Merge pull request #189 from mycroes/add-datetime-support

Add DateTime support

S7.Net.UnitTest/S7.Net.UnitTest.csproj

@@ -79,6 +79,7 @@
     <Compile Include="S7NetTestsSync.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />
     <Compile Include="Helpers\TestLongStruct.cs" />
+    <Compile Include="TypeTests\DateTimeTests.cs" />
     <Compile Include="TypeTests\StringExTests.cs" />
     <Compile Include="TypeTests\StringTests.cs" />
   </ItemGroup>

S7.Net.UnitTest/TypeTests/DateTimeTests.cs

@@ -0,0 +1,176 @@
+using System;
+using System.Linq;
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+
+namespace S7.Net.UnitTest.TypeTests
+{
+    public static class DateTimeTests
+    {
+        private static readonly DateTime SampleDateTime = new DateTime(1993, 12, 25, 8, 12, 34, 567);
+
+        private static readonly byte[] SampleByteArray = {0x93, 0x12, 0x25, 0x08, 0x12, 0x34, 0x56, 7 << 4 | 7};
+
+        private static readonly byte[] SpecMinByteArray =
+        {
+            0x90, 0x01, 0x01, 0x00, 0x00, 0x00, 0x00, (byte) (int) (Types.DateTime.SpecMinimumDateTime.DayOfWeek + 1)
+        };
+
+        private static readonly byte[] SpecMaxByteArray =
+        {
+            0x89, 0x12, 0x31, 0x23, 0x59, 0x59, 0x99, (byte) (9 << 4 | (int) (Types.DateTime.SpecMaximumDateTime.DayOfWeek + 1))
+        };
+
+        [TestClass]
+        public class FromByteArray
+        {
+            [TestMethod]
+            public void Sample()
+            {
+                AssertFromByteArrayEquals(SampleDateTime, SampleByteArray);
+            }
+
+            [TestMethod]
+            public void SpecMinimum()
+            {
+                AssertFromByteArrayEquals(Types.DateTime.SpecMinimumDateTime, SpecMinByteArray);
+            }
+
+            [TestMethod]
+            public void SpecMaximum()
+            {
+                AssertFromByteArrayEquals(Types.DateTime.SpecMaximumDateTime, SpecMaxByteArray);
+            }
+
+            [TestMethod, ExpectedException(typeof(ArgumentOutOfRangeException))]
+            public void ThrowsOnLessThan8Bytes()
+            {
+                Types.DateTime.FromByteArray(new byte[7]);
+            }
+
+            [TestMethod, ExpectedException(typeof(ArgumentOutOfRangeException))]
+            public void ThrowsOnMoreTHan8Bytes()
+            {
+                Types.DateTime.FromByteArray(new byte[9]);
+            }
+
+            [TestMethod, ExpectedException(typeof(ArgumentOutOfRangeException))]
+            public void ThrowsOnInvalidYear()
+            {
+                Types.DateTime.FromByteArray(MutateSample(0, 0xa0));
+            }
+
+            [TestMethod, ExpectedException(typeof(ArgumentOutOfRangeException))]
+            public void ThrowsOnZeroMonth()
+            {
+                Types.DateTime.FromByteArray(MutateSample(1, 0x00));
+            }
+
+            [TestMethod, ExpectedException(typeof(ArgumentOutOfRangeException))]
+            public void ThrowsOnTooLargeMonth()
+            {
+                Types.DateTime.FromByteArray(MutateSample(1, 0x13));
+            }
+
+            [TestMethod, ExpectedException(typeof(ArgumentOutOfRangeException))]
+            public void ThrowsOnZeroDay()
+            {
+                Types.DateTime.FromByteArray(MutateSample(2, 0x00));
+            }
+
+            [TestMethod, ExpectedException(typeof(ArgumentOutOfRangeException))]
+            public void ThrowsOnTooLargeDay()
+            {
+                Types.DateTime.FromByteArray(MutateSample(2, 0x32));
+            }
+
+            [TestMethod, ExpectedException(typeof(ArgumentOutOfRangeException))]
+            public void ThrowsOnInvalidHour()
+            {
+                Types.DateTime.FromByteArray(MutateSample(3, 0x24));
+            }
+
+            [TestMethod, ExpectedException(typeof(ArgumentOutOfRangeException))]
+            public void ThrowsOnInvalidMinute()
+            {
+                Types.DateTime.FromByteArray(MutateSample(4, 0x60));
+            }
+
+            [TestMethod, ExpectedException(typeof(ArgumentOutOfRangeException))]
+            public void ThrowsOnInvalidSecond()
+            {
+                Types.DateTime.FromByteArray(MutateSample(5, 0x60));
+            }
+
+            [TestMethod, ExpectedException(typeof(ArgumentOutOfRangeException))]
+            public void ThrowsOnInvalidFirstTwoMillisecondDigits()
+            {
+                Types.DateTime.FromByteArray(MutateSample(6, 0xa0));
+            }
+
+            [TestMethod, ExpectedException(typeof(ArgumentOutOfRangeException))]
+            public void ThrowsOnInvalidThirdMillisecondDigit()
+            {
+                Types.DateTime.FromByteArray(MutateSample(7, 10 << 4));
+            }
+
+            [TestMethod, ExpectedException(typeof(ArgumentOutOfRangeException))]
+            public void ThrowsOnZeroDayOfWeek()
+            {
+                Types.DateTime.FromByteArray(MutateSample(7, 0));
+            }
+
+            [TestMethod, ExpectedException(typeof(ArgumentOutOfRangeException))]
+            public void ThrowsOnTooLargeDayOfWeek()
+            {
+                Types.DateTime.FromByteArray(MutateSample(7, 8));
+            }
+
+            private static void AssertFromByteArrayEquals(DateTime expected, params byte[] bytes)
+            {
+                Assert.AreEqual(expected, Types.DateTime.FromByteArray(bytes));
+            }
+
+            private static byte[] MutateSample(int index, byte value) =>
+                SampleByteArray.Select((b, i) => i == index ? value : b).ToArray();
+        }
+
+        [TestClass]
+        public class ToByteArray
+        {
+            [TestMethod]
+            public void Sample()
+            {
+                AssertToByteArrayEquals(SampleDateTime, SampleByteArray);
+            }
+
+            [TestMethod]
+            public void SpecMinimum()
+            {
+                AssertToByteArrayEquals(Types.DateTime.SpecMinimumDateTime, SpecMinByteArray);
+            }
+
+            [TestMethod]
+            public void SpecMaximum()
+            {
+                AssertToByteArrayEquals(Types.DateTime.SpecMaximumDateTime, SpecMaxByteArray);
+            }
+
+            [TestMethod, ExpectedException(typeof(ArgumentOutOfRangeException))]
+            public void ThrowsOnTimeBeforeSpecMinimum()
+            {
+                Types.DateTime.ToByteArray(new DateTime(1970, 1, 1));
+            }
+
+            [TestMethod, ExpectedException(typeof(ArgumentOutOfRangeException))]
+            public void ThrowsOnTimeAfterSpecMaximum()
+            {
+                Types.DateTime.ToByteArray(new DateTime(2090, 1, 1));
+            }
+
+            private static void AssertToByteArrayEquals(DateTime value, params byte[] expected)
+            {
+                CollectionAssert.AreEqual(expected, Types.DateTime.ToByteArray(value));
+            }
+        }
+    }
+}

