lib/multi_index.rb

   1 module ActsAsFerret #:nodoc:
   2
   3       # this class is not threadsafe
   4       class MultiIndex
   5
   6         def initialize(model_classes, options = {})
   7           @model_classes = model_classes
   8           # ensure all models indexes exist
   9           @model_classes.each { |m| m.aaf_index.ensure_index_exists }
  10           default_fields = @model_classes.inject([]) do |fields, c|
  11             fields + c.aaf_configuration[:ferret][:default_field]
  12           end
  13           @options = {
  14             :default_field => default_fields
  15           }.update(options)
  16         end
  17
  18         def search(query, options={})
  19           #puts "querystring: #{query.to_s}"
  20           query = process_query(query)
  21           #puts "parsed query: #{query.to_s}"
  22           searcher.search(query, options)
  23         end
  24
  25         def search_each(query, options = {}, &block)
  26           query = process_query(query)
  27           searcher.search_each(query, options, &block)
  28         end
  29
  30         # checks if all our sub-searchers still are up to date
  31         def latest?
  32           return false unless @reader
  33           # segfaults with 0.10.4 --> TODO report as bug @reader.latest?
  34           @sub_readers.each do |r|
  35             return false unless r.latest?
  36           end
  37           true
  38         end
  39
  40         def searcher
  41           ensure_searcher
  42           @searcher
  43         end
  44
  45         def doc(i)
  46           searcher[i]
  47         end
  48         alias :[] :doc
  49
  50         def query_parser
  51           @query_parser ||= Ferret::QueryParser.new(@options)
  52         end
  53
  54         def process_query(query)
  55           query = query_parser.parse(query) if query.is_a?(String)
  56           return query
  57         end
  58
  59         def close
  60           @searcher.close if @searcher
  61           @reader.close if @reader
  62         end
  63
  64         protected
  65
  66           def ensure_searcher
  67             unless latest?
  68               @sub_readers = @model_classes.map { |clazz|
  69                 begin
  70                   reader = Ferret::Index::IndexReader.new(clazz.aaf_configuration[:index_dir])
  71                 rescue Exception
  72                   raise "error opening #{clazz.aaf_configuration[:index_dir]}: #{$!}"
  73                 end
  74               }
  75               close
  76               @reader = Ferret::Index::IndexReader.new(@sub_readers)
  77               @searcher = Ferret::Search::Searcher.new(@reader)
  78             end
  79           end
  80
  81       end # of class MultiIndex
  82
  83 end