基于redis的SearchSuggestion

SearchSuggestion.rb

class SearchSuggestion 
   def self.terms_for(prefix)
     return if prefix.blank?
     puts "prefix:#{prefix}"
     
     prefix_array = prefix.split
     puts prefix_array
     unless prefix_array.empty?
       $redis.zinterstore "$tmp",prefix_array
       terms = $redis.zrevrange "$tmp", 0, 4   
       puts terms 
       product_ids = []
      
       terms.each do |term|
         product_id = term.split("|").last
         product_ids << product_id if product_id.to_i > 0
       end
      
       @productrs = Product.
             where(:id=>product_ids).
             includes(:product_category,:merchant).
             select("name value,price,image_url")
     end
   end 
   
   def self.index_products
     begin_at = Time.now
       
     puts "#{begin_at.strftime('%Y-%m-%d %H:%M:%S')}\tbegin"
     $redis.flushdb  #flushall
     Product.find_each do |product|
       print '.'
       product.name.split.each { |term| index_term(term,product.id,product.name) }
     end
     
     end_at = Time.now
     puts "\n#{end_at.strftime('%Y-%m-%d %H:%M:%S')}\tend,cost:#{end_at - begin_at}s"
   end

   def self.index_term(term,product_id,product_name)
     product_name = product_name.gsub(/\s+/," ").gsub(" ","/")
     1.upto(term.length) do |n|
       prefix = term[0, n]
       $redis.zincrby "#{prefix.downcase}", 1, "#{product_name.downcase}|#{product_id}"
     end
   end
end