first open-source versionHEADmaster

1 files changed, 66 insertions, 0 deletions

diff --git a/protocol/client_recv.go b/protocol/client_recv.go
new file mode 100644
index 0000000..eb406c2
--- /dev/null
+++ b/protocol/client_recv.go
@@ -0,0 +1,66 @@
+package protocol
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+)
+
+func (c *Client) Receive() (Message, error) {
+	var cmd [3]byte
+	_, err := io.ReadFull(c.rx, cmd[:])
+	if err != nil {
+		return nil, err
+	}
+	typ := Command(cmd[:])
+	switch typ {
+	case CmdMsg:
+		var length uint64
+		err = c.read(&length)
+		if err != nil {
+			return nil, err
+		}
+		data := make([]byte, length)
+		_, err = io.ReadFull(c.rx, data)
+		if err != nil {
+			return nil, err
+		}
+		return commandMsg{
+			data: data,
+		}, nil
+	case CmdNop:
+		fallthrough
+	case CmdBye:
+		fallthrough
+	case CmdNil:
+		return trivialCommand(typ), nil
+	default:
+		return nil, fmt.Errorf("unknown command from server: %v", string(cmd[:]))
+	}
+}
+
+type Message interface {
+	Command() Command
+	// Consume calls messageConsumer is this message contains a data message to the upper level.
+	Consume(messageConsumer func(reader io.Reader, length int64))
+}
+
+type trivialCommand Command
+
+func (t trivialCommand) Consume(func(reader io.Reader, length int64)) {}
+
+func (t trivialCommand) Command() Command {
+	return Command(t)
+}
+
+type commandMsg struct {
+	data []byte
+}
+
+func (c commandMsg) Consume(messageConsumer func(reader io.Reader, length int64)) {
+	messageConsumer(bytes.NewReader(c.data), int64(len(c.data)))
+}
+
+func (c commandMsg) Command() Command {
+	return CmdMsg
+}