poc(batch_operation): track dossier processed safely

app/jobs/batch_operation_process_one_job.rb

@@ -5,21 +5,11 @@ class BatchOperationProcessOneJob < ApplicationJob
     success = true
     begin
       batch_operation.process_one(dossier)
-      dossier.update(batch_operation: nil)
     rescue => error
       success = false
       raise error
     ensure
-      batch_operation.reload # reload before deciding if it has been finished
+      batch_operation.track_dossier_processed(success, dossier)
-      batch_operation.run_at = Time.zone.now if batch_operation.called_for_first_time?
-      batch_operation.finished_at = Time.zone.now if batch_operation.called_for_last_time?
-      if success # beware to this one, will be refactored for stronger atomicity
-        batch_operation.success_dossier_ids.push(dossier.id)
-        batch_operation.failed_dossier_ids = batch_operation.failed_dossier_ids.reject { |d| d.dossier.id }
-      else
-        batch_operation.failed_dossier_ids.push(dossier.id)
-      end
-      batch_operation.save!
     end
   end
 end

app/models/batch_operation.rb

@@ -31,6 +31,29 @@ class BatchOperation < ApplicationRecord
       .map { |dossier| BatchOperationProcessOneJob.perform_later(self, dossier) }
   end
 
+  def track_dossier_processed(success, dossier)
+    transaction do
+      dossier.update(batch_operation: nil)
+      reload
+      manager = Arel::UpdateManager.new.table(arel_table).where(arel_table[:id].eq(id))
+      values = []
+      values.push([arel_table[:run_at], Time.zone.now]) if called_for_first_time?
+      values.push([arel_table[:finished_at], Time.zone.now]) if called_for_last_time?
+      if success
+        values.push([arel_table[:success_dossier_ids],Arel::Nodes::NamedFunction.new('array_append', [arel_table[:success_dossier_ids], dossier.id])])
+        values.push([arel_table[:failed_dossier_ids], Arel::Nodes::NamedFunction.new('array_remove', [arel_table[:failed_dossier_ids], dossier.id])])
+      else
+        values.push([arel_table[:failed_dossier_ids], Arel::Nodes::NamedFunction.new('array_append', [arel_table[:failed_dossier_ids], dossier.id])])
+      end
+      manager.set(values)
+      ActiveRecord::Base.connection.update(manager.to_sql)
+    end
+  end
+
+  def arel_table
+    BatchOperation.arel_table
+  end
+
   def process_one(dossier)
     case operation
     when BatchOperation.operations.fetch(:archiver)

spec/jobs/batch_operation_process_one_job_spec.rb

@@ -25,7 +25,7 @@ describe BatchOperationProcessOneJob, type: :job do
     context 'when it succeed' do
       it 'pushes dossier_job id to batch_operation.success_dossier_ids' do
         expect { subject.perform_now }
-          .to change { batch_operation.success_dossier_ids }
+          .to change { batch_operation.reload.success_dossier_ids }
           .from([])
           .to([dossier_job.id])
       end
@@ -44,7 +44,7 @@ describe BatchOperationProcessOneJob, type: :job do
         run_at = 2.minutes.ago
         Timecop.freeze(run_at) do
           expect { subject.perform_now }
-            .to change { batch_operation.run_at }
+            .to change { batch_operation.reload.run_at }
             .from(nil)
             .to(run_at)
         end