Class: MedPipe::BatchReader

Inherits:
Object
  • Object
show all
Defined in:
lib/med_pipe/batch_reader.rb

Overview

大量データを分割取得するためのクラス in_batches では scope が全クエリに含まれるが、本クラスではidの取得でのみ scope を使用する

Instance Method Summary collapse

Constructor Details

#initialize(model_class, scope: nil, pluck_columns: [:id], batch_size: 1_000, max_id_load_size: 100_000) ⇒ BatchReader

Returns a new instance of BatchReader.



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# File 'lib/med_pipe/batch_reader.rb', line 6

def initialize(model_class, scope: nil, pluck_columns: [:id], batch_size: 1_000,
               max_id_load_size: 100_000)
  @model_class = model_class
  @scope = scope || model_class.all
  @pluck_columns = pluck_columns
  @batch_size = batch_size
  @max_id_load_size = max_id_load_size
  @around_load_callback = nil
  validate_parameters
end

Instance Method Details

#around_load(&block) ⇒ Object

EXAMPLE:

MedPipe::BatchReader.new(User)
  .around_load { |&block| ApplicationRecord.connected_to(role: :reading, &block) }



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# File 'lib/med_pipe/batch_reader.rb', line 20

def around_load(&block)
  @around_load_callback = block
  self
end

#each {|pluck結果を1件ずつ渡す| ... } ⇒ Object

Yield Parameters:

  • pluck結果を1件ずつ渡す (Array) 


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# File 'lib/med_pipe/batch_reader.rb', line 26

def each(&block)
  return enum_for(:each) unless block

  each_ids = MedPipe::BatchIdFetcher.new(@scope, batch_size: @batch_size, max_load_size: @max_id_load_size).each
  loop do
    records = @around_load_callback&.call { batch_load(each_ids) } || batch_load(each_ids)
    records.each(&block)
  rescue StopIteration
    break
  end
end