BUGFIX: Chinese search was broken

BUGFIX: User locale was used index data
BUGFIX: missing Norwegian fulltext config
FEATURE: store the text used to index stuff in fulltext (for diagnostics / in page search)
FEATURE: re-index posts when locale changes (in bg job)
FEATURE: allow reindexing by trucating post_search_data

Note: I removed japanese specific config cause it requires custom pg config,
  happy to add it once our base docker config ships with it

Gemfile

@@ -223,6 +223,8 @@ gem 'gctools', require: false, platform: :mri_21
 gem 'stackprof', require: false, platform: :mri_21
 gem 'memory_profiler', require: false, platform: :mri_21
 
+gem 'rmmseg-cpp', require: false
+
 # This silly path comment just makes it easier for me to do dev
 # will be removed in a few weeks
 gem 'logster'#, path: '../logster'

Gemfile.lock

@@ -283,6 +283,7 @@ GEM
     rest-client (1.6.7)
       mime-types (>= 1.16)
     rinku (1.7.3)
+    rmmseg-cpp (0.2.9)
     rspec (2.14.1)
       rspec-core (~> 2.14.0)
       rspec-expectations (~> 2.14.0)
@@ -462,6 +463,7 @@ DEPENDENCIES
   redis
   rest-client
   rinku
+  rmmseg-cpp
   rspec-given
   rspec-rails
   ruby-readability

app/jobs/scheduled/periodical_updates.rb

@@ -31,6 +31,8 @@ module Jobs
       unless UserAvatar.where("last_gravatar_download_attempt IS NULL").limit(1).first
         Post.rebake_old(250)
       end
+
+      Search.rebuild_problem_posts
     end
 
   end

app/models/search_observer.rb

@@ -8,6 +8,8 @@ class SearchObserver < ActiveRecord::Observer
   end
 
   def self.update_index(table, id, search_data)
+    search_data = Search.prepare_data(search_data)
+
     table_name = "#{table}_search_data"
     foreign_key = "#{table}_id"
 
@@ -16,9 +18,18 @@ class SearchObserver < ActiveRecord::Observer
 
     # Would be nice to use AR here but not sure how to execut Postgres functions
     # when inserting data like this.
-    rows = Post.exec_sql_row_count("UPDATE #{table_name} SET search_data = TO_TSVECTOR('#{stemmer}', ?) WHERE #{foreign_key} = ?", search_data, id)
+    rows = Post.exec_sql_row_count("UPDATE #{table_name}
+                                   SET
+                                      raw_data = :search_data,
+                                      locale = :locale,
+                                      search_data = TO_TSVECTOR('#{stemmer}', :search_data)
+                                   WHERE #{foreign_key} = :id",
+                                    search_data: search_data, id: id, locale: SiteSetting.default_locale)
     if rows == 0
-      Post.exec_sql("INSERT INTO #{table_name} (#{foreign_key}, search_data) VALUES (?, TO_TSVECTOR('#{stemmer}', ?))", id, search_data)
+      Post.exec_sql("INSERT INTO #{table_name}
+                    (#{foreign_key}, search_data, locale, raw_data)
+                    VALUES (:id, TO_TSVECTOR('#{stemmer}', :search_data), :locale, :search_data)",
+                                    search_data: search_data, id: id, locale: SiteSetting.default_locale)
     end
   rescue
     # don't allow concurrency to mess up saving a post
@@ -39,7 +50,7 @@ class SearchObserver < ActiveRecord::Observer
     update_index('category', category_id, name)
   end
 
-  def after_save(obj)
+  def self.index(obj)
     if obj.class == Post && obj.cooked_changed?
       if obj.topic
         category_name = obj.topic.category.name if obj.topic.category
@@ -67,6 +78,10 @@ class SearchObserver < ActiveRecord::Observer
     end
   end
 
