X-Git-Url: http://git.tuebingen.mpg.de/?a=blobdiff_plain;f=mood.c;h=d47c54efa360b856c63b660fd4cdb5b81d442b68;hb=81bc7110ff6a4c2d002618b94fcf5aa60cd4cad2;hp=a228b2432f9b56d3bc51535c13d74094314e7da9;hpb=c20e3e67fc2be1d5f8778b9c482271e023bbdcb8;p=paraslash.git

diff --git a/mood.c b/mood.c
index a228b243..d47c54ef 100644
--- a/mood.c
+++ b/mood.c
@@ -138,7 +138,7 @@ static void destroy_mood(struct mood *m)
 
 static struct mood *alloc_new_mood(const char *name)
 {
-	struct mood *m = para_calloc(sizeof(struct mood));
+	struct mood *m = zalloc(sizeof(struct mood));
 	if (name)
 		m->name = para_strdup(name);
 	return m;
@@ -249,20 +249,22 @@ int mood_check_callback(struct afs_callback_arg *aca)
  * 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)
 {
-	long score = -normalized_value(afsi->num_played, statistics.num,
-		statistics.num_played_sum, statistics.num_played_qd);
-	score -= normalized_value(afsi->last_played, statistics.num,
-		statistics.last_played_sum, statistics.last_played_qd);
-	return score / 2;
+	int64_t mean_n, mean_l,score_n, score_l;
+
+	assert(statistics.normalization_divisor > 0);
+	assert(statistics.num > 0);
+	mean_n = statistics.num_played_sum / statistics.num;
+	mean_l = statistics.last_played_sum / statistics.num;
+
+	score_n = -((int64_t)afsi->num_played - mean_n)
+		* statistics.num_played_correction
+		/ statistics.normalization_divisor;
+	score_l = -((int64_t)afsi->last_played - mean_l)
+		* statistics.last_played_correction
+		/ statistics.normalization_divisor;
+	return (score_n + score_l) / 2;
 }
 
 static int add_afs_statistics(const struct osl_row *row)
@@ -363,8 +365,8 @@ static int add_if_admissible(struct osl_row *aft_row, void *data)
 	if (statistics.num >= aa->size) {
 		aa->size *= 2;
 		aa->size += 100;
-		aa->array = para_realloc(aa->array,
-			aa->size * sizeof(struct osl_row *));
+		aa->array = arr_realloc(aa->array, aa->size,
+			sizeof(struct osl_row *));
 	}
 	aa->array[statistics.num] = aft_row;
 	return add_afs_statistics(aft_row);
@@ -715,9 +717,17 @@ static int reload_current_mood(void)
  * \param pb Unused.
  * \param data Its type depends on the event.
  *
- * This function performs actions required due to the occurrence of the given
- * event. Possible actions include reload of the current mood and update of the
- * score of an audio file.
+ * This function updates the score table according to the event that has
+ * occurred. Two actions are possible: (a) reload the current mood, or (b)
+ * add/remove/update the row of the score table which corresponds to the audio
+ * file that has been modified or whose afs info has been changed. It depends
+ * on the type of the event which action (if any) is performed.
+ *
+ * The callbacks of command handlers such as com_add() or com_touch() which
+ * modify the audio file table call this function. The virtual streaming system
+ * also calls this after it has updated the afs info of the file it is about to
+ * stream (the one with the highest score). If the file stays admissible, its
+ * score is recomputed so that a different file is picked next time.
  *
  * \return Standard.
  */