ceph/src/arrow/ruby/red-arrow/example/read-file.rb

   1 #!/usr/bin/env ruby
   2 #
   3 # Licensed to the Apache Software Foundation (ASF) under one
   4 # or more contributor license agreements.  See the NOTICE file
   5 # distributed with this work for additional information
   6 # regarding copyright ownership.  The ASF licenses this file
   7 # to you under the Apache License, Version 2.0 (the
   8 # "License"); you may not use this file except in compliance
   9 # with the License.  You may obtain a copy of the License at
  10 #
  11 #   http://www.apache.org/licenses/LICENSE-2.0
  12 #
  13 # Unless required by applicable law or agreed to in writing,
  14 # software distributed under the License is distributed on an
  15 # "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
  16 # KIND, either express or implied.  See the License for the
  17 # specific language governing permissions and limitations
  18 # under the License.
  19
  20 require "arrow"
  21
  22 Arrow::MemoryMappedInputStream.open("/tmp/file.arrow") do |input|
  23   reader = Arrow::RecordBatchFileReader.new(input)
  24   fields = reader.schema.fields
  25   reader.each_with_index do |record_batch, i|
  26     puts("=" * 40)
  27     puts("record-batch[#{i}]:")
  28     fields.each do |field|
  29       field_name = field.name
  30       values = record_batch.collect do |record|
  31         record[field_name]
  32       end
  33       puts("  #{field_name}: #{values.inspect}")
  34     end
  35   end
  36 end