# File lib/active_record/connection_adapters/abstract/query_cache.rb, line 9 def dirties_query_cache(base, *method_names) method_names.each do |method_name| base.class_eval " def #{method_name}(*) # def update_with_query_dirty(*) clear_query_cache if @query_cache_enabled # clear_query_cache if @query_cache_enabled super # super end # end ", __FILE__, __LINE__ + 1 end end
Enable the query cache within the block.
# File lib/active_record/connection_adapters/abstract/query_cache.rb, line 24 def cache old, @query_cache_enabled = @query_cache_enabled, true yield ensure clear_query_cache @query_cache_enabled = old end
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 lib/active_record/connection_adapters/abstract/query_cache.rb, line 54 def clear_query_cache @query_cache.clear end
# File lib/active_record/connection_adapters/abstract/query_cache.rb, line 36 def disable_query_cache! @query_cache_enabled = false end
# File lib/active_record/connection_adapters/abstract/query_cache.rb, line 32 def enable_query_cache! @query_cache_enabled = true end
# File lib/active_record/connection_adapters/abstract/query_cache.rb, line 58 def select_all(arel, name = nil, binds = []) if @query_cache_enabled && !locked?(arel) sql = to_sql(arel, binds) cache_sql(sql, binds) { super(sql, name, binds) } else super end end
Disable the query cache within the block.
# File lib/active_record/connection_adapters/abstract/query_cache.rb, line 41 def uncached old, @query_cache_enabled = @query_cache_enabled, false yield ensure @query_cache_enabled = old end
# File lib/active_record/connection_adapters/abstract/query_cache.rb, line 69 def cache_sql(sql, binds) result = if @query_cache[sql].key?(binds) ActiveSupport::Notifications.instrument("sql.active_record", :sql => sql, :binds => binds, :name => "CACHE", :connection_id => object_id) @query_cache[sql][binds] else @query_cache[sql][binds] = yield end # FIXME: we should guarantee that all cached items are Result # objects. Then we can avoid this conditional if ActiveRecord::Result === result result.dup else result.collect { |row| row.dup } end end
If arel is locked this is a SELECT … FOR UPDATE or somesuch. Such queries should not be cached.
# File lib/active_record/connection_adapters/abstract/query_cache.rb, line 90 def locked?(arel) arel.respond_to?(:locked) && arel.locked end