data_bastard.rb

#!/usr/bin/ruby
# A really rough multiple-grouping hash datastore proof-of-concept

module DBastard
end

# internal format: @objects = { :some_identifier => "some blob", :other_identifier => "other blob" }
class DBastard::ObjectStore
  # This is where everything gets stored
  def objects
    @objects ||= Hash.new
  end

  # Returns a value
  def [] identifier
    objects.fetch self.class.identifierize(identifier), nil
  end

  def pull *list_or_array_of_identifiers
    list_or_array_of_identifiers = list_or_array_of_identifiers.first if list_or_array_of_identifiers.length == 1
    objects.values_at *self.class.identifier_collect(list_or_array_of_identifiers)
  end

  # Sets a value
  def update identifier, blob = ''
    identifier, blob = self.class.identifierize(identifier), blob.to_s
    objects.store identifier, blob
    return identifier
  end

  def []= identifier, blob
    self.update identifier, blob
  end

  def new identifier, blob
    self.update identifier, blob
  end

  # Invalidates identifiers
  def invalidate identifier
    object.delete identifier
  end

  class << self
    def identifierize object
      object.to_s.to_sym
    end
    
    def bloberize object
      object.to_s
    end

    def identifier_collect object_identifier_or_array
      case object_identifier_or_array
      when Array
        object_identifier_or_array.map{|element| identifierize(element)}
      when nil
        []
      else
        [identifierize(object_identifier_or_array)]
      end
    end
  end
end

# internal format: @groups = { :some_group_identifier => [:array, :of, :object, :keys], :other_group_identifier => [:other, :array, :of, :object, :keys] }
class DBastard::ObjectGroupStore

  # Where groups are stored
  def groups
    @groups ||= Hash.new
  end

  def object_store
    @object_store ||= DBastard::ObjectStore.new
  end

  # Gets the array of object identifiers in the nammed group 
  def get group_identifier
    groups.fetch self.class.identifierize(group_identifier), nil
  end

  def [] group_identifier
    self.get group_identifier
  end

  # Adds a new group to the store
  def new group_identifier, object_identifier_or_array = []
    groups.store self.class.identifierize(group_identifier), self.class.identifier_collect(object_identifier_or_array)
  end

  # Adds an object identifier to a group
  # You should also be able to add individual identifiers the manual way by doing my_group[:my_group_identifier] << :new_object_identifier
  def add_to_group group_identifier, object_identifier_or_array
    group  = self.get group_identifier
    group += identifier_collect(object_identifier_or_array)
    return group
  end

  class << self
    def identifierize object
      object.to_s.to_sym
    end

    def identifier_collect object_identifier_or_array
      case object_identifier_or_array
      when Array
        object_identifier_or_array.map{|element| DBastard::ObjectStore.identifierize(element)}
      when nil
        []
      else
        [DBastard::ObjectStore.identifierize(object_identifier_or_array)]
      end
    end
  end
end

objects = DBastard::ObjectStore.new
groups  = DBastard::ObjectGroupStore.new

objects.new :session_1234, {:id => 1, :bar => 134837}
objects.new :session_2345, {:id => 2, :bar => 184677}
objects.new :session_3456, {:id => 3, :bar => 1387}
objects.new :session_4567, {:id => 4, :bar => 1979887}
objects.new :session_5678, {:id => 5, :bar => 185677}
objects.new :session_6789, {:id => 6, :bar => 121487}
objects.new :session_7890, {:id => 7, :bar => 18327}

groups.new :admins, [:session_1234, :session_7890]
groups.new :business, [:session_1234, :session_2345, :session_3456]
groups.new :sales, [:session_5678, :session_6789]
groups.new :contractors, :session_3456
groups.new :organization, [:session_1234, :session_2345, :session_4567,:session_5678, :session_6789, :session_7890]

puts "objects[:session_6789]"
puts objects[:session_6789]
puts "groups[:organization]"
puts objects.pull groups[:organization]
puts "groups[:business]"
puts objects.pull groups[:business]