public static Array MakeArrayBuffer <T>(IArrowType dataType,
int length,
IEnumerable <T> data)
where T : struct
{
ArrowBuffer.Builder <T> builder = new ArrowBuffer.Builder <T>();
builder.AppendRange(data);
ArrowBuffer buffer = builder.Build();
ArrayData arrayData = new ArrayData(dataType,
length,
0,
0,
new[]
{
buffer
});
Array array = ArrowArrayFactory.BuildArray(arrayData) as Array;
return(array);
}
public static Table BuildTable(List <TDataLayout> data)
{
PropertyInfo[] properties = typeof(TDataLayout).GetProperties(BindingFlags.Public | BindingFlags.Instance).Where(p => p.GetCustomAttribute <ArrowPropertyAttribute>() != null).ToArray();
//int length = data.Count;
List <Field> fields = new List <Field>(properties.Length);
Apache.Arrow.Schema.Builder schemaBuilder = new Apache.Arrow.Schema.Builder();
foreach (PropertyInfo property in properties)
{
ArrowPropertyAttribute arrowPropertyAttribute = property.GetCustomAttribute <ArrowPropertyAttribute>();
Field field = new Field.Builder().Name(arrowPropertyAttribute.Name).DataType(arrowPropertyAttribute.ArrowType()).Build();
schemaBuilder.Field(field);
fields.Add(field);
}
List <List <object> > transformData = new List <List <object> >(properties.Length);
for (int i = 0; i < properties.Length; ++i)
{
transformData.Add(new List <object>(data.Count));
}
for (int i = 0; i < data.Count; ++i)
{
int j = 0;
foreach (object property in data[i])
{
transformData[j++][i] = property;
}
}
List <Column> columns = new List <Column>(properties.Length);
for (int i = 0; i < properties.Length; ++i)
{
Array array = ArrowUtilities.MakeArrayBuffer(fields[i].DataType,
transformData[i]);
Column column = new Column(fields[i],
new Array[]
{
array
});
columns.Add(column);
}
//NativeMemoryAllocator memoryAllocator = new NativeMemoryAllocator(32);
Table table = new Table(schemaBuilder.Build(),
columns);
return(table);
}
