Merge pull request #5299 from matrix-org/rav/server_keys/05-rewrite-gsvk-again

Rewrite get_server_verify_keys, again.
This commit is contained in:
Richard van der Hoff 2019-05-31 17:07:31 +01:00 committed by GitHub
commit 37b165620d
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2 changed files with 54 additions and 48 deletions

1
changelog.d/5299.misc Normal file
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@ -0,0 +1 @@
Rewrite get_server_verify_keys, again.

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@ -280,59 +280,21 @@ class Keyring(object):
verify_requests (list[VerifyKeyRequest]): list of verify requests
"""
remaining_requests = set(
(rq for rq in verify_requests if not rq.deferred.called)
)
@defer.inlineCallbacks
def do_iterations():
with Measure(self.clock, "get_server_verify_keys"):
# dict[str, set(str)]: keys to fetch for each server
missing_keys = {}
for verify_request in verify_requests:
missing_keys.setdefault(verify_request.server_name, set()).update(
verify_request.key_ids
)
for f in self._key_fetchers:
results = yield f.get_keys(missing_keys.items())
# We now need to figure out which verify requests we have keys
# for and which we don't
missing_keys = {}
requests_missing_keys = []
for verify_request in verify_requests:
if verify_request.deferred.called:
# We've already called this deferred, which probably
# means that we've already found a key for it.
continue
server_name = verify_request.server_name
# see if any of the keys we got this time are sufficient to
# complete this VerifyKeyRequest.
result_keys = results.get(server_name, {})
for key_id in verify_request.key_ids:
fetch_key_result = result_keys.get(key_id)
if fetch_key_result:
with PreserveLoggingContext():
verify_request.deferred.callback(
(
server_name,
key_id,
fetch_key_result.verify_key,
)
)
break
else:
# The else block is only reached if the loop above
# doesn't break.
missing_keys.setdefault(server_name, set()).update(
verify_request.key_ids
)
requests_missing_keys.append(verify_request)
if not missing_keys:
break
if not remaining_requests:
return
yield self._attempt_key_fetches_with_fetcher(f, remaining_requests)
# look for any requests which weren't satisfied
with PreserveLoggingContext():
for verify_request in requests_missing_keys:
for verify_request in remaining_requests:
verify_request.deferred.errback(
SynapseError(
401,
@ -343,13 +305,56 @@ class Keyring(object):
)
def on_err(err):
# we don't really expect to get here, because any errors should already
# have been caught and logged. But if we do, let's log the error and make
# sure that all of the deferreds are resolved.
logger.error("Unexpected error in _get_server_verify_keys: %s", err)
with PreserveLoggingContext():
for verify_request in verify_requests:
for verify_request in remaining_requests:
if not verify_request.deferred.called:
verify_request.deferred.errback(err)
run_in_background(do_iterations).addErrback(on_err)
@defer.inlineCallbacks
def _attempt_key_fetches_with_fetcher(self, fetcher, remaining_requests):
"""Use a key fetcher to attempt to satisfy some key requests
Args:
fetcher (KeyFetcher): fetcher to use to fetch the keys
remaining_requests (set[VerifyKeyRequest]): outstanding key requests.
Any successfully-completed requests will be reomved from the list.
"""
# dict[str, set(str)]: keys to fetch for each server
missing_keys = {}
for verify_request in remaining_requests:
# any completed requests should already have been removed
assert not verify_request.deferred.called
missing_keys.setdefault(verify_request.server_name, set()).update(
verify_request.key_ids
)
results = yield fetcher.get_keys(missing_keys.items())
completed = list()
for verify_request in remaining_requests:
server_name = verify_request.server_name
# see if any of the keys we got this time are sufficient to
# complete this VerifyKeyRequest.
result_keys = results.get(server_name, {})
for key_id in verify_request.key_ids:
key = result_keys.get(key_id)
if key:
with PreserveLoggingContext():
verify_request.deferred.callback(
(server_name, key_id, key.verify_key)
)
completed.append(verify_request)
break
remaining_requests.difference_update(completed)
class KeyFetcher(object):
def get_keys(self, server_name_and_key_ids):