SaneTsv/SaneTsv.cs

@@ -75,6 +75,7 @@ public class SaneTsv
     return (CommentedTsv<T>)Parse<T>(inputBuffer, FormatType.COMMENTED_TSV);
   }
 
+  // TODO: Have parsing errors include line / column #
   protected static Tsv<T> Parse<T>(byte[] inputBuffer, FormatType format) where T : TsvRecord, new()
   {
     Tsv<T> parsed;
@@ -112,6 +113,285 @@ public class SaneTsv
     var fields = new List<byte[]>();
     var currentComment = new StringBuilder();
 
+    int numFields = -1;
+    int line = 1;
+    int currentLineStart = 0;
+    for (int i = 0; i < inputBuffer.Count(); i++)
+    {
+      if (inputBuffer[i] == '\\')
+      {
+        if (i + 1 == inputBuffer.Count())
+        {
+          throw new Exception($"Found '\\' at end of input");
+        }
+        if (inputBuffer[i + 1] == 'n')
+        {
+          fieldBytes.Add((byte)'\n');
+          i++;
+        }
+        else if (inputBuffer[i + 1] == '\\')
+        {
+          fieldBytes.Add((byte)'\\');
+          i++;
+        }
+        else if (inputBuffer[i + 1] == 't')
+        {
+          fieldBytes.Add((byte)'\t');
+          i++;
+        }
+        else if (inputBuffer[i + 1] == '#')
+        {
+          fieldBytes.Add((byte)'#');
+          i++;
+        }
+        else
+        {
+          throw new Exception($"Expected 'n', 't', '#', or '\\' after '\\' at line {line} column {i - currentLineStart}");
+        }
+      }
+      else if (inputBuffer[i] == '\t')
+      {
+        // end of field
+        fields.Add(fieldBytes.ToArray());
+        fieldBytes.Clear();
+      }
+      else if (inputBuffer[i] == '\n')
+      {
+        fields.Add(fieldBytes.ToArray());
+        fieldBytes.Clear();
+
+        if (numFields < 0)
+        {
+          // This is the header
+
+          numFields = fields.Count;
+
+          int numTypesBlank = 0;
+
+          for (int j = 0; j < fields.Count; j++)
+          {
+            string columnString;
+            try
+            {
+              columnString = Encoding.UTF8.GetString(fields[j]);
+            }
+            catch (Exception e)
+            {
+              throw new Exception($"Header {fields.Count} is not valid UTF-8", e);
+            }
+
+            string columnTypeString;
+            string columnName;
+            if (columnString.Contains(':'))
+            {
+              if (format == FormatType.SIMPLE_TSV)
+              {
+                throw new Exception($"Header {fields.Count} contain ':', which is not allowed for column names");
+              }
+              columnTypeString = columnString.Split(":").Last();
+              columnName = columnString.Substring(0, columnString.Length - columnTypeString.Length - 1);
+            }
+            else
+            {
+              if (format > FormatType.SIMPLE_TSV)
+              {
+                throw new Exception($"Header {fields.Count} has no type");
+              }
+              columnTypeString = "";
+              columnName = columnString;
+            }
+
+            Type type;
+
+            switch (columnTypeString)
+            {
+              case "":
+                numTypesBlank++;
+                type = typeof(StringType);
+                break;
+              case "string":
+                type = typeof(StringType);
+                break;
+              case "boolean":
+                type = typeof(BooleanType);
+                break;
+              case "float32":
+                type = typeof(Float32Type);
+                break;
+              case "float32-le":
+                type = typeof(Float32LEType);
+                break;
+              case "float64":
+                type = typeof(Float64Type);
+                break;
+              case "float64-le":
+                type = typeof(Float64LEType);
+                break;
+              case "uint32":
+                type = typeof(UInt32Type);
+                break;
+              case "uint64":
+                type = typeof(UInt64Type);
+                break;
+              case "int32":
+                type = typeof(Int32Type);
+                break;
+              case "int64":
+                type = typeof(Int64Type);
+                break;
+              case "binary":
+                type = typeof(BinaryType);
+                break;
+              default:
+                throw new Exception($"Invalid type '{columnTypeString}' for column {j}");
+            }
+
+            // TODO: Check column name uniqueness
+            // TODO: Allow lax parsing (only worry about parsing columns that are given in the specifying type
