Implement driver.DriverContext and driver.Connector interfaces in sql/driver

sql/driver/driver.go

@@ -6,6 +6,7 @@ import (
 	"database/sql/driver"
 	"errors"
 	"io"
+	"runtime"
 	"sync"
 
 	"github.com/genjidb/genji"
@@ -20,58 +21,68 @@ func init() {
 	sql.Register("genji", sqlDriver{})
 }
 
+var (
+	_ driver.Driver        = (*sqlDriver)(nil)
+	_ driver.DriverContext = (*sqlDriver)(nil)
+)
+
 // sqlDriver is a driver.Driver that can open a new connection to a Genji database.
 // It is the driver used to register Genji against the database/sql package.
 type sqlDriver struct{}
 
 func (d sqlDriver) Open(name string) (driver.Conn, error) {
+	return nil, errors.New("requires go1.10 or greater")
+}
+
+func (d sqlDriver) OpenConnector(name string) (driver.Connector, error) {
 	db, err := genji.Open(name)
 	if err != nil {
 		return nil, err
 	}
 
-	return &conn{db: db}, nil
-}
-
-// proxyDriver is used to turn an existing DB into a driver.Driver.
-type proxyDriver struct {
-	db *genji.DB
-}
-
-func newDriver(db *genji.DB) driver.Driver {
-	return proxyDriver{
-		db: db,
+	c := &connector{
+		db:     db,
+		driver: d,
 	}
-}
+	runtime.SetFinalizer(c, (*connector).Close)
 
-func (d proxyDriver) Open(name string) (driver.Conn, error) {
-	return &conn{db: d.db}, nil
+	return c, nil
 }
 
-type proxyConnector struct {
+var (
+	_ driver.Connector = (*connector)(nil)
+	_ io.Closer        = (*connector)(nil)
+)
+
+type connector struct {
 	driver driver.Driver
-}
 
-func newProxyConnector(db *genji.DB) driver.Connector {
-	return proxyConnector{
-		driver: newDriver(db),
-	}
+	db *genji.DB
+
+	closeOnce sync.Once
 }
 
-func (c proxyConnector) Connect(ctx context.Context) (driver.Conn, error) {
-	return c.driver.Open("")
+func (c *connector) Connect(ctx context.Context) (driver.Conn, error) {
+	return &conn{db: c.db}, nil
 }
 
-func (c proxyConnector) Driver() driver.Driver {
+func (c *connector) Driver() driver.Driver {
 	return c.driver
 }
 
+func (c *connector) Close() error {
+	var err error
+	c.closeOnce.Do(func() {
+		err = c.db.Close()
+	})
+	return err
+}
+
 // conn represents a connection to the Genji database.
 // It implements the database/sql/driver.Conn interface.
 type conn struct {
-	db            *genji.DB
-	tx            *genji.Tx
-	nonPromotable bool
+	db *genji.DB
+	tx *genji.Tx
 }
 
 // Prepare returns a prepared statement, bound to this connection.