adding yasli

git-svn-id: svn://svn.code.sf.net/p/loki-lib/code/trunk@215 7ec92016-0320-0410-acc4-a06ded1c099a

include/loki/yasli/random.h

@@ -0,0 +1,52 @@
+#ifndef RANDOM_H_
+#define RANDOM_H_
+
+#include <ctime>
+
+class Random 
+{
+    unsigned int seed_;
+public:
+    Random(unsigned int seed = 0)
+        : seed_(seed ? seed : static_cast<unsigned int>(std::time(0)))
+    {
+    }
+    unsigned short nextShort()
+    {
+        /* Use any number from this list for "a"
+            18000 18030 18273 18513 18879 19074 19098 19164 19215 19584       
+            19599 19950 20088 20508 20544 20664 20814 20970 21153 21243       
+            21423 21723 21954 22125 22188 22293 22860 22938 22965 22974       
+            23109 23124 23163 23208 23508 23520 23553 23658 23865 24114       
+            24219 24660 24699 24864 24948 25023 25308 25443 26004 26088       
+            26154 26550 26679 26838 27183 27258 27753 27795 27810 27834       
+            27960 28320 28380 28689 28710 28794 28854 28959 28980 29013       
+            29379 29889 30135 30345 30459 30714 30903 30963 31059 31083
+        */
+        static const unsigned int a = 18000;
+        return static_cast<unsigned short>(seed_ = 
+            a * (seed_ & 65535) + 
+                (seed_ >> 16));
+    }
+
+    unsigned int nextUint()
+    {
+        return (unsigned int)nextShort() << (CHAR_BIT * sizeof(unsigned short)) |
+            nextShort();
+    }
+    unsigned int nextUint(unsigned int high)
+    {
+        assert(high < ULONG_MAX - 1);
+        ++high;
+        const unsigned int bucket_size = ULONG_MAX / high;
+        unsigned int a;
+        do 
+        {
+            a = nextUint() / bucket_size;
+        }
+        while (a >= high);
+        return a;
+    }
+};
+
+#endif // RANDOM_H_