+
+            if (headerNames[j] != columnName)
+            {
+              throw new Exception($"Column {j} has name {columnName}, but expected {headerNames[j]}");
+            }
+
+            if (headerTypes[j] != type)
+            {
+              throw new Exception($"Column {j} has type {type}, but expected {headerTypes[j]}");
+            }
+          }
+
+          if (currentComment.Length > 0)
+          {
+            if (parsed is CommentedTsv<T> commentedParsed)
+            {
+              commentedParsed.FileComment = currentComment.ToString();
+              currentComment.Clear();
+            }
+            else
+            {
+              throw new Exception("Found a file comment, but parser wasn't expecting a comment");
+            }
+          }
+
+
+          fields.Clear();
+        }
+        else if (numFields != fields.Count)
+        {
+          throw new Exception($"Expected {numFields} fields on line {line}, but found {fields.Count}");
+        }
+        else
+        {
+          string comment = null;
+          if (currentComment.Length > 0)
+          {
+            comment = currentComment.ToString();
+            currentComment.Clear();
+          }
+          parsed.Records.Add(ParseCurrentRecord<T>(headerTypes.ToArray(), headerPropertyInfos.ToArray(), fields, comment, line));
+          fields.Clear();
+        }
+
+        line++;
+        currentLineStart = i + 1;
+      }
+      else if (inputBuffer[i] == '#')
+      {
+        if (i == currentLineStart && format >= FormatType.COMMENTED_TSV)
+        {
+          int j = i;
+          for (; j < inputBuffer.Length && inputBuffer[j] != '\n'; j++) { }
+          if (j < inputBuffer.Length)
+          {
+            var commentBytes = new byte[j - i - 1];
+            Array.Copy(inputBuffer, i + 1, commentBytes, 0, j - i - 1);
+            if (currentComment.Length > 0)
+            {
+              currentComment.Append('\n');
+            }
+            currentComment.Append(Encoding.UTF8.GetString(commentBytes));
+            i = j;
+            currentLineStart = i + 1;
+            line++;
+          }
+          else
+          {
+            throw new Exception("Comments at end of file are not allowed");
+          }
+        }
+        else
+        {
+          throw new Exception($"Found unescaped '#' at line {line}, column {i - currentLineStart}");
+        }
+      }
+      else
+      {
+        fieldBytes.Add(inputBuffer[i]);
+      }
+    }
+
+    fields.Add(fieldBytes.ToArray());
+
+    if (fields.Count == 0)
+    {
+      throw new Exception("Found 0 fields on last line. Possibly because of extra \\n after last record");
+    }
+    if (numFields != fields.Count)
+    {
+      throw new Exception($"Expected {numFields} fields on line {parsed.Records.Count + 2}, but found {fields.Count}");
+    }
+    else
+    {
+      string comment = null;
+      if (currentComment.Length > 0)
+      {
+        comment = currentComment.ToString();
+        currentComment.Clear();
+      }
+      parsed.Records.Add(ParseCurrentRecord<T>(headerTypes.ToArray(), headerPropertyInfos.ToArray(), fields, comment, line));
+      fields.Clear();
+    }
+
+    return parsed;
+  }
+
+  protected static Tsv<T> ParseParallel<T>(byte[] inputBuffer, FormatType format) where T : TsvRecord, new()
+  {
+    Tsv<T> parsed;
+    if (format == FormatType.COMMENTED_TSV)
+    {
+      parsed = new CommentedTsv<T>();
+    }
+    else
+    {
+      parsed = new Tsv<T>();
+    }
+    parsed.Records = new List<T>();
+
+    var headerTypes = new List<Type>();
+    var headerNames = new List<string>();
+    var headerPropertyInfos = new List<PropertyInfo>();
+    int columnCount = 0;
+
+    foreach (PropertyInfo property in typeof(T).GetProperties())
+    {
+      TypedTsvColumnAttribute attribute = (TypedTsvColumnAttribute)Attribute.GetCustomAttribute(property, typeof(TypedTsvColumnAttribute));
+      if (attribute == null)
+      {
+        continue;
+      }
+
+      headerNames.Add(attribute.ColumnName ?? property.Name);
+      headerTypes.Add(attribute.ColumnType ?? GetColumnFromType(property.PropertyType));
+      headerPropertyInfos.Add(property);
+      // TODO: Check that the property type and given column type are compatible
+      columnCount++;
+    }
+
+    var fieldBytes = new List<byte>();
+    var fields = new List<byte[]>();
+    var currentComment = new StringBuilder();
+
     int numFields = -1;
     int line = 1;
     int currentLineStart = 0;
@@ -308,40 +588,9 @@ public class SaneTsv
       }
     }
 
