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# Licensed to the Apache Software Foundation (ASF) under one
# or more contributor license agreements. See the NOTICE file
# distributed with this work for additional information
# regarding copyright ownership. The ASF licenses this file
# to you under the Apache License, Version 2.0 (the
# "License"); you may not use this file except in compliance
# with the License. You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing,
# software distributed under the License is distributed on an
# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
# KIND, either express or implied. See the License for the
# specific language governing permissions and limitations
# under the License.
require_relative "array"
require_relative "field"
require_relative "record-batch"
require_relative "schema"
require_relative "type"
require_relative "org/apache/arrow/flatbuf/binary"
require_relative "org/apache/arrow/flatbuf/bool"
require_relative "org/apache/arrow/flatbuf/date"
require_relative "org/apache/arrow/flatbuf/date_unit"
require_relative "org/apache/arrow/flatbuf/decimal"
require_relative "org/apache/arrow/flatbuf/dictionary_encoding"
require_relative "org/apache/arrow/flatbuf/dictionary_batch"
require_relative "org/apache/arrow/flatbuf/duration"
require_relative "org/apache/arrow/flatbuf/fixed_size_binary"
require_relative "org/apache/arrow/flatbuf/floating_point"
require_relative "org/apache/arrow/flatbuf/int"
require_relative "org/apache/arrow/flatbuf/interval"
require_relative "org/apache/arrow/flatbuf/interval_unit"
require_relative "org/apache/arrow/flatbuf/large_binary"
require_relative "org/apache/arrow/flatbuf/large_list"
require_relative "org/apache/arrow/flatbuf/large_utf8"
require_relative "org/apache/arrow/flatbuf/list"
require_relative "org/apache/arrow/flatbuf/map"
require_relative "org/apache/arrow/flatbuf/message"
require_relative "org/apache/arrow/flatbuf/null"
require_relative "org/apache/arrow/flatbuf/precision"
require_relative "org/apache/arrow/flatbuf/record_batch"
require_relative "org/apache/arrow/flatbuf/schema"
require_relative "org/apache/arrow/flatbuf/struct_"
require_relative "org/apache/arrow/flatbuf/time"
require_relative "org/apache/arrow/flatbuf/time_unit"
require_relative "org/apache/arrow/flatbuf/timestamp"
require_relative "org/apache/arrow/flatbuf/union"
require_relative "org/apache/arrow/flatbuf/union_mode"
require_relative "org/apache/arrow/flatbuf/utf8"
module ArrowFormat
module Readable
private
def read_schema(fb_schema)
fields = fb_schema.fields.collect do |fb_field|
read_field(fb_field)
end
Schema.new(fields)
end
def read_field(fb_field)
fb_type = fb_field.type
case fb_type
when Org::Apache::Arrow::Flatbuf::Null
type = NullType.singleton
when Org::Apache::Arrow::Flatbuf::Bool
type = BooleanType.singleton
when Org::Apache::Arrow::Flatbuf::Int
type = read_type_int(fb_type)
when Org::Apache::Arrow::Flatbuf::FloatingPoint
case fb_type.precision
when Org::Apache::Arrow::Flatbuf::Precision::SINGLE
type = Float32Type.singleton
when Org::Apache::Arrow::Flatbuf::Precision::DOUBLE
type = Float64Type.singleton
end
when Org::Apache::Arrow::Flatbuf::Date
case fb_type.unit
when Org::Apache::Arrow::Flatbuf::DateUnit::DAY
type = Date32Type.singleton
when Org::Apache::Arrow::Flatbuf::DateUnit::MILLISECOND
type = Date64Type.singleton
end
when Org::Apache::Arrow::Flatbuf::Time
case fb_type.bit_width
when 32
case fb_type.unit
when Org::Apache::Arrow::Flatbuf::TimeUnit::SECOND
type = Time32Type.new(:second)
when Org::Apache::Arrow::Flatbuf::TimeUnit::MILLISECOND
type = Time32Type.new(:millisecond)
end
when 64
case fb_type.unit
when Org::Apache::Arrow::Flatbuf::TimeUnit::MICROSECOND
type = Time64Type.new(:microsecond)
when Org::Apache::Arrow::Flatbuf::TimeUnit::NANOSECOND
type = Time64Type.new(:nanosecond)
end
end
when Org::Apache::Arrow::Flatbuf::Timestamp
unit = fb_type.unit.name.downcase.to_sym
type = TimestampType.new(unit, fb_type.timezone)
when Org::Apache::Arrow::Flatbuf::Interval
case fb_type.unit
when Org::Apache::Arrow::Flatbuf::IntervalUnit::YEAR_MONTH
type = YearMonthIntervalType.new
when Org::Apache::Arrow::Flatbuf::IntervalUnit::DAY_TIME
type = DayTimeIntervalType.new
when Org::Apache::Arrow::Flatbuf::IntervalUnit::MONTH_DAY_NANO
type = MonthDayNanoIntervalType.new
end
when Org::Apache::Arrow::Flatbuf::Duration
unit = fb_type.unit.name.downcase.to_sym
type = DurationType.new(unit)
when Org::Apache::Arrow::Flatbuf::List
