Store
A cache store implementation which stores data in Memcached: www.danga.com/memcached/
This is currently the most popular cache store for production websites.
Special features:
Clustering and load balancing. One can specify multiple memcached servers, and MemCacheStore will load balance between all available servers. If a server goes down, then MemCacheStore will ignore it until it goes back online.
Time-based expiry support. See write and the :expires_in option.
Per-request in memory cache for all communication with the MemCache server(s).
# File lib/active_support/cache/mem_cache_store.rb, line 26 def self.build_mem_cache(*addresses) addresses = addresses.flatten options = addresses.extract_options! addresses = ["localhost"] if addresses.empty? MemCache.new(addresses, options) end
Creates a new MemCacheStore 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::MemCacheStore.new("localhost", "server-downstairs.localnetwork:8229")
If no addresses are specified, then MemCacheStore will connect to localhost port 11211 (the default memcached port).
Instead of addresses one can pass in a MemCache-like object. For example:
require 'memcached' # gem install memcached; uses C bindings to libmemcached ActiveSupport::Cache::MemCacheStore.new(Memcached::Rails.new("localhost:11211"))
# File lib/active_support/cache/mem_cache_store.rb, line 46 def initialize(*addresses) if addresses.first.respond_to?(:get) @data = addresses.first else @data = self.class.build_mem_cache(*addresses) end extend Strategy::LocalCache end
# File lib/active_support/cache/mem_cache_store.rb, line 129 def clear @data.flush_all end
Reads multiple keys from the cache.
# File lib/active_support/cache/mem_cache_store.rb, line 57 def read_multi(*keys) @data.get_multi keys end
# File lib/active_support/cache/mem_cache_store.rb, line 133 def stats @data.stats end
Writes a value to the cache.
Possible options:
:unless_exist - set to true if you don't want to update the cache if the key is already set.
:expires_in - the number of seconds that this value may stay in the cache. See ActiveSupport::Cache::Store#write for an example.
# File lib/active_support/cache/mem_cache_store.rb, line 76 def write(key, value, options = nil) super method = options && options[:unless_exist] ? :add : :set # memcache-client will break the connection if you send it an integer # in raw mode, so we convert it to a string to be sure it continues working. value = value.to_s if raw?(options) response = @data.send(method, key, value, expires_in(options), raw?(options)) response == Response::STORED rescue MemCache::MemCacheError => e logger.error("MemCacheError (#{e}): #{e.message}") false end
Generated with the Darkfish Rdoc Generator 2.