Hi, I''ve made a model cache for rails, to use when you want to cache
model instance methods, rather than controller calls. Does anything
similar exist already? Any comments on the implementation?
Since it serializes cached data, it might be good to add the following
to environment.rb to get YAML-support for the rails class autoloading
mechanism.
-- add to environment.rb
# YAML support for class autoloading
YAML.add_domain_type("ActiveRecord,2007", "") do |type, val|
klass = type.split('':'').last.constantize
YAML.object_maker(klass, val)
end
class ActiveRecord::Base
def to_yaml_type
"!ActiveRecord,2007/#{self.class}"
end
def to_yaml_properties # only store the attributes
[''@attributes'']
end
end
-- model_cache_helper.rb
# ModelCache to use on an ActiveRecord class to cache method calls.
Example:
#
# Class X < ActiveRecord::Base
# def heavy_calculation(a, b)
# "result #{self.x} #{a} #{b}"
# end
#
# include ModelCacheHelper
# cache_method :heavy_calculation
# end
#
# The created method X.heavy_calculation(id, arg1, arg2) will then
check if the
# result is cached, otherwise it will do
X.find(1).heavy_calculation(arg1, arg2)
# and cache the result. Calling heavy_calculation on an instance of X
will also
# cache the result.
#
# The instance method expire_cache, will expire the cache for that
object. It
# can be used with an optional argument, expire_cache(method), to only
expire
# the cache for a certain method.
#
# Non-string result will be serialized with YAML and automatically
deserialized
# when loaded.
module ModelCacheHelper
def self.included(klass)
klass.extend ClassMethods
end
module ClassMethods
def check_cache(url, args)
c = ActionController::Base.new
return yield unless c.perform_caching
url += args.map do |a|
[String,Fixnum,Symbol,TrueClass,FalseClass].member?(a.class) ?
a.to_s : nil
end.join("-")
unless f = c.read_fragment(url)
res = yield
c.write_fragment(url, res.is_a?(String) ? res : res.to_yaml)
res
else
(f[0..3] == "--- ") ? YAML.load(f) : f
end
end
def cache_method(method)
controller = self.class_name.underscore.pluralize
self.class_eval %Q{
def self.#{method}(id, *args)
check_cache("#{controller}/\#{id}-#{method}-", args) do
self.find(id).#{method}_without_cache(*args)
end
end
def #{method}_with_cache(*args)
self.class.check_cache("#{controller}/\#{id}-#{method}-",
args) do
#{method}_without_cache(*args)
end
end
alias_method_chain :#{method}, :cache
}
end
end
def expire_cache(method = false)
c = ActionController::Base.new
return unless c.perform_caching
controller = self.class.class_name.underscore.pluralize
puts "expire #{controller} - id #{self.id}"
unless method
c.expire_fragment %r{#{controller}/#{self.id}-.*}
else
c.expire_fragment %r{#{controller}/#{self.id}-#{method}-.*}
end
end
end
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Tobias Numiranta wrote:>Hi Tobias. Do you have benchmarks for this that show a significant performance improvement over re-calling the DB? I believe that EDGE Rails (and maybe the current version now) have model caching, simply storing DB calls in case the call is made again within the same transaction. I believe however that you are keeping your cache for multiple transactions. -- Posted via http://www.ruby-forum.com/. --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Ruby on Rails: Talk" group. To post to this group, send email to rubyonrails-talk-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org To unsubscribe from this group, send email to rubyonrails-talk-unsubscribe-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org For more options, visit this group at http://groups.google.com/group/rubyonrails-talk?hl=en -~----------~----~----~----~------~----~------~--~---
Hi. Yes, I get nice performance improvements since some of the model methods takes a few seconds with a disabled cache. Seems like a nice feature when you have database-intensive method calls. Yes, EDGE seems to have some model caching, but only for a code-block. Instead, these results are cached until you explicitly call expire_cache, just like the cache in a controller. On May 8, 2:26 pm, Douglas Shearer <rails-mailing-l...-ARtvInVfO7ksV2N9l4h3zg@public.gmane.org> wrote:> Tobias Numiranta wrote: > > Hi Tobias. > > Do you have benchmarks for this that show a significant performance > improvement over re-calling the DB? > > I believe that EDGE Rails (and maybe the current version now) have model > caching, simply storing DB calls in case the call is made again within > the same transaction. I believe however that you are keeping your cache > for multiple transactions. > > -- > Posted viahttp://www.ruby-forum.com/.--~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Ruby on Rails: Talk" group. To post to this group, send email to rubyonrails-talk-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org To unsubscribe from this group, send email to rubyonrails-talk-unsubscribe-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org For more options, visit this group at http://groups.google.com/group/rubyonrails-talk?hl=en -~----------~----~----~----~------~----~------~--~---
Tobias,
A tiny detail but if you add
ActiveRecord::Base.send(:include, ModelCacheHelper)
in environment.rb, you''ll no longer have to explicitely include it,
and you''d just have to write:
cache_method :heavy_calculation
Alain Ravet
----
blog.ravet.com
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