Merge pull request #32 from HongGeonUi/randEvent

feat: Add RandEvent, RandEventParser

src/MySqlCdc/Events/RandEvent.cs

@@ -0,0 +1,21 @@
+namespace MySqlCdc.Events;
+
+    /// <summary>
+    /// Represents two seed values that set the rand_seed1 and rand_seed2 system variables that are used to compute the random number.
+    /// <a href="https://mariadb.com/kb/en/rand_event/">See more</a>
+    /// </summary>
+    /// <remarks>
+    /// Creates a new <see cref="RandEvent"/>.
+    /// </remarks>
+    public record RandEvent(ulong Seed1, ulong Seed2) : IBinlogEvent
+    {
+        /// <summary>
+        /// Gets the rand_seed1
+        /// </summary>
+        public ulong Seed1 {get; } = Seed1;
+
+        /// <summary>
+        /// Gets the rand_seed2
+        /// </summary>
+        public ulong Seed2 { get; } = Seed2;
+    }

src/MySqlCdc/Parsers/RandEventParser.cs

@@ -0,0 +1,23 @@
+using MySqlCdc.Events;
+using MySqlCdc.Protocol;
+
+namespace MySqlCdc.Parsers;
+
+    /// <summary>
+    /// Parses <see cref="RandEvent"/> events.
+    /// Supports all versions of MariaDB and MySQL.
+    /// </summary>
+
+    public class RandEventParser : IEventParser
+    {
+        /// <summary>
+        /// Parses <see cref="RandEvent"/> from the buffer.
+        /// </summary>
+        public IBinlogEvent ParseEvent(EventHeader header, ref PacketReader reader) 
+        {
+            var seed1 = reader.ReadUInt64LittleEndian();
+            var seed2 = reader.ReadUInt64LittleEndian();
+
+            return new RandEvent(seed1, seed2);
+        }
+    }

src/MySqlCdc/Protocol/PacketReader.cs

@@ -66,6 +66,16 @@ public UInt32 ReadUInt32BigEndian()
         return result;
     }
 
+    /// <summary>
+    /// Reads 64-bit long written in little-endian format.
+    /// </summary>
+    public UInt64 ReadUInt64LittleEndian()
+    {
+        UInt64 result = BinaryPrimitives.ReadUInt64LittleEndian(_span.Slice(_offset));
+        _offset += 8;
+        return result;
+    }
+
     /// <summary>
     /// Reads 64-bit long written in little-endian format.
     /// </summary>

tests/MySqlCdc.Tests/Parsers/RandEventParserTests.cs

@@ -0,0 +1,29 @@
+
+using MySqlCdc.Events;
+using MySqlCdc.Parsers;
+using MySqlCdc.Protocol;
+using Xunit;
+
+namespace MySqlCdc.Tests.Parsers;
+
+public class RandEventParserTests
+{
+    private static byte[] Payload = {
+        0x5f, 0x56, 0x75, 0x65, 0x0d, 0x01, 0x00, 0x00, 0x00, 0x27, 0x00,
+        0x00, 0x00, 0x02, 0x07, 0x00, 0x00, 0x00, 0x00, 0x0c, 0xdb, 0x85, 0x2d, 0x00, 0x00,
+        0x00, 0x00, 0x07, 0x97, 0xbc, 0x04, 0x00, 0x00, 0x00, 0x00, 0xa4, 0x6e, 0x46, 0xdd
+    };
+
+    [Fact]
+    public void Test_RandEvent_ReturnsEvent()
+    {
+        var reader = new PacketReader(Payload);
+        var eventHeader = EventHeader.Read(ref reader);
+
+        var parser = new RandEventParser();
+        var @event = (RandEvent)parser.ParseEvent(eventHeader, ref reader);
+        ;
+        Assert.Equal(763747084UL, @event.Seed1);
+        Assert.Equal(79468295UL, @event.Seed2);
+    }
+}