Added cache_contents block around get_contents to cache requests when a cache path is set.

lib/models/music_brainz.rb

@@ -1,6 +1,7 @@
 module MusicBrainz
   @@last_query_time = 0
   @@query_interval = 1.5 # Min: 1.0 Safe: 1.5
+  @@cache_path = nil
   
   WEB_SERVICE_URL = 'http://musicbrainz.org/ws/2/'
   USER_AGENT = "gem musicbrainz (https://github.com/magnolia-fan/musicbrainz) @ " + Socket.gethostname
@@ -9,34 +10,71 @@ module MusicBrainz
     @@query_interval = sec.to_f
   end
   
+  def self.cache_path= path
+    @@cache_path = path
+  end
+  
   def self.load resourse, params = {}
     url = WEB_SERVICE_URL + resourse.to_s.gsub('_', '-') + '/' + (params[:id].to_s || '')
     params.delete(:id) unless params[:id].nil?
     url << '?' + params.map{ |k, v|
       k.to_s.gsub('_', '-') + '=' + (v.is_a?(Array) ? v.map{ |_| _.to_s.gsub('_', '-') }.join('+') : v.to_s)
     }.join('&') unless params.empty?
-    self.get_contents url
+    self.cache_contents(url) do 
+      self.get_contents url
+    end
+  end
+  
+  def self.clear_cache
+    FileUtils.rm_r(@@cache_path) if @@cache_path && File.exist?(@@cache_path)
   end
   
 private
 
+  def self.cache_contents url
+    response = nil
+    url_parts = url.split('/')
+    file_name = url_parts.pop
+    directory = url_parts.pop
+    file_path = @@cache_path ? "#{@@cache_path}/#{directory}/#{file_name}" : nil
+        
+    if file_path && File.exist?(file_path)
+      response = File.open(file_path).gets
+    else
+      response = yield
+        
+      unless response.nil? || file_path.nil?
+        FileUtils.mkdir_p file_path.split('/')[0..-2].join('/')
+        file = File.new(file_path, 'w')
+        file.puts(response.gets.force_encoding('UTF-8'))
+        file.chmod(0755)
+        file.close
+        response.rewind
+      end
+    end
+    
+    response
+  end
+
   def self.get_contents url
+    self.get_contents_intern
+    
     response = nil
     
     5.times do
       time_passed = Time.now.to_f - @@last_query_time
       sleep @@query_interval - time_passed if time_passed < @@query_interval
-    
+      
       begin
         response = open(url, "User-Agent" => USER_AGENT)
         @@last_query_time = Time.now.to_f
       rescue => e
-        return nil if e.io.status[0].to_i == 404
+        response = nil if e.io.status[0].to_i == 404
       end
       
-      break unless response.nil?
+      break unless response.nil? 
     end
     
     response
   end
-end
+end