* Removed memcaching for TagImplication (too many latent race conditions)

* Added Post.exact_tag_match to skip normalization/metatag parsing
* Added DelayedJob support for tag alias/implication processing

app/models/post.rb

@@ -41,6 +41,7 @@ class Post < ActiveRecord::Base
   scope :available_for_moderation, lambda {where(["id NOT IN (SELECT pd.post_id FROM post_disapprovals pd WHERE pd.user_id = ?)", CurrentUser.id])}
   scope :hidden_from_moderation, lambda {where(["id IN (SELECT pd.post_id FROM post_disapprovals pd WHERE pd.user_id = ?)", CurrentUser.id])}
   scope :tag_match, lambda {|query| Post.tag_match_helper(query)}
+  scope :exact_tag_match, lambda {|query| Post.exact_tag_match_helper(query)}
   scope :positive, where("score > 1")
   scope :negative, where("score < -1")
   search_methods :tag_match
@@ -501,6 +502,11 @@ class Post < ActiveRecord::Base
       
       relation
     end
+    
+    def exact_tag_match_helper(q)
+      arel = Post.scoped
+      add_tag_string_search_relation({:related => [q].flatten, :include => [], :exclude => []}, arel)
+    end
 
     def tag_match_helper(q)
       unless q.is_a?(Hash)

app/models/tag_alias.rb

@@ -1,11 +1,7 @@
 class TagAlias < ActiveRecord::Base
-  attr_accessor :creator_ip_addr
-  after_save :update_posts
-  after_save :clear_cache
-  after_save :clear_remote_cache
+  before_save :clear_all_cache
   after_save :update_cache
-  after_destroy :clear_cache
-  after_destroy :clear_remote_cache
+  after_destroy :clear_all_cache
   before_validation :initialize_creator, :on => :create
   validates_presence_of :creator_id
   validates_uniqueness_of :antecedent_name
@@ -25,8 +21,17 @@ class TagAlias < ActiveRecord::Base
     alias_hash.values.flatten.uniq
   end
   
+  def process!
+    update_column(:status, "processing")
+    update_posts
+    update_column(:status, "active")
+  rescue Exception => e
+    update_column(:status, "error: #{e}")
+  end
+  
   def initialize_creator
     self.creator_id = CurrentUser.user.id
+    self.creator_ip_addr = CurrentUser.ip_addr
   end
   
   def antecedent_tag
@@ -44,6 +49,11 @@ class TagAlias < ActiveRecord::Base
       false
     end
   end
+  
+  def clear_all_cache
+    clear_cache
+    clear_remote_cache
+  end
 
   def clear_cache
     Cache.delete("ta:#{Cache.sanitize(antecedent_name)}")
@@ -60,13 +70,15 @@ class TagAlias < ActiveRecord::Base
   end
   
   def update_posts
-    Post.tag_match(antecedent_name).find_each do |post|
+    Post.exact_tag_match(antecedent_name).find_each do |post|
       escaped_antecedent_name = Regexp.escape(antecedent_name)
       fixed_tags = post.tag_string.sub(/(?:\A| )#{escaped_antecedent_name}(?:\Z| )/, " #{consequent_name} ").strip
       
-      post.update_attributes(
-        :tag_string => fixed_tags
-      )
+      CurrentUser.scoped(creator, creator_ip_addr) do
+        post.update_attributes(
+          :tag_string => fixed_tags
+        )
+      end
     end
   end
 end

app/models/tag_implication.rb

@@ -1,43 +1,19 @@
 class TagImplication < ActiveRecord::Base
-  before_save :clear_cache
   before_save :update_descendant_names
   after_save :update_descendant_names_for_parent
-  after_save :update_cache
-  after_save :update_posts
-  after_destroy :clear_cache
-  after_destroy :clear_remote_cache
   belongs_to :creator, :class_name => "User"
   before_validation :initialize_creator, :on => :create
   validates_presence_of :creator_id
   validates_uniqueness_of :antecedent_name, :scope => :consequent_name
   validate :absence_of_circular_relation
-  
-  module CacheMethods
-    def clear_cache
-      Cache.delete("ti:#{Cache.sanitize(antecedent_name)}")
-      @descendants = nil
-    end
-
-    def clear_remote_cache
-      Danbooru.config.other_server_hosts.each do |server|
-        Net::HTTP.delete(URI.parse("http://#{server}/tag_implications/#{id}/cache"))
-      end
-    end
-
-    def update_cache
-      descendant_names_array
-      true
-    end
-  end
 
   module DescendantMethods
     extend ActiveSupport::Concern
     
     module ClassMethods
+      # assumes names are normalized
       def with_descendants(names)
-        names + Cache.get_multi(names.flatten, "ti") do |name|
-          ([name] + where(["antecedent_name = ?", name]).all.map {|x| x.descendant_names_array}).flatten
-        end.values.flatten.uniq
+        (names + where("antecedent_name in (?)", names).map(&:descendant_names_array)).flatten.uniq
       end
     end
     
@@ -55,9 +31,7 @@ class TagImplication < ActiveRecord::Base
     end
 
     def descendant_names_array
-      Cache.get("ti:#{Cache.sanitize(antecedent_name)}") do
-        descendant_names.split(/ /)
-      end
+      descendant_names.split(/ /)
     end
 
     def update_descendant_names
@@ -93,12 +67,20 @@ class TagImplication < ActiveRecord::Base
     end
   end
   
-  include CacheMethods
   include DescendantMethods
   include ParentMethods
   
   def initialize_creator
     self.creator_id = CurrentUser.user.id
+    self.creator_ip_addr = CurrentUser.ip_addr
+  end
+  
+  def process!
+    update_column(:status, "processing")
+    update_posts
+    update_column(:status, "active")
+  rescue Exception => e
+    update_column(:status, "error: #{e}")
   end
   
   def absence_of_circular_relation
@@ -110,12 +92,14 @@ class TagImplication < ActiveRecord::Base
   end
   
   def update_posts
-    Post.tag_match(antecedent_name).find_each do |post|
+    Post.exact_tag_match(antecedent_name).find_each do |post|
       escaped_antecedent_name = Regexp.escape(antecedent_name)
       fixed_tags = post.tag_string.sub(/(?:\A| )#{escaped_antecedent_name}(?:\Z| )/, " #{antecedent_name} #{descendant_names} ").strip
-      post.update_attributes(
-        :tag_string => fixed_tags
-      )
+      CurrentUser.scoped(creator, creator_ip_addr) do
+        post.update_attributes(
+          :tag_string => fixed_tags
+        )
+      end
     end
   end