Changes search index format to fasten `pod search --full` command.

- Previous implementation was having the drawback of traversing and performing `gsub` on all index strings for each pod specification.
- New implementation stores words as keys and list of pods containing corresponding word inside their specification as the values for corresponding hash keys. Therefore, while searching for a query, we only need to check if query is matched with any key in index hash, if so, we will add corresponding list of spec names to a Set object. Resulted Set object gives us the search result. Using this policy, sources manager can perform a faster search operation.

lib/cocoapods/config.rb

@@ -274,7 +274,7 @@ module Pod
     # @return [Pathname] The file to use to cache the search data.
     #
     def search_index_file
-      cache_root + 'search_index.yaml'
+      cache_root + 'search_index.json'
     end
 
     private

lib/cocoapods/sources_manager.rb

@@ -110,25 +110,18 @@ module Pod
       #
       # @raise  If no source including the set can be found.
       #
-      # @note   Full text search requires to load the specification for each
-      #         pod, hence is considerably slower.
-      #
       # @return [Array<Set>]  The sets that contain the search term.
       #
       def search_by_name(query, full_text_search = false)
         if full_text_search
-          set_names = []
+          set_names = Set.new
           query_regexp = /#{query}/i
-          updated_search_index.each do |name, set_data|
-            texts = [name]
-            if full_text_search
-              texts << set_data['authors'].to_s if set_data['authors']
-              texts << set_data['summary']      if set_data['summary']
-              texts << set_data['description']  if set_data['description']
+          updated_search_index.each_value do |word_spec_hash|
+            word_spec_hash.each_pair do |word, spec_names|
+              set_names.merge(spec_names) unless word !~ query_regexp
             end
-            set_names << name unless texts.grep(query_regexp).empty?
           end
-          sets = set_names.sort.map do |name|
+          sets = set_names.map do |name|
             aggregate.representative_set(name)
           end
         else
@@ -142,39 +135,62 @@ module Pod
         sets
       end
 
-      # Creates or updates the search data and returns it. The search data
-      # groups by name the following information for each set:
+      # Returns the search data. If a saved search data exists, retrieves it from file and returns it.
+      # Else, creates the search data from scratch, saves it to file system, and returns it.
+      # Search data is grouped by source repos. For each source, it contains a hash where keys are words
+      # and values are the pod names containing corresponding word.
       #
+      # For each source, list of unique words are generated from the following spec information.
       #   - version
       #   - summary
       #   - description
       #   - authors
       #
-      # @note   This operation is fairly expensive, because of the YAML
-      #         conversion.
-      #
-      # @return [Hash{String => String}] The up to date search data.
+      # @return [Hash{String => Hash{String => Array<String>}}] The up to date search data.
       #
       def updated_search_index
+        index = stored_search_index
+        unless index
+          # Create index from scratch
+          UI.puts 'Creating search index..'
+          index = {}
+          all.each do |source|
+            source_name = source.name
+            index[source_name] = aggregate.generate_search_index_for_source(source)
+          end
+          save_search_index(index)
+          UI.puts 'Search index creation done!'
+        end
+        index
+      end
+
+      # Returns the search data stored in the file system.
+      # If existing data in the file system is not valid, returns nil.
+      #
+      def stored_search_index
         unless @updated_search_index
           if search_index_path.exist?
-            require 'yaml'
-            stored_index = YAML.load(search_index_path.read)
-            if stored_index && stored_index.is_a?(Hash)
-              search_index = aggregate.update_search_index(stored_index)
-            else
-              search_index = aggregate.generate_search_index
+            require 'json'
+            index = JSON.parse(search_index_path.read)
+            if index && index.is_a?(Hash) # TODO: should we also check if hash has correct hierarchy?
+              return @updated_search_index = index
             end
-          else
-            search_index = aggregate.generate_search_index
+          end
+          @updated_search_index = nil
+        end
+        @updated_search_index
       end
 
+      # Stores given search data in the file system.
+      # @param [Hash] index
+      #        Index to be saved in file system
+      #
+      def save_search_index(index)
+        require 'json'
+        @updated_search_index = index
         File.open(search_index_path, 'w') do |file|
-            file.write(search_index.to_yaml)
+          file.write(@updated_search_index.to_json)
         end
-          @updated_search_index = search_index
-        end
-        @updated_search_index
       end
 
