Simplify codebase per audit of 7aff773

internal/jsonlines/jsonlines.go

@@ -0,0 +1,55 @@
+package jsonlines
+
+import (
+	"bufio"
+	"bytes"
+	"io"
+	"log/slog"
+	"sync/atomic"
+	"time"
+)
+
+type Stream struct {
+	vendor   string
+	onBad    func(line []byte, reason string)
+	lastLine atomic.Int64
+}
+
+func New(vendor string, onBad func(line []byte, reason string)) *Stream {
+	s := &Stream{vendor: vendor, onBad: onBad}
+	s.lastLine.Store(time.Now().UnixNano())
+	return s
+}
+
+func (s *Stream) LastLine() time.Time {
+	return time.Unix(0, s.lastLine.Load())
+}
+
+func (s *Stream) BadLine(line []byte, reason string) {
+	slog.Warn("bad "+s.vendor+" line", "reason", reason, "line", string(line))
+	if s.onBad != nil {
+		s.onBad(line, reason)
+	}
+}
+
+func (s *Stream) Read(stdout io.Reader, handle func(line []byte)) {
+	r := bufio.NewReader(stdout)
+	for {
+		line, err := r.ReadBytes('\n')
+		line = bytes.TrimRight(line, "\r\n")
+		if len(line) > 0 {
+			s.lastLine.Store(time.Now().UnixNano())
+			if line[0] == '{' {
+				handle(line)
+			} else {
+				s.BadLine(line, "not a JSON object")
+			}
+		}
+		if err != nil {
+			if err != io.EOF {
+				slog.Error("read "+s.vendor+" stdout", "err", err)
+			}
+			return
+		}
+	}
+}