Added zlib compression for absolutely zero reason

internal/compression/types.go

@@ -4,7 +4,7 @@ import "io"
 
 //Compressor is a squashfs decompressor interface. Allows for easy compression.
 type Compressor interface {
-	Compress(io.Reader) ([]byte, error)
+	Compress([]byte) ([]byte, error)
 }
 
 //Decompressor is a squashfs decompressor interface. Allows for easy decompression no matter the type of compression.

internal/compression/zlib.go

@@ -22,3 +22,19 @@ func (z *Zlib) Decompress(r io.Reader) ([]byte, error) {
 	}
 	return data.Bytes(), nil
 }
+
+//Compress compresses the given data (as a byte array) and returns the compressed data.
+func (z *Zlib) Compress(data []byte) ([]byte, error) {
+	var buf bytes.Buffer
+	wrt := zlib.NewWriter(&buf)
+	defer wrt.Close()
+	_, err := wrt.Write(data)
+	if err != nil {
+		return nil, err
+	}
+	err = wrt.Flush()
+	if err != nil {
+		return nil, err
+	}
+	return buf.Bytes(), nil
+}