-    // TODO: need to figure out where the crossover is
-    // Complication: it probably depends on processor count
-    if (inputBuffer.Length < 10000)
-    {
-      parsed.Records.AddRange(Parse<T>(inputBuffer, format, headerPropertyInfos.ToArray(), headerTypes.ToArray(), currentLineStart - 1, inputBuffer.Length));
-      return parsed;
-    }
-    else
-    {
-      int parseStart = currentLineStart;
-      int tasks = Environment.ProcessorCount - 1;
-      int splitCount = (inputBuffer.Length - parseStart) / tasks;
-      T[][] parsedValues = new T[tasks][];
-      Parallel.For(0, tasks, i =>
-      {
-        int startIndex = i * splitCount + parseStart - 1;
-        int endIndex;
-        if (i == tasks - 1)
-        {
-          endIndex = inputBuffer.Length;
-        }
-        else
-        {
-          endIndex = (i + 1) * splitCount + parseStart;
-        }
+    T[] parsedRecords = ParseParallel<T>(inputBuffer, format, headerPropertyInfos.ToArray(), headerTypes.ToArray(), currentLineStart - 1, inputBuffer.Length);
 
-        parsedValues[i] = Parse<T>(inputBuffer, format, headerPropertyInfos.ToArray(), headerTypes.ToArray(), startIndex, endIndex);
-      });
-
-      for (int i = 0; i < tasks; i++)
-      {
-        parsed.Records.AddRange(parsedValues[i]);
-      }
-    }
+    parsed.Records.AddRange(parsedRecords);
 
     return parsed;
   }
@@ -351,7 +600,7 @@ public class SaneTsv
   // startIndex is in we'd have to go back to the start of the record's comment, and to know 
   // exactly where that comment started we'd have to go back to the start of the record before that
   // (not including that other record's comment).
-  protected static T[] Parse<T>(byte[] inputBuffer, FormatType format, PropertyInfo[] headerPropertyInfos, Type[] headerTypes, int startIndex, int endIndex) where T : TsvRecord, new()
+  protected static T[] ParseParallel<T>(byte[] inputBuffer, FormatType format, PropertyInfo[] headerPropertyInfos, Type[] headerTypes, int startIndex, int endIndex) where T : TsvRecord, new()
   {
     var fieldBytes = new List<byte>();
     var fields = new List<byte[]>();
@@ -481,11 +730,6 @@ public class SaneTsv
       }
     }
 
-    if (endIndex < inputBuffer.Length)
-    {
-      return parsed.ToArray();
-    }
-
     fields.Add(fieldBytes.ToArray());
    
     if (fields.Count == 0)
@@ -705,6 +949,103 @@ public class SaneTsv
   }
 
   public static byte[] SerializeSimpleTsv(IList<string> header, IList<IList<string>> data)
+  {
+    var escapedString = new StringBuilder();
+
+    // Serialize header
+    for (int i = 0; i < header.Count; i++)
+    {
+      if (header[i].Contains(':'))
+      {
+        throw new Exception($"Column {i} contains the character ':'");
+      }
+
+      for (int j = i + 1; j < header.Count; j++)
+      {
+        if (header[i] == header[j])
+        {
+          throw new Exception("Column names in header must be unique");
+        }
+      }
+
+      for (int j = 0; j < header[i].Count(); j++)
+      {
+        if (header[i][j] == '\n')
+        {
+          escapedString.Append("\\n");
+        }
+        else if (header[i][j] == '\t')
+        {
+          escapedString.Append("\\t");
+        }
+        else if (header[i][j] == '\\')
+        {
+          escapedString.Append("\\\\");
+        }
+        else if (header[i][j] == '#')
+        {
+          escapedString.Append("\\#");
+        }
+        else
+        {
+          escapedString.Append(header[i][j]);
+        }
+      }
+
+      if (i == header.Count - 1)
+      {
+        escapedString.Append('\n');
+      }
+      else
+      {
+        escapedString.Append('\t');
+      }
+    }
+
+    // Serialize data
+    for (int i = 0; i < data.Count; i++)
+    {
+      for (int j = 0; j < data[i].Count; j++)
+      {
+        for (int k = 0; k < data[i][j].Length; k++)
+        {
+          if (data[i][j][k] == '\n')
+          {
+            escapedString.Append("\\n");
+          }
+          else if (data[i][j][k] == '\t')
+          {
+            escapedString.Append("\\t");
+          }
+          else if (data[i][j][k] == '\\')
+          {
+            escapedString.Append("\\\\");
+          }
+          else if (data[i][j][k] == '#')
+          {
+            escapedString.Append("\\#");
+          }
+          else
+          {
+            escapedString.Append(data[i][j][k]);
+          }
+        }
+
+        if (j < data[i].Count - 1)
+        {
+          escapedString.Append('\t');
+        }
+        else if (i < data.Count - 1)
+        {
+          escapedString.Append('\n');
+        }
+      }
+    }
+
+    return Encoding.UTF8.GetBytes(escapedString.ToString());
+  }
+
+  public static byte[] SerializeSimpleTsvParallel(IList<string> header, IList<IList<string>> data)
   {
     var serialized = new List<byte>();
     var escapedString = new StringBuilder();
@@ -765,7 +1106,7 @@ public class SaneTsv
     // Complication: it probably depends on processor count
     if (data.Count < 100)
     {
-      serialized.AddRange(Encoding.UTF8.GetBytes(SerializeSimpleTsv(data, 0, data.Count)));
+      serialized.AddRange(Encoding.UTF8.GetBytes(SerializeSimpleTsvParallel(data, 0, data.Count)));
     }
     else
     {
@@ -783,7 +1124,7 @@ public class SaneTsv
         {
           endIndex = (i + 1) * splitCount;
         }
-        string escapedString = SerializeSimpleTsv(data, i * splitCount, endIndex);
+        string escapedString = SerializeSimpleTsvParallel(data, i * splitCount, endIndex);
         bytes[i] = Encoding.UTF8.GetBytes(escapedString);
       });
 
