module ActiveRecord::ConnectionAdapters::QueryCache

Attributes

Public Class Methods

dirties_query_cache (base, *method_names)

# File activerecord/lib/active_record/connection_adapters/abstract/query_cache.rb, line 20
        def dirties_query_cache(base, *method_names)
          method_names.each do |method_name|
            base.class_eval <<-end_code, __FILE__, __LINE__ + 1
              def #{method_name}(...)
                ActiveRecord::Base.clear_query_caches_for_current_thread
                super
              end
            end_code
          end
        end

new (*)

Calls superclass method

# File activerecord/lib/active_record/connection_adapters/abstract/query_cache.rb, line 55
def initialize(*)
  super
  @query_cache         = {}
  @query_cache_enabled = false
  @query_cache_max_size = nil
end

Public Instance Methods

cache () { || ... }

Enable the query cache within the block.

# File activerecord/lib/active_record/connection_adapters/abstract/query_cache.rb, line 63
def cache
  old, @query_cache_enabled = @query_cache_enabled, true
  yield
ensure
  @query_cache_enabled = old
  clear_query_cache unless @query_cache_enabled
end

clear_query_cache ()

Clears the query cache.

One reason you may wish to call this method explicitly is between queries that ask the database to randomize results. Otherwise the cache would see the same SQL query and repeatedly return the same result each time, silently undermining the randomness you were expecting.

# File activerecord/lib/active_record/connection_adapters/abstract/query_cache.rb, line 94
def clear_query_cache
  @lock.synchronize do
    @query_cache.clear
  end
end

disable_query_cache! ()

# File activerecord/lib/active_record/connection_adapters/abstract/query_cache.rb, line 75
def disable_query_cache!
  @query_cache_enabled = false
  clear_query_cache
end

enable_query_cache! ()

# File activerecord/lib/active_record/connection_adapters/abstract/query_cache.rb, line 71
def enable_query_cache!
  @query_cache_enabled = true
end

uncached () { || ... }

Disable the query cache within the block.

# File activerecord/lib/active_record/connection_adapters/abstract/query_cache.rb, line 81
def uncached
  old, @query_cache_enabled = @query_cache_enabled, false
  yield
ensure
  @query_cache_enabled = old
end