support duplicate tags during resend (#6)

* send raw body bytes when doing a resend * always set body bytes * add test, rename --------- Co-authored-by: Vikas Khurana <[email protected]>
clear-street · Mar 6, 2023 · 7cd1cb6 · 7cd1cb6
1 parent 8de72de
commit 7cd1cb6
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Showing 3 changed files with 38 additions and 4 deletions.
diff --git a/in_session.go b/in_session.go
@@ -238,7 +238,7 @@ func (state inSession) resendMessages(session *session, beginSeqNo, endSeqNo int
 		}
 
 		session.log.OnEventf("Resending Message: %v", sentMessageSeqNum)
-		msgBytes = msg.build()
+		msgBytes = msg.buildFromBodyBytes()
 		session.EnqueueBytesAndSend(msgBytes)
 
 		seqNum = sentMessageSeqNum + 1

diff --git a/message.go b/message.go
@@ -212,14 +212,14 @@ func ParseMessageWithDataDictionary(
 			trailerBytes = rawBytes
 			msg.Body.add(msg.fields[fieldIndex : fieldIndex+1])
 		}
-		if parsedFieldBytes.tag == tagCheckSum {
-			break
-		}
 
 		if !foundBody {
 			msg.bodyBytes = rawBytes
 		}
 
+		if parsedFieldBytes.tag == tagCheckSum {
+			break
+		}
 		fieldIndex++
 	}
 
@@ -373,9 +373,34 @@ func (m *Message) build() []byte {
 	return b.Bytes()
 }
 
+// introduced to work around issue with resending messages with repeating groups
+// issue described: https://github.com/quickfixgo/quickfix/issues/276
+func (m *Message) buildFromBodyBytes() []byte {
+	m.cookFromBodyBytes()
+
+	var b bytes.Buffer
+	m.Header.write(&b)
+	b.Write(m.bodyBytes)
+	m.Trailer.write(&b)
+	return b.Bytes()
+}
+
 func (m *Message) cook() {
 	bodyLength := m.Header.length() + m.Body.length() + m.Trailer.length()
 	m.Header.SetInt(tagBodyLength, bodyLength)
 	checkSum := (m.Header.total() + m.Body.total() + m.Trailer.total()) % 256
 	m.Trailer.SetString(tagCheckSum, formatCheckSum(checkSum))
 }
+
+func (m *Message) cookFromBodyBytes() {
+	bodyLength := m.Header.length() + len(m.bodyBytes) + m.Trailer.length()
+	m.Header.SetInt(tagBodyLength, bodyLength)
+
+	bodyTotal := 0
+	for _, b := range []byte(m.bodyBytes) {
+		bodyTotal += int(b)
+	}
+
+	checkSum := (m.Header.total() + bodyTotal + m.Trailer.total()) % 256
+	m.Trailer.SetString(tagCheckSum, formatCheckSum(checkSum))
+}
diff --git a/message_test.go b/message_test.go
@@ -88,6 +88,15 @@ func (s *MessageSuite) TestParseOutOfOrder() {
 	s.Nil(ParseMessage(s.msg, rawMsg))
 }
 
+func (s *MessageSuite) TestRoundtripBuildFromBodyBytes() {
+	expected := bytes.NewBufferString("8=FIX.4.29=14235=D34=143=Y49=ISLD52=20230305-21:16:44.00256=TW122=20230305-21:16:44.00211=11=tag1group12=tag2group112=11=tag1group22=tag2group210=099")
+	err := ParseMessage(s.msg, expected)
+	s.NoError(err)
+
+	actual := s.msg.buildFromBodyBytes()
+	s.Equal(expected.Bytes(), actual)
+}
+
 func (s *MessageSuite) TestBuild() {
 	s.msg.Header.SetField(tagBeginString, FIXString(BeginStringFIX44))
 	s.msg.Header.SetField(tagMsgType, FIXString("A"))