Sketch out how to use the jobs queue for trace insertion and deletion

Refs openstreetmap#1852

app/controllers/traces_controller.rb

@@ -127,6 +127,7 @@ def create
         flash[:notice] = t ".trace_uploaded"
         flash[:warning] = t ".traces_waiting", :count => current_user.traces.where(:inserted => false).count if current_user.traces.where(:inserted => false).count > 4
 
+        TraceImporterJob.perform_later(@trace)
         redirect_to :action => :index, :display_name => current_user.display_name
       else
         flash[:error] = t("traces.create.upload_failed") if @trace.valid?
@@ -210,6 +211,7 @@ def delete
       trace.visible = false
       trace.save
       flash[:notice] = t ".scheduled_for_deletion"
+      TraceDestroyerJob.perform_later(trace)
       redirect_to :action => :index, :display_name => trace.user.display_name
     end
   rescue ActiveRecord::RecordNotFound

app/jobs/application_job.rb

@@ -0,0 +1,7 @@
+class ApplicationJob < ActiveJob::Base
+  # Automatically retry jobs that encountered a deadlock
+  # retry_on ActiveRecord::Deadlocked
+
+  # Most jobs are safe to ignore if the underlying records are no longer available
+  # discard_on ActiveJob::DeserializationError
+end

app/jobs/trace_destroyer_job.rb

@@ -0,0 +1,10 @@
+class TraceDestroyerJob < ApplicationJob
+  queue_as :default
+
+  def perform(trace)
+    trace.destroy
+  rescue StandardError => ex
+    logger.info ex.to_s
+    ex.backtrace.each { |l| logger.info l }
+  end
+end

app/jobs/trace_importer_job.rb

@@ -0,0 +1,19 @@
+class TraceImporterJob < ApplicationJob
+  queue_as :default
+
+  def perform(trace)
+    gpx = trace.import
+
+    if gpx.actual_points.positive?
+      Notifier.gpx_success(trace, gpx.actual_points).deliver_later
+    else
+      Notifier.gpx_failure(trace, "0 points parsed ok. Do they all have lat,lng,alt,timestamp?").deliver_later
+      trace.destroy
+    end
+  rescue StandardError => ex
+    logger.info ex.to_s
+    ex.backtrace.each { |l| logger.info l }
+    Notifier.gpx_failure(trace, ex.to_s + "\n" + ex.backtrace.join("\n")).deliver_later
+    trace.destroy
+  end
+end

test/jobs/trace_destroyer_job_test.rb

@@ -0,0 +1,7 @@
+require 'test_helper'
+
+class TraceDestroyerJobTest < ActiveJob::TestCase
+  # test "the truth" do
+  #   assert true
+  # end
+end

test/jobs/trace_importer_job_test.rb

@@ -0,0 +1,7 @@
+require 'test_helper'
+
+class TraceImporterJobTest < ActiveJob::TestCase
+  # test "the truth" do
+  #   assert true
+  # end
+end