add WithNoRetryHosts optionFunc to handle all-hosts-invalid case better

conn.go

@@ -76,6 +76,7 @@ type Conn struct {
  xid uint32
  sessionTimeoutMs int32 // session timeout in milliseconds
  passwd []byte
+ noRetryHosts bool // if true, will abort when all hosts have been tried (once) and failed
 
  dialer Dialer
  hostProvider HostProvider
@@ -271,6 +272,12 @@ func WithEventCallback(cb EventCallback) connOption {
  }
 }
 
+func WithNoRetryHosts() connOption {
+ return func(c *Conn) {
+ c.noRetryHosts = true
+ }
+}
+
 // WithMaxBufferSize sets the maximum buffer size used to read and decode
 // packets received from the Zookeeper server. The standard Zookeeper client for
 // Java defaults to a limit of 1mb. For backwards compatibility, this Go client
@@ -375,10 +382,19 @@ func (c *Conn) connect() error {
 
  if retryStart {
  c.flushUnsentRequests(ErrNoServer)
- select {
- case <-time.After(time.Second):
- // pass
- case <-c.shouldQuit:
+
+ shouldQuit := c.noRetryHosts
+
+ if !shouldQuit {
+ select {
+ case <-time.After(time.Second):
+ // pass
+ case <-c.shouldQuit:
+ shouldQuit = true
+ }
+ }
+
+ if shouldQuit {
  c.setState(StateDisconnected)
  c.flushUnsentRequests(ErrClosing)
  return ErrClosing