From 6e1cb54a05df3dd614acb022a665458cc1c9698f Mon Sep 17 00:00:00 2001 From: Richard van der Hoff Date: Mon, 21 May 2018 16:58:20 +0100 Subject: Fix logcontext leak in HttpTransactionCache ONE DAY I WILL PURGE THE WORLD OF THIS EVIL --- synapse/rest/client/transactions.py | 46 +++++++++++++++++-------------------- 1 file changed, 21 insertions(+), 25 deletions(-) (limited to 'synapse/rest/client/transactions.py') diff --git a/synapse/rest/client/transactions.py b/synapse/rest/client/transactions.py index 93ce0f5348..20fa6678ef 100644 --- a/synapse/rest/client/transactions.py +++ b/synapse/rest/client/transactions.py @@ -19,6 +19,7 @@ import logging from synapse.api.auth import get_access_token_from_request from synapse.util.async import ObservableDeferred +from synapse.util.logcontext import make_deferred_yieldable, run_in_background logger = logging.getLogger(__name__) @@ -80,31 +81,26 @@ class HttpTransactionCache(object): Returns: Deferred which resolves to a tuple of (response_code, response_dict). """ - try: - return self.transactions[txn_key][0].observe() - except (KeyError, IndexError): - pass # execute the function instead. - - deferred = fn(*args, **kwargs) - - observable = ObservableDeferred(deferred, consumeErrors=False) - self.transactions[txn_key] = (observable, self.clock.time_msec()) - - # if the request fails with an exception, remove it from the - # transaction map. This is done to ensure that we don't cache - # transient errors like rate-limiting errors, etc. - # - # (make sure we add this errback *after* adding the key above, in case - # the deferred has already failed and is running errbacks - # synchronously) - def remove_from_map(err): - self.transactions.pop(txn_key, None) - # we deliberately do not propagate the error any further, as we - # expect the observers to have reported it. - - deferred.addErrback(remove_from_map) - - return observable.observe() + if txn_key in self.transactions: + observable = self.transactions[txn_key][0] + else: + # execute the function instead. + deferred = run_in_background(fn, *args, **kwargs) + + observable = ObservableDeferred(deferred) + self.transactions[txn_key] = (observable, self.clock.time_msec()) + + # if the request fails with an exception, remove it + # from the transaction map. This is done to ensure that we don't + # cache transient errors like rate-limiting errors, etc. + def remove_from_map(err): + self.transactions.pop(txn_key, None) + # we deliberately do not propagate the error any further, as we + # expect the observers to have reported it. + + deferred.addErrback(remove_from_map) + + return make_deferred_yieldable(observable.observe()) def _cleanup(self): now = self.clock.time_msec() -- cgit 1.4.1