v1.5.3

RELEASENOTES.md

@@ -5,6 +5,9 @@ Release Notes
 
 ### Minor revisions
 
+#### v1.5.3
+- performance improvements
+
 #### v1.5.2
 - fixed race condition in connection conn and stmt methods in case of context cancelling
 

driver/connattrs.go

@@ -54,7 +54,6 @@ const (
 // connAttrs is holding connection relevant attributes.
 type connAttrs struct {
 	mu                sync.RWMutex
-	_host             string
 	_timeout          time.Duration
 	_pingInterval     time.Duration
 	_bufferSize       int
@@ -72,7 +71,6 @@ type connAttrs struct {
 	_cesu8Decoder     func() transform.Transformer
 	_cesu8Encoder     func() transform.Transformer
 	_emptyDateAsNull  bool
-	_databaseName     string
 	_logger           *slog.Logger
 }
 
@@ -103,7 +101,6 @@ func (c *connAttrs) clone() *connAttrs {
 	defer c.mu.RUnlock()
 
 	return &connAttrs{
-		_host:             c._host,
 		_timeout:          c._timeout,
 		_pingInterval:     c._pingInterval,
 		_bufferSize:       c._bufferSize,
@@ -121,7 +118,6 @@ func (c *connAttrs) clone() *connAttrs {
 		_cesu8Decoder:     c._cesu8Decoder,
 		_cesu8Encoder:     c._cesu8Encoder,
 		_emptyDateAsNull:  c._emptyDateAsNull,
-		_databaseName:     c._databaseName,
 		_logger:           c._logger,
 	}
 }
@@ -192,9 +188,6 @@ func (c *connAttrs) setDfv(dfv int) {
 	c._dfv = dfv
 }
 
-// Host returns the host of the connector.
-func (c *connAttrs) Host() string { c.mu.RLock(); defer c.mu.RUnlock(); return c._host }
-
 // Timeout returns the timeout of the connector.
 func (c *connAttrs) Timeout() time.Duration { c.mu.RLock(); defer c.mu.RUnlock(); return c._timeout }
 
@@ -444,13 +437,6 @@ func (c *connAttrs) SetEmptyDateAsNull(emptyDateAsNull bool) {
 	c._emptyDateAsNull = emptyDateAsNull
 }
 
-// DatabaseName returns the tenant database name of the connector.
-func (c *connAttrs) DatabaseName() string {
-	c.mu.RLock()
-	defer c.mu.RUnlock()
-	return c._databaseName
-}
-
 // Logger returns the Logger instance of the connector.
 func (c *connAttrs) Logger() *slog.Logger {
 	c.mu.RLock()
@@ -462,5 +448,8 @@ func (c *connAttrs) Logger() *slog.Logger {
 func (c *connAttrs) SetLogger(logger *slog.Logger) {
 	c.mu.Lock()
 	defer c.mu.Unlock()
+	if logger == nil {
+		logger = slog.Default()
+	}
 	c._logger = logger
 }

driver/connection.go

@@ -206,17 +206,10 @@ func isAuthError(err error) bool {
 	return hdbErrors.Code() == p.HdbErrAuthenticationFailed
 }
 
-func connect(ctx context.Context, metrics *metrics, connAttrs *connAttrs, authAttrs *authAttrs) (driver.Conn, error) {
-	// if database name fetch tenant database host
-	if connAttrs._databaseName != "" {
-		if err := fetchHost(ctx, metrics, connAttrs); err != nil {
-			return nil, err
-		}
-	}
-
+func connect(ctx context.Context, host string, metrics *metrics, connAttrs *connAttrs, authAttrs *authAttrs) (driver.Conn, error) {
 	// can we connect via cookie?
 	if auth := authAttrs.cookieAuth(); auth != nil {
-		conn, err := newSession(ctx, metrics, connAttrs, auth)
+		conn, err := newSession(ctx, host, metrics, connAttrs, auth)
 		if err == nil {
 			return conn, nil
 		}
@@ -226,14 +219,13 @@ func connect(ctx context.Context, metrics *metrics, connAttrs *connAttrs, authAt
 		authAttrs.invalidateCookie() // cookie auth was not successful - do not try again with the same data
 	}
 
