counting_reader.go

package metadata

import "io"

var (
	_ io.Reader     = (*countingReader)(nil)
	_ io.ByteReader = (*countingReader)(nil)
)

type countingReader struct {
	readCount int64
	r         io.Reader
}

func (c *countingReader) ReadByte() (byte, error) {
	b := []byte{0}
	_, err := c.Read(b)
	return b[0], err
}

func (c *countingReader) Read(b []byte) (n int, err error) {
	read, err := c.r.Read(b)
	c.readCount += int64(read)
	return read, err
}