github.com/demonoid81/moby@v0.0.0-20200517203328-62dd8e17c460/pkg/broadcaster/unbuffered.go (about) 1 package broadcaster // import "github.com/demonoid81/moby/pkg/broadcaster" 2 3 import ( 4 "io" 5 "sync" 6 ) 7 8 // Unbuffered accumulates multiple io.WriteCloser by stream. 9 type Unbuffered struct { 10 mu sync.Mutex 11 writers []io.WriteCloser 12 } 13 14 // Add adds new io.WriteCloser. 15 func (w *Unbuffered) Add(writer io.WriteCloser) { 16 w.mu.Lock() 17 w.writers = append(w.writers, writer) 18 w.mu.Unlock() 19 } 20 21 // Write writes bytes to all writers. Failed writers will be evicted during 22 // this call. 23 func (w *Unbuffered) Write(p []byte) (n int, err error) { 24 w.mu.Lock() 25 var evict []int 26 for i, sw := range w.writers { 27 if n, err := sw.Write(p); err != nil || n != len(p) { 28 // On error, evict the writer 29 evict = append(evict, i) 30 } 31 } 32 for n, i := range evict { 33 w.writers = append(w.writers[:i-n], w.writers[i-n+1:]...) 34 } 35 w.mu.Unlock() 36 return len(p), nil 37 } 38 39 // Clean closes and removes all writers. Last non-eol-terminated part of data 40 // will be saved. 41 func (w *Unbuffered) Clean() error { 42 w.mu.Lock() 43 for _, sw := range w.writers { 44 sw.Close() 45 } 46 w.writers = nil 47 w.mu.Unlock() 48 return nil 49 }