-	const maxRetry = 1
-	numRetry := 0
+	refreshed := false
 	lastVersion := authAttrs.version.Load()
 
 	for {
 		authHnd := authAttrs.authHnd()
 
-		conn, err := newSession(ctx, metrics, connAttrs, authHnd)
+		conn, err := newSession(ctx, host, metrics, connAttrs, authHnd)
 		if err == nil {
 			if method, ok := authHnd.Selected().(auth.CookieGetter); ok {
 				authAttrs.setCookie(method.Cookie())
@@ -243,7 +235,7 @@ func connect(ctx context.Context, metrics *metrics, connAttrs *connAttrs, authAt
 		if !isAuthError(err) {
 			return nil, err
 		}
-		if numRetry >= maxRetry {
+		if refreshed {
 			return nil, err
 		}
 
@@ -257,7 +249,7 @@ func connect(ctx context.Context, metrics *metrics, connAttrs *connAttrs, authAt
 		}
 		lastVersion = version
 
-		numRetry++
+		refreshed = true
 	}
 }
 
@@ -295,8 +287,8 @@ func (nvs namedValues) LogValue() slog.Value {
 // unique connection number.
 var connNo atomic.Uint64
 
-func newConn(ctx context.Context, metrics *metrics, attrs *connAttrs) (*conn, error) {
-	netConn, err := attrs._dialer.DialContext(ctx, attrs._host, dial.DialerOptions{Timeout: attrs._timeout, TCPKeepAlive: attrs._tcpKeepAlive})
+func newConn(ctx context.Context, host string, metrics *metrics, attrs *connAttrs) (*conn, error) {
+	netConn, err := attrs._dialer.DialContext(ctx, host, dial.DialerOptions{Timeout: attrs._timeout, TCPKeepAlive: attrs._tcpKeepAlive})
 	if err != nil {
 		return nil, err
 	}
@@ -339,24 +331,24 @@ func newConn(ctx context.Context, metrics *metrics, attrs *connAttrs) (*conn, er
 	return c, nil
 }
 
-func fetchHost(ctx context.Context, metrics *metrics, attrs *connAttrs) error {
-	c, err := newConn(ctx, metrics, attrs)
+func fetchRedirectHost(ctx context.Context, host, databaseName string, metrics *metrics, attrs *connAttrs) (string, error) {
+	c, err := newConn(ctx, host, metrics, attrs)
 	if err != nil {
-		return err
+		return "", err
 	}
 	defer c.Close()
-	dbi, err := c._dbConnectInfo(ctx, attrs._databaseName)
+	dbi, err := c._dbConnectInfo(ctx, databaseName)
 	if err != nil {
-		return err
+		return "", err
 	}
-	if !dbi.IsConnected { // if databaseName == "SYSTEMDB" and isConnected == true host and port are initial
-		attrs._host = net.JoinHostPort(dbi.Host, strconv.Itoa(dbi.Port))
+	if dbi.IsConnected { // if databaseName == "SYSTEMDB" and isConnected == true host and port are initial
+		return host, nil
 	}
-	return nil
+	return net.JoinHostPort(dbi.Host, strconv.Itoa(dbi.Port)), nil
 }
 
-func newSession(ctx context.Context, metrics *metrics, attrs *connAttrs, authHnd *p.AuthHnd) (driver.Conn, error) {
-	c, err := newConn(ctx, metrics, attrs)
+func newSession(ctx context.Context, host string, metrics *metrics, attrs *connAttrs, authHnd *p.AuthHnd) (driver.Conn, error) {
+	c, err := newConn(ctx, host, metrics, attrs)
 	if err != nil {
 		return nil, err
 	}

driver/connector.go

@@ -5,21 +5,29 @@ import (
 	"database/sql/driver"
 	"os"
 	"path"
+	"sync"
 