@@ -796,7 +1137,7 @@ public class SaneTsv
     return serialized.ToArray();
   }
 
-  public static string SerializeSimpleTsv(IList<IList<string>> data, int startIndex, int endIndex)
+  public static string SerializeSimpleTsvParallel(IList<IList<string>> data, int startIndex, int endIndex)
   {
     var escapedString = new StringBuilder();
 
@@ -843,7 +1184,159 @@ public class SaneTsv
     return escapedString.ToString();
   }
 
+
   public static (string[] columns, string[][] data) ParseSimpleTsv(byte[] inputBuffer)
+  {
+    string[] columnNames = null;
+
+    var fieldBytes = new List<byte>();
+    var fields = new List<byte[]>();
+    var records = new List<string[]>();
+
+    int numFields = -1;
+    int line = 1;
+    int currentLineStart = 0;
+    for (int i = 0; i < inputBuffer.Count(); i++)
+    {
+      if (inputBuffer[i] == '\\')
+      {
+        if (i + 1 == inputBuffer.Count())
+        {
+          throw new Exception($"Found '\\' at end of input");
+        }
+        if (inputBuffer[i + 1] == 'n')
+        {
+          fieldBytes.Add((byte)'\n');
+          i++;
+        }
+        else if (inputBuffer[i + 1] == '\\')
+        {
+          fieldBytes.Add((byte)'\\');
+          i++;
+        }
+        else if (inputBuffer[i + 1] == 't')
+        {
+          fieldBytes.Add((byte)'\t');
+          i++;
+        }
+        else if (inputBuffer[i + 1] == '#')
+        {
+          fieldBytes.Add((byte)'#');
+          i++;
+        }
+        else
+        {
+          throw new Exception($"Expected 'n', 't', '#', or '\\' after '\\' at line {line} column {i - currentLineStart}");
+        }
+      }
+      else if (inputBuffer[i] == '\t')
+      {
+        // end of field
+        fields.Add(fieldBytes.ToArray());
+        fieldBytes.Clear();
+      }
+      else if (inputBuffer[i] == '\n')
+      {
+        fields.Add(fieldBytes.ToArray());
+        fieldBytes.Clear();
+
+        if (numFields < 0)
+        {
+          // This is the header
+
+          numFields = fields.Count;
+
+          columnNames = new string[numFields];
+
+          for (int j = 0; j < fields.Count; j++)
+          {
+            string columnString;
+            try
+            {
+              columnString = Encoding.UTF8.GetString(fields[j]);
+            }
+            catch (Exception e)
+            {
+              throw new Exception($"Column name {fields.Count} is not valid UTF-8", e);
+            }
+
+            if (columnString.Contains(':'))
+            {
+              throw new Exception($"Header {fields.Count} contain ':', which is not allowed for column names");
+            }
+
+            columnNames[j] = columnString;
+          }
+
+          fields.Clear();
+        }
+        else if (numFields != fields.Count)
+        {
+          throw new Exception($"Expected {numFields} fields on line {line}, but found {fields.Count}");
+        }
+        else
+        {
+          var fieldStrings = new string[fields.Count];
+          for (int j = 0; j < fields.Count; j++)
+          {
+            try
+            {
+              fieldStrings[j] = Encoding.UTF8.GetString(fields[j]);
+            }
+            catch (Exception e)
+            {
+              throw new Exception($"Line {line}, column {j} is not valid UTF-8", e);
+            }
+          }
+          records.Add(fieldStrings);
+          fields.Clear();
+        }
+
+        line++;
+        currentLineStart = i + 1;
+      }
+      else if (inputBuffer[i] == '#')
+      {
+        throw new Exception($"Found unescaped '#' at line {line}, column {i - currentLineStart}");
+      }
+      else
+      {
+        fieldBytes.Add(inputBuffer[i]);
+      }
+    }
+
+    fields.Add(fieldBytes.ToArray());
+
+    if (numFields == 0)
+    {
+      throw new Exception("Found 0 fields on last line. Possibly because of extra \\n after last record");
+    }
+    if (numFields != fields.Count)
+    {
+      throw new Exception($"Expected {numFields} fields on line {line}, but found {fields.Count}");
+    }
+    else
+    {
+      var fieldStrings = new string[fields.Count];
+      for (int j = 0; j < fields.Count; j++)
+      {
+        try
+        {
+          fieldStrings[j] = Encoding.UTF8.GetString(fields[j]);
+        }
+        catch (Exception e)
+        {
+          throw new Exception($"Line {line}, column {j} is not valid UTF-8", e);
+        }
+      }
+      records.Add(fieldStrings);
+      fields.Clear();
+    }
+
+    return (columnNames, records.ToArray());
+  }
+
+  public static (string[] columns, string[][] data) ParseSimpleTsvParallel(byte[] inputBuffer)
   {
     string[] columnNames = null;
     var headers = new List<byte[]>();
@@ -930,10 +1423,10 @@ public class SaneTsv
       }
     }
 
