Module: ActiveRecordCacheExtension

Extended by:
ActiveSupport::Concern
Defined in:
app/models/active_record_cache_extension.rb

Overview

To understand our caching conventions, have a look at our wiki page: github.com/fiedl/wingolfsplattform/wiki/Caching

Defined Under Namespace

Modules: ClassMethods

Instance Method Summary collapse

Instance Method Details

#bulk_delete_cached(method_name, objects) ⇒ Object 



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# File 'app/models/active_record_cache_extension.rb', line 105

def bulk_delete_cached(method_name, objects)
  ids = objects.map &:id
  regex = /.*\/(#{ids.join('|')})(-.*|)\/#{method_name}.*/
  # p "DEBUG BULK DELETE CACHE #{regex}"
  Rails.cache.delete_regex regex
end

#cache_created_at(method_name, arguments = nil) ⇒ Object 



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# File 'app/models/active_record_cache_extension.rb', line 117

def cache_created_at(method_name, arguments = nil)
  CacheAdditions
  Rails.cache.created_at [self, method_name, arguments]
end

#cached(method_name = nil, arguments = nil, &block) ⇒ Object

Case 1: Use it to call a cached method result.

user.cached(:name)

Case 2: Use it to call a cached method with arguments. Use this with care, since there is a cache for each argument!

user.cached(:membership_in, group)

Case 3: Use it with a block within a method definition. This moves the responsibility to cache into the model itself.

class User
  def name
    cached { "#{first_name} #{last_name}" }
  end
end

user.name  # already uses the cache!



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# File 'app/models/active_record_cache_extension.rb', line 28

def cached(method_name = nil, arguments = nil, &block)
  if method_name
    cached_method(method_name, arguments)
  else
    cached_block(&block)
  end
end

#delete_cache ⇒ Object 



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# File 'app/models/active_record_cache_extension.rb', line 112

def delete_cache
  # p "DEBUG DELETE CACHE #{self}"
  Rails.cache.delete_matched "#{self.cache_key}/*"
end

#delete_cached(method_name) ⇒ Object 



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# File 'app/models/active_record_cache_extension.rb', line 99

def delete_cached(method_name)
  # p "DEBUG DELETE CACHED #{self} #{method_name}"
  Rails.cache.delete [self, method_name]
  Rails.cache.delete_matched "#{self.cache_key}/#{method_name}/*"
end

#invalidate_cache ⇒ Object 



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# File 'app/models/active_record_cache_extension.rb', line 94

def invalidate_cache
  # Be careful in specs. This takes one second to count as invalid.
  self.touch
end

#uncached(method_name, args = nil) ⇒ Object

This method ensures that no app cache is used to produce the result. If you call

user.uncached :title

this calls ‘user.title` but makes sure, no app cache is used at all. Note: This does not prevent the sql cache to be used.

You could use this in specs:

user.cached(:title).should == user.uncached(:title)

## What about user.title?

Usually, user.title returns the uncached version; but if cached methods are used in the implementation of ‘User#title` then `user.title` does use these caches. If you call `user.uncached(:title)`, all app caches are ignored.



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# File 'app/models/active_record_cache_extension.rb', line 140

def uncached(method_name, args = nil)
  Rails.cache.uncached do
    if args
      self.send method_name, *args
    else
      self.send method_name
    end
  end
end