Module: Cache

Defined in:
lib/lydown/cache.rb

Constant Summary collapse

CACHE_DIR = 
"/tmp/lydown/cache"

Class Method Summary collapse

Class Method Details

.calculate_hash(*params) ⇒ Object 



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# File 'lib/lydown/cache.rb', line 27

def calculate_hash(*params)
  params.map do |p|
    Digest::MD5.hexdigest(p.is_a?(String) ? p : p.to_s)
  end.join('-')
end

.disable! ⇒ Object 



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# File 'lib/lydown/cache.rb', line 6

def disable!
  @disabled = true
end

.enable! ⇒ Object 



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# File 'lib/lydown/cache.rb', line 10

def enable!
  @disabled = false
end

.filename(cache_key) ⇒ Object 



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# File 'lib/lydown/cache.rb', line 53

def filename(cache_key)
  "#{CACHE_DIR}/#{cache_key}"
end

.get(cache_key) ⇒ Object 



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# File 'lib/lydown/cache.rb', line 33

def get(cache_key)
  fn = filename(cache_key)
  if File.file?(fn)
    Marshal.load(IO.read(fn))
  else
    nil
  end
rescue
  nil
end

.hit(*params) ⇒ Object 



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# File 'lib/lydown/cache.rb', line 14

def hit(*params)
  return yield if @disabled
  
  cache_key = calculate_hash(*params)
  if result = get(cache_key)
    result
  else
    result = yield
    set(cache_key, result)
    result
  end
end

.set(cache_key, value) ⇒ Object 



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# File 'lib/lydown/cache.rb', line 44

def set(cache_key, value)
  File.open(filename(cache_key), 'w+') do |f|
    f << Marshal.dump(value)
  end
end