Add comments re handling block and stream formats

decode.go

@@ -52,6 +52,8 @@ const (
 // Otherwise, a newly allocated slice will be returned.
 //
 // The dst and src must not overlap. It is valid to pass a nil dst.
+//
+// Decode handles the Snappy block format, not the Snappy stream format.
 func Decode(dst, src []byte) ([]byte, error) {
 	dLen, s, err := decodedLen(src)
 	if err != nil {
@@ -83,6 +85,8 @@ func NewReader(r io.Reader) *Reader {
 }
 
 // Reader is an io.Reader that can read Snappy-compressed bytes.
+//
+// Reader handles the Snappy stream format, not the Snappy block format.
 type Reader struct {
 	r       io.Reader
 	err     error

encode.go

@@ -15,6 +15,8 @@ import (
 // Otherwise, a newly allocated slice will be returned.
 //
 // The dst and src must not overlap. It is valid to pass a nil dst.
+//
+// Encode handles the Snappy block format, not the Snappy stream format.
 func Encode(dst, src []byte) []byte {
 	if n := MaxEncodedLen(len(src)); n < 0 {
 		panic(ErrTooLarge)
@@ -139,6 +141,8 @@ func NewBufferedWriter(w io.Writer) *Writer {
 }
 
 // Writer is an io.Writer that can write Snappy-compressed bytes.
+//
+// Writer handles the Snappy stream format, not the Snappy block format.
 type Writer struct {
 	w   io.Writer
 	err error