mood.c: Avoid overflow in update_quadratic_deviation().

[paraslash.git] / mood.c

diff --git a/mood.c b/mood.c
index 74b00d35b2ddc4efd07f2e8783d1a37fcc3117b4..45b051a7267cdd9cd1a9049a00685a150681a1cb 100644 (file)
--- a/mood.c
+++ b/mood.c
@@ -1,5 +1,5 @@
 /*
 /*

- * Copyright (C) 2007-2012 Andre Noll <maan@systemlinux.org>
+ * Copyright (C) 2007-2013 Andre Noll <maan@systemlinux.org>

  *
  * Licensed under the GPL v2. For licencing details see COPYING.
  */
  *
  * Licensed under the GPL v2. For licencing details see COPYING.
  */


@@ -386,7 +386,7 @@ static int load_mood(const struct osl_row *mood_row, struct mood **m)
        if (!*mood_name)
                return -E_DUMMY_ROW;
        mlpd.m = alloc_new_mood(mood_name);
        if (!*mood_name)
                return -E_DUMMY_ROW;
        mlpd.m = alloc_new_mood(mood_name);

-       ret = for_each_line_ro(mood_def.data, mood_def.size,
+       ret = for_each_line(FELF_READ_ONLY, mood_def.data, mood_def.size,

                parse_mood_line, &mlpd);
        osl_close_disk_object(&mood_def);
        if (ret < 0) {
                parse_mood_line, &mlpd);
        osl_close_disk_object(&mood_def);
        if (ret < 0) {


@@ -418,7 +418,7 @@ static int check_mood(struct osl_row *mood_row, void *data)
        ret = para_printf(pb, "checking mood %s...\n", mood_name);
        if (ret < 0)
                goto out;
        ret = para_printf(pb, "checking mood %s...\n", mood_name);
        if (ret < 0)
                goto out;

-       ret = for_each_line_ro(mood_def.data, mood_def.size,
+       ret = for_each_line(FELF_READ_ONLY, mood_def.data, mood_def.size,

                parse_mood_line, &mlpd);
        if (ret < 0)
                para_printf(pb, "%s line %u: %s\n", mood_name, mlpd.line_num,
                parse_mood_line, &mlpd);
        if (ret < 0)
                para_printf(pb, "%s line %u: %s\n", mood_name, mlpd.line_num,


@@ -472,7 +472,7 @@ static int64_t normalized_value(int64_t x, int64_t n, int64_t sum, int64_t qd)
 {
        if (!n || !qd)
                return 0;
 {
        if (!n || !qd)
                return 0;

-       return 100 * (n * x - sum) / (int64_t)int_sqrt(n * qd);
+       return 100 * (n * x - sum) / (int64_t)int_sqrt(n) / (int64_t)int_sqrt(qd);

 }
 
 static long compute_num_played_score(struct afs_info *afsi)
 }
 
 static long compute_num_played_score(struct afs_info *afsi)


@@ -504,7 +504,7 @@ static long compute_dynamic_score(const struct osl_row *aft_row)
 
 static int add_afs_statistics(const struct osl_row *row)
 {
 
 static int add_afs_statistics(const struct osl_row *row)
 {

-       uint64_t n, x, s;
+       uint64_t n, x, s, q;

        struct afs_info afsi;
        int ret;
 
        struct afs_info afsi;
        int ret;
 


@@ -514,14 +514,18 @@ static int add_afs_statistics(const struct osl_row *row)
        n = statistics.num;
        x = afsi.last_played;
        s = statistics.last_played_sum;
        n = statistics.num;
        x = afsi.last_played;
        s = statistics.last_played_sum;

-       if (n > 0)
-               statistics.last_played_qd += (x - s / n) * (x - s / n) * n / (n + 1);
+       if (n > 0) {
+               q = (x > s / n)? x - s / n : s / n - x;
+               statistics.last_played_qd += q * q * n / (n + 1);
+       }

        statistics.last_played_sum += x;
 
        x = afsi.num_played;
        s = statistics.num_played_sum;
        statistics.last_played_sum += x;
 
        x = afsi.num_played;
        s = statistics.num_played_sum;

-       if (n > 0)
-               statistics.num_played_qd += (x - s / n) * (x - s / n) * n / (n + 1);
+       if (n > 0) {
+               q = (x > s / n)? x - s / n : s / n - x;
+               statistics.num_played_qd += q * q * n / (n + 1);
+       }

        statistics.num_played_sum += x;
        statistics.num++;
        return 1;
        statistics.num_played_sum += x;
        statistics.num++;
        return 1;


@@ -648,7 +652,8 @@ static int add_if_admissible(struct osl_row *aft_row, void *data)
  * the last number a_n was replaced by b) may be computed in O(1) time in terms
  * of n, q, a_n, b, and S as
  *
  * the last number a_n was replaced by b) may be computed in O(1) time in terms
  * of n, q, a_n, b, and S as
  *

- *     q' = q + d * s - (2 * S + d) * d / n,
+ *     q' = q + d * s - (2 * S + d) * d / n
+ *        = q + d * (s - 2 * S / n - d /n),

  *
  * where d = b - a_n, and s = b + a_n.
  *
  *
  * where d = b - a_n, and s = b + a_n.
  *


@@ -665,7 +670,7 @@ _static_inline_ int64_t update_quadratic_deviation(int64_t n, int64_t old_qd,
 {
        int64_t delta = new_val - old_val;
        int64_t sigma = new_val + old_val;
 {
        int64_t delta = new_val - old_val;
        int64_t sigma = new_val + old_val;

-       return old_qd + delta * sigma - (2 * old_sum + delta) * delta / n;
+       return old_qd + delta * (sigma - 2 * old_sum / n - delta / n);

 }
 
 static int update_afs_statistics(struct afs_info *old_afsi, struct afs_info *new_afsi)
 }
 
 static int update_afs_statistics(struct afs_info *old_afsi, struct afs_info *new_afsi)


@@ -896,6 +901,9 @@ static int reload_current_mood(void)
        int ret;
        char *mood_name = NULL;
 
        int ret;
        char *mood_name = NULL;
 

+       ret = clear_score_table();
+       if (ret < 0)
+               return ret;

        if (!current_mood)
                return 1;
        PARA_NOTICE_LOG("reloading %s\n", current_mood->name?
        if (!current_mood)
                return 1;
        PARA_NOTICE_LOG("reloading %s\n", current_mood->name?


@@ -918,12 +926,12 @@ static int reload_current_mood(void)
  * 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 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.

+ *
+ * \return Standard.

  */
 int moods_event_handler(enum afs_events event, __a_unused struct para_buffer *pb,
                void *data)
 {
  */
 int moods_event_handler(enum afs_events event, __a_unused struct para_buffer *pb,
                void *data)
 {

-       int ret;
-

        if (!current_mood)
                return 0;
        switch (event) {
        if (!current_mood)
                return 0;
        switch (event) {


@@ -936,10 +944,6 @@ int moods_event_handler(enum afs_events event, __a_unused struct para_buffer *pb
        case BLOB_ADD:
                if (data == moods_table || data == playlists_table)
                        return 1; /* no reload necessary for these */
        case BLOB_ADD:
                if (data == moods_table || data == playlists_table)
                        return 1; /* no reload necessary for these */

-               ret = clear_score_table();
-               if (ret < 0)
-                       PARA_CRIT_LOG("clear score table returned %s\n",
-                               para_strerror(-ret));

                return reload_current_mood();
        /* these also require reload of the score table */
        case ATTRIBUTE_ADD:
                return reload_current_mood();
        /* these also require reload of the score table */
        case ATTRIBUTE_ADD: