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 Attribute Summary collapse

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 36

def initialize(*addresses)
  addresses = addresses.flatten
  options = addresses.extract_options!
  @options = options.dup
  @options[:compress] ||= @options[:compression]
  @raise_errors = !!@options[:raise_errors]
  servers = if addresses.empty?
              nil # use the default from Dalli::Client
            else
              addresses
            end
  @data = Dalli::Client.new(servers, @options)
end

Instance Attribute Details

#options ⇒ Object (readonly)

Returns the value of attribute options.



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# File 'lib/active_support/cache/dalli_store.rb', line 8

def options
  @options
end

#silence ⇒ Object (readonly) Also known as: silence?

Returns the value of attribute silence.



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# File 'lib/active_support/cache/dalli_store.rb', line 8

def silence
  @silence
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 170

def clear(options=nil)
  instrument(:clear, 'flushing all keys') do
    @data.flush_all
  end
rescue Dalli::DalliError => e
  logger.error("DalliError: #{e.message}") if logger
  raise if @raise_errors
  nil
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 154

def decrement(name, amount = 1, options=nil)
  options ||= {}
  name = expanded_key name
  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
  raise if @raise_errors
  nil
end

#delete(name, options = nil) ⇒ Object 



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# File 'lib/active_support/cache/dalli_store.rb', line 105

def delete(name, options=nil)
  options ||= {}
  name = expanded_key name

  log(:delete, name, options)
  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 97

def exist?(name, options=nil)
  options ||= {}
  name = expanded_key name

  log(:exist, name, options)
  !read_entry(name, options).nil?
end

#fetch(name, options = nil) ⇒ Object 



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# File 'lib/active_support/cache/dalli_store.rb', line 50

def fetch(name, options=nil)
  options ||= {}
  name = expanded_key name

  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.nil?
      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 135

def increment(name, amount = 1, options=nil)
  options ||= {}
  name = expanded_key name
  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
  raise if @raise_errors
  nil
end

#logger ⇒ Object 



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# File 'lib/active_support/cache/dalli_store.rb', line 189

def logger
  Dalli.logger
end

#logger=(new_logger) ⇒ Object 



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# File 'lib/active_support/cache/dalli_store.rb', line 193

def logger=(new_logger)
  Dalli.logger = new_logger
end

#mute ⇒ Object

Silence the logger within a block.



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# File 'lib/active_support/cache/dalli_store.rb', line 18

def mute
  previous_silence, @silence = defined?(@silence) && @silence, true
  yield
ensure
  @silence = previous_silence
end

#read(name, options = nil) ⇒ Object 



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# File 'lib/active_support/cache/dalli_store.rb', line 77

def read(name, options=nil)
  options ||= {}
  name = expanded_key name

  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 115

def read_multi(*names)
  names.extract_options!
  names = names.flatten
  mapping = names.inject({}) { |memo, name| memo[escape(expanded_key(name))] = name; memo }
  instrument(:read_multi, names) do
    results = @data.get_multi(mapping.keys)
    results.inject({}) do |memo, (inner, _)|
      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 185

def reset
  @data.reset
end

#silence! ⇒ Object

Silence the logger.



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# File 'lib/active_support/cache/dalli_store.rb', line 12

def silence!
  @silence = true
  self
end

#stats ⇒ Object

Get the statistics from the memcached servers.



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# File 'lib/active_support/cache/dalli_store.rb', line 181

def stats
  @data.stats
end

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



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# File 'lib/active_support/cache/dalli_store.rb', line 88

def write(name, value, options=nil)
  options ||= {}
  name = expanded_key name

  instrument(:write, name, options) do |payload|
    write_entry(name, value, options)
  end
end