database/sql: add Pinger interface to driver Conn

Change-Id: If6eb3a7c9ad48a517e584567b1003479c1df6cca
Reviewed-on: https://go-review.googlesource.com/32136
Reviewed-by: Daniel Theophanes <kardianos@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

1 files changed, 11 insertions, 0 deletions

diff --git a/src/database/sql/driver/driver.go b/src/database/sql/driver/driver.go
index bc6aa3b26e..e2ee7a9b28 100644
--- a/src/database/sql/driver/driver.go
+++ b/src/database/sql/driver/driver.go
@@ -69,6 +69,17 @@ var ErrSkip = errors.New("driver: skip fast-path; continue as if unimplemented")
 // you shouldn't return ErrBadConn.
 var ErrBadConn = errors.New("driver: bad connection")
 
+// Pinger is an optional interface that may be implemented by a Conn.
+//
+// If a Conn does not implement Pinger, the sql package's DB.Ping and
+// DB.PingContext will check if there is at least one Conn available.
+//
+// If Conn.Ping returns ErrBadConn, DB.Ping and DB.PingContext will remove
+// the Conn from pool.
+type Pinger interface {
+	Ping(ctx context.Context) error
+}
+
 // Execer is an optional interface that may be implemented by a Conn.
 //
 // If a Conn does not implement Execer, the sql package's DB.Exec will