Add parallel parsing/serialization for Simple TSV

Doesn't give as much of a performance bonus as hoped

SaneTsv.cs

@@ -644,6 +644,146 @@ public class SaneTsv
     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();
+
+    // 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');
+      }
+    }
+
+    serialized.AddRange(Encoding.UTF8.GetBytes(escapedString.ToString()));
+
+    // TODO: need to figure out where the crossover it
+    // Complication: it probably depends on processor count
+    if (data.Count < 100)
+    {
+      serialized.AddRange(Encoding.UTF8.GetBytes(SerializeSimpleTsvParallel(data, 0, data.Count)));
+    }
+    else
+    {
+      int tasks = Environment.ProcessorCount - 1;
+      int splitCount = data.Count / tasks;
+      byte[][] bytes = new byte[tasks][];
+      Parallel.For(0, tasks, i =>
+      {
+        int endIndex;
+        if (i == tasks - 1)
+        {
+          endIndex = data.Count;
+        }
+        else
+        {
+          endIndex = (i + 1) * splitCount;
+        }
+        string escapedString = SerializeSimpleTsvParallel(data, i * splitCount, endIndex);
+        bytes[i] = Encoding.UTF8.GetBytes(escapedString);
+      });
+
+      for (int i = 0; i < tasks; i++)
+      {
+        serialized.AddRange(bytes[i]);
+      }
+    }
+
+    return serialized.ToArray();
+  }
+
+  public static string SerializeSimpleTsvParallel(IList<IList<string>> data, int startIndex, int endIndex)
+  {
+    var escapedString = new StringBuilder();
+
+    // Serialize data
+    for (int i = startIndex; i < endIndex; 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 escapedString.ToString();
+  }
+
+
   public static (string[] columns, string[][] data) ParseSimpleTsv(byte[] inputBuffer)
   {
     string[] columnNames = null;
@@ -795,6 +935,225 @@ public class SaneTsv
     return (columnNames, records.ToArray());
   }
 
+  public static (string[] columns, string[][] data) ParseSimpleTsvParallel(byte[] inputBuffer)
+  {
+    string[] columnNames = null;
+    var headers = new List<byte[]>();
+    var fieldBytes = new List<byte>();
+    int startOfData = -1;
+    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 {1} column {i}");
+        }
+      }
+      else if (inputBuffer[i] == '\t')
+      {
+        // end of field
+        headers.Add(fieldBytes.ToArray());
+        fieldBytes.Clear();
+      }
+      else if (inputBuffer[i] == '\n')
+      {
+        // This is the end of the header
+        headers.Add(fieldBytes.ToArray());
+        startOfData = i + 1;
+
+        columnNames = new string[headers.Count];
+        fieldBytes.Clear();
+
+        for (int j = 0; j < headers.Count; j++)
+        {
+          string columnString;
+          try
+          {
+            columnString = Encoding.UTF8.GetString(headers[j]);
+          }
+          catch (Exception e)
+          {
+            throw new Exception($"Column {headers.Count} name is not valid UTF-8", e);
+          }
+
+          if (columnString.Contains(':'))
+          {
+            throw new Exception($"Header {headers.Count} contain ':', which is not allowed for column names");
+          }
+
+          columnNames[j] = columnString;
+        }
+
+        // Done parsing header
+        break;
+      }
+      else if (inputBuffer[i] == '#')
+      {
+        throw new Exception($"Found unescaped '#' at line 1, column {i}");
+      }
+      else
+      {
+        fieldBytes.Add(inputBuffer[i]);
+      }
+    }
+
+    return (columnNames, ParseSimpleTsvParallel(inputBuffer, columnNames.Length, startOfData, inputBuffer.Length));
+  }
+
+  public static string[][] ParseSimpleTsvParallel(byte[] inputBuffer, int numFields, int startIndex, int endIndex)
+  {
+    var fieldBytes = new List<byte>();
+    var fields = new List<byte[]>();
+    var records = new List<string[]>();
+
+    int line = 1;
+    int currentLineStart = 0;
+
+    // Go back to the start of the current line
+    int i = startIndex;
+    while (inputBuffer[i] != '\n')
+    {
+      i--;
+    }
+
+    // We want to start at the first byte of the current line
+    i++;
+
+    for (; i < endIndex; i++)
+    {
+      if (inputBuffer[i] == '\\')
+      {
+        if (i + 1 == inputBuffer.Count())
+        {
+          throw new Exception($"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($"Expected 'n', 't', '#', or '\\' after '\\' at line {line} column {i - currentLineStart}");
+        }
+      }
+      else if (inputBuffer[i] == '\t')
+      {
+        // end of field
+        fields.Add(fieldBytes.ToArray());
+        fieldBytes.Clear();
+      }
+      else if (inputBuffer[i] == '\n')
+      {
+        fields.Add(fieldBytes.ToArray());
+        fieldBytes.Clear();
+
+        if (numFields != fields.Count)
+        {
+          throw new Exception($"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 (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($"Expected {numFields} fields on line {line}, but found {fields.Count}");
+    }
+    else
+    {
+      var fieldStrings = new string[fields.Count];
+      for (int j = 0; j < fields.Count; j++)
+      {
+        try
+        {
+          fieldStrings[j] = Encoding.UTF8.GetString(fields[j]);
+        }
+        catch (Exception e)
+        {
+          throw new Exception($"Line {line}, column {j} is not valid UTF-8", e);
+        }
+      }
+      records.Add(fieldStrings);
+      fields.Clear();
+    }
+    
+    return records.ToArray();
+  }
+
   public static Type GetColumnFromType(Type type)
   {
     if (type == typeof(string))
@@ -893,7 +1252,7 @@ public class SaneTsv
 
