initial import of yaml codec

Signed-off-by: Vasiliy Tolstov <v.tolstov@unistack.org>

yaml.go

@@ -0,0 +1,91 @@
+// Package yaml provides a yaml codec
+package yaml
+
+import (
+	"io"
+	"io/ioutil"
+
+	"github.com/ghodss/yaml"
+
+	"github.com/unistack-org/micro/v3/codec"
+)
+
+type yamlCodec struct{}
+
+func (c *yamlCodec) Marshal(b interface{}) ([]byte, error) {
+	switch m := b.(type) {
+	case nil:
+		return nil, nil
+	case *codec.Frame:
+		return m.Data, nil
+	}
+
+	return yaml.Marshal(b)
+}
+
+func (c *yamlCodec) Unmarshal(b []byte, v interface{}) error {
+	if b == nil {
+		return nil
+	}
+	switch m := v.(type) {
+	case nil:
+		return nil
+	case *codec.Frame:
+		m.Data = b
+		return nil
+	}
+
+	return yaml.Unmarshal(b, v)
+}
+
+func (c *yamlCodec) ReadHeader(conn io.ReadWriter, m *codec.Message, t codec.MessageType) error {
+	return nil
+}
+
+func (c *yamlCodec) ReadBody(conn io.ReadWriter, b interface{}) error {
+	switch m := b.(type) {
+	case nil:
+		return nil
+	case *codec.Frame:
+		buf, err := ioutil.ReadAll(conn)
+		if err != nil {
+			return err
+		}
+		m.Data = buf
+		return nil
+	}
+
+	buf, err := ioutil.ReadAll(conn)
+	if err != nil {
+		return err
+	}
+
+	return yaml.Unmarshal(buf, b)
+}
+
+func (c *yamlCodec) Write(conn io.ReadWriter, m *codec.Message, b interface{}) error {
+	switch m := b.(type) {
+	case nil:
+		return nil
+	case *codec.Frame:
+		_, err := conn.Write(m.Data)
+		return err
+	}
+
+	buf, err := yaml.Marshal(b)
+	if err != nil {
+		return err
+	}
+
+	_, err = conn.Write(buf)
+
+	return err
+}
+
+func (c *yamlCodec) String() string {
+	return "yaml"
+}
+
+func NewCodec() codec.Codec {
+	return &yamlCodec{}
+}