dmitryame

#jruby hacks

jps -ml #show java processes running

jstack <pid>  #get a jvm stack info

jruby -J-Djruby.reify.classes=true   # a flag that tell jruby to compile ruby classes to real (matching) java classes

jvisualvm #great profiling tool

dmitryame

If you set has_and_belongs_to_many on one side only, then you need to 
set :inverse_of to nil. For example: 
class A 
  include Mongoid::Document 
  has_and_belongs_to_many :bs, :inverse_of => nil 
end 
class B 
  include Mongoid::Document 
end 
That should work with no trouble. Since you do not have the 

dmitryame

class String
  def character_occurance
    result = {}
    each_char do |character|
      result[character] = 0 if result[character] == nil
      result[character] += 1
    end
    result    
  end
end

dmitryame

class Object
  def html_safe?
    true
  end
end



class String
  def html_safe?

dmitryame

What is the best way to model user/follower (twitter style) relationships with mongo? Most prominent solution is to embed an array of followers ids in every user object. I'm an idealist, and believe that if we are modeling twitter, we eventually will run into a situation when a user has millions of followers which will blow. The relational many_to_many is not easy to model with mongo, mongo_id tries to offer some implementation of basic associations, but the many_no_many, or has_many through is not there yet and I doubt it ever will be. 
My solution is a compromise between relational normalization and "embed everything in one document".


class User
  include Mongoid::Document
  include Mongoid::Timestamps

  # user will have many followerships, each will embedd a follower user, 
  # the user_id is stored on the followership object

dmitryame

rvm install 1.9.2
rvm use 1.9.2
gem list
gem install rails
gem list


rails new blog

cd blog

dmitryame

class ActiveResource::Connection
#   Creates new Net::HTTP instance for communication with
#   remote service and resources.
   def http
     http = Net::HTTP.new(@site.host, @site.port)
     http.use_ssl = @site.is_a?(URI::HTTPS)
     http.verify_mode = OpenSSL::SSL::VERIFY_NONE if http.use_ssl
     http.read_timeout = @timeout if @timeout
     #Here's the addition that allows you to see the output
     http.set_debug_output $stderr

dmitryame

// sample data
{ "_id" : ObjectId("4caf19200d282159bf000001"), "date" : "2010-10-06", "seq" : "00:00:00,000", "method" : "getUserByScbeId", "duration" : 3 }
{ "_id" : ObjectId("4caf19200d282159bf000002"), "date" : "2010-10-06", "seq" : "00:00:00,116", "method" : "createTicket", "duration" : 116 }
{ "_id" : ObjectId("4caf19200d282159bf000003"), "date" : "2010-10-06", "seq" : "00:00:00,131", "method" : "getCollectionMetadata", "duration" : 11 }
{ "_id" : ObjectId("4caf19200d282159bf000004"), "date" : "2010-10-06", "seq" : "00:00:00,137", "method" : "getParticipation", "duration" : 6 }
{ "_id" : ObjectId("4caf19200d282159bf000005"), "date" : "2010-10-06", "seq" : "00:00:00,139", "method" : "updateSocialObjectModified", "duration" : 371 }
{ "_id" : ObjectId("4caf19200d282159bf000006"), "date" : "2010-10-06", "seq" : "00:00:00,143", "method" : "getUserByScbeId", "duration" : 4 }