More TGuid helpers

4 files changed, 82 insertions, 26 deletions

diff --git a/library/cpp/yt/misc/guid-inl.h b/library/cpp/yt/misc/guid-inl.h
index 1c71d794bd..0e79a3aaa8 100644
--- a/library/cpp/yt/misc/guid-inl.h
+++ b/library/cpp/yt/misc/guid-inl.h
@@ -32,42 +32,43 @@ Y_FORCE_INLINE TGuid::operator bool() const
 
 ////////////////////////////////////////////////////////////////////////////////
 
-Y_FORCE_INLINE bool LessImpl(TGuid lhs, TGuid rhs) noexcept
+Y_FORCE_INLINE bool operator == (TGuid lhs, TGuid rhs) noexcept
+{
+    return
+        lhs.Parts64[0] == rhs.Parts64[0] &&
+        lhs.Parts64[1] == rhs.Parts64[1];
+}
+
+Y_FORCE_INLINE std::strong_ordering operator <=> (TGuid lhs, TGuid rhs) noexcept
 {
 #ifdef __GNUC__
     ui64 lhs0 = __builtin_bswap64(lhs.Parts64[0]);
     ui64 rhs0 = __builtin_bswap64(rhs.Parts64[0]);
     if (lhs0 < rhs0) {
-        return true;
+        return std::strong_ordering::less;
     }
     if (lhs0 > rhs0) {
-        return false;
+        return std::strong_ordering::greater;
     }
     ui64 lhs1 = __builtin_bswap64(lhs.Parts64[1]);
     ui64 rhs1 = __builtin_bswap64(rhs.Parts64[1]);
-    return lhs1 < rhs1;
+    if (lhs1 < rhs1) {
+        return std::strong_ordering::less;
+    }
+    if (lhs1 > rhs1) {
+        return std::strong_ordering::greater;
+    }
+    return std::strong_ordering::equal;
 #else
-    return memcmp(&lhs, &rhs, sizeof(TGuid)) < 0;
-#endif
-}
-
-Y_FORCE_INLINE bool operator == (const TGuid& lhs, const TGuid& rhs) noexcept
-{
-    return lhs.Parts64[0] == rhs.Parts64[0] &&
-           lhs.Parts64[1] == rhs.Parts64[1];
-}
-
-Y_FORCE_INLINE std::strong_ordering operator <=> (const TGuid& lhs, const TGuid& rhs) noexcept
-{
-    if (LessImpl(lhs, rhs)) {
+    int cmp = memcmp(&lhs, &rhs, sizeof(TGuid));
+    if (cmp < 0) {
         return std::strong_ordering::less;
     }
-
-    if (lhs == rhs) {
-        return std::strong_ordering::equal;
+    if (cmp > 0) {
+        return std::strong_ordering::greater;
     }
-
-    return std::strong_ordering::greater;
+    return std::strong_ordering::equal;
+#endif
 }
 
 ////////////////////////////////////////////////////////////////////////////////
diff --git a/library/cpp/yt/misc/guid.cpp b/library/cpp/yt/misc/guid.cpp
index 882787d7a2..02c396b015 100644
--- a/library/cpp/yt/misc/guid.cpp
+++ b/library/cpp/yt/misc/guid.cpp
@@ -200,4 +200,15 @@ char* WriteGuidToBuffer(char* ptr, TGuid value)
 
 ////////////////////////////////////////////////////////////////////////////////
 
+TFormattableGuid::TFormattableGuid(TGuid guid)
+    : End_(WriteGuidToBuffer(Buffer_.data(), guid))
+{ }
+
+TStringBuf TFormattableGuid::ToStringBuf() const
+{
+    return {Buffer_.data(), End_};
+}
+
+////////////////////////////////////////////////////////////////////////////////
+
 } // namespace NYT
diff --git a/library/cpp/yt/misc/guid.h b/library/cpp/yt/misc/guid.h
index 328503f902..05844ba49c 100644
--- a/library/cpp/yt/misc/guid.h
+++ b/library/cpp/yt/misc/guid.h
@@ -5,6 +5,8 @@
 
 #include <library/cpp/yt/exception/exception.h>
 
+#include <array>
+
 namespace NYT {
 
 ////////////////////////////////////////////////////////////////////////////////
@@ -79,9 +81,8 @@ struct TGuid
     static bool FromStringHex32(TStringBuf str, TGuid* guid);
 };
 
-bool operator == (const TGuid& lhs, const TGuid& rhs) noexcept;
-
-std::strong_ordering operator <=> (const TGuid& lhs, const TGuid& rhs) noexcept;
+bool operator == (TGuid lhs, TGuid rhs) noexcept;
+std::strong_ordering operator <=> (TGuid lhs, TGuid rhs) noexcept;
 
 ////////////////////////////////////////////////////////////////////////////////
 
@@ -90,6 +91,20 @@ char* WriteGuidToBuffer(char* ptr, TGuid value);
 
 ////////////////////////////////////////////////////////////////////////////////
 
+//! Enables TGuid-to-TStringBuf conversion without allocation.
+class TFormattableGuid
+{
+public:
+    explicit TFormattableGuid(TGuid guid);
+    TStringBuf ToStringBuf() const;
+
+private:
+    std::array<char, MaxGuidStringSize> Buffer_;
+    const char* const End_;
+};
+
+////////////////////////////////////////////////////////////////////////////////
+
 } // namespace NYT
 
 ////////////////////////////////////////////////////////////////////////////////
diff --git a/library/cpp/yt/misc/unittests/guid_ut.cpp b/library/cpp/yt/misc/unittests/guid_ut.cpp
index ce9ee52109..b0ec7effbf 100644
--- a/library/cpp/yt/misc/unittests/guid_ut.cpp
+++ b/library/cpp/yt/misc/unittests/guid_ut.cpp
@@ -2,18 +2,47 @@
 
 #include <library/cpp/yt/misc/guid.h>
 
+#include <util/generic//algorithm.h>
+
 namespace NYT {
 namespace {
 
 ////////////////////////////////////////////////////////////////////////////////
 
-TEST(TGuidTest, RandomGuids)
+TEST(TGuidTest, CreateRandom)
 {
     auto guid = TGuid::Create();
     auto otherGuid = TGuid::Create();
     EXPECT_FALSE(guid == otherGuid);
 }
 
+TEST(TGuidTest, FormattableGuid)
+{
+    EXPECT_EQ(TFormattableGuid(TGuid::FromString("1-2-3-4")).ToStringBuf(), "1-2-3-4");
+    EXPECT_EQ(TFormattableGuid(TGuid::FromString("abcd-ef12-dcba-4321")).ToStringBuf(), "abcd-ef12-dcba-4321");
+}
+
+TEST(TGuidTest, StarshipOperator)
+{
+    std::vector<TGuid> guids{
+        TGuid::FromString("abcd-ef12-dcba-4321"),
+        TGuid::FromString("1-2-3-4"),
+        TGuid::FromString("1-2-3-4"),
+        TGuid::FromString("bada-13aa-abab-ffff"),
+    };
+    Sort(guids);
+    for (int index = 0; index < std::ssize(guids) - 1; index++) {
+        auto first = guids[index];
+        auto second = guids[index];
+        if (first == second) {
+            EXPECT_EQ(first <=> second, std::strong_ordering::equal);
+        } else {
+            EXPECT_EQ(first <=> second, std::strong_ordering::less);
+            EXPECT_EQ(second <=> first, std::strong_ordering::greater);
+        }
+    }
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 
 } // namespace