act/pkg/common/line_writer.go

51 lines
891 B
Go

package common
import (
"bytes"
"io"
)
// LineHandler is a callback function for handling a line
type LineHandler func(line string) bool
type lineWriter struct {
buffer bytes.Buffer
handlers []LineHandler
}
// NewLineWriter creates a new instance of a line writer
func NewLineWriter(handlers ...LineHandler) io.Writer {
w := new(lineWriter)
w.handlers = handlers
return w
}
func (lw *lineWriter) Write(p []byte) (n int, err error) {
pBuf := bytes.NewBuffer(p)
written := 0
for {
line, err := pBuf.ReadString('\n')
w, _ := lw.buffer.WriteString(line)
written += w
if err == nil {
lw.handleLine(lw.buffer.String())
lw.buffer.Reset()
} else if err == io.EOF {
break
} else {
return written, err
}
}
return written, nil
}
func (lw *lineWriter) handleLine(line string) {
for _, h := range lw.handlers {
ok := h(line)
if !ok {
break
}
}
}