feat: Processor for actions on AR instances.

Prompted by discussion in #1215, this provides a direct interface to
perform index-related operations on an ActiveRecord index.

    processor = ThinkingSphinx::Processor.new(instance)
    processor.delete
    processor.upsert # real-time indices only

lib/thinking_sphinx.rb

@@ -86,6 +86,7 @@ module Subscribers; end
 require 'thinking_sphinx/masks'
 require 'thinking_sphinx/middlewares'
 require 'thinking_sphinx/panes'
+require 'thinking_sphinx/processor'
 require 'thinking_sphinx/query'
 require 'thinking_sphinx/rake_interface'
 require 'thinking_sphinx/scopes'

lib/thinking_sphinx/active_record/callbacks/delete_callbacks.rb

@@ -20,18 +20,8 @@ def after_rollback
   private
 
   def delete_from_sphinx
-    return if ThinkingSphinx::Callbacks.suspended? || instance.new_record?
+    return if ThinkingSphinx::Callbacks.suspended?
 
-    indices.each { |index|
-      ThinkingSphinx::Deletion.perform(
-        index, instance.public_send(index.primary_key)
-      )
-    }
-  end
-
-  def indices
-    ThinkingSphinx::Configuration.instance.index_set_class.new(
-      :instances => [instance], :classes => [instance.class]
-    ).to_a
+    ThinkingSphinx::Processor.new(instance).delete
   end
 end

lib/thinking_sphinx/processor.rb

@@ -0,0 +1,37 @@
+# frozen_string_literal: true
+
+class ThinkingSphinx::Processor
+  def initialize(instance)
+    @instance = instance
+  end
+
+  def delete
+    return if instance.new_record?
+
+    indices.each { |index|
+      ThinkingSphinx::Deletion.perform(
+        index, instance.public_send(index.primary_key)
+      )
+    }
+  end
+
+  def upsert
+    real_time_indices.each do |index|
+      ThinkingSphinx::RealTime::Transcriber.new(index).copy instance
+    end
+  end
+
+  private
+
+  attr_reader :instance
+
+  def indices
+    ThinkingSphinx::Configuration.instance.index_set_class.new(
+      :instances => [instance], :classes => [instance.class]
+    ).to_a
+  end
+
+  def real_time_indices
+    indices.select { |index| index.is_a? ThinkingSphinx::RealTime::Index }
+  end
+end

spec/acceptance/real_time_updates_spec.rb

@@ -27,4 +27,29 @@
     expect(Admin::Person.search('Death').to_a).to be_empty
     expect(Admin::Person.search('Mort').to_a).to eq([person])
   end
+
+  it "can use a direct interface for processing records" do
+    Admin::Person.connection.execute <<~SQL
+      INSERT INTO admin_people (name, created_at, updated_at)
+      VALUES ('Pat', now(), now());
+    SQL
+
+    expect(Admin::Person.search('Pat').to_a).to be_empty
+
+    instance = Admin::Person.find_by(:name => 'Pat')
+    ThinkingSphinx::Processor.new(instance).upsert
+
+    expect(Admin::Person.search('Pat').to_a).to eq([instance])
+
+    Admin::Person.connection.execute <<~SQL
+      UPDATE admin_people SET name = 'Patrick' WHERE name = 'Pat';
+    SQL
+
+    expect(Admin::Person.search('Patrick').to_a).to be_empty
+
+    instance.reload
+    ThinkingSphinx::Processor.new(instance).upsert
+
+    expect(Admin::Person.search('Patrick').to_a).to eq([instance])
+  end
 end