-    return (columnNames, ParseSimpleTsv(inputBuffer, columnNames.Length, startOfData, inputBuffer.Length));
+    return (columnNames, ParseSimpleTsvParallel(inputBuffer, columnNames.Length, startOfData, inputBuffer.Length));
   }
 
-  public static string[][] ParseSimpleTsv(byte[] inputBuffer, int numFields, int startIndex, int endIndex)
+  public static string[][] ParseSimpleTsvParallel(byte[] inputBuffer, int numFields, int startIndex, int endIndex)
   {
     var fieldBytes = new List<byte>();
     var fields = new List<byte[]>();
@@ -1173,7 +1666,282 @@ public class SaneTsv
     return SerializeTsv<T>(data, FormatType.COMMENTED_TSV);
   }
 
-  protected static byte[] SerializeTsv<T>(IList<T> data, FormatType tsvFormat)
+  protected static byte[] SerializeTsv<T>(IList<T> data, FormatType tsvFormat) where T : TsvRecord
+  {
+    var bytes = new List<byte>();
+
+    var headerTypes = new List<Type>();
+    var headerNames = new List<string>();
+    var headerPropertyInfos = new List<PropertyInfo>();
+    int columnCount = 0;
+
+    foreach (PropertyInfo property in typeof(T).GetProperties())
+    {
+      TsvColumnAttribute attribute = (TsvColumnAttribute)Attribute.GetCustomAttribute(property, typeof(TsvColumnAttribute));
+      if (attribute == null)
+      {
+        continue;
+      }
+
+      string headerName = attribute.ColumnName ?? property.Name;
+      headerNames.Add(headerName);
+      Type headerType = attribute.ColumnType ?? GetColumnFromType(property.PropertyType);
+      if (tsvFormat == FormatType.SIMPLE_TSV && headerType != typeof(StringType))
+      {
+        throw new Exception($"Serializing Simple TSV requires all columns be of type string, but column '{headerName}' has type '{headerType}'");
+      }
+      headerTypes.Add(headerType);
+      headerPropertyInfos.Add(property);
+      // TODO: Check that the property type and given column type are compatible
+      columnCount++;
+    }
+
+    // Serialize header
+    for (int i = 0; i < headerNames.Count; i++)
+    {
+      for (int j = i + 1; j < headerNames.Count; j++)
+      {
+        if (headerNames[i] == headerNames[j])
+        {
+          throw new Exception("Column names in header must be unique");
+        }
+      }
+
+      byte[] nameEncoded = Encoding.UTF8.GetBytes(headerNames[i]);
+
+      for (int j = 0; j < nameEncoded.Length; j++)
+      {
+        if (nameEncoded[j] == '\n')
+        {
+          bytes.Add((byte)'\\');
+          bytes.Add((byte)'n');
+        }
+        else if (nameEncoded[j] == '\t')
+        {
+          bytes.Add((byte)'\\');
+          bytes.Add((byte)'t');
+        }
+        else if (nameEncoded[j] == '\\')
+        {
+          bytes.Add((byte)'\\');
+          bytes.Add((byte)'\\');
+        }
+        else if (nameEncoded[j] == '#')
+        {
+          bytes.Add((byte)'\\');
+          bytes.Add((byte)'#');
+        }
+        else
+        {
+          bytes.Add(nameEncoded[j]);
+        }
+      }
+
+      if (tsvFormat != FormatType.SIMPLE_TSV)
+      {
+        bytes.Add((byte)':');
+        try
+        {
+          bytes.AddRange(Encoding.UTF8.GetBytes(GetNameFromColumn(headerTypes[i])));
+        }
+        catch (Exception e)
+        {
+          throw new Exception($"Invalid header type for column {i}", e);
+        }
+      }
+
+      if (i == headerNames.Count - 1)
+      {
+        bytes.Add((byte)'\n');
+      }
+      else
+      {
+        bytes.Add((byte)'\t');
+      }
+    }
+
+    // Serialize data
+    for (int i = 0; i < data.Count; i++)
+    {
+      for (int j = 0; j < columnCount; j++)
+      {
+        object datum = headerPropertyInfos[j].GetValue(data[i]);
+
+        try
+        {
+          byte[] fieldEncoded = null;
+          // Some fields definitely don't need escaping, so we add them directly to bytes
+          bool skipEscaping = false;
+
+          if (headerTypes[j] == typeof(StringType))
+          {
+            fieldEncoded = Encoding.UTF8.GetBytes((string)datum);
+          }
+          else if (headerTypes[j] == typeof(BooleanType))
+          {
+            bytes.AddRange((bool)datum ? TrueEncoded : FalseEncoded);
+            skipEscaping = true;
+          }
+          else if (headerTypes[j] == typeof(Float32Type))
+          {
+            if (datum is float f)
+            {
+              if (float.IsNegativeInfinity(f))
+              {
+                bytes.AddRange(Encoding.UTF8.GetBytes("-inf"));
+              }
+              else if (float.IsPositiveInfinity(f))
+              {
+                bytes.AddRange(Encoding.UTF8.GetBytes("+inf"));
+              }
+              else
+              {
+                // See https://learn.microsoft.com/en-us/dotnet/standard/base-types/standard-numeric-format-strings#round-trip-format-specifier-r
