Created transparent form of Azure::Core::Uuid (#4534)

* Created transparent form of Azure::Core::Uuid

* Pull request feedback

* Update sdk/core/azure-core/CHANGELOG.md

Co-authored-by: Ahson Khan <ahson_ahmedk@yahoo.com>

* Update sdk/core/azure-core/inc/azure/core/uuid.hpp

Co-authored-by: Ahson Khan <ahson_ahmedk@yahoo.com>

---------

Co-authored-by: Ahson Khan <ahson_ahmedk@yahoo.com>

sdk/core/azure-core/CHANGELOG.md

@@ -4,6 +4,9 @@
 
 ### Features Added
 
+- Added `Azure::Core::Uuid::AsArray()` and `Azure::Core::Uuid::FromArray()` to enable reading or writing from an existing UUID.
+This is useful when the UUID was generated outside the Azure SDK, or needs to be used from a component outside the Azure SDK.
+
 ### Breaking Changes
 
 ### Bugs Fixed

sdk/core/azure-core/inc/azure/core/uuid.hpp

@@ -10,6 +10,7 @@
 
 #include "azure/core/platform.hpp"
 
+#include <array>
 #include <cstring>
 #include <string>
 
@@ -22,7 +23,7 @@ namespace Azure { namespace Core {
   private:
     static constexpr size_t UuidSize = 16;
 
-    uint8_t m_uuid[UuidSize];
+    std::array<uint8_t, UuidSize> m_uuid;
     // The UUID reserved variants.
     static constexpr uint8_t ReservedNCS = 0x80;
     static constexpr uint8_t ReservedRFC4122 = 0x40;
@@ -30,7 +31,7 @@ namespace Azure { namespace Core {
     static constexpr uint8_t ReservedFuture = 0x00;
 
   private:
-    Uuid(uint8_t const uuid[UuidSize]) { std::memcpy(m_uuid, uuid, UuidSize); }
+    Uuid(uint8_t const uuid[UuidSize]) { std::memcpy(m_uuid.data(), uuid, UuidSize); }
 
   public:
     /**
@@ -39,10 +40,23 @@ namespace Azure { namespace Core {
      */
     std::string ToString();
 
+    /**
+     * @brief Returns the binary value of the Uuid for consumption by clients who need non-string
+     * representation of the Uuid
+     * @returns An array with the binary representation of the Uuid.
+     */
+    std::array<uint8_t, UuidSize> const& AsArray() const { return m_uuid; }
+
     /**
      * @brief Creates a new random UUID.
      *
      */
     static Uuid CreateUuid();
+
+    /**
+     * @brief Construct a Uuid from an existing UUID represented as an array of bytes.
+     * @details Creates a Uuid from a UUID created in an external scope.
+     */
+    static Uuid FromArray(std::array<uint8_t, UuidSize> const& uuid);
   };
 }} // namespace Azure::Core

sdk/core/azure-core/src/uuid.cpp

@@ -70,11 +70,17 @@ namespace Azure { namespace Core {
     // SetVariant to ReservedRFC4122
     uuid[8] = (uuid[8] | ReservedRFC4122) & 0x7F;
 
-    constexpr uint8_t version = 4;
+    constexpr uint8_t version = 4; // Version 4: Pseudo-random number
 
     uuid[6] = (uuid[6] & 0xF) | (version << 4);
 
     return Uuid(uuid);
   }
 
+  Uuid Uuid::FromArray(std::array<uint8_t, UuidSize> const& uuid)
+  {
+    Uuid rv{uuid.data()};
+    return rv;
+  }
+
 }} // namespace Azure::Core

sdk/core/azure-core/test/ut/uuid_test.cpp

@@ -14,6 +14,14 @@ TEST(Uuid, Basic)
   EXPECT_EQ(uuid.ToString().length(), 36);
 }
 
+TEST(Uuid, Transparent)
+{
+  auto uuid1 = Uuid::CreateUuid();
+  auto arrayUuid1(uuid1.AsArray());
+  auto uuid2 = Azure::Core::Uuid::FromArray(arrayUuid1);
+  EXPECT_EQ(uuid1.ToString(), uuid2.ToString());
+}
+
 TEST(Uuid, Randomness)
 {
   const int size = 100000;