Merge pull request #886 from gbirchmeier/tostring

change Message.ToString() to not change object state anymore

Examples/JsonToFix/Program.cs

@@ -11,7 +11,7 @@ static void JsonMsgToFix(string json, QuickFix.DataDictionary.DataDictionary ses
         {
             var msg = new Message();
             msg.FromJson(json, true, sessionDataDictionary, appDataDictionary, msgFactory);
-            Console.WriteLine(msg.ToString());
+            Console.WriteLine(msg.ConstructString());
         }
 
         static void JsonToFix(string fname, QuickFix.DataDictionary.DataDictionary sessionDataDictionary, QuickFix.DataDictionary.DataDictionary appDataDictionary)

Examples/TradeClient/TradeClientApp.cs

@@ -27,7 +27,7 @@ public void ToAdmin(Message message, SessionID sessionID) { }
 
         public void FromApp(Message message, SessionID sessionID)
         {
-            Console.WriteLine("IN:  " + message.ToString());
+            Console.WriteLine("IN:  " + message.ConstructString());
             try
             {
                 Crack(message, sessionID);
@@ -57,7 +57,7 @@ public void ToApp(Message message, SessionID sessionID)
             { }
 
             Console.WriteLine();
-            Console.WriteLine("OUT: " + message.ToString());
+            Console.WriteLine("OUT: " + message.ConstructString());
         }
         #endregion
 

QuickFIXn/Fields/Converters/CheckSumConverter.cs

@@ -1,13 +1,22 @@
-
-namespace QuickFix.Fields.Converters
+namespace QuickFix.Fields.Converters
 {
     public static class CheckSumConverter
     {
+        /// <summary>
+        /// Convert input string to int
+        /// </summary>
+        /// <param name="i"></param>
+        /// <returns></returns>
         public static int Convert(string i)
         {
             return IntConverter.Convert(i);
         }
 
+        /// <summary>
+        /// Convert input int to 3-character string
+        /// </summary>
+        /// <param name="i"></param>
+        /// <returns></returns>
         public static string Convert(int i)
         {
             return i.ToString("000");

QuickFIXn/Message/FieldMap.cs

@@ -579,11 +579,21 @@ public int CalculateLength()
             return total;
         }
 
+        /// <summary>
+        /// Creates a FIX (ish) string representation of this FieldMap (does not change the object state)
+        /// </summary>
+        /// <returns></returns>
         public virtual string CalculateString()
         {
             return CalculateString(new StringBuilder(), FieldOrder);
         }
 
+        /// <summary>
+        /// Creates a FIX (ish) string representation of this FieldMap (does not change the object state)
+        /// </summary>
+        /// <param name="sb"></param>
+        /// <param name="preFields"></param>
+        /// <returns></returns>
         public virtual string CalculateString(StringBuilder sb, int[] preFields)
         {
             HashSet<int> groupCounterTags = new HashSet<int>(_groups.Keys);

QuickFIXn/Message/Group.cs

@@ -63,6 +63,10 @@ public virtual Group Clone()
         /// </summary>
         public int Delim { get; }
 
+        /// <summary>
+        /// Creates a FIX (ish) string representation of this FieldMap (does not change the object state)
+        /// </summary>
+        /// <returns></returns>
         public override string CalculateString() {
             return base.CalculateString(new StringBuilder(), FieldOrder ?? new[] { Delim });
         }

QuickFIXn/Message/Header.cs

@@ -15,10 +15,20 @@ public Header(Header src)
             : base(src) {
         }
 
+        /// <summary>
+        /// Creates a FIX (ish) string representation of this FieldMap (does not change the object state)
+        /// </summary>
+        /// <returns></returns>
         public override string CalculateString() {
             return base.CalculateString(new StringBuilder(), HEADER_FIELD_ORDER);
         }
 
+        /// <summary>
+        /// Creates a FIX (ish) string representation of this FieldMap (does not change the object state)
+        /// </summary>
+        /// <param name="sb"></param>
+        /// <param name="preFields"></param>
+        /// <returns></returns>
         public override string CalculateString(StringBuilder sb, int[] preFields) {
             return base.CalculateString(sb, HEADER_FIELD_ORDER);
         }

QuickFIXn/Message/Message.cs

@@ -793,10 +793,15 @@ public SessionID GetSessionID(Message m)
                 m.Header.GetString(Tags.TargetCompID));
         }
 
-        private Object lock_ToString = new Object();
-        public override string ToString()
+        private Object lock_ConstructString = new Object();
+        /// <summary>
+        /// Update BodyLength in Header, update CheckSum in Trailer, and return a FIX string.
+        /// (This function changes the object state!)
+        /// </summary>
+        /// <returns></returns>
+        public string ConstructString()
         {
-            lock (lock_ToString)
+            lock (lock_ConstructString)
             {
                 Header.SetField(new BodyLength(BodyLength()), true);
                 Trailer.SetField(new CheckSum(Fields.Converters.CheckSumConverter.Convert(CheckSum())), true);
@@ -805,6 +810,16 @@ public override string ToString()
             }
         }
 