+                bytes.AddRange(Encoding.UTF8.GetBytes(((float)datum).ToString("G9")));
+              }
+            }
+            else
+            {
+              throw new InvalidCastException();
+            }
+            skipEscaping = true;
+          }
+          else if (headerTypes[j] == typeof(Float32LEType))
+          {
+            if (LittleEndian)
+            {
+              fieldEncoded = BitConverter.GetBytes((float)datum);
+            }
+            else
+            {
+              byte[] floatBytes = BitConverter.GetBytes((float)datum);
+              fieldEncoded = new byte[sizeof(float)];
+              for (int k = 0; k < sizeof(float); k++)
+              {
+                fieldEncoded[k] = floatBytes[sizeof(float) - 1 - k];
+              }
+            }
+          }
+          else if (headerTypes[j] == typeof(Float64Type))
+          {
+            if (datum is double d)
+            {
+              if (double.IsNegativeInfinity(d))
+              {
+                bytes.AddRange(Encoding.UTF8.GetBytes("-inf"));
+              }
+              else if (double.IsPositiveInfinity(d))
+              {
+                bytes.AddRange(Encoding.UTF8.GetBytes("+inf"));
+              }
+              else
+              {
+                // See https://learn.microsoft.com/en-us/dotnet/standard/base-types/standard-numeric-format-strings#round-trip-format-specifier-r
+                bytes.AddRange(Encoding.UTF8.GetBytes((d).ToString("G17")));
+              }
+            }
+            else
+            {
+              throw new InvalidCastException();
+            }
+            skipEscaping = true;
+          }
+          else if (headerTypes[j] == typeof(Float64LEType))
+          {
+            if (LittleEndian)
+            {
+              fieldEncoded = BitConverter.GetBytes((double)datum);
+            }
+            else
+            {
+              byte[] doubleBytes = BitConverter.GetBytes((double)datum);
+              fieldEncoded = new byte[sizeof(double)];
+              for (int k = 0; k < sizeof(double); k++)
+              {
+                fieldEncoded[k] = doubleBytes[sizeof(double) - 1 - k];
+              }
+            }
+          }
+          else if (headerTypes[j] == typeof(UInt32Type))
+          {
+            bytes.AddRange(Encoding.UTF8.GetBytes(((UInt32)datum).ToString()));
+            skipEscaping = true;
+          }
+          else if (headerTypes[j] == typeof(UInt64Type))
+          {
+            bytes.AddRange(Encoding.UTF8.GetBytes(((UInt64)datum).ToString()));
+            skipEscaping = true;
+          }
+          else if (headerTypes[j] == typeof(Int32Type))
+          {
+            bytes.AddRange(Encoding.UTF8.GetBytes(((Int32)datum).ToString()));
+            skipEscaping = true;
+          }
+          else if (headerTypes[j] == typeof(Int64Type))
+          {
+            bytes.AddRange(Encoding.UTF8.GetBytes(((Int64)datum).ToString()));
+            skipEscaping = true;
+          }
+          else if (headerTypes[j] == typeof(BinaryType))
+          {
+            fieldEncoded = (byte[])datum;
+          }
+          else
+          {
+            throw new Exception($"Unexpected column type {headerTypes[j]} for column {j}");
+          }
+
+          if (!skipEscaping)
+          {
+            for (int k = 0; k < fieldEncoded.Length; k++)
+            {
+              if (fieldEncoded[k] == '\n')
+              {
+                bytes.Add((byte)'\\');
+                bytes.Add((byte)'n');
+              }
+              else if (fieldEncoded[k] == '\t')
+              {
+                bytes.Add((byte)'\\');
+                bytes.Add((byte)'t');
+              }
+              else if (fieldEncoded[k] == '\\')
+              {
+                bytes.Add((byte)'\\');
+                bytes.Add((byte)'\\');
+              }
+              else if (fieldEncoded[k] == '#')
+              {
+                bytes.Add((byte)'\\');
+                bytes.Add((byte)'#');
+              }
+              else
+              {
+                bytes.Add(fieldEncoded[k]);
+              }
+            }
+          }
+
+          if (j < columnCount - 1)
+          {
+            bytes.Add((byte)'\t');
+          }
+          else if (i < data.Count - 1)
+          {
+            bytes.Add((byte)'\n');
+          }
+        }
+        catch (InvalidCastException e)
+        {
+          throw new Exception($"Record {i}, field {j} expected type compatible with {GetNameFromColumn(headerTypes[j])}", e);
+        }
+      }
+    }
+
+    return bytes.ToArray();
+  }
+
+  protected static byte[] SerializeTsvParallel<T>(IList<T> data, FormatType tsvFormat)
   {
     var bytes = new List<byte>();
 
