From f901806559cce23b4a1c21c3e8447419a708a97a Mon Sep 17 00:00:00 2001
From: Jean-Paul Calderone <exarkun@twistedmatrix.com>
Date: Thu, 10 Oct 2019 13:00:01 -0400
Subject: [PATCH] Avoid spending passes on slot_testv_and_readv_and_writev
calls without writes
---
src/_zkapauthorizer/_storage_client.py | 7 ++++++-
src/_zkapauthorizer/_storage_server.py | 4 +++-
.../tests/test_storage_protocol.py | 18 +++++++++++++++---
3 files changed, 24 insertions(+), 5 deletions(-)
diff --git a/src/_zkapauthorizer/_storage_client.py b/src/_zkapauthorizer/_storage_client.py
index 7eebdc5..eafc119 100644
--- a/src/_zkapauthorizer/_storage_client.py
+++ b/src/_zkapauthorizer/_storage_client.py
@@ -37,6 +37,7 @@ from .storage_common import (
add_lease_message,
renew_lease_message,
slot_testv_and_readv_and_writev_message,
+ has_writes,
)
@implementer(IStorageServer)
@@ -170,9 +171,13 @@ class ZKAPAuthorizerStorageClient(object):
tw_vectors,
r_vector,
):
+ if has_writes(tw_vectors):
+ passes = self._get_encoded_passes(slot_testv_and_readv_and_writev_message(storage_index), 1)
+ else:
+ passes = []
return self._rref.callRemote(
"slot_testv_and_readv_and_writev",
- self._get_encoded_passes(slot_testv_and_readv_and_writev_message(storage_index), 1),
+ passes,
storage_index,
secrets,
tw_vectors,
diff --git a/src/_zkapauthorizer/_storage_server.py b/src/_zkapauthorizer/_storage_server.py
index 7ae60c3..b95eb3b 100644
--- a/src/_zkapauthorizer/_storage_server.py
+++ b/src/_zkapauthorizer/_storage_server.py
@@ -246,7 +246,9 @@ class ZKAPAuthorizerStorageServer(Referenceable):
self._clock.seconds(),
):
# Passes may be supplied with the write to create the
- # necessary lease as part of the same operation.
+ # necessary lease as part of the same operation. This must be
+ # supported because there is no separate protocol action to
+ # *create* a slot. Clients just begin writing to it.
valid_passes = self._validate_passes(
slot_testv_and_readv_and_writev_message(storage_index),
passes,
diff --git a/src/_zkapauthorizer/tests/test_storage_protocol.py b/src/_zkapauthorizer/tests/test_storage_protocol.py
index c736881..d0fe8bb 100644
--- a/src/_zkapauthorizer/tests/test_storage_protocol.py
+++ b/src/_zkapauthorizer/tests/test_storage_protocol.py
@@ -159,14 +159,21 @@ def assume_one_pass(test_and_write_vectors_for_shares):
class ShareTests(TestCase):
"""
Tests for interaction with shares.
+
+ :ivar int spent_passes: The number of passes which have been spent so far
+ in the course of a single test (in the case of Hypothesis, every
+ iteration of the test so far, probably; so make relative comparisons
+ instead of absolute ones).
"""
def setUp(self):
super(ShareTests, self).setUp()
self.canary = LocalReferenceable(None)
self.anonymous_storage_server = self.useFixture(AnonymousStorageServer()).storage_server
self.signing_key = random_signing_key()
+ self.spent_passes = 0
def get_passes(message, count):
+ self.spent_passes += count
return list(
Pass(pass_.decode("ascii"))
for pass_
@@ -397,7 +404,7 @@ class ShareTests(TestCase):
def test_create_mutable(self, storage_index, secrets, test_and_write_vectors_for_shares):
"""
Mutable share data written using *slot_testv_and_readv_and_writev* can be
- read back.
+ read back as-written and without spending any more passes.
"""
# XXX
assume_one_pass(test_and_write_vectors_for_shares)
@@ -418,19 +425,24 @@ class ShareTests(TestCase):
r_vector=[],
),
)
-
self.assertThat(
wrote,
Equals(True),
u"Server rejected a write to a new mutable slot",
)
-
self.assertThat(
read,
Equals({}),
u"Server gave back read results when we asked for none.",
)
+ # Now we can read it back without spending any more passes.
+ before_spent_passes = self.spent_passes
assert_read_back_data(self, storage_index, secrets, test_and_write_vectors_for_shares)
+ after_spent_passes = self.spent_passes
+ self.assertThat(
+ before_spent_passes,
+ Equals(after_spent_passes),
+ )
@given(
storage_index=storage_indexes(),
--
GitLab