Add ActiveRecordBatchProcessor (no specs)

lib/processor/data/active_record_batch_processor.rb

@@ -0,0 +1,40 @@
+require_relative "null_processor"
+
+module Processor
+  module Data
+    class ActiveRecordBatchProcessor < NullProcessor
+      attr_reader :source
+
+      def initialize(source:, presenter: -> { Hash.new }, output:, batch_size: 1000)
+        @source = source
+        @presenter = presenter
+        @output = output
+        @batch_size = batch_size
+      end
+
+      def records
+        source.find_each(batch_size: batch_size)
+      end
+
+      def process(record)
+        output.write presenter.call(record)
+        "OK"
+      end
+
+      def record_id(record)
+        record.id
+      end
+
+      def finalize
+        output.close
+      end
+
+      def total_records
+        @total_records ||= source.count
+      end
+
+      private
+      attr_reader :presenter, :output, :batch_size
+    end
+  end
+end