Perform UTF-8 conversion at compile time.

Author: bgrainger

src/MySqlConnector/Core/ServerSession.cs

@@ -1921,14 +1921,14 @@ protected override void OnStatementBegin(int index)
 
 	private static ReadOnlySpan<byte> BeginCertificateBytes => "-----BEGIN CERTIFICATE-----"u8;
 	private static readonly IMySqlConnectorLogger Log = MySqlConnectorLogManager.CreateLogger(nameof(ServerSession));
-	private static readonly PayloadData s_setNamesUtf8NoAttributesPayload = QueryPayload.Create(false, "SET NAMES utf8;");
-	private static readonly PayloadData s_setNamesUtf8mb4NoAttributesPayload = QueryPayload.Create(false, "SET NAMES utf8mb4;");
-	private static readonly PayloadData s_setNamesUtf8WithAttributesPayload = QueryPayload.Create(true, "SET NAMES utf8;");
-	private static readonly PayloadData s_setNamesUtf8mb4WithAttributesPayload = QueryPayload.Create(true, "SET NAMES utf8mb4;");
-	private static readonly PayloadData s_sleepNoAttributesPayload = QueryPayload.Create(false, "SELECT SLEEP(0) INTO @\uE001MySqlConnector\uE001Sleep;");
-	private static readonly PayloadData s_sleepWithAttributesPayload = QueryPayload.Create(true, "SELECT SLEEP(0) INTO @\uE001MySqlConnector\uE001Sleep;");
-	private static readonly PayloadData s_selectConnectionIdVersionNoAttributesPayload = QueryPayload.Create(false, "SELECT CONNECTION_ID(), VERSION();");
-	private static readonly PayloadData s_selectConnectionIdVersionWithAttributesPayload = QueryPayload.Create(true, "SELECT CONNECTION_ID(), VERSION();");
+	private static readonly PayloadData s_setNamesUtf8NoAttributesPayload = QueryPayload.Create(false, "SET NAMES utf8;"u8);
+	private static readonly PayloadData s_setNamesUtf8mb4NoAttributesPayload = QueryPayload.Create(false, "SET NAMES utf8mb4;"u8);
+	private static readonly PayloadData s_setNamesUtf8WithAttributesPayload = QueryPayload.Create(true, "SET NAMES utf8;"u8);
+	private static readonly PayloadData s_setNamesUtf8mb4WithAttributesPayload = QueryPayload.Create(true, "SET NAMES utf8mb4;"u8);
+	private static readonly PayloadData s_sleepNoAttributesPayload = QueryPayload.Create(false, "SELECT SLEEP(0) INTO @\uE001MySqlConnector\uE001Sleep;"u8);
+	private static readonly PayloadData s_sleepWithAttributesPayload = QueryPayload.Create(true, "SELECT SLEEP(0) INTO @\uE001MySqlConnector\uE001Sleep;"u8);
+	private static readonly PayloadData s_selectConnectionIdVersionNoAttributesPayload = QueryPayload.Create(false, "SELECT CONNECTION_ID(), VERSION();"u8);
+	private static readonly PayloadData s_selectConnectionIdVersionWithAttributesPayload = QueryPayload.Create(true, "SELECT CONNECTION_ID(), VERSION();"u8);
 	private static int s_lastId;
 
 	private readonly object m_lock;

src/MySqlConnector/Protocol/Payloads/QueryPayload.cs

@@ -4,14 +4,13 @@ namespace MySqlConnector.Protocol.Payloads;
 
 internal static class QueryPayload
 {
-	public static PayloadData Create(bool supportsQueryAttributes, string query)
+	public static PayloadData Create(bool supportsQueryAttributes, ReadOnlySpan<byte> query)
 	{
-		var length = Encoding.UTF8.GetByteCount(query);
-		var payload = new byte[length + 1 + (supportsQueryAttributes ? 2 : 0)];
+		var payload = new byte[query.Length + 1 + (supportsQueryAttributes ? 2 : 0)];
 		payload[0] = (byte) CommandKind.Query;
 		if (supportsQueryAttributes)
 			payload[2] = 1;
-		Encoding.UTF8.GetBytes(query, 0, query.Length, payload, supportsQueryAttributes ? 3 : 1);
+		query.CopyTo(payload.AsSpan(supportsQueryAttributes ? 3 : 1));
 		return new PayloadData(payload);
 	}
 }