docs/api/events.go

79 lines
1.8 KiB
Go

package api
import (
"fmt"
"io"
"net/http"
"sync"
"github.com/docker/swarm/cluster"
)
type eventsHandler struct {
sync.RWMutex
ws map[string]io.Writer
cs map[string]chan struct{}
}
// NewEventsHandler creates a new eventsHandler for a cluster.
// The new eventsHandler is initialized with no writers or channels.
func NewEventsHandler() *eventsHandler {
return &eventsHandler{
ws: make(map[string]io.Writer),
cs: make(map[string]chan struct{}),
}
}
// Add adds the writer and a new channel for the remote address.
func (eh *eventsHandler) Add(remoteAddr string, w io.Writer) {
eh.Lock()
eh.ws[remoteAddr] = w
eh.cs[remoteAddr] = make(chan struct{})
eh.Unlock()
}
// Wait waits on a signal from the remote address.
func (eh *eventsHandler) Wait(remoteAddr string) {
<-eh.cs[remoteAddr]
}
// Handle writes information about a cluster event to each remote address in the cluster that has been added to the events handler.
// After a successful write to a remote address, the associated channel is closed and the address is removed from the events handler.
func (eh *eventsHandler) Handle(e *cluster.Event) error {
eh.RLock()
str := fmt.Sprintf("{%q:%q,%q:%q,%q:%q,%q:%d,%q:{%q:%q,%q:%q,%q:%q,%q:%q}}",
"status", e.Status,
"id", e.Id,
"from", e.From+" node:"+e.Engine.Name,
"time", e.Time,
"node",
"Name", e.Engine.Name,
"Id", e.Engine.ID,
"Addr", e.Engine.Addr,
"Ip", e.Engine.IP)
for key, w := range eh.ws {
if _, err := fmt.Fprintf(w, str); err != nil {
close(eh.cs[key])
delete(eh.ws, key)
delete(eh.cs, key)
continue
}
if f, ok := w.(http.Flusher); ok {
f.Flush()
}
}
eh.RUnlock()
return nil
}
// Size returns the number of remote addresses that the events handler currently contains.
func (eh *eventsHandler) Size() int {
eh.RLock()
defer eh.RUnlock()
return len(eh.ws)
}