mood: Fix compute_score().

[paraslash.git] / mood.c

diff --git a/mood.c b/mood.c
index bcc9bc57d1a37520ca71f93d5d93a7fe1e2e2927..d47c54efa360b856c63b660fd4cdb5b81d442b68 100644 (file)
--- a/mood.c
+++ b/mood.c
@@ -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)