Add new types to S7ValueConverter.ReadFromBuffer

Sharp7.Rx.Tests/S7ValueConverterTests/ConverterTestBase.cs

@@ -30,17 +30,17 @@ internal abstract class ConverterTestBase
         yield return new ConverterTestCase((short) 4660, "DB99.Int5", [0x12, 0x34]);
         yield return new ConverterTestCase((short) -3532, "DB99.Int5", [0xF2, 0x34]);
         yield return new ConverterTestCase((ushort) 4660, "DB99.UInt5", [0x12, 0x34]);
-        yield return new ConverterTestCase((ushort) 3532, "DB99.UInt5", [0xF2, 0x34]);
+        yield return new ConverterTestCase((ushort) 62004, "DB99.UInt5", [0xF2, 0x34]);
         yield return new ConverterTestCase(305419879, "DB99.DInt5", [0x12, 0x34, 0x56, 0x67]);
         yield return new ConverterTestCase(-231451033, "DB99.DInt5", [0xF2, 0x34, 0x56, 0x67]);
         yield return new ConverterTestCase(305419879u, "DB99.UDInt5", [0x12, 0x34, 0x56, 0x67]);
-        yield return new ConverterTestCase(231451033u, "DB99.UDInt5", [0xF2, 0x34, 0x56, 0x67]);
+        yield return new ConverterTestCase(4063516263u, "DB99.UDInt5", [0xF2, 0x34, 0x56, 0x67]);
         yield return new ConverterTestCase(1311768394163015151L, "DB99.LInt5", [0x12, 0x34, 0x56, 0x67, 0x89, 0xAB, 0xCD, 0xEF]);
         yield return new ConverterTestCase(-994074615050678801L, "DB99.LInt5", [0xF2, 0x34, 0x56, 0x67, 0x89, 0xAB, 0xCD, 0xEF]);
         yield return new ConverterTestCase(1311768394163015151uL, "DB99.ULInt5", [0x12, 0x34, 0x56, 0x67, 0x89, 0xAB, 0xCD, 0xEF]);
         yield return new ConverterTestCase(17452669458658872815uL, "DB99.ULInt5", [0xF2, 0x34, 0x56, 0x67, 0x89, 0xAB, 0xCD, 0xEF]);
         yield return new ConverterTestCase(0.25f, "DB99.Real5", [0x3E, 0x80, 0x00, 0x00]);
-        yield return new ConverterTestCase(0.25, "DB99.LReal5", [0x3E, 0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00]);
+        yield return new ConverterTestCase(0.25, "DB99.LReal5", [0x3F, 0xD0, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00]);
 
         yield return new ConverterTestCase(new byte[] {0x12, 0x34, 0x56, 0x67}, "DB99.Byte5.4", [0x12, 0x34, 0x56, 0x67]);
 
@@ -57,7 +57,6 @@ internal abstract class ConverterTestBase
         yield return new ConverterTestCase((byte) 18, "DB99.DBB0", [0x12]);
         yield return new ConverterTestCase((short) 4660, "DB99.INT0", [0x12, 0x34]);
         yield return new ConverterTestCase((short) -3532, "DB99.INT0", [0xF2, 0x34]);
-        yield return new ConverterTestCase(-3532, "DB99.INT0", [0xF2, 0x34]);
         yield return new ConverterTestCase(305419879, "DB99.DINT0", [0x12, 0x34, 0x56, 0x67]);
         yield return new ConverterTestCase(-231451033, "DB99.DINT0", [0xF2, 0x34, 0x56, 0x67]);
         yield return new ConverterTestCase(1311768394163015151L, "DB99.dul0", [0x12, 0x34, 0x56, 0x67, 0x89, 0xAB, 0xCD, 0xEF]);
@@ -81,6 +80,6 @@ internal abstract class ConverterTestBase
     {
         public S7VariableAddress VariableAddress => Parser.Parse(Address);
 
-        public override string ToString() => $"{Address} {Value} ({Value.GetType().Name})";
+        public override string ToString() => $"{Value.GetType().Name}, {Address}: {Value}";
     }
 }