S7.Net/Enums.cs

@@ -181,6 +181,11 @@
         /// <summary>
         /// Counter variable type
         /// </summary>
-        Counter
+        Counter,
+
+        /// <summary>
+        /// DateTIme variable type
+        /// </summary>
+        DateTime
     }
 }

S7.Net/PLCHelpers.cs

@@ -2,6 +2,7 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
+using DateTime = S7.Net.Types.DateTime;
 
 namespace S7.Net
 {
@@ -146,6 +147,15 @@ namespace S7.Net
                     {
                         return Bit.ToBitArray(bytes);
                     }
+                case VarType.DateTime:
+                    if (varCount == 1)
+                    {
+                        return DateTime.FromByteArray(bytes);
+                    }
+                    else
+                    {
+                        return DateTime.ToArray(bytes);
+                    }
                 default:
                     return null;
             }
@@ -178,6 +188,8 @@ namespace S7.Net
                 case VarType.DInt:
                 case VarType.Real:
                     return varCount * 4;
+                case VarType.DateTime:
+                    return varCount * 8;
                 default:
                     return 0;
             }

S7.Net/Protocol/Serialization.cs

@@ -41,6 +41,8 @@ namespace S7.Net.Protocol
                     return Types.Double.ToByteArray((double)value);
                 case "Single":
                     return Types.Single.ToByteArray((float)value);
+                case "DateTime":
+                    return Types.DateTime.ToByteArray((System.DateTime) value);
                 case "Byte[]":
                     return (byte[])value;
                 case "Int16[]":
@@ -60,6 +62,8 @@ namespace S7.Net.Protocol
                     // if the consumer does not pay attention to string length.
                     var stringVal = (string) value;
                     return Types.String.ToByteArray(stringVal, stringVal.Length);
+                case "DateTime[]":
+                    return Types.DateTime.ToByteArray((System.DateTime[]) value);
                 default:
                     throw new InvalidVariableTypeException();
             }

