static pid_t rescan_pid = -1; /* rescanner PID */
static int initialized, opened; /* state */
-/* tracks matched by required_tags */
-static char **reqtracks;
-static size_t nreqtracks;
-
/* comparison function for keys */
static int compare(DB attribute((unused)) *db_,
const DBT *a, const DBT *b) {
return compare_path_raw(a->data, a->size, b->data, b->size);
}
+ /** @brief Test whether the track database can be read
+ * @return 1 if it can, 0 if it cannot
+ */
+ int trackdb_readable(void) {
+ char *usersdb;
+
+ byte_xasprintf(&usersdb, "%s/users.db", config->home);
+ return access(usersdb, R_OK) == 0;
+ }
+
/** @brief Open database environment
* @param flags Flags word
*
}
/* Parse and de-dupe a tag list. If S=0 then assumes "". */
-static char **parsetags(const char *s) {
+char **parsetags(const char *s) {
const char *t;
struct vector v;
for(n = 0; w[n]; ++n)
if((err = register_tag(track, w[n], tid)))
return err;
- reqtracks = 0;
/* only store the tracks.db entry if it has changed */
if(t_changed && (err = trackdb_putdata(trackdb_tracksdb, track, t, tid, 0)))
return err;
if(trackdb_delkeydata(trackdb_tagsdb,
w[n], track, tid) == DB_LOCK_DEADLOCK)
return err;
- reqtracks = 0;
/* update tracks.db */
if(trackdb_delkey(trackdb_tracksdb, track, tid) == DB_LOCK_DEADLOCK)
return err;
++newtags;
}
}
- reqtracks = 0;
}
}
err = 0;
}
/* return 1 iff sorted tag lists A and B have at least one member in common */
-static int tag_intersection(char **a, char **b) {
+int tag_intersection(char **a, char **b) {
int cmp;
/* Same sort of logic as trackdb_set() above */
return 0;
}
-/* Check whether a track is suitable for random play. Returns 0 if it is,
- * DB_NOTFOUND if it is not or DB_LOCK_DEADLOCK if the database gave us
- * that. */
-static int check_suitable(const char *track,
- DB_TXN *tid,
- char **required_tags,
- char **prohibited_tags) {
- char **track_tags;
- time_t last, now;
- struct kvp *p, *t;
- const char *pick_at_random, *played_time;
-
- /* don't pick tracks that aren't in any surviving collection (for instance
- * you've edited the config but the rescan hasn't done its job yet) */
- if(!find_track_root(track)) {
- info("found track not in any collection: %s", track);
- return DB_NOTFOUND;
- }
- /* don't pick aliases - only pick the canonical form */
- if(gettrackdata(track, &t, &p, 0, 0, tid) == DB_LOCK_DEADLOCK)
- return DB_LOCK_DEADLOCK;
- if(kvp_get(t, "_alias_for"))
- return DB_NOTFOUND;
- /* check that random play is not suppressed for this track */
- if((pick_at_random = kvp_get(p, "pick_at_random"))
- && !strcmp(pick_at_random, "0"))
- return DB_NOTFOUND;
- /* don't pick a track that's been played in the last 8 hours */
- if((played_time = kvp_get(p, "played_time"))) {
- last = atoll(played_time);
- now = time(0);
- if(now < last + 8 * 3600) /* TODO configurable */
- return DB_NOTFOUND;
- }
- track_tags = parsetags(kvp_get(p, "tags"));
- /* check that no prohibited tag is present for this track */
- if(prohibited_tags && tag_intersection(track_tags, prohibited_tags))
- return DB_NOTFOUND;
- /* check that at least one required tags is present for this track */
- if(*required_tags && !tag_intersection(track_tags, required_tags))
- return DB_NOTFOUND;
+static pid_t choose_pid = -1;
+static int choose_fd;
+static random_callback *choose_callback;
+static struct dynstr choose_output;
+static unsigned choose_complete;
+static int choose_status;
+#define CHOOSE_RUNNING 1
+#define CHOOSE_READING 2
+
+static void choose_finished(ev_source *ev, unsigned which) {
+ choose_complete |= which;
+ if(choose_complete != (CHOOSE_RUNNING|CHOOSE_READING))
+ return;
+ choose_pid = -1;
+ if(choose_status == 0 && choose_output.nvec > 0) {
+ dynstr_terminate(&choose_output);
+ choose_callback(ev, xstrdup(choose_output.vec));
+ } else
+ choose_callback(ev, 0);
+}
+
+/** @brief Called when @c disorder-choose terminates */
+static int choose_exited(ev_source *ev,
+ pid_t attribute((unused)) pid,
+ int status,
+ const struct rusage attribute((unused)) *rusage,
+ void attribute((unused)) *u) {
+ if(status)
+ error(0, "disorder-choose %s", wstat(status));
+ choose_status = status;
+ choose_finished(ev, CHOOSE_RUNNING);
return 0;
}
-/* attempt to pick a random non-alias track */
