Class: Cache

Inherits:
Object
  • Object
show all
Defined in:
lib/fresnel/cache.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(options = Hash.new) ⇒ Cache

Returns a new instance of Cache.



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# File 'lib/fresnel/cache.rb', line 4

def initialize(options=Hash.new)
  @active=options[:active]||true
end

Instance Attribute Details

#active ⇒ Object

Returns the value of attribute active.



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# File 'lib/fresnel/cache.rb', line 2

def active
  @active
end

#timeout ⇒ Object

Returns the value of attribute timeout.



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# File 'lib/fresnel/cache.rb', line 2

def timeout
  @timeout
end

Instance Method Details

#clear(options) ⇒ Object 



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# File 'lib/fresnel/cache.rb', line 68

def clear(options)
  log "clearing cache /tmp/fresnel_#{options[:name]}.yml"
  File.delete("/tmp/fresnel_#{options[:name]}.yml") if File.exists?("/tmp/fresnel_#{options[:name]}.yml")
end

#create(options, &block) ⇒ Object 



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# File 'lib/fresnel/cache.rb', line 16

def create(options, &block)
  log "eval #{options[:action]}"
  if block
    data = block.call
  elsif options[:action]
    data=eval(options[:action])
  else
    raise ArgumentError, "No block or code to eval for a cache-able value"
  end
  log "creating cache file #{options[:name]}..."
  File.open("/tmp/fresnel_#{options[:name]}.yml",'w+'){ |f| f.write(YAML::dump(data)) }
  def data.age=(seconds)
    @age_in_seconds=seconds
  end
  def data.age
    @age_in_seconds
  end
  data.age=0
  return data
end

#load(options, &block) ⇒ Object 



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# File 'lib/fresnel/cache.rb', line 37

def load(options, &block)
  if self.active
    cache_timeout=options[:timeout]||@@cache_timeout
    log "caching is active !"
    if File.exists?("/tmp/fresnel_#{options[:name]}.yml")
      created_at=File.mtime("/tmp/fresnel_#{options[:name]}.yml")
      if (Time.now-created_at) < cache_timeout
        log "returning cached info (age : #{(Time.now-created_at).round}, timeout : #{cache_timeout})"
        data=YAML::load_file("/tmp/fresnel_#{options[:name]}.yml")
        def data.age=(seconds)
          @age_in_seconds=seconds
        end
        def data.age
          @age_in_seconds
        end
        data.age=(Time.now-created_at).round
        return data
      else
        log "refreshing data because the cached is older then the timeout (age : #{(Time.now-created_at).round}, timeout : #{cache_timeout})"
        self.create(options, &block)
      end
    else
      log "no cache data found, calling create..."
      self.create(options, &block)
    end
  else
    log "cache disabled, fetching life data (and creating cache file for future use...once cache is enabled)"
    self.create(options, &block)
  end
end

#log(str) ⇒ Object 



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

def log(str)
  if @@debug
    puts str
  end
end