Sharp7.Rx/Exceptions/S7Exception.cs

@@ -11,6 +11,44 @@ public abstract class S7Exception : Exception
     }
 }
 
+public class DataTypeMissmatchException : S7Exception
+{
+    internal DataTypeMissmatchException(string message, Type type, S7VariableAddress address) : base(message)
+    {
+        Type = type;
+        Address = address.ToString();
+    }
+
+    internal DataTypeMissmatchException(string message, Exception innerException, Type type, S7VariableAddress address) : base(message, innerException)
+    {
+        Type = type;
+        Address = address.ToString();
+    }
+
+    public string Address { get; }
+
+    public Type Type { get; }
+}
+
+public class UnsupportedS7TypeException : S7Exception
+{
+    internal UnsupportedS7TypeException(string message, Type type, S7VariableAddress address) : base(message)
+    {
+        Type = type;
+        Address = address.ToString();
+    }
+
+    internal UnsupportedS7TypeException(string message, Exception innerException, Type type, S7VariableAddress address) : base(message, innerException)
+    {
+        Type = type;
+        Address = address.ToString();
+    }
+
+    public string Address { get; }
+
+    public Type Type { get; }
+}
+
 public class InvalidS7AddressException : S7Exception
 {
     public InvalidS7AddressException(string message, string input) : base(message)
@@ -23,5 +61,5 @@ public class InvalidS7AddressException : S7Exception
         Input = input;
     }
 
-    public string Input { get; private set; }
+    public string Input { get; }
 }

Sharp7.Rx/S7ValueConverter.cs

@@ -7,60 +7,92 @@ namespace Sharp7.Rx;
 
 internal static class S7ValueConverter
 {
-    public static TValue ReadFromBuffer<TValue>(byte[] buffer, S7VariableAddress address)
+    private static readonly Dictionary<Type, Func<byte[], S7VariableAddress, object>> readFunctions = new()
     {
-        if (typeof(TValue) == typeof(bool))
-            return (TValue) (object) (((buffer[0] >> address.Bit) & 1) > 0);
+        {typeof(bool), (buffer, address) => (buffer[0] >> address.Bit & 1) > 0},
+
+        {typeof(byte), (buffer, address) => buffer[0]},
+        {typeof(byte[]), (buffer, address) => buffer},
+
+        {typeof(short), (buffer, address) => BinaryPrimitives.ReadInt16BigEndian(buffer)},
+        {typeof(ushort), (buffer, address) => BinaryPrimitives.ReadUInt16BigEndian(buffer)},
+        {typeof(int), (buffer, address) => BinaryPrimitives.ReadInt32BigEndian(buffer)},
+        {typeof(uint), (buffer, address) => BinaryPrimitives.ReadUInt32BigEndian(buffer)},
+        {typeof(long), (buffer, address) => BinaryPrimitives.ReadInt64BigEndian(buffer)},
+        {typeof(ulong), (buffer, address) => BinaryPrimitives.ReadUInt64BigEndian(buffer)},
 
-        if (typeof(TValue) == typeof(int))
         {
-            if (address.Length == 2)
-                return (TValue) (object) (int) BinaryPrimitives.ReadInt16BigEndian(buffer);
-            if (address.Length == 4)
-                return (TValue) (object) BinaryPrimitives.ReadInt32BigEndian(buffer);
-
-            throw new InvalidOperationException($"length must be 2 or 4 but is {address.Length}");
-        }
-
-        if (typeof(TValue) == typeof(long))
-            return (TValue) (object) BinaryPrimitives.ReadInt64BigEndian(buffer);
-
-        if (typeof(TValue) == typeof(ulong))
-            return (TValue) (object) BinaryPrimitives.ReadUInt64BigEndian(buffer);
-
-        if (typeof(TValue) == typeof(short))
-            return (TValue) (object) BinaryPrimitives.ReadInt16BigEndian(buffer);
-
-        if (typeof(TValue) == typeof(byte))
-            return (TValue) (object) buffer[0];
-
-        if (typeof(TValue) == typeof(byte[]))
-            return (TValue) (object) buffer;
-        
-        if (typeof(TValue) == typeof(float))
+            typeof(float), (buffer, address) =>
             {
+                // Todo: Use BinaryPrimitives when switched to newer .net
                 var d = new UInt32SingleMap
                 {
                     UInt32 = BinaryPrimitives.ReadUInt32BigEndian(buffer)
                 };
-            return (TValue) (object) d.Single;
+                return d.Single;
             }
+        },
 