@@ -1269,12 +2037,12 @@ public class SaneTsv
     }
 
     // Serialize data
-    SerializeTsv<T>(data, bytes, headerPropertyInfos.ToArray(), headerTypes.ToArray(), tsvFormat, 0, data.Count);
+    SerializeTsvParallel<T>(data, bytes, headerPropertyInfos.ToArray(), headerTypes.ToArray(), tsvFormat, 0, data.Count);
 
     return bytes.ToArray();
   }
 
-  protected static void SerializeTsv<T>(IList<T> data, List<byte> bytes, PropertyInfo[] headerPropertyInfos, Type[] headerTypes, FormatType tsvFormat, int startIndex, int endIndex)
+  protected static void SerializeTsvParallel<T>(IList<T> data, List<byte> bytes, PropertyInfo[] headerPropertyInfos, Type[] headerTypes, FormatType tsvFormat, int startIndex, int endIndex)
   {
     // Serialize data
     for (int i = 0; i < data.Count; i++)

SaneTsv/SaneTsvTest/Program.cs

@@ -348,6 +348,222 @@ internal class Program : SaneTsv
       Console.WriteLine($"Unspecced parse time: {unspeccedParseTime}");
     }
 
+    {
+      string testName = "Check parallel Simple TSV serialization";
+
+      int N = 100000;
+      var records = new StringTestRecord[N];
+      var rand = new Random(1);
+
+      for (int i = 0; i < N; i++)
+      {
+        records[i] = new StringTestRecord()
+        {
+          Column1 = rand.Next().ToString(),
+          column2 = rand.Next().ToString(),
+          Column3 = rand.Next().ToString(),
+        };
+      }
+
+      string[][] recordStrings = records.Select(record => new string[] { record.Column1, record.column2, record.Column3 }).ToArray();
+
+      DateTime lastTime = DateTime.Now;
+      byte[] serialized1 = SaneTsv.SerializeSimpleTsv(new string[] { "column1", "column2", "columnthree\nyep" }, recordStrings);
+      TimeSpan unparallelTime = DateTime.Now - lastTime;
+      lastTime = DateTime.Now;
+      byte[] serialized2 = SaneTsv.SerializeSimpleTsvParallel(new string[] { "column1", "column2", "columnthree\nyep" }, recordStrings);
+      TimeSpan parallelTime = DateTime.Now - lastTime;
+
+      Console.WriteLine($"Unparallel serialization time: {unparallelTime}");
+      Console.WriteLine($"Parallel serialization time: {parallelTime}");
+
+      bool matching = true;
+      for (int i = 0; i < Math.Min(serialized1.Length, serialized2.Length); i++)
+      {
+        if (serialized1[i] != serialized2[i])
+        {
+          matching = false;
+          break;
+        }
+      }
+
+      if (matching)
+      {
+        Console.WriteLine($"Passed {testName}");
+      }
+      else
+      {
+        Console.WriteLine($"Failed {testName}");
+      }
+    }
+
+    {
+      string testName = "Check Simple TSV parallel parsing";
+
+      int N = 100000;
+      var records = new StringTestRecord[N];
+      var rand = new Random(1);
+
+      for (int i = 0; i < N; i++)
+      {
+        records[i] = new StringTestRecord()
+        {
+          Column1 = rand.Next().ToString(),
+          column2 = rand.Next().ToString(),
+          Column3 = rand.Next().ToString(),
+        };
+      }
+
+      byte[] serialized = SaneTsv.SerializeSimpleTsv<StringTestRecord>(records);
+
+      DateTime lastTime = DateTime.Now;
+      (string[] headers2, string[][] data2) = SaneTsv.ParseSimpleTsv(serialized);
+      TimeSpan unparallelTime = DateTime.Now - lastTime;
+      lastTime = DateTime.Now;
+      (string[] headers, string[][] data) = SaneTsv.ParseSimpleTsvParallel(serialized);
+      TimeSpan parallelTime = DateTime.Now - lastTime;
+
+      Console.WriteLine($"Unparallel parse time: {unparallelTime}");
+      Console.WriteLine($"Parallel parse time: {parallelTime}");
+
+      bool matching = true;
+      for (int j = 0; j < Math.Min(headers2.Length, headers.Length); j++)
+      {
+        if (headers[j] != headers2[j])
+        {
+          matching = false;
+          break;
+        }
+      }
+
+      for (int i = 0; i < Math.Min(data.Length, data2.Length) && matching; i++)
+      {