       # Allows to clear the search index.
@@ -192,6 +208,35 @@ module Pod
       extend Executable
       executable :git
 
+      # Updates the stored search index if there are changes in spec repos while updating them.
+      # Update is performed incrementally. Only the changed pods' search data is re-generated and updated.
+      # @param  [Hash{Source => Array<String>}] changed_spec_paths
+      #                  A hash containing changed specification paths for each source.
+      def update_search_index_if_needed(changed_spec_paths)
+        search_index = nil
+        changed_spec_paths.each_pair do |source, spec_paths|
+          source_name = source.name
+          next unless spec_paths.length > 0
+          search_index = stored_search_index
+          updated_pods = source.pods_for_specification_paths(spec_paths)
+          new_index = aggregate.generate_search_index_for_changes_in_source(source, spec_paths)
+          next unless search_index && search_index[source_name]
+          # First traverse search_index and update existing words
+          # Removed traversed words from new_index after adding to search_index,
+          # so that only non existing words will remain in new_index after enumeration completes.
+          search_index[source_name].each_pair do |word, _|
+            if new_index[word]
+              search_index[source_name][word] |= new_index[word]
+            else
+              search_index[source_name][word] -= updated_pods
+            end
+          end
+          # Now add non existing words remained in new_index to search_index
+          search_index[source_name].merge!(new_index)
+        end
+        save_search_index(search_index) if search_index
+      end
+
       # Updates the local clone of the spec-repo with the given name or of all
       # the git repos if the name is omitted.
       #
@@ -208,11 +253,14 @@ module Pod
           sources =  git_sources
         end
 
+        changed_spec_paths = {}
         sources.each do |source|
           UI.section "Updating spec repo `#{source.name}`" do
             Dir.chdir(source.repo) do
               begin
+                prev_commit_hash = (git! %w(rev-parse HEAD)).strip
                 output = git! %w(pull --ff-only)
+                changed_spec_paths[source] = (git! %W(diff --name-only #{prev_commit_hash}..HEAD)).strip.split("\n")
                 UI.puts output if show_output && !config.verbose?
               rescue Informative
                 UI.warn 'CocoaPods was not able to update the ' \
@@ -224,6 +272,11 @@ module Pod
             check_version_information(source.repo)
           end
         end
+        # Perform search index update operation as a subprocess.
+        fork do
+          update_search_index_if_needed(changed_spec_paths)
+          exit
+        end
       end
 
       # Returns whether a source is a GIT repo.

spec/spec_helper/pre_flight.rb

@@ -28,7 +28,7 @@ module Bacon
       SpecHelper.temporary_directory.mkpath
 
       # TODO
-      ::Pod::SourcesManager.stubs(:search_index_path).returns(temporary_directory + 'search_index.yaml')
+      ::Pod::SourcesManager.stubs(:search_index_path).returns(temporary_directory + 'search_index.json')
 
       old_run_requirement.bind(self).call(description, spec)
     end

spec/unit/config_spec.rb

@@ -161,7 +161,7 @@ module Pod
       end
 
       it 'returns the search index file' do
-        @config.search_index_file.to_s.should.end_with?('search_index.yaml')
+        @config.search_index_file.to_s.should.end_with?('search_index.json')
       end
     end
 

spec/unit/sources_manager_spec.rb

@@ -86,17 +86,7 @@ module Pod
 
       it "generates the search index before performing a search if it doesn't exits" do
         SourcesManager.stubs(:all).returns([@test_source])
-        Source::Aggregate.any_instance.expects(:generate_search_index).returns('BananaLib' => {})
-        Source::Aggregate.any_instance.expects(:update_search_index).never
-        SourcesManager.updated_search_index = nil
-        SourcesManager.search_by_name('BananaLib', true)
-      end
-
-      it 'updates the search index before performing a search if it exits' do
-        File.open(SourcesManager.search_index_path, 'w') { |file| file.write("---\nBananaLib:\n  version: 0.0.1") }
-        SourcesManager.stubs(:all).returns([@test_source])
-        Source::Aggregate.any_instance.expects(:generate_search_index).never
-        Source::Aggregate.any_instance.expects(:update_search_index).returns('BananaLib' => {})
+        Source::Aggregate.any_instance.expects(:generate_search_index_for_source).with(@test_source).returns('BananaLib' => ['BananaLib'])
         SourcesManager.updated_search_index = nil
         SourcesManager.search_by_name('BananaLib', true)
       end
@@ -105,7 +95,7 @@ module Pod
         SourcesManager.unstub(:search_index_path)
         config.cache_root = Config::DEFAULTS[:cache_root]
         path = SourcesManager.search_index_path.to_s
-        path.should.match %r{Library/Caches/CocoaPods/search_index.yaml}
+        path.should.match %r{Library/Caches/CocoaPods/search_index.json}
       end
 
       describe 'managing sources by URL' do
@@ -241,12 +231,6 @@ module Pod
         UI.output.should.match /is up to date/
       end
 
-      it 'uses the only fast forward git option' do
-        set_up_test_repo_for_update
-        SourcesManager.expects(:git!).with { |options| options.should.include? '--ff-only' }
-        SourcesManager.update(test_repo_path.basename.to_s, true)
-      end
-
       it 'prints a warning if the update failed' do
         UI.warnings = ''
         set_up_test_repo_for_update