-        if (typeof(TValue) == typeof(string))
-            if (address.Type == DbType.String)
+        {
+            typeof(double), (buffer, address) =>
+            {
+                // Todo: Use BinaryPrimitives when switched to newer .net
+                var d = new UInt64DoubleMap
+                {
+                    UInt64 = BinaryPrimitives.ReadUInt64BigEndian(buffer)
+                };
+                return d.Double;
+            }
+        },
+
+        {
+            typeof(string), (buffer, address) =>
+            {
+                return address.Type switch
+                {
+                    DbType.String => ParseString(),
+                    DbType.WString => ParseWString(),
+                    DbType.Byte => Encoding.ASCII.GetString(buffer),
+                    _ => throw new DataTypeMissmatchException($"Cannot read string from {address.Type}", typeof(string), address)
+                };
+
+                string ParseString()
                 {
                     // First byte is maximal length
                     // Second byte is actual length
-                // https://cache.industry.siemens.com/dl/files/480/22506480/att_105176/v1/s7_scl_string_parameterzuweisung_e.pdf
+                    // https://support.industry.siemens.com/cs/mdm/109747174?c=94063831435&lc=de-DE
 
                     var length = Math.Min(address.Length, buffer[1]);
 
-                return (TValue) (object) Encoding.ASCII.GetString(buffer, 2, length);
+                    return Encoding.ASCII.GetString(buffer, 2, length);
                 }
-            else
-                return (TValue) (object) Encoding.ASCII.GetString(buffer).Trim();
 
-        throw new InvalidOperationException($"type '{typeof(TValue)}' not supported.");
+                string ParseWString()
+                {
+                    // First 2 bytes are maximal length
+                    // Second 2 bytes are actual length
+                    // https://support.industry.siemens.com/cs/mdm/109747174?c=94063855243&lc=de-DE
+
+                    // the length of the string is two bytes per 
+                    var length = Math.Min(address.Length, BinaryPrimitives.ReadUInt16BigEndian(buffer.AsSpan(2,2))) * 2;
+
+                    return Encoding.BigEndianUnicode.GetString(buffer, 4, length);
+                }
+            }
+        },
+    };
+
+    public static TValue ReadFromBuffer<TValue>(byte[] buffer, S7VariableAddress address)
+    {
+        // Todo: Change to Span<byte> when switched to newer .net
+
+        var type = typeof(TValue);
+
+        if (!readFunctions.TryGetValue(type, out var readFunc))
+            throw new UnsupportedS7TypeException($"{type.Name} is not supported. {address}", type, address);
+
+        var result = readFunc(buffer, address);
+        return (TValue) result;
     }
 
     public static void WriteToBuffer<TValue>(Span<byte> buffer, TValue value, S7VariableAddress address)
@@ -145,4 +177,11 @@ internal static class S7ValueConverter
         [FieldOffset(0)] public uint UInt32;
         [FieldOffset(0)] public float Single;
     }
+
+    [StructLayout(LayoutKind.Explicit)]
+    private struct UInt64DoubleMap
+    {
+        [FieldOffset(0)] public ulong UInt64;
+        [FieldOffset(0)] public double Double;
+    }
 }

Sharp7.Rx/S7VariableAddress.cs

@@ -19,4 +19,14 @@ internal class S7VariableAddress
         DbType.WString => (ushort) (Length * 2 + 4),
         _ => Length
     };
+
+    public override string ToString() =>
+        Type switch
+        {
+            DbType.Bit => $"{Operand}{DbNr}.{Type}{Start}.{Bit}",
+            DbType.String => $"{Operand}{DbNr}.{Type}{Start}.{Length}",
+            DbType.WString => $"{Operand}{DbNr}.{Type}{Start}.{Length}",
+            DbType.Byte => Length == 1 ? $"{Operand}{DbNr}.{Type}{Start}" : $"{Operand}{DbNr}.{Type}{Start}.{Length}",
+            _ => $"{Operand}{DbNr}.{Type}{Start}",
+        };
 }