Patch Ancestry::InstanceMethods#cast_primary_key

Prevents a new version of the STRING_BASED_KEYS array from being
instantiated every time that cast_primary_key is called.

* * *

Before/After
------------

Total allocated: 324542397 bytes (3095350 objects)   |   Total allocated: 318431331 bytes (2943673 objects)
                                                     |
allocated objects by gem                             |   allocated objects by gem
-----------------------------------                  |   -----------------------------------
   1576834  activerecord-5.0.7                       |      1576834  activerecord-5.0.7
    477120  manageiq/app                             |       477120  manageiq/app
    418737  ancestry-2.2.2  <<<<<<<<<<               |       274449  activemodel-5.0.7
    274449  activemodel-5.0.7                        |       267060  ancestry-2.2.2  <<<<<<<<<<
    106559  activesupport-5.0.7                      |       106559  activesupport-5.0.7
     82799  pending                                  |        82799  pending
     74117  ruby-2.3.3/lib                           |        74117  ruby-2.3.3/lib
     ...                                             |        ...

app/models/orchestration_stack.rb

@@ -1,4 +1,6 @@
 require 'ancestry'
+require 'ancestry_patch'
+
 class OrchestrationStack < ApplicationRecord
   require_nested :Status
 

app/models/relationship.rb

@@ -1,4 +1,5 @@
 require 'ancestry'
+require 'ancestry_patch'
 
 class Relationship < ApplicationRecord
   has_ancestry

app/models/service.rb

@@ -1,4 +1,5 @@
 require 'ancestry'
+require 'ancestry_patch'
 
 class Service < ApplicationRecord
   DEFAULT_PROCESS_DELAY_BETWEEN_GROUPS = 120

app/models/tenant.rb

@@ -1,4 +1,5 @@
 require 'ancestry'
+require 'ancestry_patch'
 
 class Tenant < ApplicationRecord
   HARDCODED_LOGO = "custom_logo.png"

lib/patches/ancestry_patch.rb

@@ -0,0 +1,14 @@
+module Ancestry
+  module InstanceMethods
+
+    STRING_BASED_KEYS = [:string, :uuid, :text].freeze
+    def cast_primary_key(key)
+      if STRING_BASED_KEYS.include? primary_key_type
+        key
+      else
+        key.to_i
+      end
+    end
+
+  end
+end