diff options
Diffstat (limited to 'activerecord/lib/active_record/connection_handling.rb')
| -rw-r--r-- | activerecord/lib/active_record/connection_handling.rb | 68 |
1 files changed, 55 insertions, 13 deletions
diff --git a/activerecord/lib/active_record/connection_handling.rb b/activerecord/lib/active_record/connection_handling.rb index 3ce9aad5fc..c8cefa9906 100644 --- a/activerecord/lib/active_record/connection_handling.rb +++ b/activerecord/lib/active_record/connection_handling.rb @@ -85,14 +85,14 @@ module ActiveRecord # based on the requested role: # # ActiveRecord::Base.connected_to(role: :writing) do - # Dog.create! # creates dog using dog connection + # Dog.create! # creates dog using dog writing connection # end # # ActiveRecord::Base.connected_to(role: :reading) do # Dog.create! # throws exception because we're on a replica # end # - # ActiveRecord::Base.connected_to(role: :unknown_ode) do + # ActiveRecord::Base.connected_to(role: :unknown_role) do # # raises exception due to non-existent role # end # @@ -100,11 +100,20 @@ module ActiveRecord # you can use +connected_to+ with a +database+ argument. The +database+ argument # expects a symbol that corresponds to the database key in your config. # - # This will connect to a new database for the queries inside the block. - # # ActiveRecord::Base.connected_to(database: :animals_slow_replica) do # Dog.run_a_long_query # runs a long query while connected to the +animals_slow_replica+ # end + # + # This will connect to a new database for the queries inside the block. By + # default the `:writing` role will be used since all connections must be assigned + # a role. If you would like to use a different role you can pass a hash to database: + # + # ActiveRecord::Base.connected_to(database: { readonly_slow: :animals_slow_replica }) do + # # runs a long query while connected to the +animals_slow_replica+ using the readonly_slow role. + # Dog.run_a_long_query + # end + # + # When using the database key a new connection will be established every time. def connected_to(database: nil, role: nil, &blk) if database && role raise ArgumentError, "connected_to can only accept a `database` or a `role` argument, but not both arguments." @@ -112,17 +121,14 @@ module ActiveRecord if database.is_a?(Hash) role, database = database.first role = role.to_sym - else - role = database.to_sym end config_hash = resolve_config_for_connection(database) handler = lookup_connection_handler(role) - with_handler(role) do - handler.establish_connection(config_hash) - yield - end + handler.establish_connection(config_hash) + + with_handler(role, &blk) elsif role with_handler(role.to_sym, &blk) else @@ -130,7 +136,31 @@ module ActiveRecord end end + # Returns true if role is the current connected role. + # + # ActiveRecord::Base.connected_to(role: :writing) do + # ActiveRecord::Base.connected_to?(role: :writing) #=> true + # ActiveRecord::Base.connected_to?(role: :reading) #=> false + # end + def connected_to?(role:) + current_role == role.to_sym + end + + # Returns the symbol representing the current connected role. + # + # ActiveRecord::Base.connected_to(role: :writing) do + # ActiveRecord::Base.current_role #=> :writing + # end + # + # ActiveRecord::Base.connected_to(role: :reading) do + # ActiveRecord::Base.current_role #=> :reading + # end + def current_role + connection_handlers.key(connection_handler) + end + def lookup_connection_handler(handler_key) # :nodoc: + handler_key ||= ActiveRecord::Base.writing_role connection_handlers[handler_key] ||= ActiveRecord::ConnectionAdapters::ConnectionHandler.new end @@ -143,7 +173,7 @@ module ActiveRecord raise "Anonymous class is not allowed." unless name config_or_env ||= DEFAULT_ENV.call.to_sym - pool_name = self == Base ? "primary" : name + pool_name = primary_class? ? "primary" : name self.connection_specification_name = pool_name resolver = ConnectionAdapters::ConnectionSpecification::Resolver.new(Base.configurations) @@ -153,6 +183,15 @@ module ActiveRecord config_hash end + # Clears the query cache for all connections associated with the current thread. + def clear_query_caches_for_current_thread + ActiveRecord::Base.connection_handlers.each_value do |handler| + handler.connection_pool_list.each do |pool| + pool.connection.clear_query_cache if pool.active_connection? + end + end + end + # Returns the connection currently associated with the class. This can # also be used to "borrow" the connection to do database work unrelated # to any of the specific Active Records. @@ -165,11 +204,15 @@ module ActiveRecord # Return the specification name from the current class or its parent. def connection_specification_name if !defined?(@connection_specification_name) || @connection_specification_name.nil? - return self == Base ? "primary" : superclass.connection_specification_name + return primary_class? ? "primary" : superclass.connection_specification_name end @connection_specification_name end + def primary_class? # :nodoc: + self == Base || defined?(ApplicationRecord) && self == ApplicationRecord + end + # Returns the configuration of the associated connection as a hash: # # ActiveRecord::Base.connection_config @@ -213,7 +256,6 @@ module ActiveRecord :clear_all_connections!, :flush_idle_connections!, to: :connection_handler private - def swap_connection_handler(handler, &blk) # :nodoc: old_handler, ActiveRecord::Base.connection_handler = ActiveRecord::Base.connection_handler, handler yield |