Static Record Cache

This plugin has two options for caching records of Static classes which change rarely or never

acts_as_static_record

Permanently caches subclasses of ActiveRecord that contains data that changes rarely.

Includes support for:

• Find by Id, all, first (association lookups)
• Cached caluculations: Neighborhood.counts, sum, max, min
• Convenience lookups: Neighborhood[:seattle]
• Additional support for column name lookups: Neighborhood.find_by_name ‘Seattle’

Install

  sudo gem install static_record_cache --source=http://gemcutter.org

  script/plugin install git://github.com/blythedunham/static_record_cache.git

Usage

  class SomeMostlyStaticClass < ActiveRecord::Base
    acts_as_static_record
  end

Any finds that do not contain additional conditions, joins, and other arguments become a cache call. One advantage over the query cache is that the static cache is searched eliminating the need for ActiveRecord to generate SQL

When a cache key is specified with option :key, additional finder methods for ids and fields such as find_by_id and find_by_name_and_mother are overwritten to search the cache when no arguments (conditions) are specified. If the cache key is not a column, then a finder method will be defined.

  acts_as_static_record :key => :some_instance_method

Will define find_by_some_instance_method(value)

Options

• :key - a method or column of the instance used to specify a cache key. This should be unique.
• :find an additional find scope to specify :conditions,:joins, :select, <tt>:joins</ff> etc
• :find_by_attribute_support - set to true to add additional functionality for finders such as find_by_id_and_name to use a cache search. This option is probably best for Rails 2.3
• :lookup_key - access the record from the class by a key name like User[:snowgiraffe]. :lookup_key is the column on which do do the lookup.

Examples

Caches on Id and telephone carrier name

 class TelephoneCarrier < ActiveRecord::Base
   acts_as_static_method :key => :name
 end

Caches the WhiteList on phone_number_digits (in addition to ID)

 create_table :sms_white_list, :force => true do |t|
   t.column :phone_number_id, :integer, :null => false
   t.column :notes, :string, :length => 100, :default => nil
 end

 class SmsWhiteList < ActiveRecord::Base
   belongs_to :phone_number

   acts_as_static_record :key => :phone_number_digits,
              :find => :select => 'carriers.*, phone_number.number as phone_number_digits'
                       :joins => 'inner join phone_numbers on phone_numbers.carrier_id = carriers.id'

   def phone_number_digits
     self['phone_number_digits']||self.phone_number.number
   end
 end

Direct cache hits

 SmsWhiteList.find_by_phone_number_digits('12065551234')
 SmsWhiteList.find_by_id(5)
 SmsWhiteList.find :all

Searched cache hits

 SmsWhiteList.find_by_notes('Some note')

Calculation Support

Now with calculate support for sum, min, and max for integer columns and count for all columns Cache hits do not occur if options other than distinct are used.

Cache hits:

 Neighborhood.count
 Neighborhood.count :name, :distinct => true
 Neighborhood.sum :id
 Neighborhood.max :id

Not cache hits:

 Neighborhood.max :name
 Neighborhood.count :zip_code, :conditions => ['name = ?', 'Seattle']

Convenience lookup

Similar to acts_as_enumeration model returns the record where the acts_as_static_record :key option matches lookup If no key is specified, the primary_id column is used

  class User < ActiveRecord::Base
    acts_as_static_record :key => :user_name
  end

Then later we can reference the objects by the user_name

  User[:blythe]
  User['snowgiraffe']

The key used will be the underscore version of the name. Punctuation marks are removed. The following are equivalent:

 User[:blythe_snowgiraffeawesome]
 User['blythe-SNOWGIRaffe   AWESome']

 user = User.first
 User[user.user_name] == user

StaticActiveRecordContext

Extends the active_record_context plugin, svn.techno-weenie.net/projects/plugins/active_record_context/ to permanently cache records for an ActiveRecord subclass

Finds on records IDS (as used by associations) will be cached for the life of the class. This works both in and outside a with_context block.

Example

  class TelephoneCarriers < ActiveRecord::Base
    extend StaticActiveRecordContext
  end

  phone_number.carrier

Developers

• Blythe Dunham snowgiraffe.com

Docs

• Rdoc: snowgiraffe.com/rdocs/static_record_cache/

Homepage

• Github Project: github.com/blythedunham/static_record_cache/tree/master
• Install: script/plugin install git://github.com/blythedunham/static_record_cache.git