Module: Cachier

Extended by:
Cachier
Included in:
Cachier
Defined in:
lib/cachier.rb,
lib/cachier/version.rb,
lib/cachier/matchers.rb,
lib/cachier/controller_helper.rb

Overview

Hooks into ApplicationController’s write_fragment method. write_fragment is used for action and fragment caching. Create an alias method chain to call our customer method which stores the associated key with the tag in a Redis Set. Then we can expire all those keys from anywhere in the code using Rails.cache.delete

I use alias_method_chain instead of calling ‘super’ because there is a very rare case where someone may have redfined ‘write_fragment’ in their own controllers. Using an alias method chain keeps those methods intact.

Defined Under Namespace

Modules: ControllerHelper, Matchers

Constant Summary collapse

CACHE_KEY = 
'cachier-tags'
VERSION = 
"0.0.1"

Instance Method Summary collapse

Instance Method Details

#clear ⇒ Object 



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# File 'lib/cachier.rb', line 59

def clear
  expire(*tags)
  Rails.cache.delete(CACHE_KEY)
end

#expire(*tags) ⇒ Object 



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# File 'lib/cachier.rb', line 36

def expire(*tags)
  return unless perform_caching?

  # delete them from the cache
  tags.each do |tag|
    if fragment_keys = Rails.cache.fetch(tag)
      fragment_keys.each do |fragment_key|
        Rails.cache.delete(fragment_key)
      end
    end
    
    Rails.cache.delete(tag)
  end

  # now remove them from the list
  # of stored tags
  remove_tags_from_tag_list(tags)
end

#fetch(cache_key, cache_params = {}) ⇒ Object

Fetch from cache, this function accepts a block



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# File 'lib/cachier.rb', line 12

def fetch(cache_key, cache_params = {})
  tags = cache_params.delete(:tag) || []
  store_fragment(cache_key, tags)

  if block_given?
    returned_object = Rails.cache.fetch(cache_key, cache_params) {
      yield
    }  
  else
    Rails.cache.read(cache_key)
  end
end

#keys ⇒ Object 



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# File 'lib/cachier.rb', line 68

def keys
  tags.inject([]) do |arry, tag|
    arry += (Rails.cache.fetch(tag) || [])
  end.compact
end

#keys_for(tag) ⇒ Object 



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# File 'lib/cachier.rb', line 74

def keys_for(tag)
  Rails.cache.fetch(tag) || []
end

#perform_caching? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/cachier.rb', line 7

def perform_caching?
  ::ApplicationController.perform_caching
end

#store_fragment(fragment, *tags) ⇒ Object 



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# File 'lib/cachier.rb', line 25

def store_fragment(fragment, *tags)
  return unless perform_caching?

  tags.each do |tag|
    fragments = Rails.cache.fetch(tag) || []
    Rails.cache.write(tag, fragments + [fragment])
  end

  add_tags_to_tag_list(tags)
end

#tags ⇒ Object 



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# File 'lib/cachier.rb', line 55

def tags
  Rails.cache.fetch(CACHE_KEY) || []
end

#wipe ⇒ Object 



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# File 'lib/cachier.rb', line 64

def wipe
  clear
end