private void Initialize()
{
int index = 0;
foreach (var field in schema.Fields)
{
if (field.DataType is ArrayType)
{
Func <DataType, int, StructType> convertArrayTypeToStructTypeFunc = (dataType, length) =>
{
StructField[] fields = new StructField[length];
for (int i = 0; i < length; i++)
{
fields[i] = new StructField(string.Format("_array_{0}", i), dataType);
}
return(new StructType(fields));
};
var elementType = (field.DataType as ArrayType).ElementType;
// Note: When creating object from json, PySpark converts Json array to Python List (https://github.com/apache/spark/blob/branch-1.4/python/pyspark/sql/types.py, _create_cls(dataType)),
// then Pyrolite unpickler converts Python List to C# ArrayList (https://github.com/irmen/Pyrolite/blob/v4.10/README.txt). So values[index] should be of type ArrayList;
// In case Python changes its implementation, which means value is not of type ArrayList, try cast to object[] because Pyrolite unpickler convert Python Tuple to C# object[].
object[] valueOfArray = values[index] is ArrayList ? (values[index] as ArrayList).ToArray() : values[index] as object[];
if (valueOfArray == null)
{
throw new ArgumentException("Cannot parse data of ArrayType: " + field.Name);
}
values[index] = new RowImpl(valueOfArray, elementType as StructType ?? convertArrayTypeToStructTypeFunc(elementType, valueOfArray.Length)).values;
}
else if (field.DataType is MapType)
{
//TODO
throw new NotImplementedException();
}
else if (field.DataType is StructType)
{
dynamic value = values[index];
if (value != null)
{
var subRow = new RowImpl(values[index], field.DataType as StructType);
values[index] = subRow;
}
}
else if (field.DataType is DecimalType)
{
//TODO
throw new NotImplementedException();
}
else if (field.DataType is DateType)
{
//TODO
throw new NotImplementedException();
}
else if (field.DataType is StringType)
{
if (values[index] != null)
{
values[index] = values[index].ToString();
}
}
else
{
values[index] = values[index];
}
index++;
}
}
private Func <dynamic, dynamic>[] ConstructPickleConverters()
{
var funcs = new Func <dynamic, dynamic> [fields.Count];
int index = 0;
foreach (var field in fields)
{
if (field.DataType is StringType)
{
funcs[index] = x => x?.ToString();
}
/*else if (field.DataType is LongType)
* {
* funcs[index] = x => x==null?null:(dynamic)(long)x ;
* }*/
/*else if (field.DataType is DateType)
* {
* funcs[index] = x => x;
* }*/
else if (field.DataType is ArrayType)
{
Func <DataType, int, StructType> convertArrayTypeToStructTypeFunc = (dataType, length) =>
{
StructField[] f = new StructField[length];
for (int i = 0; i < length; i++)
{
f[i] = new StructField(string.Format("_array_{0}", i), dataType);
}
return(new StructType(f));
};
var elementType = (field.DataType as ArrayType).ElementType;
funcs[index] = x =>
{
// Note: When creating object from json, PySpark converts Json array to Python List (https://github.com/apache/spark/blob/branch-1.4/python/pyspark/sql/types.py, _create_cls(dataType)),
// then Pyrolite unpickler converts Python List to C# ArrayList (https://github.com/irmen/Pyrolite/blob/v4.10/README.txt). So values[index] should be of type ArrayList;
// In case Python changes its implementation, which means value is not of type ArrayList, try cast to object[] because Pyrolite unpickler convert Python Tuple to C# object[].
object[] valueOfArray = (x as ArrayList)?.ToArray() ?? x as object[];
if (valueOfArray == null)
{
throw new ArgumentException("Cannot parse data of ArrayType: " + field.Name);
}
return(new RowImpl(valueOfArray,
elementType as StructType ?? convertArrayTypeToStructTypeFunc(elementType, valueOfArray.Length)).Values); // TODO: this part may have some problems, not verified
};
}
else if (field.DataType is MapType)
{
//TODO
throw new NotImplementedException();
}
else if (field.DataType is StructType)
{
funcs[index] = x => x != null ? new RowImpl(x, field.DataType as StructType) : null;
}
else
{
funcs[index] = x => x;
}
index++;
}
return(funcs);
}