class ActiveSupport::Cache::DalliStore

Constants

ESCAPE_KEY_CHARS

Attributes

options[R]
silence[R]
silence?[R]

Public Class Methods

new(*addresses) click to toggle source

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).

Connection Pool support

If you are using multithreaded Rails, the Rails.cache singleton can become a source of contention. You can use a connection pool of Dalli clients with Rails.cache by passing :pool_size and/or :pool_timeout:

config.cache_store = :dalli_store, 'localhost:11211', :pool_size => 10

Both pool options default to 5. You must include the `connection_pool` gem if you wish to use pool support.

# File lib/active_support/cache/dalli_store.rb, line 46
def initialize(*addresses)
  addresses = addresses.flatten
  options = addresses.extract_options!
  @options = options.dup

  pool_options = {}
  pool_options[:size] = options[:pool_size] if options[:pool_size]
  pool_options[:timeout] = options[:pool_timeout] if options[:pool_timeout]

  @options[:compress] ||= @options[:compression]

  addresses.compact!
  servers = if addresses.empty?
              nil # use the default from Dalli::Client
            else
              addresses
            end
  if pool_options.empty?
    @data = Dalli::Client.new(servers, @options)
  else
    @data = ::ConnectionPool.new(pool_options) { Dalli::Client.new(servers, @options.merge(:threadsafe => false)) }
  end

  extend Strategy::LocalCache
end

Public Instance Methods

cleanup(options=nil) click to toggle source

Clear any local cache

# File lib/active_support/cache/dalli_store.rb, line 262
def cleanup(options=nil)
end
clear(options=nil) click to toggle source

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

# File lib/active_support/cache/dalli_store.rb, line 251
def clear(options=nil)
  instrument(:clear, 'flushing all keys') do
    with { |c| c.flush_all }
  end
rescue Dalli::DalliError => e
  logger.error("DalliError: #{e.message}") if logger
  raise if raise_errors?
  nil
end
dalli() click to toggle source

Access the underlying Dalli::Client or ConnectionPool instance for access to get_multi, etc.

# File lib/active_support/cache/dalli_store.rb, line 75
def dalli
  @data
end
decrement(name, amount = 1, options=nil) click to toggle source

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.

# File lib/active_support/cache/dalli_store.rb, line 235
def decrement(name, amount = 1, options=nil)
  options ||= {}
  name = namespaced_key(name, options)
  initial = options.has_key?(:initial) ? options[:initial] : 0
  expires_in = options[:expires_in]
  instrument(:decrement, name, :amount => amount) do
    with { |c| c.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) click to toggle source
# File lib/active_support/cache/dalli_store.rb, line 145
def delete(name, options=nil)
  options ||= {}
  name = namespaced_key(name, options)

  instrument(:delete, name, options) do |payload|
    delete_entry(name, options)
  end
end
exist?(name, options=nil) click to toggle source
# File lib/active_support/cache/dalli_store.rb, line 137
def exist?(name, options=nil)
  options ||= {}
  name = namespaced_key(name, options)

  log(:exist, name, options)
  !read_entry(name, options).nil?
end
fetch(name, options=nil) { || ... } click to toggle source
# File lib/active_support/cache/dalli_store.rb, line 83
def fetch(name, options=nil)
  options ||= {}
  namespaced_name = namespaced_key(name, options)

  if block_given?
    unless options[:force]
      entry = instrument(:read, namespaced_name, options) do |payload|
        read_entry(namespaced_name, options).tap do |result|
          if payload
            payload[:super_operation] = :fetch
            payload[:hit] = !result.nil?
          end
        end
      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
fetch_multi(*names) { |name| ... } click to toggle source

Fetches data from the cache, using the given keys. If there is data in the cache with the given keys, then that data is returned. Otherwise, the supplied block is called for each key for which there was no data, and the result will be written to the cache and returned.

# File lib/active_support/cache/dalli_store.rb, line 186
def fetch_multi(*names)
  options = names.extract_options!
  mapping = names.inject({}) { |memo, name| memo[namespaced_key(name, options)] = name; memo }

  instrument(:fetch_multi, names) do
    with do |connection|
      results = connection.get_multi(mapping.keys)

      connection.multi do
        mapping.inject({}) do |memo, (expanded, name)|
          memo[name] = results[expanded]
          if memo[name].nil?
            value = yield(name)
            memo[name] = value
            options = options.merge(:connection => connection)
            write_entry(expanded, value, options)
          end

          memo
        end
      end
    end
  end
end
increment(name, amount = 1, options=nil) click to toggle source

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.

