struct mp_context *parser_context;
/** To compute the score. */
struct afs_statistics stats;
+ /** NULL means to operate on the global score table. */
+ struct osl_table *score_table;
};
/*
if (!m)
return;
mp_shutdown(m->parser_context);
+ if (m->score_table)
+ score_close(m->score_table);
free(m->name);
free(m);
}
static int check_mood(struct osl_row *mood_row, void *data)
{
- struct para_buffer *pb = data;
+ struct afs_callback_arg *aca = data;
char *mood_name, *errmsg;
struct osl_object mood_def;
struct mood_instance *m;
int ret = mood_get_name_and_def_by_row(mood_row, &mood_name, &mood_def);
if (ret < 0) {
- para_printf(pb, "cannot read mood\n");
+ afs_error(aca, "cannot read mood\n");
return ret;
}
if (!*mood_name) /* ignore dummy row */
ret = mp_init(mood_def.data, mood_def.size, &m->parser_context,
&errmsg);
if (ret < 0) {
- para_printf(pb, "%s: %s\n", mood_name, errmsg);
+ afs_error(aca, "%s: %s\n%s\n", mood_name, errmsg,
+ para_strerror(-ret));
free(errmsg);
- para_printf(pb, "%s\n", para_strerror(-ret));
} else
destroy_mood(m);
ret = 1; /* don't fail the loop on invalid mood definitions */
/**
* Check all moods for syntax errors.
*
- * \param aca Only ->pbout is used for diagnostics.
+ * \param aca Output goes to ->pbout, errors to ->fd on the error band.
*
* \return Negative on fatal errors. Inconsistent mood definitions are not
* considered an error.
int mood_check_callback(struct afs_callback_arg *aca)
{
para_printf(&aca->pbout, "checking moods...\n");
- return osl(osl_rbtree_loop(moods_table, BLOBCOL_ID, &aca->pbout,
- check_mood));
+ return osl(osl_rbtree_loop(moods_table, BLOBCOL_ID, aca, check_mood));
}
/*
* overflows and rounding errors we store the common divisor of the
* correction factors separately.
*/
-static int64_t normalized_value(int64_t x, int64_t n, int64_t sum, int64_t qd)
-{
- if (!n || !qd)
- return 0;
- return 100 * (n * x - sum) / (int64_t)int_sqrt(n) / (int64_t)int_sqrt(qd);
-}
-
static long compute_score(struct afs_info *afsi,
const struct afs_statistics *stats)
{
- long score = -normalized_value(afsi->num_played, stats->num,
- stats->num_played_sum, stats->num_played_qd);
- score -= normalized_value(afsi->last_played, stats->num,
- stats->last_played_sum, stats->last_played_qd);
- return score / 2;
+ int64_t mean_n, mean_l,score_n, score_l;
+
+ assert(stats->normalization_divisor > 0);
+ assert(stats->num > 0);
+ mean_n = stats->num_played_sum / stats->num;
+ mean_l = stats->last_played_sum / stats->num;
+
+ score_n = -((int64_t)afsi->num_played - mean_n)
+ * stats->num_played_correction
+ / stats->normalization_divisor;
+ score_l = -((int64_t)afsi->last_played - mean_l)
+ * stats->last_played_correction
+ / stats->normalization_divisor;
+ return (score_n + score_l) / 2;
}
static int add_afs_statistics(const struct osl_row *row,
}
static int add_to_score_table(const struct osl_row *aft_row,
- const struct afs_statistics *stats)
+ struct mood_instance *m)
{
long score;
struct afs_info afsi;
if (ret < 0)
return ret;
- score = compute_score(&afsi, stats);
- return score_add(aft_row, score);
+ score = compute_score(&afsi, &m->stats);
+ return score_add(aft_row, score, m->score_table);
}
static int delete_from_statistics_and_score_table(const struct osl_row *aft_row)
ret = add_afs_statistics(aft_row, ¤t_mood->stats);
if (ret < 0)
return ret;
- return add_to_score_table(aft_row, ¤t_mood->stats);
+ return add_to_score_table(aft_row, current_mood);
}
/* update score */
ret = get_afsi_of_row(aft_row, &afsi);
unsigned n = m->stats.num;
int mean_days, sigma_days;
+ if (n == 0)
+ return make_message("no admissible files\n");
mean_days = (sse - m->stats.last_played_sum / n) / 3600 / 24;
sigma_days = int_sqrt(m->stats.last_played_qd / n) / 3600 / 24;
return make_message(
);
}
-/** Free all resources of the current mood, if any. */
-void mood_unload(void)
+/**
+ * Free all resources of a mood instance.