-const char *trackdb_random(int tries) {
- DBT key, data;
- DB_BTREE_STAT *sp;
- int err, n;
- DB_TXN *tid;
- const char *track, *candidate;
- db_recno_t r;
- const char *tags;
- char **required_tags, **prohibited_tags, **tp;
- hash *h;
- DBC *c = 0;
+/** @brief Called with data from @c disorder-choose pipe */
+static int choose_readable(ev_source *ev,
+ ev_reader *reader,
+ void *ptr,
+ size_t bytes,
+ int eof,
+ void attribute((unused)) *u) {
+ dynstr_append_bytes(&choose_output, ptr, bytes);
+ ev_reader_consume(reader, bytes);
+ if(eof)
+ choose_finished(ev, CHOOSE_READING);
+ return 0;
+}
- for(;;) {
- tid = trackdb_begin_transaction();
- if((err = trackdb_get_global_tid("required-tags", tid, &tags)))
- goto fail;
- required_tags = parsetags(tags);
- if((err = trackdb_get_global_tid("prohibited-tags", tid, &tags)))
- goto fail;
- prohibited_tags = parsetags(tags);
- track = 0;
- if(*required_tags) {
- /* Bung all the suitable tracks into a hash and convert to a list of keys
- * (to eliminate duplicates). We cache this list since it is possible
- * that it will be very large. */
- if(!reqtracks) {
- h = hash_new(0);
- for(tp = required_tags; *tp; ++tp) {
- c = trackdb_opencursor(trackdb_tagsdb, tid);
- memset(&key, 0, sizeof key);
- key.data = *tp;
- key.size = strlen(*tp);
- n = 0;
- err = c->c_get(c, &key, prepare_data(&data), DB_SET);
- while(err == 0) {
- hash_add(h, xstrndup(data.data, data.size), 0,
- HASH_INSERT_OR_REPLACE);
- ++n;
- err = c->c_get(c, &key, prepare_data(&data), DB_NEXT_DUP);
- }
- switch(err) {
- case 0:
- case DB_NOTFOUND:
- break;
- case DB_LOCK_DEADLOCK:
- goto fail;
- default:
- fatal(0, "error querying tags.db: %s", db_strerror(err));
- }
- trackdb_closecursor(c);
- c = 0;
- if(!n)
- error(0, "required tag %s does not match any tracks", *tp);
- }
- nreqtracks = hash_count(h);
- reqtracks = hash_keys(h);
- }
- while(nreqtracks && !track && tries-- > 0) {
- r = (rand() * (double)nreqtracks / (RAND_MAX + 1.0));
- candidate = reqtracks[r];
- switch(check_suitable(candidate, tid,
- required_tags, prohibited_tags)) {
- case 0:
- track = candidate;
- break;
- case DB_NOTFOUND:
- break;
- case DB_LOCK_DEADLOCK:
- goto fail;
- }
- }
- } else {
- /* No required tags. We pick random record numbers in the database
- * instead. */
- switch(err = trackdb_tracksdb->stat(trackdb_tracksdb, tid, &sp, 0)) {
- case 0:
- break;
- case DB_LOCK_DEADLOCK:
- error(0, "error querying tracks.db: %s", db_strerror(err));
- goto fail;
- default:
- fatal(0, "error querying tracks.db: %s", db_strerror(err));
- }
- if(!sp->bt_nkeys)
- error(0, "cannot pick tracks at random from an empty database");
- while(sp->bt_nkeys && !track && tries-- > 0) {
- /* record numbers count from 1 upwards */
- r = 1 + (rand() * (double)sp->bt_nkeys / (RAND_MAX + 1.0));
- memset(&key, sizeof key, 0);
- key.flags = DB_DBT_MALLOC;
- key.size = sizeof r;
- key.data = &r;
- switch(err = trackdb_tracksdb->get(trackdb_tracksdb, tid, &key, prepare_data(&data),
- DB_SET_RECNO)) {
- case 0:
- break;
- case DB_LOCK_DEADLOCK:
- error(0, "error querying tracks.db: %s", db_strerror(err));
- goto fail;
- default:
- fatal(0, "error querying tracks.db: %s", db_strerror(err));
- }
- candidate = xstrndup(key.data, key.size);
- switch(check_suitable(candidate, tid,
- required_tags, prohibited_tags)) {
- case 0:
- track = candidate;
- break;
- case DB_NOTFOUND:
- break;
- case DB_LOCK_DEADLOCK:
- goto fail;
- }
- }
- }
- break;
-fail:
- trackdb_closecursor(c);
- c = 0;
- trackdb_abort_transaction(tid);
- }
- trackdb_commit_transaction(tid);
- if(!track)
- error(0, "could not pick a random track");
- return track;
+static int choose_read_error(ev_source *ev,
+ int errno_value,
+ void attribute((unused)) *u) {
+ error(errno_value, "error reading disorder-choose pipe");
+ choose_finished(ev, CHOOSE_READING);
+ return 0;
+}
+
+/** @brief Request a random track
+ * @param ev Event source
+ * @param callback Called with random track or NULL
+ * @return 0 if a request was initiated, else -1
+ *
+ * Initiates a random track choice. @p callback will later be called back with
+ * the choice (or NULL on error). If a choice is already underway then -1 is
+ * returned and there will be no additional callback.
