Method: MemCache#get_multi

Defined in:
lib/memcache.rb

#get_multi(*keys) ⇒ Object

Retrieves multiple values from memcached in parallel, if possible.

The memcached protocol supports the ability to retrieve multiple keys in a single request. Pass in an array of keys to this method and it will:

  1. map the key to the appropriate memcached server

  2. send a single request to each server that has one or more key values

Returns a hash of values.

cache["a"] = 1
cache["b"] = 2
cache.get_multi "a", "b" # => { "a" => 1, "b" => 2 }

Note that get_multi assumes the values are marshalled. You can pass in :raw => true to bypass value marshalling.

cache.get_multi('a', 'b', ..., :raw => true)



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# File 'lib/memcache.rb', line 297

def get_multi(*keys)
  raise MemCacheError, 'No active servers' unless active?

  opts = keys.last.is_a?(Hash) ? keys.pop : {}

  keys.flatten!
  key_count = keys.length
  cache_keys = {}
  server_keys = Hash.new { |h,k| h[k] = [] }

  # map keys to servers
  keys.each do |key|
    server, cache_key = request_setup key
    cache_keys[cache_key] = key
    server_keys[server] << cache_key
  end

  results = {}
  raw = opts[:raw] || false
  server_keys.each do |server, keys_for_server|
    keys_for_server_str = keys_for_server.join ' '
    begin
      values = cache_get_multi server, keys_for_server_str
      values.each do |key, value|
        results[cache_keys[key]] = raw ? value : Marshal.load(value)
      end
    rescue IndexError => e
      # Ignore this server and try the others
      logger.warn { "Unable to retrieve #{keys_for_server.size} elements from #{server.inspect}: #{e.message}"} if logger
    end
  end

  return results
rescue TypeError => err
  handle_error nil, err
end