+        for (int j = 0; j < data[0].Length; j++)
+        {
+          if (data[i][j] != data2[i][j])
+          {
+            matching = false;
+            break;
+          }
+        }
+      }
+
+      if (matching)
+      {
+        Console.WriteLine($"Passed {testName}");
+      }
+      else
+      {
+        Console.WriteLine($"Failed {testName}");
+      }
+    }
+
+    {
+      string testName = "Check parallel serialization";
+
+      int N = 1000;
+      var records = new BoolTestRecord[N];
+      var rand = new Random(1);
+
+      for (int i = 0; i < N; i++)
+      {
+        byte[] bytes = new byte[rand.Next(50)];
+        rand.NextBytes(bytes);
+        records[i] = new BoolTestRecord()
+        {
+          Column1 = rand.NextDouble() > 0.5,
+          column2 = bytes,
+          Column3 = rand.Next().ToString(),
+        };
+      }
+
+      DateTime lastTime = DateTime.Now;
+      byte[] serialized1 = SaneTsv.SerializeTsv<BoolTestRecord>(records, FormatType.COMMENTED_TSV);
+      TimeSpan unparallelTime = DateTime.Now - lastTime;
+      lastTime = DateTime.Now;
+      byte[] serialized2 = SaneTsv.SerializeTsvParallel<BoolTestRecord>(records, FormatType.COMMENTED_TSV);
+      TimeSpan parallelTime = DateTime.Now - lastTime;
+
+      Console.WriteLine($"Unparallel serialization time: {unparallelTime}");
+      Console.WriteLine($"Parallel serialization time: {parallelTime}");
+
+      bool matching = true;
+      for (int i = 0; i < Math.Min(serialized1.Length, serialized2.Length); i++)
+      {
+        if (serialized1[i] != serialized2[i])
+        {
+          matching = false;
+          break;
+        }
+      }
+
+      if (matching)
+      {
+        Console.WriteLine($"Passed {testName}");
+      }
+      else
+      {
+        Console.WriteLine($"Failed {testName}");
+      }
+    }
+
+    {
+      string testName = "Check parallel parsing";
+
+      int N = 1000;
+      var records = new BoolTestRecord[N];
+      var rand = new Random(1);
+
+      for (int i = 0; i < N; i++)
+      {
+        byte[] bytes = new byte[rand.Next(50)];
+        rand.NextBytes(bytes);
+        records[i] = new BoolTestRecord()
+        {
+          Column1 = rand.NextDouble() > 0.5,
+          column2 = bytes,
+          Column3 = rand.Next().ToString(),
+        };
+      }
+
+      byte[] serialized2 = SaneTsv.SerializeTsvParallel<BoolTestRecord>(records, FormatType.COMMENTED_TSV);
+
+      DateTime lastTime = DateTime.Now;
+      CommentedTsv<BoolTestRecord> parsed = (CommentedTsv<BoolTestRecord>)SaneTsv.Parse<BoolTestRecord>(serialized2, FormatType.COMMENTED_TSV);
+      TimeSpan unparallelTime = DateTime.Now - lastTime;
+      lastTime = DateTime.Now;
+      CommentedTsv<BoolTestRecord> parsed2 = (CommentedTsv<BoolTestRecord>)SaneTsv.ParseParallel<BoolTestRecord>(serialized2, FormatType.COMMENTED_TSV);
+      TimeSpan parallelTime = DateTime.Now - lastTime;
+
+      Console.WriteLine($"Unparallel parsing time: {unparallelTime}");
+      Console.WriteLine($"Parallel parsing time: {parallelTime}");
+
+      bool matching = parsed.FileComment == parsed2.FileComment;
+
+      matching &= parsed.Records.Count == parsed2.Records.Count;
+
+      for (int i = 0; matching && i < parsed.Records.Count; i++)
+      {
+        matching &= parsed.Records[i].Comment == parsed2.Records[i].Comment;
+        matching &= parsed.Records[i].Column1 == parsed2.Records[i].Column1;
+        matching &= parsed.Records[i].column2.Length == parsed2.Records[i].column2.Length;
+        for (int j = 0; matching && j < parsed.Records[i].column2.Length; j++)
+        {
+          matching &= parsed.Records[i].column2[j] == parsed2.Records[i].column2[j];
+        }
+      }
+
+      if (matching)
+      {
+        Console.WriteLine($"Passed {testName}");
+      }
+      else
+      {
+        Console.WriteLine($"Failed {testName}");
+      }
+    }
+
+
     Console.WriteLine("Done with tests");
   }
 }