Merge pull request #565 from ZachBray/feature/throw-on-max-group-size-exceeded

[C#] Check max group size not exceeded #564

Author: mjpt777

csharp/sbe-tests/Issue564Tests.cs

@@ -0,0 +1,54 @@
+using System;
+using Baseline;
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+using Org.SbeTool.Sbe.Dll;
+
+namespace Org.SbeTool.Sbe.Tests
+{
+    [TestClass]
+    public class Issue564Tests
+    {
+        [TestMethod]
+        public void ShouldFailToEncodeGroupsThatExceedTheMaximumRepresentableSize()
+        {
+            // Arrange
+            var expectedSize = 1024 + (8 + 8 + 8 + 20) * ushort.MaxValue;
+            var buffer = new DirectBuffer(new byte[expectedSize]);
+            var car = new Car();
+            car.WrapForEncode(buffer, 0);
+            car.SerialNumber = 1234;
+            car.ModelYear = 2013;
+            car.Available = BooleanType.T;
+            car.Code = Model.A;
+            for (int i = 0, size = Car.SomeNumbersLength; i < size; i++)
+            {
+                car.SetSomeNumbers(i, (uint)i);
+            }
+            car.SetVehicleCode(System.Text.Encoding.ASCII.GetBytes("abcdef"), 0);
+            car.Extras = OptionalExtras.CruiseControl | OptionalExtras.SportsPack;
+
+            car.Engine.Capacity = 2000;
+            car.Engine.NumCylinders = 4;
+            car.Engine.SetManufacturerCode(System.Text.Encoding.ASCII.GetBytes("123"), 0);
+            car.Engine.Efficiency = 35;
+            car.Engine.BoosterEnabled = BooleanType.T;
+            car.Engine.Booster.BoostType = BoostType.NITROUS;
+            car.Engine.Booster.HorsePower = 200;
+            
+            // Act + Assert
+            Assert.ThrowsException<ArgumentOutOfRangeException>(() =>
+            {
+                int countUnrepresentableByGroupSizeEncoding = 1 + ushort.MaxValue;
+                var fuelFigures = car.FuelFiguresCount(countUnrepresentableByGroupSizeEncoding);
+                for (int i = 0; i < countUnrepresentableByGroupSizeEncoding; i++)
+                {
+                    fuelFigures.Next();
+                    fuelFigures.Speed = 30;
+                    fuelFigures.Mpg = 35.9f;
+                    var description = System.Text.Encoding.ASCII.GetBytes($"i={i}");
+                    fuelFigures.SetUsageDescription(description, 0, description.Length);
+                }
+            });
+        }
+    }
+}

sbe-tool/src/main/java/uk/co/real_logic/sbe/generation/csharp/CSharpGenerator.java

@@ -197,23 +197,32 @@ private void generateGroupClassHeader(
 
         final int blockLength = tokens.get(index).encodedLength();
         final String typeForBlockLength = cSharpTypeName(tokens.get(index + 2).encoding().primitiveType());
-        final String typeForNumInGroup = cSharpTypeName(tokens.get(index + 3).encoding().primitiveType());
+        final Token numInGroupToken = tokens.get(index + 3);
+        final String typeForNumInGroup = cSharpTypeName(numInGroupToken.encoding().primitiveType());
 
         sb.append(String.format("\n" +
             indent + INDENT + "public void WrapForEncode(%1$s parentMessage, DirectBuffer buffer, int count)\n" +
             indent + INDENT + "{\n" +
+            indent + INDENT + INDENT + "if (count < %2$d || count > %3$d)\n" +
+            indent + INDENT + INDENT + "{\n" +
+            indent + INDENT + INDENT + INDENT + "throw new ArgumentOutOfRangeException(\"count\",\n" +
+            indent + INDENT + INDENT + INDENT + INDENT + "\"Outside allowed range: count=\" + count +\n" +
+            indent + INDENT + INDENT + INDENT + INDENT + "\", min=%2$d, max=%3$d\");\n" +
+            indent + INDENT + INDENT + "}\n\n" +
             indent + INDENT + INDENT + "_parentMessage = parentMessage;\n" +
             indent + INDENT + INDENT + "_buffer = buffer;\n" +
             indent + INDENT + INDENT + "_dimensions.Wrap(buffer, parentMessage.Limit, _actingVersion);\n" +
-            indent + INDENT + INDENT + "_dimensions.BlockLength = (%2$s)%3$d;\n" +
-            indent + INDENT + INDENT + "_dimensions.NumInGroup = (%4$s)count;\n" +
+            indent + INDENT + INDENT + "_dimensions.BlockLength = (%4$s)%5$d;\n" +
+            indent + INDENT + INDENT + "_dimensions.NumInGroup = (%6$s)count;\n" +
             indent + INDENT + INDENT + "_index = -1;\n" +
             indent + INDENT + INDENT + "_count = count;\n" +
-            indent + INDENT + INDENT + "_blockLength = %3$d;\n" +
+            indent + INDENT + INDENT + "_blockLength = %5$d;\n" +
             indent + INDENT + INDENT + "_actingVersion = SchemaVersion;\n" +
             indent + INDENT + INDENT + "parentMessage.Limit = parentMessage.Limit + SbeHeaderSize;\n" +
             indent + INDENT + "}\n",
             parentMessageClassName,
+            numInGroupToken.encoding().applicableMinValue().longValue(),
+            numInGroupToken.encoding().applicableMaxValue().longValue(),
             typeForBlockLength,
             blockLength,
             typeForNumInGroup));