text: # -*- coding: utf-8 -*-
  # Copyright 2014-2016 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 twisted.internet import defer
  
  from .persistence import TransactionActions
  from .units import Transaction
  
  from synapse.api.errors import HttpResponseException
  from synapse.util.async import run_on_reactor
  from synapse.util.logutils import log_function
  from synapse.util.logcontext import PreserveLoggingContext
  from synapse.util.retryutils import (
      get_retry_limiter, NotRetryingDestination,
  )
  import synapse.metrics
  
  import logging
  
  
  logger = logging.getLogger(__name__)
  
  metrics = synapse.metrics.get_metrics_for(__name__)
  
  
  class TransactionQueue(object):
      """This class makes sure we only have one transaction in flight at
      a time for a given destination.
  
      It batches pending PDUs into single transactions.
      """
  
      def __init__(self, hs, transport_layer):
          self.server_name = hs.hostname
  
          self.store = hs.get_datastore()
          self.transaction_actions = TransactionActions(self.store)
  
          self.transport_layer = transport_layer
  
          self._clock = hs.get_clock()
  
          # Is a mapping from destinations -> deferreds. Used to keep track
          # of which destinations have transactions in flight and when they are
          # done
          self.pending_transactions = {}
  
          metrics.register_callback(
              "pending_destinations",
              lambda: len(self.pending_transactions),
          )
  
          # Is a mapping from destination -> list of
          # tuple(pending pdus, deferred, order)
          self.pending_pdus_by_dest = pdus = {}
          # destination -> list of tuple(edu, deferred)
          self.pending_edus_by_dest = edus = {}
  
          metrics.register_callback(
              "pending_pdus",
              lambda: sum(map(len, pdus.values())),
          )
          metrics.register_callback(
              "pending_edus",
              lambda: sum(map(len, edus.values())),
          )
  
          # destination -> list of tuple(failure, deferred)
          self.pending_failures_by_dest = {}
  
          # HACK to get unique tx id
          self._next_txn_id = int(self._clock.time_msec())
  
      def can_send_to(self, destination):
          """Can we send messages to the given server?
  
          We can't send messages to ourselves. If we are running on localhost
          then we can only federation with other servers running on localhost.
          Otherwise we only federate with servers on a public domain.
  
          Args:
              destination(str): The server we are possibly trying to send to.
          Returns:
              bool: True if we can send to the server.
          """
  
          if destination == self.server_name:
              return False
          if self.server_name.startswith("localhost"):
              return destination.startswith("localhost")
          else:
              return not destination.startswith("localhost")
  
      def enqueue_pdu(self, pdu, destinations, order):
          # We loop through all destinations to see whether we already have
          # a transaction in progress. If we do, stick it in the pending_pdus
          # table and we'll get back to it later.
  
          destinations = set(destinations)
          destinations = set(
              dest for dest in destinations if self.can_send_to(dest)
          )
  
          logger.debug("Sending to: %s", str(destinations))
  
          if not destinations:
              return
  
          deferreds = []
  
          for destination in destinations:
              deferred = defer.Deferred()
              self.pending_pdus_by_dest.setdefault(destination, []).append(
                  (pdu, deferred, order)
              )
  
              def chain(failure):
                  if not deferred.called:
                      deferred.errback(failure)
  
              def log_failure(f):
                  logger.warn("Failed to send pdu to %s: %s", destination, f.value)
  
              deferred.addErrback(log_failure)
  
              with PreserveLoggingContext():
                  self._attempt_new_transaction(destination).addErrback(chain)
  
              deferreds.append(deferred)
  
      # NO inlineCallbacks
      def enqueue_edu(self, edu):
          destination = edu.destination
  
          if not self.can_send_to(destination):
              return
  
          deferred = defer.Deferred()
          self.pending_edus_by_dest.setdefault(destination, []).append(
              (edu, deferred)
          )
  
          def chain(failure):
              if not deferred.called:
                  deferred.errback(failure)
  
          def log_failure(f):
              logger.warn("Failed to send edu to %s: %s", destination, f.value)
  
          deferred.addErrback(log_failure)
  
          with PreserveLoggingContext():
              self._attempt_new_transaction(destination).addErrback(chain)
  
          return deferred
  
      @defer.inlineCallbacks
      def enqueue_failure(self, failure, destination):
          if destination == self.server_name or destination == "localhost":
              return
  
          deferred = defer.Deferred()
  
          if not self.can_send_to(destination):
              return
  
          self.pending_failures_by_dest.setdefault(
              destination, []
          ).append(
              (failure, deferred)
          )
  
          def chain(f):
              if not deferred.called:
                  deferred.errback(f)
  
          def log_failure(f):
              logger.warn("Failed to send failure to %s: %s", destination, f.value)
  
          deferred.addErrback(log_failure)
  
          with PreserveLoggingContext():
              self._attempt_new_transaction(destination).addErrback(chain)
  
          yield deferred
  
      @defer.inlineCallbacks
      @log_function
      def _attempt_new_transaction(self, destination):
          yield run_on_reactor()
  