+ *
+ * The caller shouldn't assume that the track returned actually exists (it
+ * might be removed between the choice and the callback, or between being added
+ * to the queue and being played).
+ */
+int trackdb_request_random(ev_source *ev,
+ random_callback *callback) {
+ int p[2];
+
+ if(choose_pid != -1)
+ return -1; /* don't run concurrent chooses */
+ xpipe(p);
+ cloexec(p[0]);
+ choose_pid = subprogram(ev, p[1], "disorder-choose", (char *)0);
+ choose_fd = p[0];
+ xclose(p[1]);
+ choose_callback = callback;
+ choose_output.nvec = 0;
+ choose_complete = 0;
+ ev_reader_new(ev, p[0], choose_readable, choose_read_error, 0,
+ "disorder-choose reader"); /* owns p[0] */
+ ev_child(ev, choose_pid, 0, choose_exited, 0); /* owns the subprocess */
+ return 0;
}
/* get a track name given the prefs. Set *used_db to 1 if we got the answer
int trackdb_scan(const char *root,
int (*callback)(const char *track,
struct kvp *data,
+ struct kvp *prefs,
void *u,
DB_TXN *tid),
void *u,
DB_TXN *tid) {
DBC *cursor;
- DBT k, d;
+ DBT k, d, pd;
const size_t root_len = root ? strlen(root) : 0;
int err, cberr;
- struct kvp *data;
+ struct kvp *data, *prefs;
const char *track;
cursor = trackdb_opencursor(trackdb_tracksdb, tid);
data = kvp_urldecode(d.data, d.size);
if(kvp_get(data, "_path")) {
track = xstrndup(k.data, k.size);
+ /* TODO: trackdb_prefsdb is currently a DB_HASH. This means we have to
+ * do a lookup for every single track. In fact this is quite quick:
+ * with around 10,000 tracks a complete scan is around 0.3s on my
+ * 2.2GHz Athlon. However, if it were a DB_BTREE, we could do the same
+ * linear walk as we already do over trackdb_tracksdb, and probably get
+ * even higher performance. That would require upgrade logic to
+ * translate old databases though.
+ */
+ switch(err = trackdb_prefsdb->get(trackdb_prefsdb, tid, &k,
+ prepare_data(&pd), 0)) {
+ case 0:
+ prefs = kvp_urldecode(pd.data, pd.size);
+ break;
+ case DB_NOTFOUND:
+ prefs = 0;
+ break;
+ case DB_LOCK_DEADLOCK:
+ error(0, "getting prefs: %s", db_strerror(err));
+ trackdb_closecursor(cursor);
+ return err;
+ default:
+ fatal(0, "getting prefs: %s", db_strerror(err));
+ }
/* Advance to the next track before the callback so that the callback
* may safely delete the track */
err = cursor->c_get(cursor, &k, &d, DB_NEXT);
- if((cberr = callback(track, data, u, tid))) {
+ if((cberr = callback(track, data, prefs, u, tid))) {
err = cberr;
break;
}
who ? who : "-");
eventlog("state", state ? "enable_random" : "disable_random", (char *)0);
}
- if(!strcmp(name, "required-tags"))
- reqtracks = 0;
}
int trackdb_set_global_tid(const char *name,
return -1;
}
} else if(!strcmp(key, "email")) {
- if(!strchr(value, '@')) {
- error(0, "invalid email address '%s' for user '%s'", user, value);
- return -1;
- }
+ if(*value) {
+ if(!strchr(value, '@')) {
+ error(0, "invalid email address '%s' for user '%s'", user, value);
+ return -1;
+ }
+ } else
+ value = 0; /* no email -> remove key */
} else if(!strcmp(key, "created")) {
error(0, "cannot change creation date for user '%s'", user);
return -1;
~mdw / disorder / commitdiff