S7.Net/Types/DateTime.cs

@@ -0,0 +1,156 @@
+using System;
+using System.Collections.Generic;
+
+namespace S7.Net.Types
+{
+    /// <summary>
+    /// Contains the methods to convert between <see cref="T:System.DateTime"/> and S7 representation of datetime values.
+    /// </summary>
+    public static class DateTime
+    {
+        /// <summary>
+        /// The minimum <see cref="T:System.DateTime"/> value supported by the specification.
+        /// </summary>
+        public static readonly System.DateTime SpecMinimumDateTime = new System.DateTime(1990, 1, 1);
+
+        /// <summary>
+        /// The maximum <see cref="T:System.DateTime"/> value supported by the specification.
+        /// </summary>
+        public static readonly System.DateTime SpecMaximumDateTime = new System.DateTime(2089, 12, 31, 23, 59, 59, 999);
+
+        /// <summary>
+        /// Parses a <see cref="T:System.DateTime"/> value from bytes.
+        /// </summary>
+        /// <param name="bytes">Input bytes read from PLC.</param>
+        /// <returns>A <see cref="T:System.DateTime"/> object representing the value read from PLC.</returns>
+        /// <exception cref="ArgumentOutOfRangeException">Thrown when the length of
+        ///   <paramref name="bytes"/> is not 8 or any value in <paramref name="bytes"/>
+        ///   is outside the valid range of values.</exception>
+        public static System.DateTime FromByteArray(byte[] bytes)
+        {
+            return FromByteArrayImpl(bytes);
+        }
+
+        /// <summary>
+        /// Parses an array of <see cref="T:System.DateTime"/> values from bytes.
+        /// </summary>
+        /// <param name="bytes">Input bytes read from PLC.</param>
+        /// <returns>An array of <see cref="T:System.DateTime"/> objects representing the values read from PLC.</returns>
+        /// <exception cref="ArgumentOutOfRangeException">Thrown when the length of
+        ///   <paramref name="bytes"/> is not a multiple of 8 or any value in
+        ///   <paramref name="bytes"/> is outside the valid range of values.</exception>
+        public static System.DateTime[] ToArray(byte[] bytes)
+        {
+            if (bytes.Length % 8 != 0)
+                throw new ArgumentOutOfRangeException(nameof(bytes), bytes.Length,
+                    $"Parsing an array of DateTime requires a multiple of 8 bytes of input data, input data is '{bytes.Length}' long.");
+
+            var cnt = bytes.Length / 8;
+            var result = new System.DateTime[bytes.Length / 8];
+
+            for (var i = 0; i < cnt; i++)
+                result[i] = FromByteArrayImpl(new ArraySegment<byte>(bytes, i * 8, 8));
+
+            return result;
+        }
+
+        private static System.DateTime FromByteArrayImpl(IList<byte> bytes)
+        {
+            if (bytes.Count != 8)
+                throw new ArgumentOutOfRangeException(nameof(bytes), bytes.Count,
+                    $"Parsing a DateTime requires exactly 8 bytes of input data, input data is {bytes.Count} bytes long.");
+
+            int DecodeBcd(byte input) => 10 * (input >> 4) + (input & 0b00001111);
+
+            int ByteToYear(byte bcdYear)
+            {
+                var input = DecodeBcd(bcdYear);
+                if (input < 90) return input + 2000;
+                if (input < 100) return input + 1900;
+
+                throw new ArgumentOutOfRangeException(nameof(bcdYear), bcdYear,
+                    $"Value '{input}' is higher than the maximum '99' of S7 date and time representation.");
+            }
+
+            int AssertRangeInclusive(int input, byte min, byte max, string field)
+            {
+                if (input < min)
+                    throw new ArgumentOutOfRangeException(nameof(input), input,
+                        $"Value '{input}' is lower than the minimum '{min}' allowed for {field}.");
+                if (input > max)
