1 files changed, 94 insertions, 0 deletions
diff --git a/internal/protocol.go b/internal/protocol.go
new file mode 100755
index 00000000..a099ce4d
--- /dev/null
+++ b/internal/protocol.go
@@ -0,0 +1,94 @@
+package internal
+
+import (
+	"os"
+
+	j "github.com/json-iterator/go"
+	"github.com/spiral/errors"
+	"github.com/spiral/goridge/v3/interfaces/relay"
+	"github.com/spiral/goridge/v3/pkg/frame"
+)
+
+var json = j.ConfigCompatibleWithStandardLibrary
+
+type StopCommand struct {
+	Stop bool `json:"stop"`
+}
+
+type pidCommand struct {
+	Pid int `json:"pid"`
+}
+
+func SendControl(rl relay.Relay, payload interface{}) error {
+	const op = errors.Op("send control frame")
+	fr := frame.NewFrame()
+	fr.WriteVersion(frame.VERSION_1)
+	fr.WriteFlags(frame.CONTROL)
+
+	if data, ok := payload.([]byte); ok {
+		// check if payload no more that 4Gb
+		if uint32(len(data)) > ^uint32(0) {
+			return errors.E(op, errors.Str("payload is more that 4gb"))
+		}
+
+		fr.WritePayloadLen(uint32(len(data)))
+		fr.WritePayload(data)
+		fr.WriteCRC()
+
+		err := rl.Send(fr)
+		if err != nil {
+			return errors.E(op, err)
+		}
+		return nil
+	}
+
+	data, err := json.Marshal(payload)
+	if err != nil {
+		return errors.E(op, errors.Errorf("invalid payload: %s", err))
+	}
+
+	fr.WritePayloadLen(uint32(len(data)))
+	fr.WritePayload(data)
+	fr.WriteCRC()
+
+	err = rl.Send(fr)
+	if err != nil {
+		return errors.E(op, err)
+	}
+
+	return nil
+}
+
+func FetchPID(rl relay.Relay) (int64, error) {
+	const op = errors.Op("fetchPID")
+	err := SendControl(rl, pidCommand{Pid: os.Getpid()})
+	if err != nil {
+		return 0, errors.E(op, err)
+	}
+
+	frameR := frame.NewFrame()
+	err = rl.Receive(frameR)
+	if !frameR.VerifyCRC() {
+		return 0, errors.E(op, errors.Str("CRC mismatch"))
+	}
+	if err != nil {
+		return 0, errors.E(op, err)
+	}
+	if frameR == nil {
+		return 0, errors.E(op, errors.Str("nil frame received"))
+	}
+
+	flags := frameR.ReadFlags()
+
+	if flags&(byte(frame.CONTROL)) == 0 {
+		return 0, errors.E(op, errors.Str("unexpected response, header is missing, no CONTROL flag"))
+	}
+
+	link := &pidCommand{}
+	err = json.Unmarshal(frameR.Payload(), link)
+	if err != nil {
+		return 0, errors.E(op, err)
+	}
+
+	return int64(link.Pid), nil
+}