+  def after_save(object)
+    SearchObserver.index(object)
+  end
+
 
   class HtmlScrubber < Nokogiri::XML::SAX::Document
     attr_reader :scrubbed

db/migrate/20140624044600_add_raw_data_to_search.rb

@@ -0,0 +1,11 @@
+class AddRawDataToSearch < ActiveRecord::Migration
+  def change
+    add_column :post_search_data, :raw_data, :text
+    add_column :user_search_data, :raw_data, :text
+    add_column :category_search_data, :raw_data, :text
+
+    add_column :post_search_data, :locale, :string
+    add_column :user_search_data, :locale, :text
+    add_column :category_search_data, :locale, :text
+  end
+end

lib/search.rb

@@ -19,25 +19,67 @@ class Search
   end
 
   def self.long_locale
-    case I18n.locale         # Currently-present in /conf/locales/* only, sorry :-( Add as needed
-      when :da then 'danish'
-      when :de then 'german'
-      when :en then 'english'
-      when :es then 'spanish'
-      when :fr then 'french'
-      when :it then 'italian'
-      when :ja then 'japanese'
-      when :nl then 'dutch'
-      when :pt then 'portuguese'
-      when :sv then 'swedish'
-      when :ru then 'russian'
+    # if adding a language see:
+    # /usr/share/postgresql/9.3/tsearch_data for possible options
+    # Do not add languages that are missing without amending the
+    # base docker config
+    #
+    case SiteSetting.default_locale.to_sym
+      when :da     then 'danish'
+      when :de     then 'german'
+      when :en     then 'english'
+      when :es     then 'spanish'
+      when :fr     then 'french'
+      when :it     then 'italian'
+      when :nl     then 'dutch'
+      when :nb_NO  then 'norwegian'
+      when :pt     then 'portuguese'
+      when :pt_BR  then 'portuguese'
+      when :sv     then 'swedish'
+      when :ru     then 'russian'
       else 'simple' # use the 'simple' stemmer for other languages
     end
   end
 
+  def self.rebuild_problem_posts(limit = 10000)
+    posts = Post.joins(:topic)
+            .where('posts.id NOT IN (
+               SELECT post_id from post_search_data
+                WHERE locale = ?
+              )', SiteSetting.default_locale).limit(10000)
+
+    posts.each do |post|
+      post.cooked += " "
+      SearchObserver.index(post)
+    end
+
+    nil
+  end
+
+  def self.prepare_data(search_data)
+    data = search_data.squish
+    # TODO rmmseg is designed for chinese, we need something else for Korean / Japanese
+    if ['zh_TW', 'zh_CN', 'ja', 'ko'].include?(SiteSetting.default_locale)
+      unless defined? RMMSeg
+        require 'rmmseg'
+        RMMSeg::Dictionary.load_dictionaries
+      end
+
+      algo = RMMSeg::Algorithm.new(search_data)
+
+      data = ""
+      while token = algo.next_token
+        data << token.text << " "
+      end
+    end
+
+    data.force_encoding("UTF-8")
+    data
+  end
+
   def initialize(term, opts=nil)
     if term.present?
-      @term = term.to_s
+      @term = Search.prepare_data(term.to_s)
       @original_term = PG::Connection.escape_string(@term)
     end
 

lib/sql_builder.rb

@@ -77,6 +77,10 @@ class SqlBuilder
     16 => :value_to_boolean
   }
 
+  def self.map_exec(klass, sql, args = {})
+    self.new(sql).map_exec(klass, args)
+  end
+
   def map_exec(klass = OpenStruct, args = {})
     results = exec(args)
 

spec/models/search_observer_spec.rb

@@ -0,0 +1,40 @@
+require 'spec_helper'
+
+describe SearchObserver do
+
+  def get_row(post_id)
+    SqlBuilder.map_exec(
+      OpenStruct,
+      "select * from post_search_data where post_id = :post_id",
+      post_id: post_id
+    ).first
+  end
+
+  it 'correctly indexes chinese' do
+    SiteSetting.default_locale = 'zh_CN'
+    data = "你好世界"
+    data.split(" ").length.should == 1
+
+    SearchObserver.update_posts_index(99, "你好世界", "", nil)
+
+    row = get_row(99)
+    row.raw_data.split(' ').length.should == 2
+  end
+
+  it 'correctly indexes a post' do
+    data = "<a>This</a> is a test"
+
+    SearchObserver.update_posts_index(99, data, "", nil)
+
+    row = get_row(99)
+
+    row.raw_data.should == "This is a test"
+    row.locale.should == "en"
+
+    SearchObserver.update_posts_index(99, "tester", "", nil)
+
+    row = get_row(99)
+
+    row.raw_data.should == "tester"
+  end
+end