type = ListType.new(read_field(fb_field.children[0]))
when Org::Apache::Arrow::Flatbuf::LargeList
type = LargeListType.new(read_field(fb_field.children[0]))
when Org::Apache::Arrow::Flatbuf::Struct
children = fb_field.children.collect {|child| read_field(child)}
type = StructType.new(children)
when Org::Apache::Arrow::Flatbuf::Union
children = fb_field.children.collect {|child| read_field(child)}
type_ids = fb_type.type_ids
case fb_type.mode
when Org::Apache::Arrow::Flatbuf::UnionMode::DENSE
type = DenseUnionType.new(children, type_ids)
when Org::Apache::Arrow::Flatbuf::UnionMode::SPARSE
type = SparseUnionType.new(children, type_ids)
end
when Org::Apache::Arrow::Flatbuf::Map
type = MapType.new(read_field(fb_field.children[0]))
when Org::Apache::Arrow::Flatbuf::Binary
type = BinaryType.singleton
when Org::Apache::Arrow::Flatbuf::LargeBinary
type = LargeBinaryType.singleton
when Org::Apache::Arrow::Flatbuf::Utf8
type = UTF8Type.singleton
when Org::Apache::Arrow::Flatbuf::LargeUtf8
type = LargeUTF8Type.singleton
when Org::Apache::Arrow::Flatbuf::FixedSizeBinary
type = FixedSizeBinaryType.new(fb_type.byte_width)
when Org::Apache::Arrow::Flatbuf::Decimal
case fb_type.bit_width
when 128
type = Decimal128Type.new(fb_type.precision, fb_type.scale)
when 256
type = Decimal256Type.new(fb_type.precision, fb_type.scale)
end
end
dictionary = fb_field.dictionary
if dictionary
dictionary_id = dictionary.id
index_type = read_type_int(dictionary.index_type)
type = DictionaryType.new(index_type, type, dictionary.ordered?)
else
dictionary_id = nil
end
Field.new(fb_field.name, type, fb_field.nullable?, dictionary_id)
end
def read_type_int(fb_type)
case fb_type.bit_width
when 8
if fb_type.signed?
Int8Type.singleton
else
UInt8Type.singleton
end
when 16
if fb_type.signed?
Int16Type.singleton
else
UInt16Type.singleton
end
when 32
if fb_type.signed?
Int32Type.singleton
else
UInt32Type.singleton
end
when 64
if fb_type.signed?
Int64Type.singleton
else
UInt64Type.singleton
end
end
end
def read_record_batch(fb_record_batch, schema, body)
n_rows = fb_record_batch.length
nodes = fb_record_batch.nodes
buffers = fb_record_batch.buffers
columns = schema.fields.collect do |field|
read_column(field, nodes, buffers, body)
end
RecordBatch.new(schema, n_rows, columns)
end
def read_column(field, nodes, buffers, body)
node = nodes.shift
length = node.length
return field.type.build_array(length) if field.type.is_a?(NullType)
validity_buffer = buffers.shift
if validity_buffer.length.zero?
validity = nil
else
validity = body.slice(validity_buffer.offset, validity_buffer.length)
end
case field.type
when BooleanType,
NumberType,
TemporalType
values_buffer = buffers.shift
values = body.slice(values_buffer.offset, values_buffer.length)
field.type.build_array(length, validity, values)
when VariableSizeBinaryType
offsets_buffer = buffers.shift
values_buffer = buffers.shift
offsets = body.slice(offsets_buffer.offset, offsets_buffer.length)
values = body.slice(values_buffer.offset, values_buffer.length)
field.type.build_array(length, validity, offsets, values)
when FixedSizeBinaryType
values_buffer = buffers.shift
values = body.slice(values_buffer.offset, values_buffer.length)
field.type.build_array(length, validity, values)
when VariableSizeListType
offsets_buffer = buffers.shift
offsets = body.slice(offsets_buffer.offset, offsets_buffer.length)
child = read_column(field.type.child, nodes, buffers, body)
field.type.build_array(length, validity, offsets, child)
when StructType
children = field.type.children.collect do |child|
read_column(child, nodes, buffers, body)
end
field.type.build_array(length, validity, children)
when DenseUnionType
# dense union type doesn't have validity.
types = validity
offsets_buffer = buffers.shift
offsets = body.slice(offsets_buffer.offset, offsets_buffer.length)
children = field.type.children.collect do |child|
read_column(child, nodes, buffers, body)
end
field.type.build_array(length, types, offsets, children)
when SparseUnionType
# sparse union type doesn't have validity.
types = validity
children = field.type.children.collect do |child|
read_column(child, nodes, buffers, body)
end
field.type.build_array(length, types, children)
when DictionaryType
indices_buffer = buffers.shift
indices = body.slice(indices_buffer.offset, indices_buffer.length)
dictionary = find_dictionary(field.dictionary_id)
field.type.build_array(length, validity, indices, dictionary)
end
end
end
end
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