interfaces are fun

master
Jordan Orelli 9 years ago
parent 63ab3c62e8
commit 2bf18c6fce

@ -6,11 +6,12 @@ import (
"io"
)
// Reader allows for the reading and skipping of bits and bytes.
type Reader interface {
ReadBits(uint) uint64
DiscardBits(int)
ReadByte() (byte, error)
Read([]byte) (int, error)
ReadByte() byte
Read([]byte) int
DiscardBytes(int)
Err() error
}

@ -17,6 +17,10 @@ type streamReader struct {
// ReadBits reads the given number of bits and returns them in the
// least-significant part of a uint64.
func (r *streamReader) ReadBits(bits uint) (n uint64) {
if r.err != nil {
return 0
}
for bits > r.bits {
b, err := r.src.ReadByte()
if err != nil {
@ -38,37 +42,34 @@ func (r *streamReader) DiscardBits(n int) {
}
// ReadByte reads a single byte, regardless of alignment.
func (r *streamReader) ReadByte() (byte, error) {
func (r *streamReader) ReadByte() byte {
if r.bits == 0 {
return r.src.ReadByte()
}
b := byte(r.ReadBits(8))
if err := r.Err(); err != nil {
return 0, err
b, err := r.src.ReadByte()
if err != nil {
r.err = err
return 0
}
return b
}
return b, nil
return byte(r.ReadBits(8))
}
// Read reads like an io.Reader, taking care of alignment internally.
func (r *streamReader) Read(buf []byte) (int, error) {
func (r *streamReader) Read(buf []byte) int {
for i := 0; i < len(buf); i++ {
b, err := r.ReadByte()
if err != nil {
return 0, err
b := r.ReadByte()
if r.err != nil {
return 0
}
buf[i] = b
}
return len(buf), nil
return len(buf)
}
// discards N byte of data on the reader or until EOF
func (r *streamReader) DiscardBytes(n int) {
for i := 0; i < n; i++ {
_, err := r.ReadByte()
if err != nil {
r.err = err
return
}
r.ReadByte()
}
}

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