* VRFS-3435 allow multiple onboarders to execute

ruby/lib/jam_ruby/jam_track_importer.rb

@@ -355,14 +355,54 @@ module JamRuby
       found[0] # 3 letter code
     end
 
+    #http://stackoverflow.com/questions/22740252/how-to-generate-javas-string-hashcode-using-ruby
+    def jhash(str)
+      result = 0
+      mul = 1
+      max_mod = 2**31 - 1
+
+      str.chars.reverse_each do |c|
+        result += mul * c.ord
+        result %= max_mod
+        mul *= 31
+      end
+
+      result
+    end
+
+    def prevent_concurrent_processing(metalocation)
+
+      # use a PG advisory lock to see if someone else is doing this same unit of work right now
+      track_code = jhash(metalocation)
+      locked = ActiveRecord::Base.connection.execute("SELECT pg_try_advisory_xact_lock(#{track_code})").values[0][0]
+      if locked == 'f'
+        finish("other_processing", "")
+        raise ActiveRecord::Rollback
+      end
+    end
+
     def synchronize_metadata(jam_track, metadata, metalocation, original_artist, name, options)
 
       metadata ||= {}
       self.name = metadata["name"] || name
 
+      prevent_concurrent_processing(metalocation)
+
       if jam_track.new_record?
         latest_jamtrack = JamTrack.order('created_at desc').first
+
         id = latest_jamtrack.nil? ? 1 : latest_jamtrack.id.to_i + 1
+        if ENV['NODE_NUMBER']
+          # complicated goofy code to support parallel processing of importers
+
+          node_number = ENV['NODE_NUMBER'].to_i
+          node_count = ENV['NODE_COUNT'].to_i
+          raise "NO NODE_COUNT" if node_count == 0
+          r = id % node_count
+          id = r + id # get to the same base number if both are working at the same time
+          id = id + node_number # offset by your node number
+          @@log.debug("JAM TRACK ID: #{id}")
+        end
         jam_track.id = "#{id}" # default is UUID, but the initial import was based on auto-increment ID, so we'll maintain that
         jam_track.status = 'Staging'
         jam_track.metalocation = metalocation
@@ -399,6 +439,7 @@ module JamRuby
 
       end
 
+      @@log.debug("about to save")
       saved = jam_track.save
 
       if !saved
@@ -1566,7 +1607,7 @@ module JamRuby
         @@log.info("-------")
         importers.each do |importer|
           if importer
-            if importer.reason == "success" || importer.reason == "jam_track_exists"
+            if importer.reason == "success" || importer.reason == "jam_track_exists" || importer.reason == "other_processing"
               @@log.info("#{importer.name} #{importer.reason}")
             else
               @@log.error("#{importer.name} failed to import.")
@@ -1613,7 +1654,7 @@ module JamRuby
         @@log.info("-------")
         importers.each do |importer|
           if importer
-            if importer.reason == "success" || importer.reason == "jam_track_exists"
+            if importer.reason == "success" || importer.reason == "jam_track_exists" || importer.reason == "other_processing"
               @@log.info("#{importer.name} #{importer.reason}")
             else
               @@log.error("#{importer.name} failed to import.")
@@ -1686,7 +1727,7 @@ module JamRuby
           importer = synchronize_from_meta(metalocation, options)
           importers << importer
 
-          if importer.reason != 'jam_track_exists'
+          if importer.reason != 'jam_track_exists' && importer.reason != "other_processing"
             count+=1
           end
 
@@ -1700,7 +1741,7 @@ module JamRuby
         @@log.info("-------")
         importers.each do |importer|
           if importer
-            if importer.reason == "success" || importer.reason == "jam_track_exists"
+            if importer.reason == "success" || importer.reason == "jam_track_exists" || importer.reason == "other_processing"
               @@log.info("#{importer.name} #{importer.reason}")
             else
               @@log.error("#{importer.name} failed to import.")
@@ -1851,7 +1892,10 @@ module JamRuby
       def sync_from_metadata(jam_track, meta, metalocation, options)
         jam_track_importer = JamTrackImporter.new(@storage_format)
 
+        JamTrack.connection.execute('SET SESSION TRANSACTION ISOLATION LEVEL READ UNCOMMITTED')
+
         JamTrack.transaction do
+
           #begin
           jam_track_importer.synchronize(jam_track, meta, metalocation, options)
           #rescue Exception => e

ruby/lib/jam_ruby/models/generic_state.rb

@@ -31,6 +31,5 @@ module JamRuby
       GenericState.find('default')
     end
 
-
   end
 end