Tweaks to decode interface

internal/decompress/interface.go

@@ -1,19 +1,22 @@
 package decompress
 
 import (
-	"errors"
 	"io"
 )
 
-var ErrNotResetable = errors.New("decompressor not resetable")
-
 type Decompressor interface {
 	//Creates a new decompressor reading from src.
 	Reader(src io.Reader) (io.ReadCloser, error)
-	//Reports whether Reset will work or not.
-	Resetable() bool
+}
+
+type Resetable interface {
 	//Reset attempts to re-use an old decompressor with new data.
 	//Will return ErrNotResetable if not Resetable().
 	//Must ALWAYS be provided with a reader created with Reader.
 	Reset(old, src io.Reader) error
 }
+
+type Decoder interface {
+	//Decodes a chunk of data all at once.
+	Decode(in []byte, outSize int) ([]byte, error)
+}