	xprintf("%s", t->track);
	245	}
	246
	247	int main(int argc, char **argv) {
91c9324a RK	248	int n, logsyslog = !isatty(2), err;
91c9324a RK	249	const char *tags;
bea6f6d5 RK	250
	251	set_progname(argv);
	252	mem_init();
	253	if(!setlocale(LC_CTYPE, "")) fatal(errno, "error calling setlocale");
	254	while((n = getopt_long(argc, argv, "hVc:dDSs", options, 0)) >= 0) {
	255	switch(n) {
	256	case 'h': help();
	257	case 'V': version("disorder-choose");
	258	case 'c': configfile = optarg; break;
	259	case 'd': debugging = 1; break;
	260	case 'D': debugging = 0; break;
	261	case 'S': logsyslog = 0; break;
	262	case 's': logsyslog = 1; break;
	263	default: fatal(0, "invalid option");
	264	}
	265	}
	266	if(logsyslog) {
	267	openlog(progname, LOG_PID, LOG_DAEMON);
	268	log_default = &log_syslog;
	269	}
	270	if(config_read(0)) fatal(0, "cannot read configuration");
28dc2d22 RK	271	/* Find out current queue/recent list */
	272	queue_read();
	273	recent_read();
bea6f6d5 RK	274	/* Generate the candidate track list */
	275	trackdb_init(TRACKDB_NO_RECOVER);
	276	trackdb_open(TRACKDB_NO_UPGRADE\|TRACKDB_READ_ONLY);
	277	global_tid = trackdb_begin_transaction();
91c9324a RK	278	if((err = trackdb_get_global_tid("required-tags", global_tid, &tags)))
	279	fatal(0, "error getting required-tags: %s", db_strerror(err));
	280	required_tags = parsetags(tags);
	281	if((err = trackdb_get_global_tid("prohibited-tags", global_tid, &tags)))
	282	fatal(0, "error getting prohibited-tags: %s", db_strerror(err));
	283	prohibited_tags = parsetags(tags);
bea6f6d5 RK	284	if(trackdb_scan(0, collect_tracks_callback, 0, global_tid))
	285	exit(1);
	286	trackdb_commit_transaction(global_tid);
	287	trackdb_close();
	288	trackdb_deinit();
	289	//info("ntracks=%ld total_weight=%lld", ntracks, total_weight);
	290	if(!total_weight)
	291	fatal(0, "no tracks match random choice criteria");
	292	/* Pick a track */
	293	pick_track();
	294	xfclose(stdout);
	295	return 0;
	296	}
	297
	298	/*
	299	Local Variables:
	300	c-basic-offset:2
	301	comment-column:40
	302	fill-column:79
	303	indent-tabs-mode:nil
	304	End:
	305	*/