Class: Monkeyshines::Store::ConditionalStore

Inherits:
Base
  • Object
show all
Defined in:
lib/wukong/store/conditional_store.rb

Constant Summary collapse

DEFAULT_OPTIONS = 
{
  :cache => { :type => :tyrant_rdb_key_store    },
  :store => { :type => :chunked_flat_file_store },
}

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(_options) ⇒ ConditionalStore

cache must behave like a hash (Hash and

Monkeyshines::Store::TyrantRdbKeyStore are both cromulent
choices).



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# File 'lib/wukong/store/conditional_store.rb', line 19

def initialize _options
  self.options = DEFAULT_OPTIONS.deep_merge(_options)
  self.cache  = Monkeyshines::Store.create(options[:cache])
  self.store  = Monkeyshines::Store.create(options[:store])
  self.misses = 0
end

Instance Attribute Details

#cache ⇒ Object

Returns the value of attribute cache.



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# File 'lib/wukong/store/conditional_store.rb', line 4

def cache
  @cache
end

#misses ⇒ Object

Returns the value of attribute misses.



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# File 'lib/wukong/store/conditional_store.rb', line 4

def misses
  @misses
end

#options ⇒ Object

Returns the value of attribute options.



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# File 'lib/wukong/store/conditional_store.rb', line 4

def options
  @options
end

#store ⇒ Object

Returns the value of attribute store.



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# File 'lib/wukong/store/conditional_store.rb', line 4

def store
  @store
end

Instance Method Details

#close ⇒ Object 



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# File 'lib/wukong/store/conditional_store.rb', line 51

def close()
  cache.close
  store.close
end

#log_line ⇒ Object 



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# File 'lib/wukong/store/conditional_store.rb', line 47

def log_line
  [size, "%8d misses"%misses]
end

#set(key, force = nil, &block) ⇒ Object

If key is absent, save the result of calling the block. If key is present, block is never called.

Ex:

rt_store.set(url) do
  fetcher.get url # will only be called if url isn't in rt_store
end



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# File 'lib/wukong/store/conditional_store.rb', line 35

def set key, force=nil, &block
  return if (!force) && cache.include?(key)
  cache_val, store_val = block.call()
  return unless cache_val
  cache.set_nr key, cache_val # update cache
  store << store_val          # save value
  self.misses += 1            # track the cache miss
  store_val
end

#size ⇒ Object 



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# File 'lib/wukong/store/conditional_store.rb', line 45

def size() cache.size  end