lib/tobox.rb in tobox-0.5.2 vs lib/tobox.rb in tobox-0.6.0

@@ -32,9 +32,35 @@
     def self.register_plugin(name, mod)
       h = @plugins
       h.synchronize { h[name] = mod }
     end
   end
+
+  # when using batch sizes higher than 1, this method can be used to signal multiple errors
+  # for a subset of the events which may have failed processing; these events are identified
+  # by the index inside the batch.
+  #
+  #     on(:event_type) do |*events|
+  #       successful, failed = handle_event_batch(events)
+  #
+  #       deal_with_success(successful)
+  #
+  #       batch_errors = failed.to_h do |failed_event|
+  #         [
+  #            events.index(failed_event),
+  #            MyException.new("failed handling process batch")
+  #         ]
+  #       end
+  #
+  #       Tobox.raise_batch_error(batch_errors)
+  #     end
+  def self.raise_batch_errors(batch_errors)
+    unless batch_errors.respond_to?(:to_hash) && batch_errors.all? { |k, v| k.is_a?(Integer) && v.is_a?(Exception) }
+      raise "batch errors must be an array of index-to-exception tuples"
+    end
+
+    throw(:tobox_batch_errors, batch_errors.to_h)
+  end
 end
 
 require_relative "tobox/fetcher"
 require_relative "tobox/worker"
 require_relative "tobox/pool"