Centralize cbor dumping and loading, for better control.

src/allmydata/storage/http_client.py

@@ -26,8 +26,6 @@ from attrs import define, asdict, frozen, field
 from eliot import start_action, register_exception_extractor
 from eliot.twisted import DeferredContext
 
-# TODO Make sure to import Python version?
-from cbor2 import loads, dumps
 from pycddl import Schema
 from collections_extended import RangeMap
 from werkzeug.datastructures import Range, ContentRange
@@ -65,6 +63,7 @@ from ..util.hashutil import timing_safe_compare
 from ..util.deferredutil import async_to_deferred
 from ..util.tor_provider import _Provider as TorProvider
 from ..util.cputhreadpool import defer_to_thread
+from ..util.cbor import dumps, loads
 
 try:
     from txtorcon import Tor  # type: ignore

src/allmydata/storage/http_server.py

@@ -57,8 +57,6 @@ from hyperlink import DecodedURL
 from cryptography.x509 import load_pem_x509_certificate
 
 
-# TODO Make sure to use pure Python versions?
-import cbor2
 from pycddl import Schema, ValidationError as CDDLValidationError
 from .server import StorageServer
 from .http_common import (
@@ -75,7 +73,8 @@ from ..util.hashutil import timing_safe_compare
 from ..util.base32 import rfc3548_alphabet
 from ..util.deferredutil import async_to_deferred
 from ..util.cputhreadpool import defer_to_thread
-from allmydata.interfaces import BadWriteEnablerError
+from ..util import cbor
+from ..interfaces import BadWriteEnablerError
 
 
 class ClientSecretsException(Exception):
@@ -647,7 +646,7 @@ async def read_encoded(
     # Typically deserialization to Python will not release the GIL, and
     # indeed as of Jan 2023 cbor2 didn't have any code to release the GIL
     # in the decode path. As such, running it in a different thread has no benefit.
-    return cbor2.load(request.content)
+    return cbor.load(request.content)
 
 
 class HTTPServer(BaseApp):
@@ -695,7 +694,7 @@ class HTTPServer(BaseApp):
         if accept.best == CBOR_MIME_TYPE:
             request.setHeader("Content-Type", CBOR_MIME_TYPE)
             f = TemporaryFile()
-            cbor2.dump(data, f)  # type: ignore
+            cbor.dump(data, f)  # type: ignore
 
             def read_data(offset: int, length: int) -> bytes:
                 f.seek(offset)

src/allmydata/test/test_storage_http.py

@@ -24,7 +24,6 @@ from contextlib import contextmanager
 from os import urandom
 from typing import Union, Callable, Tuple, Iterable
 from queue import Queue
-from cbor2 import dumps
 from pycddl import ValidationError as CDDLValidationError
 from hypothesis import assume, given, strategies as st, settings as hypothesis_settings
 from fixtures import Fixture, TempDir, MonkeyPatch
@@ -41,8 +40,8 @@ from werkzeug import routing
 from werkzeug.exceptions import NotFound as WNotFound
 from testtools.matchers import Equals
 from zope.interface import implementer
-import cbor2
 
+from ..util.cbor import dumps, loads
 from ..util.deferredutil import async_to_deferred
 from ..util.cputhreadpool import disable_thread_pool_for_test
 from .common import SyncTestCase
@@ -1845,5 +1844,5 @@ class MutableSharedTests(SharedImmutableMutableTestsMixin, SyncTestCase):
         for size in range(0, 65535*2, 17):
             self.assertEqual(
                 size,
-                len(cbor2.loads(cbor2.dumps(b"\12" * size)))
+                len(loads(dumps(b"\12" * size)))
             )

src/allmydata/util/cbor.py

@@ -0,0 +1,7 @@
+"""
+Unified entry point for CBOR encoding and decoding.
+"""
+
+from cbor2 import dumps, loads, dump, load
+
+__all__ = ["dumps", "loads", "dump", "load"]