intermediate changes

ref:cde9a383711a11544ce7e107a78147fb96cc4029

1 files changed, 40 insertions, 0 deletions

diff --git a/library/cpp/digest/crc32c/crc32c.cpp b/library/cpp/digest/crc32c/crc32c.cpp
new file mode 100644
index 0000000000..369b46a213
--- /dev/null
+++ b/library/cpp/digest/crc32c/crc32c.cpp
@@ -0,0 +1,40 @@
+#include "crc32c.h"
+
+#include <util/generic/singleton.h>
+
+#include <contrib/libs/crcutil/interface.h>
+
+namespace {
+    typedef crcutil_interface::CRC TCrc;
+
+    struct TCrcUtilSse4 {
+        TCrc* const Pimpl;
+
+        TCrcUtilSse4() noexcept
+            : Pimpl(TCrc::Create(0x82f63b78, 0, 32, true, 0, 0, 0, TCrc::IsSSE42Available(), nullptr))
+        {
+        }
+
+        ~TCrcUtilSse4() noexcept {
+            Pimpl->Delete();
+        }
+
+        inline ui32 Extend(ui32 init, const void* data, size_t n) const noexcept {
+            crcutil_interface::UINT64 sum = init;
+            Pimpl->Compute(data, n, &sum);
+            return (ui32)sum;
+        }
+    };
+}
+
+ui32 Crc32c(const void* p, size_t size) noexcept {
+    return Singleton<TCrcUtilSse4>()->Extend(0, p, size);
+}
+
+ui32 Crc32cExtend(ui32 init, const void* data, size_t n) noexcept {
+    return Singleton<TCrcUtilSse4>()->Extend(init, data, n);
+}
+
+bool HaveFastCrc32c() noexcept {
+    return TCrc::IsSSE42Available();
+}