MariaDB metadata skipping

AUTHORS

@@ -37,6 +37,7 @@ Daniel Montoya <dsmontoyam at gmail.com>
 Daniel Nichter <nil at codenode.com>
 Daniël van Eeden <git at myname.nl>
 Dave Protasowski <dprotaso at gmail.com>
+Diego Dupin <diego.dupin at gmail.com>
 Dirkjan Bussink <d.bussink at gmail.com>
 DisposaBoy <disposaboy at dby.me>
 Egor Smolyakov <egorsmkv at gmail.com>

auth_test.go

@@ -89,7 +89,7 @@ func TestAuthFastCachingSHA256PasswordCached(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	err = mc.writeHandshakeResponsePacket(authResp, plugin)
+	err = mc.writeHandshakeResponsePacket(authResp, 0, 0, plugin)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -134,7 +134,7 @@ func TestAuthFastCachingSHA256PasswordEmpty(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	err = mc.writeHandshakeResponsePacket(authResp, plugin)
+	err = mc.writeHandshakeResponsePacket(authResp, 0, 0, plugin)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -176,7 +176,7 @@ func TestAuthFastCachingSHA256PasswordFullRSA(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	err = mc.writeHandshakeResponsePacket(authResp, plugin)
+	err = mc.writeHandshakeResponsePacket(authResp, 0, 0, plugin)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -232,7 +232,7 @@ func TestAuthFastCachingSHA256PasswordFullRSAWithKey(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	err = mc.writeHandshakeResponsePacket(authResp, plugin)
+	err = mc.writeHandshakeResponsePacket(authResp, 0, 0, plugin)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -284,7 +284,7 @@ func TestAuthFastCachingSHA256PasswordFullSecure(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	err = mc.writeHandshakeResponsePacket(authResp, plugin)
+	err = mc.writeHandshakeResponsePacket(authResp, 0, 0, plugin)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -357,7 +357,7 @@ func TestAuthFastCleartextPassword(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	err = mc.writeHandshakeResponsePacket(authResp, plugin)
+	err = mc.writeHandshakeResponsePacket(authResp, 0, 0, plugin)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -400,7 +400,7 @@ func TestAuthFastCleartextPasswordEmpty(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	err = mc.writeHandshakeResponsePacket(authResp, plugin)
+	err = mc.writeHandshakeResponsePacket(authResp, 0, 0, plugin)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -459,7 +459,7 @@ func TestAuthFastNativePassword(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	err = mc.writeHandshakeResponsePacket(authResp, plugin)
+	err = mc.writeHandshakeResponsePacket(authResp, 0, 0, plugin)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -502,7 +502,7 @@ func TestAuthFastNativePasswordEmpty(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	err = mc.writeHandshakeResponsePacket(authResp, plugin)
+	err = mc.writeHandshakeResponsePacket(authResp, 0, 0, plugin)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -544,7 +544,7 @@ func TestAuthFastSHA256PasswordEmpty(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	err = mc.writeHandshakeResponsePacket(authResp, plugin)
+	err = mc.writeHandshakeResponsePacket(authResp, 0, 0, plugin)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -592,7 +592,7 @@ func TestAuthFastSHA256PasswordRSA(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	err = mc.writeHandshakeResponsePacket(authResp, plugin)
+	err = mc.writeHandshakeResponsePacket(authResp, 0, 0, plugin)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -641,7 +641,7 @@ func TestAuthFastSHA256PasswordRSAWithKey(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	err = mc.writeHandshakeResponsePacket(authResp, plugin)
+	err = mc.writeHandshakeResponsePacket(authResp, 0, 0, plugin)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -678,7 +678,7 @@ func TestAuthFastSHA256PasswordSecure(t *testing.T) {
 	// unset TLS config to prevent the actual establishment of a TLS wrapper
 	mc.cfg.TLS = nil
 
