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67 lines
1.3 KiB
Go
67 lines
1.3 KiB
Go
//go:generate mockgen -package internal -destination statewatcher_mock.go -source statewatcher.go etcdConn
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package internal
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import (
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"context"
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"sync"
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"google.golang.org/grpc/connectivity"
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)
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type (
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etcdConn interface {
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GetState() connectivity.State
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WaitForStateChange(ctx context.Context, sourceState connectivity.State) bool
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}
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stateWatcher struct {
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disconnected bool
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currentState connectivity.State
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listeners []func()
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// lock only guards listeners, because only listens can be accessed by other goroutines.
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lock sync.Mutex
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}
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)
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func newStateWatcher() *stateWatcher {
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return new(stateWatcher)
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}
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func (sw *stateWatcher) addListener(l func()) {
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sw.lock.Lock()
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sw.listeners = append(sw.listeners, l)
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sw.lock.Unlock()
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}
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func (sw *stateWatcher) notifyListeners() {
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sw.lock.Lock()
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defer sw.lock.Unlock()
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for _, l := range sw.listeners {
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l()
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}
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}
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func (sw *stateWatcher) updateState(conn etcdConn) {
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sw.currentState = conn.GetState()
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switch sw.currentState {
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case connectivity.TransientFailure, connectivity.Shutdown:
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sw.disconnected = true
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case connectivity.Ready:
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if sw.disconnected {
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sw.disconnected = false
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sw.notifyListeners()
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}
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}
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}
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func (sw *stateWatcher) watch(conn etcdConn) {
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sw.currentState = conn.GetState()
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for {
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if conn.WaitForStateChange(context.Background(), sw.currentState) {
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sw.updateState(conn)
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}
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}
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}
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