Module: Georeferencer::ObjectCache::ClassMethods

Defined in:
lib/georeferencer/mixins/object_cache.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Instance Attribute Details

#perform_object_caching ⇒ Object

Returns the value of attribute perform_object_caching.



28
29
30
 
# File 'lib/georeferencer/mixins/object_cache.rb', line 28

def perform_object_caching
  @perform_object_caching
end

Instance Method Details

#cache_key_base ⇒ Object

Base of the cache key for this class.



31
32
33
 
# File 'lib/georeferencer/mixins/object_cache.rb', line 31

def cache_key_base
  "georeferencer/#{Georeferencer::VERSION}/#{self.to_s.underscore}"
end

#expire_cache_for(*args) ⇒ Object

A method to expire the relevant caches for a collection of objects or ids

Parameters:

  • args (Array) —

    of either objects which respond to .id, or ids themselves



58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
 
# File 'lib/georeferencer/mixins/object_cache.rb', line 58

def expire_cache_for(*args)
  args = args.collect {|a| a.respond_to?(:id) ? a.id : a}.flatten
  # the caches we need to clear are:
  # - the object cache
  # - any collection caches which included this object
  args.each do |id|
    object_cache_key = "#{cache_key_base}/#{id}"
    object_collections = Georeferencer.configuration.cache.read("#{object_cache_key}/collection_hashes")
    if object_collections.present?
      # this object has a list of collection hashes, each of which we need to remove
      object_collections.each do |hash|
        Georeferencer.configuration.cache.delete("#{cache_key_base}/collection_query/#{hash}")
      end
      # by implication, the cached object should also be present; clear that too, along with any of its child keys
      begin
        Georeferencer.configuration.cache.delete_matched("#{object_cache_key}*")
      rescue NotImplementedError
        # rescue to removing the whole cache if delete_matched isn't supported
        Georeferencer.configuration.cache.clear
      end

    else
      # the object isn't in any collections; unfortunately we can't be sure whether this is because the object is old
      # and uncached, or new and therefore needs to be in collections which currently exist for this class.
      # Because of that, we'll aggressively remove caches for collections
      begin
        Georeferencer.configuration.cache.delete_matched("#{cache_key_base}/collection_query*")
      rescue NotImplementedError
        Georeferencer.configuration.cache.clear # rescue to cache.clear for caching methods where delete_matched isn't supported
      end
    end
    # Always remove the object's cache. There's no risk of doing this for nonexistent things.
    Georeferencer.configuration.cache.delete(object_cache_key)


  end
end

#find(*ids) ⇒ Object

Redeclare the find() method, with caching. Only pass uncached keys to the super method.



36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
 
# File 'lib/georeferencer/mixins/object_cache.rb', line 36

def find(*ids)
  if Georeferencer.configuration.perform_caching && perform_object_caching != false
    ids.uniq!
    uncached_ids = ids.reject {|i| Georeferencer.configuration.cache.read("#{cache_key_base}/#{i}").present?}
    [super(*uncached_ids)].flatten.reject(&:blank?).collect do |object|
      Georeferencer.configuration.logger.debug("Caching #{cache_key_base}/#{object.id}")
      Georeferencer.configuration.cache.write(object.cache_key, object)
    end
    all_objects = ids.collect do |id|
      Georeferencer.configuration.cache.read("#{cache_key_base}/#{id}")
    end

    all_objects.each {|o| o.run_callbacks(:find)}
    all_objects.length == 1 ? all_objects.first : all_objects
  else
    super
  end
end