133 lines
2.7 KiB
Go
133 lines
2.7 KiB
Go
package channel
|
|
|
|
import (
|
|
"sync"
|
|
)
|
|
|
|
// mutex to lock access to the
|
|
// internal map of hubs.
|
|
var mu sync.RWMutex
|
|
|
|
// a map of hubs. each hub represents a different
|
|
// channel that a set of users can listen on. For
|
|
// example, we may have a hub to stream build output
|
|
// for github.com/foo/bar or a channel to post
|
|
// updates for user octocat.
|
|
var hubs = map[string]*hub{}
|
|
|
|
type hub struct {
|
|
// Registered connections
|
|
connections map[*connection]bool
|
|
|
|
// Inbound messages from the connections.
|
|
broadcast chan string
|
|
|
|
// Register requests from the connections.
|
|
register chan *connection
|
|
|
|
// Unregister requests from connections.
|
|
unregister chan *connection
|
|
|
|
// Buffer of sent data. This is used mostly
|
|
// for build output. A client may connect after
|
|
// the build has already started, in which case
|
|
// we need to stream them the build history.
|
|
history []string
|
|
|
|
// Send a "shutdown" signal
|
|
close chan bool
|
|
|
|
// Hub responds on this channel letting you know
|
|
// if it's active
|
|
closed chan bool
|
|
|
|
// Auto shutdown when last connection removed
|
|
autoClose bool
|
|
|
|
// Send history
|
|
sendHistory bool
|
|
}
|
|
|
|
func newHub(sendHistory, autoClose bool) *hub {
|
|
h := hub{
|
|
broadcast: make(chan string),
|
|
register: make(chan *connection),
|
|
unregister: make(chan *connection),
|
|
connections: make(map[*connection]bool),
|
|
history: make([]string, 0), // This should be pre-allocated, but it's not
|
|
close: make(chan bool),
|
|
autoClose: autoClose,
|
|
closed: make(chan bool),
|
|
sendHistory: sendHistory,
|
|
}
|
|
|
|
return &h
|
|
}
|
|
|
|
func sendHistory(c *connection, history []string) {
|
|
if len(history) > 0 {
|
|
for i := range history {
|
|
c.send <- history[i]
|
|
}
|
|
}
|
|
}
|
|
|
|
func (h *hub) run() {
|
|
// make sure we don't bring down the application
|
|
// if somehow we encounter a nil pointer or some
|
|
// other unexpected behavior.
|
|
defer func() {
|
|
recover()
|
|
}()
|
|
|
|
for {
|
|
select {
|
|
case c := <-h.register:
|
|
h.connections[c] = true
|
|
if len(h.history) > 0 {
|
|
b := make([]string, len(h.history))
|
|
copy(b, h.history)
|
|
go sendHistory(c, b)
|
|
}
|
|
case c := <-h.unregister:
|
|
delete(h.connections, c)
|
|
close(c.send)
|
|
shutdown := h.autoClose && (len(h.connections) == 0)
|
|
if shutdown {
|
|
h.closed <- shutdown
|
|
return
|
|
}
|
|
h.closed <- shutdown
|
|
case m := <-h.broadcast:
|
|
if h.sendHistory {
|
|
h.history = append(h.history, m)
|
|
}
|
|
for c := range h.connections {
|
|
select {
|
|
case c.send <- m:
|
|
// do nothing
|
|
default:
|
|
delete(h.connections, c)
|
|
go c.ws.Close()
|
|
}
|
|
}
|
|
case <-h.close:
|
|
for c := range h.connections {
|
|
delete(h.connections, c)
|
|
close(c.send)
|
|
}
|
|
h.closed <- true
|
|
return
|
|
}
|
|
|
|
}
|
|
}
|
|
|
|
func (h *hub) Close() {
|
|
h.close <- true
|
|
}
|
|
|
|
func (h *hub) Write(p []byte) (n int, err error) {
|
|
h.broadcast <- string(p)
|
|
return len(p), nil
|
|
}
|