add universal tcp message reader and writer

1 files changed, 44 insertions, 0 deletions

diff --git a/internal/tcp/tcp.go b/internal/tcp/tcp.go
new file mode 100644
index 0000000..3f9bafc
--- /dev/null
+++ b/internal/tcp/tcp.go
@@ -0,0 +1,44 @@
+package tcp
+
+import (
+	"encoding/binary"
+	"io"
+)
+
+type Writer interface {
+	Write(b []byte) (n int, err error)
+}
+
+type Reader interface {
+	Read(b []byte) (n int, err error)
+}
+
+func WriteStr(w Writer, message string) error {
+	messageBytes := []byte(message)
+	sizeBytes := make([]byte, 8)
+	binary.BigEndian.PutUint64(sizeBytes, uint64(len(messageBytes)))
+
+	if _, err := w.Write(sizeBytes); err != nil {
+		return err
+	}
+	if _, err := w.Write(messageBytes); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func ReadStr(r Reader) (string, error) {
+	sizeBytes := make([]byte, 8)
+	if _, err := io.ReadFull(r, sizeBytes); err != nil {
+		return "", err
+	}
+	messageSize := binary.BigEndian.Uint64(sizeBytes)
+
+	messageBytes := make([]byte, messageSize)
+	if _, err := io.ReadFull(r, messageBytes); err != nil {
+		return "", err
+	}
+
+	return string(messageBytes), nil
+}