Move logger

debug/log/os.go

@@ -0,0 +1,97 @@
+package log
+
+import (
+	"bufio"
+	"encoding/json"
+	"os"
+	"time"
+)
+
+// Should stream from OS
+type osLog struct{}
+
+type osStream struct {
+	stream  chan Record
+	scanner *bufio.Reader
+	stop    chan bool
+}
+
+// Read reads log entries from the logger
+func (o *osLog) Read(...ReadOption) ([]Record, error) {
+	return []Record{}, nil
+}
+
+// Write writes records to log
+func (o *osLog) Write(r Record) error {
+	b, _ := json.Marshal(r)
+	_, err := os.Stderr.Write(b)
+	return err
+}
+
+// Stream log records
+func (o *osLog) Stream() (Stream, error) {
+	// read from standard error
+	scanner := bufio.NewReader(os.Stderr)
+	stream := make(chan Record, 128)
+	stop := make(chan bool)
+
+	go func() {
+		for {
+			select {
+			case <-stop:
+				return
+			default:
+				// read the line
+				line, err := scanner.ReadString('\n')
+				if err != nil {
+					return
+				}
+				// check if the line exists
+				if len(line) == 0 {
+					continue
+				}
+				// parse the record
+				var r Record
+				if line[0] == '{' {
+					json.Unmarshal([]byte(line), &r)
+				} else {
+					r = Record{
+						Timestamp: time.Now(),
+						Value:     line,
+						Metadata:  make(map[string]string),
+					}
+				}
+				// send to stream
+				select {
+				case <-stop:
+					return
+				case stream <- r:
+				}
+			}
+		}
+	}()
+
+	return &osStream{
+		stream:  stream,
+		scanner: scanner,
+		stop:    stop,
+	}, nil
+}
+
+func (o *osStream) Chan() <-chan Record {
+	return o.stream
+}
+
+func (o *osStream) Stop() error {
+	select {
+	case <-o.stop:
+		return nil
+	default:
+		close(o.stop)
+	}
+	return nil
+}
+
+func NewLog(opts ...Option) Log {
+	return &osLog{}
+}