Class: ArrowFormat::Org::Apache::Arrow::Flatbuf::Schema

Inherits:
FlatBuffers::Table
  • Object
show all
Defined in:
lib/arrow-format/org/apache/arrow/flatbuf/schema.rb

Overview

A Schema describes the columns in a row batch

Constant Summary collapse

FIELDS = 
{
  endianness: ::FlatBuffers::Field.new(:endianness, 0, 4, :short, 0),
  fields: ::FlatBuffers::Field.new(:fields, 1, 6, ["::ArrowFormat::Org::Apache::Arrow::Flatbuf::Field"], 0),
  custom_metadata: ::FlatBuffers::Field.new(:custom_metadata, 2, 8, ["::ArrowFormat::Org::Apache::Arrow::Flatbuf::KeyValue"], 0),
  features: ::FlatBuffers::Field.new(:features, 3, 10, [:long], 0),
}
Data = 
define_data_class

Instance Method Summary collapse

Instance Method Details

#custom_metadata ⇒ Object 



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# File 'lib/arrow-format/org/apache/arrow/flatbuf/schema.rb', line 29

def custom_metadata
  field_offset = @view.unpack_virtual_offset(8)
  return nil if field_offset.zero?

  element_size = 4
  @view.unpack_vector(field_offset, element_size) do |element_offset|
    @view.unpack_table(::ArrowFormat::Org::Apache::Arrow::Flatbuf::KeyValue, element_offset)
  end
end

#endianness ⇒ Object

endianness of the buffer it is Little Endian by default if endianness doesn’t match the underlying system then the vectors need to be converted



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# File 'lib/arrow-format/org/apache/arrow/flatbuf/schema.rb', line 42

def endianness
  field_offset = @view.unpack_virtual_offset(4)
  if field_offset.zero?
    enum_value = 0
  else
    enum_value = @view.unpack_short(field_offset)
  end
  ::ArrowFormat::Org::Apache::Arrow::Flatbuf::Endianness.try_convert(enum_value) || enum_value
end

#features ⇒ Object

Features used in the stream/file.



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# File 'lib/arrow-format/org/apache/arrow/flatbuf/schema.rb', line 53

def features
  field_offset = @view.unpack_virtual_offset(10)
  return nil if field_offset.zero?

  element_size = 8
  @view.unpack_vector(field_offset, element_size) do |element_offset|
    @view.unpack_long(element_offset)
  end
end

#fields ⇒ Object 



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# File 'lib/arrow-format/org/apache/arrow/flatbuf/schema.rb', line 63

def fields
  field_offset = @view.unpack_virtual_offset(6)
  return nil if field_offset.zero?

  element_size = 4
  @view.unpack_vector(field_offset, element_size) do |element_offset|
    @view.unpack_table(::ArrowFormat::Org::Apache::Arrow::Flatbuf::Field, element_offset)
  end
end