+ *
+ * \param m As obtained by \ref mood_load(). If NULL, unload the current mood.
+ *
+ * It's OK to call this with m == NULL even if no current mood is loaded.
+ */
+void mood_unload(struct mood_instance *m)
{
+ if (m)
+ return destroy_mood(m);
destroy_mood(current_mood);
current_mood = NULL;
}
}
/**
- * Change the current mood.
+ * Populate a score table with admissible files for the given mood.
+ *
+ * This consults the mood table to initialize the mood parser with the mood
+ * expression stored in the blob object which corresponds to the given name. A
+ * score table is allocated and populated with references to those entries of
+ * the audio file table which evaluate as admissible with respect to the mood
+ * expression. For each audio file a score value is computed and stored along
+ * with the file reference.
*
* \param mood_name The name of the mood to load.
+ * \param result Opaque, refers to the mood parser and the score table.
* \param msg Error message or mood info is returned here.
*
- * If \a mood_name is \a NULL, load the dummy mood that accepts every audio file
- * and uses a scoring method based only on the \a last_played information.
+ * If the mood name is NULL, the dummy mood is loaded. This mood regards every
+ * audio file as admissible.
+ *
+ * A NULL result pointer instructs the function to operate on the current mood.
+ * That is, on the mood instance which is used by the server to select the next
+ * audio file for streaming. In this mode of operation, the mood which was
+ * active before the call, if any, is unloaded on success.
+ *
+ * If result is not NULL, the current mood is unaffected and *result points to
+ * an initialized mood instance on success. The caller can pass this reference
+ * to \ref mood_loop() to iterate over the admissible files, and should call
+ * \ref mood_unload() to free the mood instance afterwards.
*
* If the message pointer is not NULL, a suitable message is returned there in
* all cases. The caller must free this string.
*
- * \return The number of admissible files on success, negative on errors. It is
+ * \return The number of admissible files on success, negative on errors. On
+ * errors, the current mood remains unaffected even if result is NULL. It is
* not considered an error if no files are admissible.
*
- * \sa struct \ref afs_info::last_played, \ref mp_eval_row().
+ * \sa \ref mp_eval_row().
*/
-int mood_load(const char *mood_name, char **msg)
+int mood_load(const char *mood_name, struct mood_instance **result, char **msg)
{
int i, ret;
struct admissible_array aa = {.size = 0};
}
clock_get_realtime(&rnow);
compute_correction_factors(rnow.tv_sec, &aa.m->stats);
- if (aa.m->stats.num == 0) {
- if (msg)
- *msg = make_message("no admissible files\n");
- ret = 0;
- goto out;
- }
+ if (result)
+ score_open(&aa.m->score_table);
for (i = 0; i < aa.m->stats.num; i++) {
- ret = add_to_score_table(aa.array[i], &aa.m->stats);
+ ret = add_to_score_table(aa.array[i], aa.m);
if (ret < 0) {
if (msg)
*msg = make_message(
if (msg)
*msg = get_statistics(aa.m, rnow.tv_sec);
ret = aa.m->stats.num;
- mood_unload();
- current_mood = aa.m;
+ if (result)
+ *result = aa.m;
+ else {
+ mood_unload(NULL);
+ current_mood = aa.m;
+ }
+ ret = 1;
out:
free(aa.array);
- if (ret < 0)
+ if (ret <= 0) /* error, or no admissible files */
destroy_mood(aa.m);
return ret;
}
+/**
+ * Iterate over the admissible files of a mood instance.
+ *
+ * This wrapper around \ref score_loop() is the mood counterpart of \ref
+ * playlist_loop().
+ *
+ * \param m Determines the score table to iterate. Must not be NULL.
+ * \param func See \ref score_loop().
+ * \param data See \ref score_loop().
+ *
+ * \return See \ref score_loop(), \ref playlist_loop().
+ */
+int mood_loop(struct mood_instance *m, osl_rbtree_loop_func *func, void *data)
+{
+ return score_loop(func, m->score_table, data);
+}
+
/*
* Empty the score table and start over.
*
- * This function is called on events which render the current list of
- * admissible files useless, for example if an attribute is removed from the
- * attribute table.
+ * This function is called on events which render the current set of admissible
+ * files invalid, for example if an attribute is removed from the attribute
+ * table.
*/
static int reload_current_mood(void)
{
current_mood->name : "(dummy)");
if (current_mood->name)
mood_name = para_strdup(current_mood->name);
- mood_unload();
- ret = mood_load(mood_name, NULL);
+ mood_unload(NULL);
+ ret = mood_load(mood_name, NULL, NULL);
free(mood_name);
return ret;
}