Add a lot of documentation

command_complete.go

@@ -11,8 +11,11 @@ type CommandComplete struct {
 	CommandTag []byte
 }
 
+// Backend identifies this message as sendable by the PostgreSQL backend.
 func (*CommandComplete) Backend() {}
 
+// Decode decodes src into dst. src must contain the complete message with the exception of the initial 1 byte message
+// type identifier and 4 byte message length.
 func (dst *CommandComplete) Decode(src []byte) error {
 	idx := bytes.IndexByte(src, 0)
 	if idx != len(src)-1 {
@@ -24,6 +27,7 @@ func (dst *CommandComplete) Decode(src []byte) error {
 	return nil
 }
 
+// Encode encodes src into dst. dst will include the 1 byte message type identifier and the 4 byte message length.
 func (src *CommandComplete) Encode(dst []byte) []byte {
 	dst = append(dst, 'C')
 	sp := len(dst)
@@ -37,6 +41,7 @@ func (src *CommandComplete) Encode(dst []byte) []byte {
 	return dst
 }
 
+// MarshalJSON implements encoding/json.Marshaler.
 func (src *CommandComplete) MarshalJSON() ([]byte, error) {
 	return json.Marshal(struct {
 		Type       string