channelsubscriber.go

package log

type channelLogger struct {
	subscribers []chan map[string]interface{}
}

// NewChannelLogger returns a Logger that sends log messages to subscribers
// as a map[string]interface{}
func NewChannelLogger() Logger {
	cl := &channelLogger{
		subscribers: make([]chan map[string]interface{}, 0),
	}
	return cl
}

func (l *channelLogger) Log(keyvals ...interface{}) error {
	n := (len(keyvals) + 1) / 2 // +1 to handle case when len is odd
	m := make(map[string]interface{}, n)
	for i := 0; i < len(keyvals); i += 2 {
		k := keyvals[i]
		var v interface{} = ErrMissingValue
		if i+1 < len(keyvals) {
			v = keyvals[i+1]
		}
		merge(m, k, v)
	}
	for _, s := range l.subscribers {
		s := s // capture s for anonymous func closure
		//clearly not safe to send if channel send blocks
		// send in goroutine so it doesn't block here
		// think of better solution tomorrow like wrapping in
		// a timeout so we don't leak goroutines on blocking sends
		// maybe the timeout is configurable and defaulted in the 
		// channelLogger struct?
		go func() {
			s <- m
		}()
	}
	return nil
}

func (l *channelLogger) Subscribe(s chan map[string]interface{}) {
	l.subscribers = append(l.subscribers, s)
	return
}