func (e *etcd) SaveRoute(route models.Route) error {
key := generateHttpRouteKey(route)
retries := 0
for retries <= maxRetries {
response, err := e.keysAPI.Get(context.Background(), key, readOpts())
// Update
if response != nil && err == nil {
var existingRoute models.Route
err = json.Unmarshal([]byte(response.Node.Value), &existingRoute)
if err != nil {
return err
}
route.ModificationTag = existingRoute.ModificationTag
route.ModificationTag.Increment()
routeJSON, _ := json.Marshal(route)
_, err = e.keysAPI.Set(context.Background(), key, string(routeJSON), updateOptsWithTTL(route.TTL, response.Node.ModifiedIndex))
if err == nil {
break
}
} else if cerr, ok := err.(client.Error); ok && cerr.Code == client.ErrorCodeKeyNotFound { //create
// Delete came in between a read and an update
if retries > 0 {
return ErrorConflict
}
var tag models.ModificationTag
tag, err = models.NewModificationTag()
if err != nil {
return err
}
route.ModificationTag = tag
routeJSON, _ := json.Marshal(route)
_, err = e.keysAPI.Set(ctx(), key, string(routeJSON), createOpts(route.TTL))
if err == nil {
break
}
}
// only retry on a compare and swap error
if cerr, ok := err.(client.Error); ok && cerr.Code == client.ErrorCodeTestFailed {
retries++
} else {
return err
}
}
if retries > maxRetries {
return ErrorConflict
}
return nil
}
func (e *etcd) SaveTcpRouteMapping(tcpMapping models.TcpRouteMapping) error {
key := generateTcpRouteMappingKey(tcpMapping)
retries := 0
for retries <= maxRetries {
response, err := e.keysAPI.Get(context.Background(), key, readOpts())
// Update
if response != nil && err == nil {
var existingTcpRouteMapping models.TcpRouteMapping
err = json.Unmarshal([]byte(response.Node.Value), &existingTcpRouteMapping)
if err != nil {
return err
}
tcpMapping.ModificationTag = existingTcpRouteMapping.ModificationTag
tcpMapping.ModificationTag.Increment()
tcpRouteJSON, _ := json.Marshal(tcpMapping)
_, err = e.keysAPI.Set(ctx(), key, string(tcpRouteJSON), updateOptsWithTTL(int(tcpMapping.TTL), response.Node.ModifiedIndex))
} else if cerr, ok := err.(client.Error); ok && cerr.Code == client.ErrorCodeKeyNotFound { //create
// Delete came in between a read and update
if retries > 0 {
return ErrorConflict
}
var tag models.ModificationTag
tag, err = models.NewModificationTag()
if err != nil {
return err
}
tcpMapping.ModificationTag = tag
tcpRouteMappingJSON, _ := json.Marshal(tcpMapping)
_, err = e.keysAPI.Set(ctx(), key, string(tcpRouteMappingJSON), createOpts(int(tcpMapping.TTL)))
}
// return when create or update is successful
if err == nil {
return nil
}
// only retry on a compare and swap error
if cerr, ok := err.(client.Error); ok && cerr.Code == client.ErrorCodeTestFailed {
retries++
} else {
return err
}
}
// number of retries exceeded
return ErrorConflict
}