intermediate changes

ref:cde9a383711a11544ce7e107a78147fb96cc4029

1 files changed, 125 insertions, 0 deletions

diff --git a/util/random/random.cpp b/util/random/random.cpp
new file mode 100644
index 0000000000..71f9323856
--- /dev/null
+++ b/util/random/random.cpp
@@ -0,0 +1,125 @@
+#include "random.h"
+#include "entropy.h"
+#include "mersenne.h"
+
+#include <util/system/getpid.h>
+#include <util/thread/singleton.h>
+#include <util/stream/multi.h>
+#include <util/stream/mem.h>
+#include <util/digest/numeric.h>
+
+namespace {
+    struct TProcStream {
+        ui32 Extra;
+        TMemoryInput MI;
+        TMultiInput TI;
+
+        static inline ui32 ExtraData() noexcept {
+            ui32 data;
+
+            EntropyPool().LoadOrFail(&data, sizeof(data));
+
+            return IntHash(data ^ GetPID());
+        }
+
+        inline TProcStream() noexcept
+            : Extra(ExtraData())
+            , MI(&Extra, sizeof(Extra))
+            , TI(&MI, &EntropyPool())
+        {
+        }
+
+        inline IInputStream& S() noexcept {
+            return TI;
+        }
+    };
+
+    template <class T>
+    struct TRndGen: public TMersenne<T> {
+        inline TRndGen()
+            : TMersenne<T>(TProcStream().S())
+        {
+        }
+
+        inline TRndGen(T seed)
+            : TMersenne<T>(seed)
+        {
+        }
+    };
+
+    template <class T>
+    static inline TRndGen<T>* GetRndGen() {
+        return FastTlsSingletonWithPriority<TRndGen<T>, 2>();
+    }
+
+    template <unsigned N>
+    struct TToRealTypeBySize {
+        using TResult = ui32;
+    };
+
+    template <>
+    struct TToRealTypeBySize<8> {
+        using TResult = ui64;
+    };
+
+    template <class T>
+    struct TToRealType {
+        using TResult = typename TToRealTypeBySize<sizeof(T)>::TResult;
+    };
+}
+
+#define DEF_RND(TY)                                               \
+    template <>                                                   \
+    TY RandomNumber<TY>() {                                       \
+        return GetRndGen<TToRealType<TY>::TResult>()->GenRand();  \
+    }                                                             \
+                                                                  \
+    template <>                                                   \
+    TY RandomNumber<TY>(TY n) {                                   \
+        return GetRndGen<TToRealType<TY>::TResult>()->Uniform(n); \
+    }
+
+DEF_RND(char)
+DEF_RND(unsigned char)
+DEF_RND(unsigned int)
+DEF_RND(unsigned long)
+DEF_RND(unsigned short)
+DEF_RND(unsigned long long)
+
+#undef DEF_RND
+
+template <>
+bool RandomNumber<bool>() {
+    return RandomNumber<ui8>() % 2 == 0;
+}
+
+template <>
+float RandomNumber<float>() {
+    float ret;
+
+    do {
+        ret = (float)GetRndGen<ui64>()->GenRandReal2();
+    } while (ret >= 1);
+
+    return ret;
+}
+
+template <>
+double RandomNumber<double>() {
+    return GetRndGen<ui64>()->GenRandReal4();
+}
+
+template <>
+long double RandomNumber<long double>() {
+    return RandomNumber<double>();
+}
+
+void ResetRandomState() {
+    *GetRndGen<ui32>() = TRndGen<ui32>();
+    *GetRndGen<ui64>() = TRndGen<ui64>();
+}
+
+void SetRandomSeed(int seed) {
+    *GetRndGen<ui32>() = TRndGen<ui32>(seed);
+    *GetRndGen<ui64>() = TRndGen<ui64>(seed);
+}