use io.LimitedReader; fix logger prefix concurrent

lib/utils/limited_reader.go

@@ -1,37 +0,0 @@
-package utils
-
-import (
-	"errors"
-	"io"
-)
-
-// LimitedReader implements io.Reader, but you can only read the given number of bytes
-type LimitedReader struct {
-	src   io.Reader
-	n     int
-	limit int
-}
-
-// NewLimitedReader wraps an io.Reader to LimitedReader
-func NewLimitedReader(src io.Reader, limit int) *LimitedReader {
-	return &LimitedReader{
-		src:   src,
-		limit: limit,
-	}
-}
-
-// Read reads up to len(p) bytes into p. if meets EOF from src or reach limit, it returns EOF
-func (r *LimitedReader) Read(p []byte) (n int, err error) {
-	if r.src == nil {
-		return 0, errors.New("no data source")
-	}
-	if r.limit > 0 && r.n >= r.limit {
-		return 0, io.EOF
-	}
-	n, err = r.src.Read(p)
-	if err != nil {
-		return n, err
-	}
-	r.n += n
-	return
-}