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 52
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
  extend LocalCacheEntryUnwrapAndRaw
end
supports_cache_versioning?() click to toggle source
# File lib/active_support/cache/dalli_store.rb, line 12
def self.supports_cache_versioning?
  true
end

Public Instance Methods

cleanup(options=nil) click to toggle source

Clear any local cache

# File lib/active_support/cache/dalli_store.rb, line 282
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 270
def clear(options=nil)
  instrument_with_log(:clear, 'flushing all keys') do
    with { |c| c.flush_all }
  end
rescue Dalli::DalliError => e
  log_dalli_error(e)
  instrument_error(e) if instrument_errors?
  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 82
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 253
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_with_log(:decrement, name, :amount => amount) do
    with { |c| c.decr(name, amount, expires_in, initial) }
  end
rescue Dalli::DalliError => e
  log_dalli_error(e)
  instrument_error(e) if instrument_errors?
  raise if raise_errors?
  nil
end
delete(name, options=nil) click to toggle source
# File lib/active_support/cache/dalli_store.rb, line 162
def delete(name, options=nil)
  options ||= {}
  name = namespaced_key(name, options)

  instrument_with_log(: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 154
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) { |name| ... } click to toggle source

Fetch the value associated with the key. If a value is found, then it is returned.

If a value is not found and no block is given, then nil is returned.

If a value is not found (or if the found value is nil and :cache_nils is false) and a block is given, the block will be invoked and its return value written to the cache and returned.

# File lib/active_support/cache/dalli_store.rb, line 98
def fetch(name, options=nil)
  options ||= {}
  options[:cache_nils] = true if @options[:cache_nils]
  namespaced_name = namespaced_key(name, options)
  not_found = options[:cache_nils] ? Dalli::Server::NOT_FOUND : nil
  if block_given?
    entry = not_found
    unless options[:force]
      entry = instrument_with_log(:read, namespaced_name, options) do |payload|
        read_entry(namespaced_name, options).tap do |result|
          if payload
            payload[:super_operation] = :fetch
            payload[:hit] = not_found != result
          end
        end
      end
    end

    if not_found == entry
      result = instrument_with_log(:generate, namespaced_name, options) do |payload|
        yield(name)
      end
      write(name, result, options)
      result
    else
      instrument_with_log(:fetch_hit, namespaced_name, options) { |payload| }
      entry
    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 203
def fetch_multi(*names)
  options = names.extract_options!
  mapping = names.inject({}) { |memo, name| memo[namespaced_key(name, options)] = name; memo }

  instrument_with_log(:fetch_multi, mapping.keys) 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 233
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_with_log(:increment, name, :amount => amount) do
    with { |c| c.incr(name, amount, expires_in, initial) }
  end
rescue Dalli::DalliError => e
  log_dalli_error(e)
  instrument_error(e) if instrument_errors?
  raise if raise_errors?
  nil
end
logger() click to toggle source
# File lib/active_support/cache/dalli_store.rb, line 294
def logger
  Dalli.logger
end
logger=(new_logger) click to toggle source
# File lib/active_support/cache/dalli_store.rb, line 298
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 23
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 131
def read(name, options=nil)
  options ||= {}
  name = namespaced_key(name, options)

  instrument_with_log(: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 173
def read_multi(*names)
  options  = names.extract_options!
  mapping = names.inject({}) { |memo, name| memo[namespaced_key(name, options)] = name; memo }
  instrument_with_log(:read_multi, mapping.keys) 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 290
def reset
  with { |c| c.reset }
end
silence!() click to toggle source

Silence the logger.

# File lib/active_support/cache/dalli_store.rb, line 17
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 286
def stats
  with { |c| c.stats }
end
with(&block) click to toggle source
# File lib/active_support/cache/dalli_store.rb, line 86
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 142
def write(name, value, options=nil)
  options ||= {}
  name = namespaced_key(name, options)

  instrument_with_log(: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, payload) { |payload| ... } click to toggle source
# File lib/active_support/cache/dalli_store.rb, line 396
def instrument(operation, payload)
  ActiveSupport::Notifications.instrument("cache_#{operation}.active_support", payload) do
    yield(payload) if block_given?
  end
end
instrument_error(error) click to toggle source
# File lib/active_support/cache/dalli_store.rb, line 392
def instrument_error(error)
  instrument(:error, { :key => 'DalliError', :message => error.message })
end
instrument_errors?() click to toggle source
# File lib/active_support/cache/dalli_store.rb, line 411
def instrument_errors?
  !!@options[:instrument_errors]
end
instrument_with_log(operation, key, options=nil) { |p| ... } click to toggle source
# File lib/active_support/cache/dalli_store.rb, line 384
def instrument_with_log(operation, key, options=nil)
  log(operation, key, options)

  payload = { :key => key }
  payload.merge!(options) if options.is_a?(Hash)
  instrument(operation, payload) { |p| yield(p) }
end
log(operation, key, options=nil) click to toggle source
# File lib/active_support/cache/dalli_store.rb, line 402
def log(operation, key, options=nil)
  return unless logger && logger.debug? && !silence?
  logger.debug("Cache #{operation}: #{key}#{options.blank? ? "" : " (#{options.inspect})"}")
end
log_dalli_error(error) click to toggle source
# File lib/active_support/cache/dalli_store.rb, line 380
def log_dalli_error(error)
  logger.error("DalliError: #{error.message}") if logger
end
namespaced_key(key, options) click to toggle source
# File lib/active_support/cache/dalli_store.rb, line 343
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 = "#{key[0, 213]}:md5:#{::Digest::MD5.hexdigest(key)}" if key && key.size > 250
  key
end
Also aliased as: normalize_key
normalize_key(key, options)
Alias for: namespaced_key
raise_errors?() click to toggle source
# File lib/active_support/cache/dalli_store.rb, line 407
def raise_errors?
  !!@options[:raise_errors]
end