/
listener.go
198 lines (143 loc) · 4.3 KB
/
listener.go
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package curator
import (
"sync"
)
type ConnectionStateListener interface {
// Called when there is a state change in the connection
StateChanged(client CuratorFramework, newState ConnectionState)
}
// Receives notifications about errors and background events
type CuratorListener interface {
// Called when a background task has completed or a watch has triggered
EventReceived(client CuratorFramework, event CuratorEvent) error
}
type UnhandledErrorListener interface {
// Called when an exception is caught in a background thread, handler, etc.
UnhandledError(err error)
}
type connectionStateListenerCallback func(client CuratorFramework, newState ConnectionState)
type connectionStateListenerStub struct {
callback connectionStateListenerCallback
}
func NewConnectionStateListener(callback connectionStateListenerCallback) ConnectionStateListener {
return &connectionStateListenerStub{callback}
}
func (l *connectionStateListenerStub) StateChanged(client CuratorFramework, newState ConnectionState) {
l.callback(client, newState)
}
type curatorListenerCallback func(client CuratorFramework, event CuratorEvent) error
type curatorListenerStub struct {
callback curatorListenerCallback
}
func NewCuratorListener(callback curatorListenerCallback) CuratorListener {
return &curatorListenerStub{callback}
}
func (l *curatorListenerStub) EventReceived(client CuratorFramework, event CuratorEvent) error {
return l.callback(client, event)
}
type unhandledErrorListenerCallback func(err error)
type unhandledErrorListenerStub struct {
callback unhandledErrorListenerCallback
}
func NewUnhandledErrorListener(callback unhandledErrorListenerCallback) UnhandledErrorListener {
return &unhandledErrorListenerStub{callback}
}
func (l *unhandledErrorListenerStub) UnhandledError(err error) {
l.callback(err)
}
// Abstracts a listenable object
type Listenable /* [T] */ interface {
Len() int
Clear()
ForEach(callback func(interface{}))
}
type ConnectionStateListenable interface {
Listenable /* [T] */
AddListener(listener ConnectionStateListener)
RemoveListener(listener ConnectionStateListener)
}
type CuratorListenable interface {
Listenable /* [T] */
AddListener(listener CuratorListener)
RemoveListener(listener CuratorListener)
}
type UnhandledErrorListenable interface {
Listenable /* [T] */
AddListener(listener UnhandledErrorListener)
RemoveListener(listener UnhandledErrorListener)
}
type ListenerContainer struct {
lock sync.RWMutex
listeners []interface{}
}
func (c *ListenerContainer) Add(listener interface{}) {
if c != nil {
c.lock.Lock()
c.listeners = append(c.listeners, listener)
c.lock.Unlock()
}
}
func (c *ListenerContainer) Remove(listener interface{}) {
if c == nil {
return
}
c.lock.Lock()
for i, l := range c.listeners {
if l == listener {
c.listeners = append(c.listeners[:i], c.listeners[i+1:]...)
break
}
}
c.lock.Unlock()
}
func (c *ListenerContainer) Len() int {
if c == nil {
return 0
}
return len(c.listeners)
}
func (c *ListenerContainer) Clear() {
if c == nil {
return
}
c.lock.Lock()
c.listeners = nil
c.lock.Unlock()
}
func (c *ListenerContainer) ForEach(callback func(interface{})) {
if c == nil {
return
}
c.lock.RLock()
for _, listener := range c.listeners {
callback(listener)
}
c.lock.RUnlock()
}
type connectionStateListenerContainer struct {
ListenerContainer
}
func (c *connectionStateListenerContainer) AddListener(listener ConnectionStateListener) {
c.Add(listener)
}
func (c *connectionStateListenerContainer) RemoveListener(listener ConnectionStateListener) {
c.Remove(listener)
}
type curatorListenerContainer struct {
ListenerContainer
}
func (c *curatorListenerContainer) AddListener(listener CuratorListener) {
c.Add(listener)
}
func (c *curatorListenerContainer) RemoveListener(listener CuratorListener) {
c.Remove(listener)
}
type unhandledErrorListenerContainer struct {
ListenerContainer
}
func (c *unhandledErrorListenerContainer) AddListener(listener UnhandledErrorListener) {
c.Add(listener)
}
func (c *unhandledErrorListenerContainer) RemoveListener(listener UnhandledErrorListener) {
c.Remove(listener)
}