Class: ActiveSupport::Cache::DalliStore

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

Constant Summary collapse

ESCAPE_KEY_CHARS = 
/[\x00-\x20%\x7F-\xFF]/

Instance Method Summary collapse

Constructor Details

#initialize(*addresses) ⇒ DalliStore

Creates a new DalliStore object, with the given memcached server addresses. Each address is either a host name, or a host-with-port string in the form of “host_name:port”. For example:

ActiveSupport::Cache::DalliStore.new("localhost", "server-downstairs.localnetwork:8229")

If no addresses are specified, then DalliStore will connect to localhost port 11211 (the default memcached port).



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# File 'lib/active_support/cache/dalli_store.rb', line 20

def initialize(*addresses)
  addresses = addresses.flatten
  options = addresses.extract_options!
  options[:compress] ||= options[:compression]
  addresses << 'localhost:11211' if addresses.empty?
  @data = Dalli::Client.new(addresses, options)
end

Instance Method Details

#clear(options = nil) ⇒ Object

Clear the entire cache on all memcached servers. This method should be used with care when using a shared cache.



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# File 'lib/active_support/cache/dalli_store.rb', line 132

def clear(options=nil)
  @data.flush_all
end

#decrement(name, amount = 1, options = nil) ⇒ Object

Decrement a cached value. This method uses the memcached decr atomic operator and can only be used on values written with the :raw option. Calling it on a value not stored with :raw will fail. :initial defaults to zero, as if the counter was initially zero. memcached counters cannot hold negative values.



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# File 'lib/active_support/cache/dalli_store.rb', line 118

def decrement(name, amount = 1, options=nil)
  options ||= {}
  initial = options.has_key?(:initial) ? options[:initial] : 0
  expires_in = options[:expires_in]
  instrument(:decrement, name, :amount => amount) do
    @data.decr(name, amount, expires_in, initial)
  end
rescue Dalli::DalliError => e
  logger.error("DalliError: #{e.message}") if logger
  nil
end

#delete(name, options = nil) ⇒ Object 



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# File 'lib/active_support/cache/dalli_store.rb', line 74

def delete(name, options=nil)
  delete_entry(name, options)
end

#exist?(name, options = nil) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/active_support/cache/dalli_store.rb', line 69

def exist?(name, options=nil)
  options ||= {}
  !!read_entry(name, options)
end

#fetch(name, options = nil) ⇒ Object 



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# File 'lib/active_support/cache/dalli_store.rb', line 28

def fetch(name, options=nil)
  options ||= {}
  if block_given?
    unless options[:force]
      entry = instrument(:read, name, options) do |payload|
        payload[:super_operation] = :fetch if payload
        read_entry(name, options)
      end
    end

    if entry
      instrument(:fetch_hit, name, options) { |payload| }
      entry
    else
      result = instrument(:generate, name, options) do |payload|
        yield
      end
      write(name, result, options)
      result
    end
  else
    read(name, options)
  end
end

#increment(name, amount = 1, options = nil) ⇒ Object

Increment a cached value. This method uses the memcached incr atomic operator and can only be used on values written with the :raw option. Calling it on a value not stored with :raw will fail. :initial defaults to the amount passed in, as if the counter was initially zero. memcached counters cannot hold negative values.



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# File 'lib/active_support/cache/dalli_store.rb', line 101

def increment(name, amount = 1, options=nil)
  options ||= {}
  initial = options.has_key?(:initial) ? options[:initial] : amount
  expires_in = options[:expires_in]
  instrument(:increment, name, :amount => amount) do
    @data.incr(name, amount, expires_in, initial)
  end
rescue Dalli::DalliError => e
  logger.error("DalliError: #{e.message}") if logger
  nil
end

#read(name, options = nil) ⇒ Object 



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# File 'lib/active_support/cache/dalli_store.rb', line 53

def read(name, options=nil)
  options ||= {}
  instrument(:read, name, options) do |payload|
    entry = read_entry(name, options)
    payload[:hit] = !!entry if payload
    entry
  end
end

#read_multi(*names) ⇒ Object

Reads multiple keys from the cache using a single call to the servers for all keys. Keys must be Strings.



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# File 'lib/active_support/cache/dalli_store.rb', line 80

def read_multi(*names)
  names.extract_options!
  names = names.flatten

  mapping = names.inject({}) { |memo, name| memo[escape(name)] = name; memo }
  instrument(:read_multi, names) do
    results = @data.get_multi(mapping.keys)
    results.inject({}) do |memo, (inner, value)|
      entry = results[inner]
      # NB Backwards data compatibility, to be removed at some point
      memo[mapping[inner]] = (entry.is_a?(ActiveSupport::Cache::Entry) ? entry.value : entry)
      memo
    end
  end
end

#reset ⇒ Object 



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# File 'lib/active_support/cache/dalli_store.rb', line 141

def reset
  @data.reset
end

#stats ⇒ Object

Get the statistics from the memcached servers.



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# File 'lib/active_support/cache/dalli_store.rb', line 137

def stats
  @data.stats
end

#write(name, value, options = nil) ⇒ Object 



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# File 'lib/active_support/cache/dalli_store.rb', line 62

def write(name, value, options=nil)
  options ||= {}
  instrument(:write, name, options) do |payload|
    write_entry(name, value, options)
  end
end