+                    throw new ArgumentOutOfRangeException(nameof(input), input,
+                        $"Value '{input}' is higher than the maximum '{max}' allowed for {field}.");
+
+                return input;
+            }
+
+            var year = ByteToYear(bytes[0]);
+            var month = AssertRangeInclusive(DecodeBcd(bytes[1]), 1, 12, "month");
+            var day = AssertRangeInclusive(DecodeBcd(bytes[2]), 1, 31, "day of month");
+            var hour = AssertRangeInclusive(DecodeBcd(bytes[3]), 0, 23, "hour");
+            var minute = AssertRangeInclusive(DecodeBcd(bytes[4]), 0, 59, "minute");
+            var second = AssertRangeInclusive(DecodeBcd(bytes[5]), 0, 59, "second");
+            var hsec = AssertRangeInclusive(DecodeBcd(bytes[6]), 0, 99, "first two millisecond digits");
+            var msec = AssertRangeInclusive(bytes[7] >> 4, 0, 9, "third millisecond digit");
+            var dayOfWeek = AssertRangeInclusive(bytes[7] & 0b00001111, 1, 7, "day of week");
+
+            return new System.DateTime(year, month, day, hour, minute, second, hsec * 10 + msec);
+        }
+
+        /// <summary>
+        /// Converts a <see cref="T:System.DateTime"/> value to a byte array.
+        /// </summary>
+        /// <param name="dateTime">The DateTime value to convert.</param>
+        /// <returns>A byte array containing the S7 date time representation of <paramref name="dateTime"/>.</returns>
+        /// <exception cref="ArgumentOutOfRangeException">Thrown when the value of
+        ///   <paramref name="dateTime"/> is before <see cref="P:SpecMinimumDateTime"/>
+        ///   or after <see cref="P:SpecMaximumDateTime"/>.</exception>
+        public static byte[] ToByteArray(System.DateTime dateTime)
+        {
+            byte EncodeBcd(int value)
+            {
+                return (byte) ((value / 10 << 4) | value % 10);
+            }
+
+            if (dateTime < SpecMinimumDateTime)
+                throw new ArgumentOutOfRangeException(nameof(dateTime), dateTime,
+                    $"Date time '{dateTime}' is before the minimum '{SpecMinimumDateTime}' supported in S7 date time representation.");
+
+            if (dateTime > SpecMaximumDateTime)
+                throw new ArgumentOutOfRangeException(nameof(dateTime), dateTime,
+                    $"Date time '{dateTime}' is after the maximum '{SpecMaximumDateTime}' supported in S7 date time representation.");
+
+            byte MapYear(int year) => (byte) (year < 2000 ? year - 1900 : year - 2000);
+
+            int DayOfWeekToInt(DayOfWeek dayOfWeek) => (int) dayOfWeek + 1;
+
+            return new[]
+            {
+                EncodeBcd(MapYear(dateTime.Year)),
+                EncodeBcd(dateTime.Month),
+                EncodeBcd(dateTime.Day),
+                EncodeBcd(dateTime.Hour),
+                EncodeBcd(dateTime.Minute),
+                EncodeBcd(dateTime.Second),
+                EncodeBcd(dateTime.Millisecond / 10),
+                (byte) (dateTime.Millisecond % 10 << 4 | DayOfWeekToInt(dateTime.DayOfWeek))
+            };
+        }
+
+        /// <summary>
+        /// Converts an array of <see cref="T:System.DateTime"/> values to a byte array.
+        /// </summary>
+        /// <param name="dateTimes">The DateTime values to convert.</param>
+        /// <returns>A byte array containing the S7 date time representations of <paramref name="dateTime"/>.</returns>
+        /// <exception cref="ArgumentOutOfRangeException">Thrown when any value of
+        ///   <paramref name="dateTimes"/> is before <see cref="P:SpecMinimumDateTime"/>
+        ///   or after <see cref="P:SpecMaximumDateTime"/>.</exception>
+        public static byte[] ToByteArray(System.DateTime[] dateTimes)
+        {
+            var bytes = new List<byte>(dateTimes.Length * 8);
+            foreach (var dateTime in dateTimes) bytes.AddRange(ToByteArray(dateTime));
+
+            return bytes.ToArray();
+        }
+    }
+}