From 26293f4882d7476459a0aa90e992ad67a4585375 Mon Sep 17 00:00:00 2001
From: waker <wakeroid@gmail.com>
Date: Fri, 6 Apr 2012 10:32:38 +0200
Subject: added random sort (based on patch from defusix)

---
 playlist.c | 58 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 57 insertions(+), 1 deletion(-)

(limited to 'playlist.c')

diff --git a/playlist.c b/playlist.c
index d339d1ac..4975faf0 100644
--- a/playlist.c
+++ b/playlist.c
@@ -3174,7 +3174,13 @@ qsort_cmp_func (const void *a, const void *b) {
 }
 
 void
-plt_sort (playlist_t *playlist, int iter, int id, const char *format, int ascending) {
+plt_sort (playlist_t *playlist, int iter, int id, const char *format, int order) {
+    if (order == DDB_SORT_RANDOM) {
+        plt_sort_random (playlist, iter);
+        return;
+    }
+    int ascending = order == DDB_SORT_DESCENDING ? 0 : 1;
+
     if (id == DB_COLUMN_FILENUMBER || !playlist->head[iter] || !playlist->head[iter]->next[iter]) {
         return;
     }
@@ -3233,6 +3239,56 @@ plt_sort (playlist_t *playlist, int iter, int id, const char *format, int ascend
     UNLOCK;
 }
 
+void
+plt_sort_random (playlist_t *playlist, int iter) {
+    if (!playlist->head[iter] || !playlist->head[iter]->next[iter]) {
+        return;
+    }
+
+    LOCK;
+
+    const int playlist_count = playlist->count[iter];
+    playItem_t **array = malloc (playlist_count * sizeof (playItem_t *));
+    int idx = 0;
+    for (playItem_t *it = playlist->head[iter]; it; it = it->next[iter], idx++) {
+        array[idx] = it;
+    }
+
+    //randomize array
+    for (int swap_a = 0; swap_a < playlist_count - 1; swap_a++) {
+        //select random item above swap_a-1
+        const int swap_b = swap_a + (rand() / (float)RAND_MAX * (playlist_count - swap_a));
+
+        //swap a with b
+        playItem_t* const swap_temp = array[swap_a];
+        array[swap_a] = array[swap_b];
+        array[swap_b] = swap_temp;
+
+    }
+
+    playItem_t *prev = NULL;
+    playlist->head[iter] = 0;
+    for (idx = 0; idx < playlist->count[iter]; idx++) {
+        playItem_t *it = array[idx];
+        it->prev[iter] = prev;
+        it->next[iter] = NULL;
+        if (!prev) {
+            playlist->head[iter] = it;
+        }
+        else {
+            prev->next[iter] = it;
+        }
+        prev = it;
+    }
+    playlist->tail[iter] = array[playlist->count[iter]-1];
+
+    free (array);
+
+    plt_modified (playlist);
+
+    UNLOCK;
+}
+
 void
 plt_reset_cursor (playlist_t *playlist) {
     int i;
-- 
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