1. 增加代码注释

2. 增加通用encoding层

code/network/encoding/encoding.go

@@ -0,0 +1,21 @@
+package encoding
+
+import "io"
+
+// Codec format data to []byte, decode data from []byte
+type Codec interface {
+	// Marshal format data to []byte
+	Marshal(interface{}) ([]byte, error)
+	// Unmarshal decode data from []byte
+	Unmarshal([]byte, interface{}) error
+}
+
+// Compressor compressor interface
+type Compressor interface {
+	// Compress get compress writer
+	Compress(io.Writer) (io.WriteCloser, error)
+	// Decompress get decompress reader
+	Decompress(io.Reader) (io.ReadCloser, error)
+	// SetLevel set compress level
+	SetLevel(int) error
+}