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).
Methods
Attributes
[R] addresses
Public Class methods
new(*addresses)

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).

Source: show | on GitHub 

    # File activesupport/lib/active_support/cache/mem_cache_store.rb, line 36
36:       def initialize(*addresses)
37:         addresses = addresses.flatten
38:         options = addresses.extract_options!
39:         addresses = ["localhost"] if addresses.empty?
40:         @addresses = addresses
41:         @data = MemCache.new(addresses, options)
42: 
43:         extend Strategy::LocalCache
44:       end
Public Instance methods
clear()

Source: show | on GitHub 

     # File activesupport/lib/active_support/cache/mem_cache_store.rb, line 114
114:       def clear
115:         @data.flush_all
116:       end
stats()

Source: show | on GitHub 

     # File activesupport/lib/active_support/cache/mem_cache_store.rb, line 118
118:       def stats
119:         @data.stats
120:       end
write(key, value, options = nil)

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.

Source: show | on GitHub 

    # File activesupport/lib/active_support/cache/mem_cache_store.rb, line 61
61:       def write(key, value, options = nil)
62:         super
63:         method = options && options[:unless_exist] ? :add : :set
64:         # memcache-client will break the connection if you send it an integer
65:         # in raw mode, so we convert it to a string to be sure it continues working.
66:         value = value.to_s if raw?(options)
67:         response = @data.send(method, key, value, expires_in(options), raw?(options))
68:         response == Response::STORED
69:       rescue MemCache::MemCacheError => e
70:         logger.error("MemCacheError (#{e}): #{e.message}")
71:         false
72:       end