text: # -*- coding: utf-8 -*-
  # Copyright 2016 OpenMarket Ltd
  #
  # Licensed under the Apache License, Version 2.0 (the "License");
  # you may not use this file except in compliance with the License.
  # You may obtain a copy of the License at
  #
  #     http://www.apache.org/licenses/LICENSE-2.0
  #
  # Unless required by applicable law or agreed to in writing, software
  # distributed under the License is distributed on an "AS IS" BASIS,
  # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  # See the License for the specific language governing permissions and
  # limitations under the License.
  
  from typing import List, Union
  
  import attr
  
  from ._base import Config, ConfigError, ShardedWorkerHandlingConfig
  from .server import ListenerConfig, parse_listener_def
  
  
  def _instance_to_list_converter(obj: Union[str, List[str]]) -> List[str]:
      """Helper for allowing parsing a string or list of strings to a config
      option expecting a list of strings.
      """
  
      if isinstance(obj, str):
          return [obj]
      return obj
  
  
  @attr.s
  class InstanceLocationConfig:
      """The host and port to talk to an instance via HTTP replication.
      """
  
      host = attr.ib(type=str)
      port = attr.ib(type=int)
  
  
  @attr.s
  class WriterLocations:
      """Specifies the instances that write various streams.
  
      Attributes:
          events: The instances that write to the event and backfill streams.
          typing: The instance that writes to the typing stream.
      """
  
      events = attr.ib(
          default=["master"], type=List[str], converter=_instance_to_list_converter
      )
      typing = attr.ib(default="master", type=str)
  
  
  class WorkerConfig(Config):
      """The workers are processes run separately to the main synapse process.
      They have their own pid_file and listener configuration. They use the
      replication_url to talk to the main synapse process."""
  
      section = "worker"
  
      def read_config(self, config, **kwargs):
          self.worker_app = config.get("worker_app")
  
          # Canonicalise worker_app so that master always has None
          if self.worker_app == "synapse.app.homeserver":
              self.worker_app = None
  
          self.worker_listeners = [
              parse_listener_def(x) for x in config.get("worker_listeners", [])
          ]
          self.worker_daemonize = config.get("worker_daemonize")
          self.worker_pid_file = config.get("worker_pid_file")
          self.worker_log_config = config.get("worker_log_config")
  
          # The host used to connect to the main synapse
          self.worker_replication_host = config.get("worker_replication_host", None)
  
          # The port on the main synapse for TCP replication
          self.worker_replication_port = config.get("worker_replication_port", None)
  
          # The port on the main synapse for HTTP replication endpoint
          self.worker_replication_http_port = config.get("worker_replication_http_port")
  
          self.worker_name = config.get("worker_name", self.worker_app)
  
          self.worker_main_http_uri = config.get("worker_main_http_uri", None)
  
          # This option is really only here to support `--manhole` command line
          # argument.
          manhole = config.get("worker_manhole")
          if manhole:
              self.worker_listeners.append(
                  ListenerConfig(
                      port=manhole, bind_addresses=["127.0.0.1"], type="manhole",
                  )
              )
  
          # Whether to send federation traffic out in this process. This only
          # applies to some federation traffic, and so shouldn't be used to
          # "disable" federation
          self.send_federation = config.get("send_federation", True)
  
          federation_sender_instances = config.get("federation_sender_instances") or []
          self.federation_shard_config = ShardedWorkerHandlingConfig(
              federation_sender_instances
          )
  
          # A map from instance name to host/port of their HTTP replication endpoint.
          instance_map = config.get("instance_map") or {}
          self.instance_map = {
              name: InstanceLocationConfig(**c) for name, c in instance_map.items()
          }
  
          # Map from type of streams to source, c.f. WriterLocations.
          writers = config.get("stream_writers") or {}
          self.writers = WriterLocations(**writers)
  
          # Check that the configured writers for events and typing also appears in
          # `instance_map`.
          for stream in ("events", "typing"):
              instances = _instance_to_list_converter(getattr(self.writers, stream))
              for instance in instances:
                  if instance != "master" and instance not in self.instance_map:
                      raise ConfigError(
                          "Instance %r is configured to write %s but does not appear in `instance_map` config."
                          % (instance, stream)
                      )
  
          self.events_shard_config = ShardedWorkerHandlingConfig(self.writers.events)
  
          # Whether this worker should run background tasks or not.
          #
          # As a note for developers, the background tasks guarded by this should
          # be able to run on only a single instance (meaning that they don't
          # depend on any in-memory state of a particular worker).
          #
          # No effort is made to ensure only a single instance of these tasks is
          # running.
          background_tasks_instance = config.get("run_background_tasks_on") or "master"
          self.run_background_tasks = (
              self.worker_name is None and background_tasks_instance == "master"
          ) or self.worker_name == background_tasks_instance
  
      def generate_config_section(self, config_dir_path, server_name, **kwargs):
          return """\
          ## Workers ##
  
          # Disables sending of outbound federation transactions on the main process.
          # Uncomment if using a federation sender worker.
          #
          #send_federation: false
  
          # It is possible to run multiple federation sender workers, in which case the
          # work is balanced across them.
          #
          # This configuration must be shared between all federation sender workers, and if
          # changed all federation sender workers must be stopped at the same time and then
          # started, to ensure that all instances are running with the same config (otherwise
          # events may be dropped).
          #
          #federation_sender_instances:
          #  - federation_sender1
  
          # When using workers this should be a map from `worker_name` to the
          # HTTP replication listener of the worker, if configured.
          #
          #instance_map:
          #  worker1:
          #    host: localhost
          #    port: 8034
  
          # Experimental: When using workers you can define which workers should
          # handle event persistence and typing notifications. Any worker
          # specified here must also be in the `instance_map`.
          #
          #stream_writers:
          #  events: worker1
          #  typing: worker1
  
          # The worker that is used to run background tasks (e.g. cleaning up expired
          # data). If not provided this defaults to the main process.
          #
          #run_background_tasks_on: worker1
          """
  
      def read_arguments(self, args):
          # We support a bunch of command line arguments that override options in
          # the config. A lot of these options have a worker_* prefix when running
          # on workers so we also have to override them when command line options
          # are specified.
  
          if args.daemonize is not None:
              self.worker_daemonize = args.daemonize
          if args.manhole is not None:
              self.worker_manhole = args.worker_manhole
  