Class: AvroUtils

Inherits:
Object
  • Object
show all
Defined in:
lib/utils/avro_utils.rb

Class Method Summary collapse

Class Method Details

.avro_schema(hash_data, record_type_name) ⇒ Object 



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# File 'lib/utils/avro_utils.rb', line 26

def avro_schema(hash_data, record_type_name)
  Avro::Schema.parse(avro_schema_hash(hash_data, record_type_name).to_json)
end

.avro_schema_hash(hash_data, record_type_name) ⇒ Object 



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# File 'lib/utils/avro_utils.rb', line 4

def avro_schema_hash(hash_data, record_type_name)
  process_data do  
    result = { 
      type: 'record',
      name: record_type_name,
      fields: []
    }

    hash_data.each do |key, value|
      if value.is_a? Hash 
        result[:fields] << { name: key, type: avro_schema_hash(value, key.to_s.singularize.camelize) }
      elsif value.is_a? Array
        result[:fields] << { name: key, type: { type: 'array', items: RUBY_AVRO_TYPE_MAPPING[value[0].class.name.to_sym] } }
      else
        result[:fields] << { name: key, type: RUBY_AVRO_TYPE_MAPPING[value.class.name.to_sym] }
      end
    end
    
    result
  end
end

.bulk_json_to_avro(collection, record_type_name, filename = nil) ⇒ Object 



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# File 'lib/utils/avro_utils.rb', line 47

def bulk_json_to_avro(collection, record_type_name, filename = nil)
  process_data do
    buffer = (filename.nil?)? StringIO.new : File.new(filename, 'wb')

    schema = avro_schema(hash_with_string_keys(collection.first), record_type_name)
    file_writer  = Avro::DataFile::Writer.new(buffer, Avro::IO::DatumWriter.new(schema), schema)

    collection.each do |json_data|
      hash_data = hash_with_string_keys(json_data)
      file_writer << hash_data
    end

    file_writer.flush

    buffer.rewind
    buffer.close if buffer.is_a? File
    buffer
  end
end

.hash_with_string_keys(json_data) ⇒ Object

Avro assumes that all the hashes use strings for keys. It does not accept Indifferent Hash. So the conversion bellow ensures that the hash data uses strings for keys.



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# File 'lib/utils/avro_utils.rb', line 69

def hash_with_string_keys(json_data)
  process_data do
    json_data = json_data.to_json if json_data.is_a? Hash
    hash_data = JSON.parse(json_data)
  end
end

.json_to_avro(json_data, record_type_name, filename = nil) ⇒ Object 



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# File 'lib/utils/avro_utils.rb', line 30

def json_to_avro(json_data, record_type_name, filename = nil)
  process_data do  
    buffer = (filename.nil?)? StringIO.new : File.new(filename, 'wb')
    hash_data = hash_with_string_keys(json_data)

    schema = avro_schema(hash_data, record_type_name)

    file_writer  = Avro::DataFile::Writer.new(buffer, Avro::IO::DatumWriter.new(schema), schema)
    file_writer << hash_data
    file_writer.flush

    buffer.rewind
    buffer.close if buffer.is_a? File
    buffer
  end
end