pkg/broadcastwriter/broadcastwriter.go
Antonio Murdaca 18180bfabf Replace aliased imports of logrus, fixes #11762
Signed-off-by: Antonio Murdaca <me@runcom.ninja>
2015-03-26 23:22:04 +01:00

101 lines
2.3 KiB
Go

package broadcastwriter
import (
"bytes"
"io"
"sync"
"time"
"github.com/Sirupsen/logrus"
"github.com/docker/docker/pkg/jsonlog"
)
// BroadcastWriter accumulate multiple io.WriteCloser by stream.
type BroadcastWriter struct {
sync.Mutex
buf *bytes.Buffer
jsLogBuf *bytes.Buffer
streams map[string](map[io.WriteCloser]struct{})
}
// AddWriter adds new io.WriteCloser for stream.
// If stream is "", then all writes proceed as is. Otherwise every line from
// input will be packed to serialized jsonlog.JSONLog.
func (w *BroadcastWriter) AddWriter(writer io.WriteCloser, stream string) {
w.Lock()
if _, ok := w.streams[stream]; !ok {
w.streams[stream] = make(map[io.WriteCloser]struct{})
}
w.streams[stream][writer] = struct{}{}
w.Unlock()
}
// Write writes bytes to all writers. Failed writers will be evicted during
// this call.
func (w *BroadcastWriter) Write(p []byte) (n int, err error) {
created := time.Now().UTC()
w.Lock()
if writers, ok := w.streams[""]; ok {
for sw := range writers {
if n, err := sw.Write(p); err != nil || n != len(p) {
// On error, evict the writer
delete(writers, sw)
}
}
}
if w.jsLogBuf == nil {
w.jsLogBuf = new(bytes.Buffer)
w.jsLogBuf.Grow(1024)
}
w.buf.Write(p)
for {
line, err := w.buf.ReadString('\n')
if err != nil {
w.buf.Write([]byte(line))
break
}
for stream, writers := range w.streams {
if stream == "" {
continue
}
jsonLog := jsonlog.JSONLog{Log: line, Stream: stream, Created: created}
err = jsonLog.MarshalJSONBuf(w.jsLogBuf)
if err != nil {
logrus.Errorf("Error making JSON log line: %s", err)
continue
}
w.jsLogBuf.WriteByte('\n')
b := w.jsLogBuf.Bytes()
for sw := range writers {
if _, err := sw.Write(b); err != nil {
delete(writers, sw)
}
}
}
w.jsLogBuf.Reset()
}
w.jsLogBuf.Reset()
w.Unlock()
return len(p), nil
}
// Clean closes and removes all writers. Last non-eol-terminated part of data
// will be saved.
func (w *BroadcastWriter) Clean() error {
w.Lock()
for _, writers := range w.streams {
for w := range writers {
w.Close()
}
}
w.streams = make(map[string](map[io.WriteCloser]struct{}))
w.Unlock()
return nil
}
func New() *BroadcastWriter {
return &BroadcastWriter{
streams: make(map[string](map[io.WriteCloser]struct{})),
buf: bytes.NewBuffer(nil),
}
}