 	"github.com/SAP/go-hdb/driver/internal/protocol/x509"
 )
 
+type redirectCacheKey struct {
+	host, databaseName string
+}
+
+var redirectCache sync.Map
+
 /*
 A Connector represents a hdb driver in a fixed configuration.
 A Connector can be passed to sql.OpenDB (starting from go 1.10) allowing users to bypass a string based data source name.
 */
 type Connector struct {
+	_host         string
+	_databaseName string
+
 	*connAttrs
 	*authAttrs
 
 	metrics *metrics
-
-	connHook func(driver.Conn) driver.Conn
 }
 
 // NewConnector returns a new Connector instance with default values.
@@ -102,27 +110,53 @@ func NewDSNConnector(dsnStr string) (*Connector, error) {
 // NativeDriver returns the concrete underlying Driver of the Connector.
 func (c *Connector) NativeDriver() Driver { return stdHdbDriver }
 
-// Connect implements the database/sql/driver/Connector interface.
-func (c *Connector) Connect(ctx context.Context) (driver.Conn, error) {
-	conn, err := connect(ctx, c.metrics, c.connAttrs.clone(), c.authAttrs)
+// Host returns the host of the connector.
+func (c *Connector) Host() string { return c._host }
+
+// DatabaseName returns the tenant database name of the connector.
+func (c *Connector) DatabaseName() string { return c._databaseName }
+
+func (c *Connector) redirect(ctx context.Context) (driver.Conn, error) {
+	connAttrs := c.connAttrs.clone()
+
+	if redirectHost, found := redirectCache.Load(redirectCacheKey{host: c._host, databaseName: c._databaseName}); found {
+		if conn, err := connect(ctx, redirectHost.(string), c.metrics, connAttrs, c.authAttrs); err == nil {
+			return conn, nil
+		}
+	}
+
+	redirectHost, err := fetchRedirectHost(ctx, c._host, c._databaseName, c.metrics, connAttrs)
 	if err != nil {
 		return nil, err
 	}
-	if c.connHook != nil {
-		conn = c.connHook(conn)
+	conn, err := connect(ctx, redirectHost, c.metrics, connAttrs, c.authAttrs)
+	if err != nil {
+		return nil, err
 	}
+
+	redirectCache.Store(redirectCacheKey{host: c._host, databaseName: c._databaseName}, redirectHost)
+
 	return conn, err
 }
 
+// Connect implements the database/sql/driver/Connector interface.
+func (c *Connector) Connect(ctx context.Context) (driver.Conn, error) {
+	if c._databaseName != "" {
+		return c.redirect(ctx)
+	}
+	return connect(ctx, c._host, c.metrics, c.connAttrs.clone(), c.authAttrs)
+}
+
 // Driver implements the database/sql/driver/Connector interface.
 func (c *Connector) Driver() driver.Driver { return stdHdbDriver }
 
 func (c *Connector) clone() *Connector {
 	return &Connector{
-		connAttrs: c.connAttrs.clone(),
-		authAttrs: c.authAttrs.clone(),
-		metrics:   c.metrics,
-		connHook:  c.connHook,
+		_host:         c._host,
+		_databaseName: c._databaseName,
+		connAttrs:     c.connAttrs.clone(),
+		authAttrs:     c.authAttrs.clone(),
+		metrics:       c.metrics,
 	}
 }
 
@@ -132,7 +166,3 @@ func (c *Connector) WithDatabase(databaseName string) *Connector {
 	nc._databaseName = databaseName
 	return nc
 }
-
-// SetConnHook sets a function for intercepting connection creation.
-// This is for internal use only and might be changed or disabled in future.
-func (c *Connector) SetConnHook(fn func(driver.Conn) driver.Conn) { c.connHook = fn }

driver/driver.go

@@ -10,7 +10,7 @@ import (
 )
 
 // DriverVersion is the version number of the hdb driver.
-const DriverVersion = "1.5.2"
+const DriverVersion = "1.5.3"
 
 // DriverName is the driver name to use with sql.Open for hdb databases.
 const DriverName = "hdb"