From 9628840efc2bcc0735f0d5b1b8d07569d2a1b369 Mon Sep 17 00:00:00 2001
From: Chris Busbey <cbusbey@connamara.com>
Date: Sun, 26 Feb 2017 14:24:44 -0600
Subject: [PATCH] use data dictionary for parsing fix messages

---
 in_session.go      |  2 +-
 message.go         | 42 ++++++++++++++++++++++++++++++++++++++++--
 message_test.go    | 23 ++++++++++++++++++++++-
 session.go         |  3 +++
 session_factory.go | 12 +++++-------
 session_state.go   |  2 +-
 6 files changed, 72 insertions(+), 12 deletions(-)

diff --git a/in_session.go b/in_session.go
index 8750d50a0..fe71b6d56 100644
--- a/in_session.go
+++ b/in_session.go
@@ -213,7 +213,7 @@ func (state inSession) resendMessages(session *session, beginSeqNo, endSeqNo int
 	nextSeqNum := seqNum
 	msg := NewMessage()
 	for _, msgBytes := range msgs {
-		_ = ParseMessage(msg, bytes.NewBuffer(msgBytes))
+		_ = ParseMessageWithDataDictionary(msg, bytes.NewBuffer(msgBytes), session.transportDataDictionary, session.appDataDictionary)
 		msgType, _ := msg.Header.GetBytes(tagMsgType)
 		sentMessageSeqNum, _ := msg.Header.GetInt(tagMsgSeqNum)
 
diff --git a/message.go b/message.go
index 7846adf1a..767e47cc3 100644
--- a/message.go
+++ b/message.go
@@ -6,6 +6,7 @@ import (
 	"math"
 	"time"
 
+	"github.com/quickfixgo/quickfix/datadictionary"
 	"github.com/quickfixgo/quickfix/enum"
 )
 
@@ -116,6 +117,16 @@ func NewMessage() *Message {
 
 //ParseMessage constructs a Message from a byte slice wrapping a FIX message.
 func ParseMessage(msg *Message, rawMessage *bytes.Buffer) (err error) {
+	return ParseMessageWithDataDictionary(msg, rawMessage, nil, nil)
+}
+
+//ParseMessageWithDataDictionary constructs a Message from a byte slice wrapping a FIX message using an optional session and application DataDictionary for reference.
+func ParseMessageWithDataDictionary(
+	msg *Message,
+	rawMessage *bytes.Buffer,
+	transportDataDictionary *datadictionary.DataDictionary,
+	applicationDataDictionary *datadictionary.DataDictionary,
+) (err error) {
 	msg.Header.Clear()
 	msg.Body.Clear()
 	msg.Trailer.Clear()
@@ -173,9 +184,9 @@ func ParseMessage(msg *Message, rawMessage *bytes.Buffer) (err error) {
 		}
 
 		switch {
-		case parsedFieldBytes.tag.IsHeader():
+		case isHeaderField(parsedFieldBytes.tag, transportDataDictionary):
 			msg.Header.add(msg.fields[fieldIndex : fieldIndex+1])
-		case parsedFieldBytes.tag.IsTrailer():
+		case isTrailerField(parsedFieldBytes.tag, transportDataDictionary):
 			msg.Trailer.add(msg.fields[fieldIndex : fieldIndex+1])
 		default:
 			foundBody = true
@@ -215,6 +226,33 @@ func ParseMessage(msg *Message, rawMessage *bytes.Buffer) (err error) {
 	}
 
 	return
+
+}
+
+func isHeaderField(tag Tag, dataDict *datadictionary.DataDictionary) bool {
+	if tag.IsHeader() {
+		return true
+	}
+
+	if dataDict == nil {
+		return false
+	}
+
+	_, ok := dataDict.Header.Fields[int(tag)]
+	return ok
+}
+
+func isTrailerField(tag Tag, dataDict *datadictionary.DataDictionary) bool {
+	if tag.IsTrailer() {
+		return true
+	}
+
+	if dataDict == nil {
+		return false
+	}
+
+	_, ok := dataDict.Trailer.Fields[int(tag)]
+	return ok
 }
 
 // MsgType returns MsgType (tag 35) field's value
diff --git a/message_test.go b/message_test.go
index fecd37f43..e2d2e1470 100644
--- a/message_test.go
+++ b/message_test.go
@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"testing"
 
+	"github.com/quickfixgo/quickfix/datadictionary"
 	"github.com/quickfixgo/quickfix/enum"
 	"github.com/stretchr/testify/suite"
 )
@@ -18,7 +19,7 @@ func BenchmarkParseMessage(b *testing.B) {
 }
 
 type MessageSuite struct {
-	suite.Suite
+	QuickFIXSuite
 	msg *Message
 }
 
@@ -53,6 +54,26 @@ func (s *MessageSuite) TestParseMessage() {
 	s.False(s.msg.IsMsgTypeOf(enum.MsgType_LOGON))
 }
 
