add other session providers (#5963)

vendor/github.com/couchbase/gomemcached/client/transport.go

@@ -0,0 +1,67 @@
+package memcached
+
+import (
+	"errors"
+	"io"
+
+	"github.com/couchbase/gomemcached"
+)
+
+var errNoConn = errors.New("no connection")
+
+// UnwrapMemcachedError converts memcached errors to normal responses.
+//
+// If the error is a memcached response, declare the error to be nil
+// so a client can handle the status without worrying about whether it
+// indicates success or failure.
+func UnwrapMemcachedError(rv *gomemcached.MCResponse,
+	err error) (*gomemcached.MCResponse, error) {
+
+	if rv == err {
+		return rv, nil
+	}
+	return rv, err
+}
+
+// ReceiveHook is called after every packet is received (or attempted to be)
+var ReceiveHook func(*gomemcached.MCResponse, int, error)
+
+func getResponse(s io.Reader, hdrBytes []byte) (rv *gomemcached.MCResponse, n int, err error) {
+	if s == nil {
+		return nil, 0, errNoConn
+	}
+
+	rv = &gomemcached.MCResponse{}
+	n, err = rv.Receive(s, hdrBytes)
+
+	if ReceiveHook != nil {
+		ReceiveHook(rv, n, err)
+	}
+
+	if err == nil && (rv.Status != gomemcached.SUCCESS && rv.Status != gomemcached.AUTH_CONTINUE) {
+		err = rv
+	}
+	return rv, n, err
+}
+
+// TransmitHook is called after each packet is transmitted.
+var TransmitHook func(*gomemcached.MCRequest, int, error)
+
+func transmitRequest(o io.Writer, req *gomemcached.MCRequest) (int, error) {
+	if o == nil {
+		return 0, errNoConn
+	}
+	n, err := req.Transmit(o)
+	if TransmitHook != nil {
+		TransmitHook(req, n, err)
+	}
+	return n, err
+}
+
+func transmitResponse(o io.Writer, res *gomemcached.MCResponse) (int, error) {
+	if o == nil {
+		return 0, errNoConn
+	}
+	n, err := res.Transmit(o)
+	return n, err
+}