Stream CSV. First working commit

Author: jparcill

app/controllers/distributions_controller.rb

@@ -7,6 +7,7 @@ class DistributionsController < ApplicationController
   include DateRangeHelper
   include DistributionHelper
   include Validatable
+  include ActionController::Live
 
   before_action :enable_turbo!, only: %i[new show]
   skip_before_action :authenticate_user!, only: %i(calendar)
@@ -74,7 +75,11 @@ def index
     respond_to do |format|
       format.html
       format.csv do
-        send_data Exports::ExportDistributionsCSVService.new(distributions: @distributions.includes(line_items: :item), organization: current_organization, filters: scope_filters).generate_csv, filename: "Distributions-#{Time.zone.today}.csv"
+        send_stream filename: "Distributions-#{Time.zone.today}.csv" do |stream| 
+          Exports::ExportDistributionsCSVService.new(distributions: @distributions.includes(line_items: :item), organization: current_organization, filters: scope_filters).generate_csv_stream do |row| 
+            stream.write(row)
+          end
+        end
       end
     end
   end

app/services/exports/export_distributions_csv_service.rb

@@ -39,6 +39,14 @@ def generate_csv_data
       csv_data
     end
 
+    def generate_csv_stream
+      yield CSV.generate_line(base_headers + item_headers)
+
+      distributions.find_each(batch_size: 500) do |distribution|
+        yield CSV.generate_line(build_row_data(distribution))
+      end
+    end
+
     private
 
     attr_reader :distributions