intermediate changes

ref:cde9a383711a11544ce7e107a78147fb96cc4029

1 files changed, 31 insertions, 0 deletions

diff --git a/library/cpp/yson/zigzag.h b/library/cpp/yson/zigzag.h
new file mode 100644
index 00000000000..2f1190508fb
--- /dev/null
+++ b/library/cpp/yson/zigzag.h
@@ -0,0 +1,31 @@
+#pragma once
+
+#include <util/system/defaults.h>
+
+namespace NYson {
+    ////////////////////////////////////////////////////////////////////////////////
+
+    //! Functions that provide coding of integers with property: 0 <= f(x) <= 2 * |x|
+    //! Actually taken 'as is' from protobuf/wire_format_lite.h
+
+    inline ui32 ZigZagEncode32(i32 n) {
+        // Note: the right-shift must be arithmetic
+        return (ui32(n) << 1) ^ (n >> 31);
+    }
+
+    inline i32 ZigZagDecode32(ui32 n) {
+        return (n >> 1) ^ -static_cast<i32>(n & 1);
+    }
+
+    inline ui64 ZigZagEncode64(i64 n) {
+        // Note: the right-shift must be arithmetic
+        return (ui64(n) << 1) ^ (n >> 63);
+    }
+
+    inline i64 ZigZagDecode64(ui64 n) {
+        return (n >> 1) ^ -static_cast<i64>(n & 1);
+    }
+
+    ////////////////////////////////////////////////////////////////////////////////
+
+} // namespace NYson