Add OpenConnector to Driver to satisfy DriverContext interface

sql.Open will use driver's OpenConnector instead of its
Open method. This will enable TCP keepalive support.

Note, testDriver was added for TestRuntimeParameters since it
expects old fashioned Driver interface (without OpenConnector).

Author: marselester

conn.go

@@ -48,6 +48,12 @@ func (d *Driver) Open(name string) (driver.Conn, error) {
 	return Open(name)
 }
 
+// OpenConnector parses the name in the same format that Driver.Open
+// parses the name parameter.
+func (d *Driver) OpenConnector(name string) (driver.Connector, error) {
+	return NewConnector(name)
+}
+
 func init() {
 	sql.Register("postgres", &Driver{})
 }

conn_test.go

@@ -14,6 +14,17 @@ import (
 	"time"
 )
 
+// testDriver is the Postgres database driver that doesn't implement DriverContext interface.
+type testDriver struct{}
+
+func (d *testDriver) Open(name string) (driver.Conn, error) {
+	return Open(name)
+}
+
+func init() {
+	sql.Register("postgres-test", &testDriver{})
+}
+
 type Fatalistic interface {
 	Fatal(args ...interface{})
 }
@@ -48,7 +59,7 @@ func testConninfo(conninfo string) string {
 }
 
 func openTestConnConninfo(conninfo string) (*sql.DB, error) {
-	return sql.Open("postgres", testConninfo(conninfo))
+	return sql.Open("postgres-test", testConninfo(conninfo))
 }
 
 func openTestConn(t Fatalistic) *sql.DB {