-	err = mc.writeHandshakeResponsePacket(authResp, plugin)
+	err = mc.writeHandshakeResponsePacket(authResp, 0, 0, plugin)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -1343,7 +1343,7 @@ func TestEd25519Auth(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	err = mc.writeHandshakeResponsePacket(authResp, plugin)
+	err = mc.writeHandshakeResponsePacket(authResp, 0, 0, plugin)
 	if err != nil {
 		t.Fatal(err)
 	}

benchmark_test.go

@@ -440,3 +440,53 @@ func BenchmarkReceiveMassiveRows(b *testing.B) {
 		}
 	})
 }
+
+// BenchmarkReceiveMetadata measures performance of receiving more metadata than real data
+func BenchmarkReceiveMetadata(b *testing.B) {
+	tb := (*TB)(b)
+	b.StopTimer()
+	b.ReportAllocs()
+
+	// Create a table with 1000 integer fields
+	createTableQuery := "CREATE TABLE large_integer_table ("
+	for i := 0; i < 1000; i++ {
+		createTableQuery += fmt.Sprintf("col_%d INT", i)
+		if i < 999 {
+			createTableQuery += ", "
+		}
+	}
+	createTableQuery += ")"
+
+	// Initialize database
+	db := initDB(b, false,
+		"DROP TABLE IF EXISTS large_integer_table",
+		createTableQuery,
+		"INSERT INTO large_integer_table VALUES ("+
+			strings.Repeat("0,", 999)+"0)", // Insert a row of zeros
+	)
+	defer db.Close()
+
+	// Prepare a SELECT query to retrieve metadata
+	stmt := tb.checkStmt(db.Prepare("SELECT * FROM large_integer_table LIMIT 1"))
+	defer stmt.Close()
+
+	b.StartTimer()
+
+	// Benchmark metadata retrieval
+	for i := 0; i < b.N; i++ {
+		rows := tb.checkRows(stmt.Query())
+
+		// Create a slice to scan all columns
+		values := make([]interface{}, 1000)
+		valuePtrs := make([]interface{}, 1000)
+		for j := range values {
+			valuePtrs[j] = &values[j]
+		}
+		rows.Next()
+		// Scan the row
+		err := rows.Scan(valuePtrs...)
+		tb.check(err)
+
+		rows.Close()
+	}
+}

connection.go

@@ -24,21 +24,22 @@ import (
 )
 
 type mysqlConn struct {
-	buf              buffer
-	netConn          net.Conn
-	rawConn          net.Conn    // underlying connection when netConn is TLS connection.
-	result           mysqlResult // managed by clearResult() and handleOkPacket().
-	compIO           *compIO
-	cfg              *Config
-	connector        *connector
-	maxAllowedPacket int
-	maxWriteSize     int
-	flags            clientFlag
-	status           statusFlag
-	sequence         uint8
-	compressSequence uint8
-	parseTime        bool
-	compress         bool
+	buf                   buffer
+	netConn               net.Conn
+	rawConn               net.Conn    // underlying connection when netConn is TLS connection.
+	result                mysqlResult // managed by clearResult() and handleOkPacket().
+	compIO                *compIO
+	cfg                   *Config
+	connector             *connector
+	maxAllowedPacket      int
+	maxWriteSize          int
+	clientCapabilities    capabilityFlag
+	clientExtCapabilities extendedCapabilityFlag
+	status                statusFlag
+	sequence              uint8
+	compressSequence      uint8
+	parseTime             bool
+	compress              bool
 
 	// for context support (Go 1.8+)
 	watching bool
@@ -223,13 +224,21 @@ func (mc *mysqlConn) Prepare(query string) (driver.Stmt, error) {
 	columnCount, err := stmt.readPrepareResultPacket()
 	if err == nil {
 		if stmt.paramCount > 0 {
-			if err = mc.readUntilEOF(); err != nil {
+			if err = mc.skipColumns(stmt.paramCount); err != nil {
 				return nil, err
 			}
 		}
 
 		if columnCount > 0 {
-			err = mc.readUntilEOF()
+			if mc.clientExtCapabilities&clientCacheMetadata != 0 {
+				if stmt.columns, err = mc.readColumns(int(columnCount)); err != nil {
+					return nil, err
+				}
+			} else {
+				if err = mc.skipColumns(int(columnCount)); err != nil {
+					return nil, err
+				}
+			}
 		}
 	}
 
