From d0f3357f7778f415f4dae25e2fac4bcc5d1ea8d1 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?J=C3=A9r=C3=A9my=20Zurcher?= <jeremy@asynk.ch>
Date: Wed, 20 Mar 2013 11:45:57 +0100
Subject: [PATCH] TES

Conflicts:
	src/lib/eina/eina_list.c
	src/lib/eina/eina_types.h
---
 src/lib/eina/eina_list.c        | 79 +++++++++++++++++++++++++++++++++
 src/lib/eina/eina_types.h       | 15 +++++++
 src/tests/eina/eina_test_list.c | 57 ++++++++++++++++++++++++
 3 files changed, 151 insertions(+)

diff --git a/src/lib/eina/eina_list.c b/src/lib/eina/eina_list.c
index 01871b20f8..4e217dd9a6 100644
--- a/src/lib/eina/eina_list.c
+++ b/src/lib/eina/eina_list.c
@@ -1094,6 +1094,85 @@ eina_list_sort(Eina_List *list, unsigned int limit, Eina_Compare_Cb func)
    return list;
 }
 
+EAPI Eina_List *
+eina_list_shuffle(Eina_List *list, Eina_Random_Cb func)
+{
+   unsigned int n, i, j;
+   Eina_List_Accounting *accounting;
+   Eina_List *shuffled_list, *shuffled_last, *li;
+
+   if (!list)
+     return NULL;
+
+   EINA_MAGIC_CHECK_LIST(list, NULL);
+
+   accounting = list->accounting;
+   n = accounting->count;
+   shuffled_list = shuffled_last = NULL;
+
+   if (n == 1)
+     return list;
+
+   while (n > 1)
+     {
+        if (func)
+          i = func(0, (n - 1));
+        else
+          i = (int) ((float)n*rand()/(RAND_MAX+1.0));
+
+        if(i == 0)
+          {
+             li = list;
+             list = list->next;
+          }
+        else if (i == (n - 1) || i == n)
+          {
+             li = accounting->last;
+             accounting->last = li->prev;
+          }
+        else
+          {
+             if (i > (n / 2))
+               for (j = n - 1,
+                    li = accounting->last;
+                    j!=i;
+                    li = li->prev, j--);
+             else
+               for (j = 0,
+                    li = list;
+                    j!=i;
+                    li = li->next, j++);
+
+             li->prev->next = li->next;
+             li->next->prev = li->prev;
+          }
+
+        n--;
+
+        if (shuffled_list == NULL)
+          {
+             li->prev = NULL;
+             shuffled_list = li;
+             shuffled_last = li;
+          }
+        else
+          {
+             shuffled_last->next = li;
+             li->prev = shuffled_last;
+             shuffled_last = li;
+          }
+     }
+
+   list->next = NULL;
+   list->prev = shuffled_last;
+   shuffled_last->next = list;
+
+   accounting->last = list;
+   shuffled_list->accounting = accounting;
+
+   return shuffled_list;
+}
+
 EAPI Eina_List *
 eina_list_merge(Eina_List *left, Eina_List *right)
 {
diff --git a/src/lib/eina/eina_types.h b/src/lib/eina/eina_types.h
index d74d200a32..d37b20f71f 100644
--- a/src/lib/eina/eina_types.h
+++ b/src/lib/eina/eina_types.h
@@ -333,6 +333,21 @@ typedef int (*Eina_Compare_Cb)(const void *data1, const void *data2);
  */
 #define EINA_COMPARE_CB(function) ((Eina_Compare_Cb)function)
 
+/**
+ * @typedef Eina_Random_Cb
+ * Function used in shuffling functions. An integer betwen min and max
+ * inclusive must be returned.
+ *
+ * @since 1.8
+ */
+typedef int (*Eina_Random_Cb)(const int min, const int max);
+
+/**
+ * @def EINA_RANDOM_CB
+ * Macro to cast to Eina_Random_Cb.
+ */
+#define EINA_RANDOM_CB(function) ((Eina_Random_Cb)function)
+
 /**
  * @typedef Eina_Each_Cb
  * A callback type used when iterating over a container.
diff --git a/src/tests/eina/eina_test_list.c b/src/tests/eina/eina_test_list.c
index 0f48688a53..fd11f8996e 100644
--- a/src/tests/eina/eina_test_list.c
+++ b/src/tests/eina/eina_test_list.c
@@ -375,6 +375,62 @@ START_TEST(eina_test_list_split)
 }
 END_TEST
 
+static int uicmp(const void *d1, const void *d2)
+{
+   const unsigned int *a = d1;
+   const unsigned int *b = d2;
+
+   if(*a == *b) return 0;
+   if(*a >  *b) return 1;
+
+   return -1;
+}
+
+#define SHUFFLE_SZ 100
+#define SHUFFLE_N 100000
+START_TEST(eina_test_shuffle)
+{
+  double d;
+  unsigned int *p;
+  unsigned int i, j;
+  unsigned int n[SHUFFLE_SZ];
+  unsigned int rand_count[SHUFFLE_SZ];
+  Eina_List *list = NULL;
+  Eina_List *item = NULL;
+
+  eina_init();
+
+  for(i = 0; i < SHUFFLE_SZ; i++)
+    {
+       n[i] = i;
+       rand_count[i] = 0;
+       list = eina_list_append(list, &n[i]);
+    }
+
+  for(i = 0; i < SHUFFLE_N; i++)
+    {
+       list = eina_list_shuffle(list, NULL);
+       p = eina_list_nth(list, SHUFFLE_SZ/2);
+       rand_count[*p]++;
+
+       j = 0;
+       list = eina_list_sort(list, 0, (Eina_Compare_Cb)&uicmp);
+       EINA_LIST_FOREACH(list, item, p)
+          fail_if(*p != j++);
+       fail_if(j != SHUFFLE_SZ);
+    }
+
+  d = SHUFFLE_SZ/(float)(SHUFFLE_N);
+  for(i = 0; i < SHUFFLE_SZ; i++)
+    {
+       fail_if(rand_count[i]*d > 1.20f);
+       fail_if(rand_count[i]*d < 0.80f);
+    }
+
+  eina_shutdown();
+}
+END_TEST
+
 void
 eina_test_list(TCase *tc)
 {
@@ -382,4 +438,5 @@ eina_test_list(TCase *tc)
    tcase_add_test(tc, eina_test_merge);
    tcase_add_test(tc, eina_test_sorted_insert);
    tcase_add_test(tc, eina_test_list_split);
+   tcase_add_test(tc, eina_test_shuffle);
 }