# File lib/active_support/cache/dalli_store.rb, line 216
def increment(name, amount = 1, options=nil)
  options ||= {}
  name = namespaced_key(name, options)
  initial = options.has_key?(:initial) ? options[:initial] : amount
  expires_in = options[:expires_in]
  instrument(:increment, name, :amount => amount) do
    with { |c| c.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() click to toggle source
# File lib/active_support/cache/dalli_store.rb, line 274
def logger
  Dalli.logger
end
logger=(new_logger) click to toggle source
# File lib/active_support/cache/dalli_store.rb, line 278
def logger=(new_logger)
  Dalli.logger = new_logger
end
mute() { || ... } click to toggle source

Silence the logger within a block.

# File lib/active_support/cache/dalli_store.rb, line 17
def mute
  previous_silence, @silence = defined?(@silence) && @silence, true
  yield
ensure
  @silence = previous_silence
end
read(name, options=nil) click to toggle source
# File lib/active_support/cache/dalli_store.rb, line 114
def read(name, options=nil)
  options ||= {}
  name = namespaced_key(name, options)

  instrument(:read, name, options) do |payload|
    entry = read_entry(name, options)
    payload[:hit] = !entry.nil? if payload
    entry
  end
end
read_multi(*names) click to toggle source

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

# File lib/active_support/cache/dalli_store.rb, line 156
def read_multi(*names)
  options  = names.extract_options!
  mapping = names.inject({}) { |memo, name| memo[namespaced_key(name, options)] = name; memo }
  instrument(:read_multi, names) do
    results = {}
    if local_cache
      mapping.each_key do |key|
        if value = local_cache.read_entry(key, options)
          results[key] = value
        end
      end
    end

    data = with { |c| c.get_multi(mapping.keys - results.keys) }
    results.merge!(data)
    results.inject({}) do |memo, (inner, _)|
      entry = results[inner]
      # NB Backwards data compatibility, to be removed at some point
      value = (entry.is_a?(ActiveSupport::Cache::Entry) ? entry.value : entry)
      memo[mapping[inner]] = value
      local_cache.write_entry(inner, value, options) if local_cache
      memo
    end
  end
end
reset() click to toggle source
# File lib/active_support/cache/dalli_store.rb, line 270
def reset
  with { |c| c.reset }
end
silence!() click to toggle source

Silence the logger.

# File lib/active_support/cache/dalli_store.rb, line 11
def silence!
  @silence = true
  self
end
stats() click to toggle source

Get the statistics from the memcached servers.

# File lib/active_support/cache/dalli_store.rb, line 266
def stats
  with { |c| c.stats }
end
with(&block) click to toggle source
# File lib/active_support/cache/dalli_store.rb, line 79
def with(&block)
  @data.with(&block)
end
write(name, value, options=nil) click to toggle source
# File lib/active_support/cache/dalli_store.rb, line 125
def write(name, value, options=nil)
  options ||= {}
  name = namespaced_key(name, options)

  instrument(:write, name, options) do |payload|
    with do |connection|
      options = options.merge(:connection => connection)
      write_entry(name, value, options)
    end
  end
end

Private Instance Methods

instrument(operation, key, options=nil) { |payload| ... } click to toggle source
# File lib/active_support/cache/dalli_store.rb, line 353
def instrument(operation, key, options=nil)
  log(operation, key, options)

  payload = { :key => key }
  payload.merge!(options) if options.is_a?(Hash)
  ActiveSupport::Notifications.instrument("cache_#{operation}.active_support", payload){ yield(payload) }
end
log(operation, key, options=nil) click to toggle source
# File lib/active_support/cache/dalli_store.rb, line 361
def log(operation, key, options=nil)
  return unless logger && logger.debug? && !silence?
  logger.debug("Cache #{operation}: #{key}#{options.blank? ? "" : " (#{options.inspect})"}")
end
namespaced_key(key, options) click to toggle source
# File lib/active_support/cache/dalli_store.rb, line 320
def namespaced_key(key, options)
  key = expanded_key(key)
  namespace = options[:namespace] if options
  prefix = namespace.is_a?(Proc) ? namespace.call : namespace
  key = "#{prefix}:#{key}" if prefix
  key
end
raise_errors?() click to toggle source
# File lib/active_support/cache/dalli_store.rb, line 366
def raise_errors?
  !!@options[:raise_errors]
end