          # list of (pending_pdu, deferred, order)
          if destination in self.pending_transactions:
              # XXX: pending_transactions can get stuck on by a never-ending
              # request at which point pending_pdus_by_dest just keeps growing.
              # we need application-layer timeouts of some flavour of these
              # requests
              logger.debug(
                  "TX [%s] Transaction already in progress",
                  destination
              )
              return
  
          pending_pdus = self.pending_pdus_by_dest.pop(destination, [])
          pending_edus = self.pending_edus_by_dest.pop(destination, [])
          pending_failures = self.pending_failures_by_dest.pop(destination, [])
  
          if pending_pdus:
              logger.debug("TX [%s] len(pending_pdus_by_dest[dest]) = %d",
                           destination, len(pending_pdus))
  
          if not pending_pdus and not pending_edus and not pending_failures:
              logger.debug("TX [%s] Nothing to send", destination)
              return
  
          try:
              self.pending_transactions[destination] = 1
  
              logger.debug("TX [%s] _attempt_new_transaction", destination)
  
              # Sort based on the order field
              pending_pdus.sort(key=lambda t: t[2])
  
              pdus = [x[0] for x in pending_pdus]
              edus = [x[0] for x in pending_edus]
              failures = [x[0].get_dict() for x in pending_failures]
              deferreds = [
                  x[1]
                  for x in pending_pdus + pending_edus + pending_failures
              ]
  
              txn_id = str(self._next_txn_id)
  
              limiter = yield get_retry_limiter(
                  destination,
                  self._clock,
                  self.store,
              )
  
              logger.debug(
                  "TX [%s] {%s} Attempting new transaction"
                  " (pdus: %d, edus: %d, failures: %d)",
                  destination, txn_id,
                  len(pending_pdus),
                  len(pending_edus),
                  len(pending_failures)
              )
  
              logger.debug("TX [%s] Persisting transaction...", destination)
  
              transaction = Transaction.create_new(
                  origin_server_ts=int(self._clock.time_msec()),
                  transaction_id=txn_id,
                  origin=self.server_name,
                  destination=destination,
                  pdus=pdus,
                  edus=edus,
                  pdu_failures=failures,
              )
  
              self._next_txn_id += 1
  
              yield self.transaction_actions.prepare_to_send(transaction)
  
              logger.debug("TX [%s] Persisted transaction", destination)
              logger.info(
                  "TX [%s] {%s} Sending transaction [%s],"
                  " (PDUs: %d, EDUs: %d, failures: %d)",
                  destination, txn_id,
                  transaction.transaction_id,
                  len(pending_pdus),
                  len(pending_edus),
                  len(pending_failures),
              )
  
              with limiter:
                  # Actually send the transaction
  
                  # FIXME (erikj): This is a bit of a hack to make the Pdu age
                  # keys work
                  def json_data_cb():
                      data = transaction.get_dict()
                      now = int(self._clock.time_msec())
                      if "pdus" in data:
                          for p in data["pdus"]:
                              if "age_ts" in p:
                                  unsigned = p.setdefault("unsigned", {})
                                  unsigned["age"] = now - int(p["age_ts"])
                                  del p["age_ts"]
                      return data
  
                  try:
                      response = yield self.transport_layer.send_transaction(
                          transaction, json_data_cb
                      )
                      code = 200
  
                      if response:
                          for e_id, r in response.get("pdus", {}).items():
                              if "error" in r:
                                  logger.warn(
                                      "Transaction returned error for %s: %s",
                                      e_id, r,
                                  )
                  except HttpResponseException as e:
                      code = e.code
                      response = e.response
  
                  logger.info(
                      "TX [%s] {%s} got %d response",
                      destination, txn_id, code
                  )
  
                  logger.debug("TX [%s] Sent transaction", destination)
                  logger.debug("TX [%s] Marking as delivered...", destination)
  
              yield self.transaction_actions.delivered(
                  transaction, code, response
              )
  
              logger.debug("TX [%s] Marked as delivered", destination)
  
              logger.debug("TX [%s] Yielding to callbacks...", destination)
  
              for deferred in deferreds:
                  if code == 200:
                      deferred.callback(None)
                  else:
                      deferred.errback(RuntimeError("Got status %d" % code))
  
                  # Ensures we don't continue until all callbacks on that
                  # deferred have fired
                  try:
                      yield deferred
                  except:
                      pass
  
              logger.debug("TX [%s] Yielded to callbacks", destination)
          except NotRetryingDestination:
              logger.info(
                  "TX [%s] not ready for retry yet - "
                  "dropping transaction for now",
                  destination,
              )
          except RuntimeError as e:
              # We capture this here as there as nothing actually listens
              # for this finishing functions deferred.
              logger.warn(
                  "TX [%s] Problem in _attempt_transaction: %s",
                  destination,
                  e,
              )
          except Exception as e:
              # We capture this here as there as nothing actually listens
              # for this finishing functions deferred.
              logger.warn(
                  "TX [%s] Problem in _attempt_transaction: %s",
                  destination,
                  e,
              )
  
              for deferred in deferreds:
                  if not deferred.called:
                      deferred.errback(e)
  
          finally:
              # We want to be *very* sure we delete this after we stop processing
              self.pending_transactions.pop(destination, None)
  
              # Check to see if there is anything else to send.
              self._attempt_new_transaction(destination)
  