+        /// <summary>
+        /// Create a FIX-style string from the message.
+        /// This does NOT add/update BodyLength or CheckSum to the message header, or otherwise change the object state.
+        /// (Use <see cref="ConstructString"/> to compute and add/update BodyLength &amp; CheckSum.)
+        /// </summary>
+        /// <returns></returns>
+        public override string ToString() {
+            return Header.CalculateString() + CalculateString() + Trailer.CalculateString();
+        }
+
         protected int BodyLength()
         {
             return Header.CalculateLength() + CalculateLength() + Trailer.CalculateLength();

QuickFIXn/Message/Trailer.cs

@@ -15,10 +15,20 @@ public Trailer(Trailer src)
             : base(src) {
         }
 
+        /// <summary>
+        /// Creates a FIX (ish) string representation of this FieldMap (does not change the object state)
+        /// </summary>
+        /// <returns></returns>
         public override string CalculateString() {
             return base.CalculateString(new StringBuilder(), TRAILER_FIELD_ORDER);
         }
 
+        /// <summary>
+        /// Creates a FIX (ish) string representation of this FieldMap (does not change the object state)
+        /// </summary>
+        /// <param name="sb"></param>
+        /// <param name="preFields"></param>
+        /// <returns></returns>
         public override string CalculateString(StringBuilder sb, int[] preFields) {
             return base.CalculateString(sb, TRAILER_FIELD_ORDER);
         }

QuickFIXn/Session.cs

@@ -789,7 +789,7 @@ protected void NextResendRequest(Message resendReq)
                             {
                                 GenerateSequenceReset(resendReq, begin, msgSeqNum);
                             }
-                            Send(msg.ToString());
+                            Send(msg.ConstructString());
                             begin = 0;
                         }
                         current = msgSeqNum + 1;
@@ -1517,7 +1517,7 @@ protected bool NextQueued(SeqNumType num)
                 }
                 else
                 {
-                    NextMessage(msg.ToString());
+                    NextMessage(msg.ConstructString());
                 }
                 return true;
             }
@@ -1567,7 +1567,7 @@ protected bool SendRaw(Message message, SeqNumType seqNum)
                     }
                 }
 
-                string messageString = message.ToString();
+                string messageString = message.ConstructString();
                 if (0 == seqNum)
                     Persist(message, messageString);
                 return Send(messageString);

RELEASE_NOTES.md

@@ -22,6 +22,8 @@ What's New
 * #878 - corrections to tag 45 "Side" in various DDs (gbirchmeier) - most people won't notice, easy fix if they do
      * fix typo in FIX50 and FIX50SP1: `CROSS_SHORT_EXXMPT` fixed to `CROSS_SHORT_EXEMPT`
      * correction in FIX41 and FIX42: `D` to `UNDISCLOSED`
+* #863 - Change Message.ToString() to not alter object state anymore. (gbirchmeier)
+         Use new function Message.ConstructString() if you need BodyLength/CheckSum to be updated.
 
 **Non-breaking changes**
 * #864 - when multiple threads race to init DefaultMessageFactory,

UnitTests/DataDictionaryTests.cs

@@ -318,7 +318,7 @@ public void CheckGroupCountTest()
             //verify that FromString didn't correct the counter
             //HEY YOU, READ THIS NOW: if these fail, first check if MessageTests::FromString_DoNotCorrectCounter() passes
             Assert.AreEqual("386=3", n.NoTradingSessions.toStringField());  
-            StringAssert.Contains("386=3", n.ToString());
+            StringAssert.Contains("386=3", n.ConstructString());
 
             Assert.Throws<QuickFix.RepeatingGroupCountMismatch>(delegate { dd.CheckGroupCount(n.NoTradingSessions, n, "D"); });
         }

UnitTests/Fields/Converters/CheckSumConverterTests.cs

@@ -0,0 +1,22 @@
+using NUnit.Framework;
+using QuickFix.Fields.Converters;
+
+namespace UnitTests.Fields.Converters;
+
+[TestFixture]
+public class CheckSumConverterTests {
+    [Test]
+    public void ConvertStringToInt() {
+        Assert.AreEqual(1, CheckSumConverter.Convert("1"));
+        Assert.AreEqual(123, CheckSumConverter.Convert("123"));
+        Assert.AreEqual(12, CheckSumConverter.Convert("012"));
+    }
+
+    [Test]
+    public void ConvertIntToString() {
+        Assert.AreEqual("001", CheckSumConverter.Convert(1));
+        Assert.AreEqual("012", CheckSumConverter.Convert(12));
+        Assert.AreEqual("123", CheckSumConverter.Convert(123));
+        Assert.AreEqual("1234", CheckSumConverter.Convert(1234));
+    }
+}