X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=blobdiff_plain;f=mood.c;h=1e15ef0e081480381fcbc4fdad2179848f429c1f;hp=9cdfd011a6ef4f2ab9fb180892f6412247eb68fe;hb=HEAD;hpb=b897cb5cf37b0329b69b0854aaf62004173495a2

diff --git a/mood.c b/mood.c
index 9cdfd011..1e15ef0e 100644
--- a/mood.c
+++ b/mood.c
@@ -59,6 +59,8 @@ struct mood_instance {
 	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;
 };
 
 /*
@@ -132,6 +134,8 @@ static void destroy_mood(struct mood_instance *m)
 	if (!m)
 		return;
 	mp_shutdown(m->parser_context);
+	if (m->score_table)
+		score_close(m->score_table);
 	free(m->name);
 	free(m);
 }
@@ -437,7 +441,7 @@ static void update_afs_statistics(struct afs_info *old_afsi,
 }
 
 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;
@@ -445,8 +449,8 @@ static int add_to_score_table(const struct osl_row *aft_row,
 
 	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)
@@ -504,7 +508,7 @@ static int mood_update_audio_file(const struct osl_row *aft_row,
 		ret = add_afs_statistics(aft_row, &current_mood->stats);
 		if (ret < 0)
 			return ret;
-		return add_to_score_table(aft_row, &current_mood->stats);
+		return add_to_score_table(aft_row, current_mood);
 	}
 	/* update score */
 	ret = get_afsi_of_row(aft_row, &afsi);
@@ -529,24 +533,37 @@ static char *get_statistics(struct mood_instance *m, int64_t sse)
 	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(
 		"loaded mood %s (%u files)\n"
 		"last_played mean/sigma: %d/%d days\n"
 		"num_played mean/sigma: %" PRId64 "/%" PRIu64 "\n"
+		"correction factor ratio: %.2lf\n"
 	,
 		m->name? m->name : "(dummy)",
 		n,
 		mean_days, sigma_days,
 		m->stats.num_played_sum / n,
-			int_sqrt(m->stats.num_played_qd / n)
+		int_sqrt(m->stats.num_played_qd / n),
+		86400.0 * m->stats.last_played_correction /
+			m->stats.num_played_correction
 	);
 }
 
-/** 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;
 }
@@ -568,23 +585,42 @@ static void compute_correction_factors(int64_t sse, struct afs_statistics *s)
 }
 
 /**
- * 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};
@@ -609,14 +645,10 @@ int mood_load(const char *mood_name, char **msg)
 	}
 	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(
@@ -628,21 +660,43 @@ int mood_load(const char *mood_name, char **msg)
 	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)
 {
@@ -655,8 +709,8 @@ 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;
 }