Class: WurflCloud::Cache::Memcached

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

Instance Method Summary collapse

Constructor Details

#initialize(options, environment) ⇒ Memcached

Returns a new instance of Memcached.



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# File 'lib/wurfl_cloud/cache/memcached.rb', line 17

def initialize(options, environment)
  opts = options.clone
  server = opts.delete(:server)
  @prefix = opts.delete(:prefix)
  opts[:expires_in] ||= 86400 
  @memcached = Dalli::Client.new(server, opts)
end

Instance Method Details

#[](key) ⇒ Object

Should return the value stored for the key, nil if the key is not in cache The Memcached cache reads from the mamcached server



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# File 'lib/wurfl_cloud/cache/memcached.rb', line 54

def [](key)
  @memcached.get("#{key_prefix}#{Digest::MD5.hexdigest(key)}")
end

#[]=(key, value) ⇒ Object

Stores the value for the key in the mamcached server



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# File 'lib/wurfl_cloud/cache/memcached.rb', line 59

def []=(key, value)
  @memcached.set("#{key_prefix}#{Digest::MD5.hexdigest(key)}", value)
end

#key_prefix ⇒ Object 



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# File 'lib/wurfl_cloud/cache/memcached.rb', line 29

def key_prefix        
  "#{prefix}:#{mtime}:"
end

#mtime ⇒ Object 



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# File 'lib/wurfl_cloud/cache/memcached.rb', line 33

def mtime
  @memcached.get("#{prefix}mtime")
end

#mtime=(new_mtime) ⇒ Object 



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# File 'lib/wurfl_cloud/cache/memcached.rb', line 37

def mtime=(new_mtime)
  @memcached.set("#{prefix}mtime", new_mtime)
end

#prefix ⇒ Object 



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# File 'lib/wurfl_cloud/cache/memcached.rb', line 25

def prefix
  "#{(@prefix.nil? || @prefix=="") ? "": "#{@prefix}:"}"
end

#validate(current_mtime) ⇒ Object

Validates the cache checks if the cache is still valid with respect to a new mtime received from the server if the new mtime is different from the one cached then it overwrites the current key prefix thus actually invalidationg the cache



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# File 'lib/wurfl_cloud/cache/memcached.rb', line 45

def validate(current_mtime)
  old_mtime = self.mtime
  if !old_mtime || old_mtime!=current_mtime
    self.mtime = current_mtime
  end
end