forked from vitessio/vitess
/
tablet_conn.go
62 lines (51 loc) · 1.96 KB
/
tablet_conn.go
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// Copyright 2012, Google Inc. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package tabletconn
import (
"flag"
"time"
log "github.com/golang/glog"
"github.com/youtube/vitess/go/vt/vttablet/queryservice"
"github.com/youtube/vitess/go/vt/vterrors"
topodatapb "github.com/youtube/vitess/go/vt/proto/topodata"
vtrpcpb "github.com/youtube/vitess/go/vt/proto/vtrpc"
)
var (
// ConnClosed is returned when the underlying connection was closed.
ConnClosed = vterrors.New(vtrpcpb.Code_UNAVAILABLE, "vttablet: Connection Closed")
)
var (
// TabletProtocol is exported for unit tests
TabletProtocol = flag.String("tablet_protocol", "grpc", "how to talk to the vttablets")
)
// TabletDialer represents a function that will return a QueryService
// object that can communicate with a tablet. Only the tablet's
// HostName and PortMap should be used (and maybe the alias for debug
// messages).
//
// When using this TabletDialer to talk to a l2vtgate, only the Hostname
// will be set to the full address to dial. Implementations should detect
// this use case as the portmap will then be empty.
//
// timeout represents the connection timeout. If set to 0, this
// connection should be established in the background and the
// TabletDialer should return right away.
type TabletDialer func(tablet *topodatapb.Tablet, timeout time.Duration) (queryservice.QueryService, error)
var dialers = make(map[string]TabletDialer)
// RegisterDialer is meant to be used by TabletDialer implementations
// to self register.
func RegisterDialer(name string, dialer TabletDialer) {
if _, ok := dialers[name]; ok {
log.Fatalf("Dialer %s already exists", name)
}
dialers[name] = dialer
}
// GetDialer returns the dialer to use, described by the command line flag
func GetDialer() TabletDialer {
td, ok := dialers[*TabletProtocol]
if !ok {
log.Fatalf("No dialer registered for tablet protocol %s", *TabletProtocol)
}
return td
}