1package buffer
 2
 3import "io"
 4
 5// Reader implements an io.Reader over a byte slice.
 6type Reader struct {
 7	buf []byte
 8	pos int
 9}
10
11// NewReader returns a new Reader for a given byte slice.
12func NewReader(buf []byte) *Reader {
13	return &Reader{
14		buf: buf,
15	}
16}
17
18// Read reads bytes into the given byte slice and returns the number of bytes read and an error if occurred.
19func (r *Reader) Read(b []byte) (n int, err error) {
20	if len(b) == 0 {
21		return 0, nil
22	}
23	if r.pos >= len(r.buf) {
24		return 0, io.EOF
25	}
26	n = copy(b, r.buf[r.pos:])
27	r.pos += n
28	return
29}
30
31// Bytes returns the underlying byte slice.
32func (r *Reader) Bytes() []byte {
33	return r.buf
34}
35
36// Reset resets the position of the read pointer to the beginning of the underlying byte slice.
37func (r *Reader) Reset() {
38	r.pos = 0
39}
40
41// Len returns the length of the buffer.
42func (r *Reader) Len() int {
43	return len(r.buf)
44}