intermediate changes

ref:cde9a383711a11544ce7e107a78147fb96cc4029

5 files changed, 103 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();
+}
diff --git a/library/cpp/digest/crc32c/crc32c.h b/library/cpp/digest/crc32c/crc32c.h
new file mode 100644
index 0000000000..17b554c8e1
--- /dev/null
+++ b/library/cpp/digest/crc32c/crc32c.h
@@ -0,0 +1,9 @@
+#pragma once
+
+#include <util/system/types.h>
+
+// Threadsafe
+ui32 Crc32c(const void* p, size_t size) noexcept;
+ui32 Crc32cExtend(ui32 init, const void* data, size_t n) noexcept;
+
+bool HaveFastCrc32c() noexcept;
diff --git a/library/cpp/digest/crc32c/crc32c_ut.cpp b/library/cpp/digest/crc32c/crc32c_ut.cpp
new file mode 100644
index 0000000000..aa31b83422
--- /dev/null
+++ b/library/cpp/digest/crc32c/crc32c_ut.cpp
@@ -0,0 +1,23 @@
+#include "crc32c.h"
+
+#include <library/cpp/testing/unittest/registar.h>
+
+Y_UNIT_TEST_SUITE(TestCrc32c) {
+    Y_UNIT_TEST(TestCalc) {
+        UNIT_ASSERT_VALUES_EQUAL(Crc32c("abc", 3), ui32(910901175));
+    }
+
+    Y_UNIT_TEST(TestUnaligned) {
+        const TString str(1000, 'a');
+        for (size_t substrLen = 0; substrLen <= str.length(); ++substrLen) {
+            const ui32 crc = Crc32c(str.data(), substrLen);
+            for (size_t offset = 1; offset + substrLen <= str.length(); ++offset) {
+                UNIT_ASSERT_VALUES_EQUAL(Crc32c(str.data() + offset, substrLen), crc);
+            }
+        }
+    }
+
+    Y_UNIT_TEST(TestExtend) {
+        UNIT_ASSERT_VALUES_EQUAL(Crc32cExtend(1, "abc", 3), ui32(2466950601));
+    }
+}
diff --git a/library/cpp/digest/crc32c/ut/ya.make b/library/cpp/digest/crc32c/ut/ya.make
new file mode 100644
index 0000000000..325622e080
--- /dev/null
+++ b/library/cpp/digest/crc32c/ut/ya.make
@@ -0,0 +1,9 @@
+UNITTEST_FOR(library/cpp/digest/crc32c)
+
+OWNER(pg)
+
+SRCS(
+    crc32c_ut.cpp
+)
+
+END()
diff --git a/library/cpp/digest/crc32c/ya.make b/library/cpp/digest/crc32c/ya.make
new file mode 100644
index 0000000000..d6faf16c9c
--- /dev/null
+++ b/library/cpp/digest/crc32c/ya.make
@@ -0,0 +1,22 @@
+LIBRARY()
+
+#!!!
+OWNER(
+    ddoarn
+    a-romanov
+    pg
+    gulin
+    dcherednik
+    g:yamr
+    g:rtmr
+)
+
+PEERDIR(
+    contrib/libs/crcutil
+)
+
+SRCS(
+    crc32c.cpp
+)
+
+END()