+func (s *MessageSuite) TestParseMessageWithDataDictionary() {
+	dict := new(datadictionary.DataDictionary)
+	dict.Header = &datadictionary.MessageDef{
+		Fields: map[int]*datadictionary.FieldDef{
+			10030: nil,
+		},
+	}
+	dict.Trailer = &datadictionary.MessageDef{
+		Fields: map[int]*datadictionary.FieldDef{
+			5050: nil,
+		},
+	}
+	rawMsg := bytes.NewBufferString("8=FIX.4.2
9=126
35=D
34=2
49=TW
52=20140515-19:49:56.659
56=ISLD
10030=CUST
11=100
21=1
40=1
54=1
55=TSLA
60=00010101-00:00:00.000
5050=HELLO
10=039
")
+
+	err := ParseMessageWithDataDictionary(s.msg, rawMsg, dict, dict)
+	s.Nil(err)
+	s.FieldEquals(Tag(10030), "CUST", s.msg.Header)
+	s.FieldEquals(Tag(5050), "HELLO", s.msg.Trailer)
+}
+
 func (s *MessageSuite) TestParseOutOfOrder() {
 	//allow fields out of order, save for validation
 	rawMsg := bytes.NewBufferString("8=FIX.4.0
9=81
35=D
11=id
21=3
38=100
40=1
54=1
55=MSFT
34=2
49=TW
52=20140521-22:07:09
56=ISLD
10=250
")
diff --git a/session.go b/session.go
index 2be5d3997..21868832d 100644
--- a/session.go
+++ b/session.go
@@ -7,6 +7,7 @@ import (
 	"sync"
 	"time"
 
+	"github.com/quickfixgo/quickfix/datadictionary"
 	"github.com/quickfixgo/quickfix/enum"
 	"github.com/quickfixgo/quickfix/internal"
 )
@@ -40,6 +41,8 @@ type session struct {
 
 	admin chan interface{}
 	internal.SessionSettings
+	transportDataDictionary *datadictionary.DataDictionary
+	appDataDictionary       *datadictionary.DataDictionary
 
 	messagePool
 }
diff --git a/session_factory.go b/session_factory.go
index ea7859313..1947acae8 100644
--- a/session_factory.go
+++ b/session_factory.go
@@ -97,16 +97,15 @@ func (f sessionFactory) newSession(
 				return
 			}
 
-			var transportDataDictionary, appDataDictionary *datadictionary.DataDictionary
-			if transportDataDictionary, err = datadictionary.Parse(transportDataDictionaryPath); err != nil {
+			if s.transportDataDictionary, err = datadictionary.Parse(transportDataDictionaryPath); err != nil {
 				return
 			}
 
-			if appDataDictionary, err = datadictionary.Parse(appDataDictionaryPath); err != nil {
+			if s.appDataDictionary, err = datadictionary.Parse(appDataDictionaryPath); err != nil {
 				return
 			}
 
-			s.validator = &fixtValidator{transportDataDictionary, appDataDictionary, validatorSettings}
+			s.validator = &fixtValidator{s.transportDataDictionary, s.appDataDictionary, validatorSettings}
 		}
 	} else if settings.HasSetting(config.DataDictionary) {
 		var dataDictionaryPath string
@@ -114,12 +113,11 @@ func (f sessionFactory) newSession(
 			return
 		}
 
-		var dataDictionary *datadictionary.DataDictionary
-		if dataDictionary, err = datadictionary.Parse(dataDictionaryPath); err != nil {
+		if s.appDataDictionary, err = datadictionary.Parse(dataDictionaryPath); err != nil {
 			return
 		}
 
-		s.validator = &fixValidator{dataDictionary, validatorSettings}
+		s.validator = &fixValidator{s.appDataDictionary, validatorSettings}
 	}
 
 	if settings.HasSetting(config.ResetOnLogon) {
diff --git a/session_state.go b/session_state.go
index 92c30bd68..0d8263fe3 100644
--- a/session_state.go
+++ b/session_state.go
@@ -70,7 +70,7 @@ func (sm *stateMachine) Incoming(session *session, m fixIn) {
 	session.log.OnIncoming(m.bytes.Bytes())
 
 	msg := session.messagePool.Get()
-	if err := ParseMessage(msg, m.bytes); err != nil {
+	if err := ParseMessageWithDataDictionary(msg, m.bytes, session.transportDataDictionary, session.appDataDictionary); err != nil {
 		session.log.OnEventf("Msg Parse Error: %v, %q", err.Error(), m.bytes)
 	} else {
 		msg.ReceiveTime = m.receiveTime