   public static byte[] SerializeSimpleTsv<T>(IList<T> data) where T : TsvRecord
   {
-    return SerializeTsv<T>(data, FormatType.TYPED_TSV);
+    return SerializeTsv<T>(data, FormatType.SIMPLE_TSV);
   }
 
   public static byte[] SerializeTypedTsv<T>(IList<T> data) where T : TsvRecord
@@ -977,6 +1336,8 @@ public class SaneTsv
         }
       }
 
+      if (tsvFormat != FormatType.SIMPLE_TSV)
+      {
         bytes.Add((byte)':');
         try
         {
@@ -986,6 +1347,7 @@ public class SaneTsv
         {
           throw new Exception($"Invalid header type for column {i}", e);
         }
+      }
 
       if (i == headerNames.Count - 1)
       {

SaneTsvTest/Program.cs

@@ -101,6 +101,18 @@ internal class Program
     public double BinFloat { get; set; }
   }
 
+  public class StringTestRecord : SaneTsv.TsvRecord
+  {
+    [SaneTsv.TypedTsvColumn("column1")]
+    public string Column1 { get; set; }
+
+    [SaneTsv.TypedTsvColumn]
+    public string column2 { get; set; }
+
+    [SaneTsv.TypedTsvColumn("columnthree\nyep")]
+    public string Column3 { get; set; }
+  }
+
   private static void Main(string[] args)
   {
     {
@@ -292,6 +304,160 @@ internal class Program
       }
     }
 
+    {
+      string testName = "Timing comparison of simple parse methods and comparison of simple serialization methods";
+
+      int N = 1000000;
+      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<StringTestRecord>(records);
+
+      TimeSpan speccedSerializationTime = DateTime.Now - lastTime;
+      Console.WriteLine($"Specced serialization time: {speccedSerializationTime}");
+      lastTime = DateTime.Now;
+
+      byte[] serialized2 = SaneTsv.SerializeSimpleTsv(new string[] { "column1", "column2", "columnthree\nyep" }, recordStrings);
+
+      TimeSpan unspeccedSerializationTime = DateTime.Now - lastTime;
+      Console.WriteLine($"Unspecced serialization time: {unspeccedSerializationTime}");
+      lastTime = DateTime.Now;
+
+      Tsv<StringTestRecord> parsed = SaneTsv.ParseSimpleTsv<StringTestRecord>(serialized1);
+
+      TimeSpan speccedParseTime = DateTime.Now - lastTime;
+      Console.WriteLine($"Specced parse time: {speccedParseTime}");
+      lastTime = DateTime.Now;
+
+      (string[] columns, string[][] data) = SaneTsv.ParseSimpleTsv(serialized2);
+
+      TimeSpan unspeccedParseTime = DateTime.Now - lastTime;
+      Console.WriteLine($"Unspecced parse time: {unspeccedParseTime}");
+    }
+
+    {
+      string testName = "Check parallel 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 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($"Unparallel serialization time: {unparallelTime}");
+      Console.WriteLine($"Parallel serialization 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}");
+      }
+    }
+
     Console.WriteLine("Done with tests");
   }
 }