@@ -370,19 +379,19 @@ func (mc *mysqlConn) exec(query string) error {
 	}
 
 	// Read Result
-	resLen, err := handleOk.readResultSetHeaderPacket()
+	resLen, _, err := handleOk.readResultSetHeaderPacket()
 	if err != nil {
 		return err
 	}
 
 	if resLen > 0 {
 		// columns
-		if err := mc.readUntilEOF(); err != nil {
+		if err := mc.skipColumns(resLen); err != nil {
 			return err
 		}
 
 		// rows
-		if err := mc.readUntilEOF(); err != nil {
+		if err := mc.skipResultSetRows(); err != nil {
 			return err
 		}
 	}
@@ -419,7 +428,7 @@ func (mc *mysqlConn) query(query string, args []driver.Value) (*textRows, error)
 
 	// Read Result
 	var resLen int
-	resLen, err = handleOk.readResultSetHeaderPacket()
+	resLen, _, err = handleOk.readResultSetHeaderPacket()
 	if err != nil {
 		return nil, err
 	}
@@ -453,22 +462,22 @@ func (mc *mysqlConn) getSystemVar(name string) ([]byte, error) {
 	}
 
 	// Read Result
-	resLen, err := handleOk.readResultSetHeaderPacket()
+	resLen, _, err := handleOk.readResultSetHeaderPacket()
 	if err == nil {
 		rows := new(textRows)
 		rows.mc = mc
 		rows.rs.columns = []mysqlField{{fieldType: fieldTypeVarChar}}
 
 		if resLen > 0 {
 			// Columns
-			if err := mc.readUntilEOF(); err != nil {
+			if err := mc.skipColumns(resLen); err != nil {
 				return nil, err
 			}
 		}
 
 		dest := make([]driver.Value, resLen)
 		if err = rows.readRow(dest); err == nil {
-			return dest[0].([]byte), mc.readUntilEOF()
+			return dest[0].([]byte), mc.skipResultSetRows()
 		}
 	}
 	return nil, err

connector.go

@@ -131,7 +131,7 @@ func (c *connector) Connect(ctx context.Context) (driver.Conn, error) {
 	mc.buf = newBuffer()
 
 	// Reading Handshake Initialization Packet
-	authData, plugin, err := mc.readHandshakePacket()
+	authData, serverCapabilities, serverExtendedCapabilities, plugin, err := mc.readHandshakePacket()
 	if err != nil {
 		mc.cleanup()
 		return nil, err
@@ -153,7 +153,7 @@ func (c *connector) Connect(ctx context.Context) (driver.Conn, error) {
 			return nil, err
 		}
 	}
-	if err = mc.writeHandshakeResponsePacket(authResp, plugin); err != nil {
+	if err = mc.writeHandshakeResponsePacket(authResp, serverCapabilities, serverExtendedCapabilities, plugin); err != nil {
 		mc.cleanup()
 		return nil, err
 	}
@@ -167,7 +167,7 @@ func (c *connector) Connect(ctx context.Context) (driver.Conn, error) {
 		return nil, err
 	}
 
-	if mc.cfg.compress && mc.flags&clientCompress == clientCompress {
+	if mc.cfg.compress && mc.clientCapabilities&clientCompress > 0 {
 		mc.compress = true
 		mc.compIO = newCompIO(mc)
 	}

const.go

@@ -43,10 +43,10 @@ const (
 )
 
 // https://dev.mysql.com/doc/internals/en/capability-flags.html#packet-Protocol::CapabilityFlags
-type clientFlag uint32
+type capabilityFlag uint32
 
 const (
-	clientLongPassword clientFlag = 1 << iota
+	clientMySQL capabilityFlag = 1 << iota
 	clientFoundRows
 	clientLongFlag
 	clientConnectWithDB
@@ -73,6 +73,20 @@ const (
 	clientDeprecateEOF
 )
 
+// https://mariadb.com/kb/en/connection/#capabilities
+type extendedCapabilityFlag uint32
+
+const (
+	progressIndicator extendedCapabilityFlag = 1 << iota
+	clientComMulti
+	clientStmtBulkOperations
+	clientExtendedMetadata
+	clientCacheMetadata
+	clientUnitBulkResult
+)
+
+// https://mariadb.com/kb/en/connection/#capabilities
+
 const (
 	comQuit byte = iota + 1
 	comInitDB