remote repos: remove support for borg < 1.1.0 (rpc data format, version)

rpc format:
ancient borg used tuples in the rpc protocol,
but recent ones use easier-to-work-with dicts.

version info:
we expect dicts with server/client version now.

src/borg/remote.py

@@ -36,7 +36,6 @@ from .helpers.datastruct import EfficientCollectionQueue
 
 logger = create_logger(__name__)
 
-RPC_PROTOCOL_VERSION = 2
 BORG_VERSION = parse_version(__version__)
 MSGID, MSG, ARGS, RESULT = "i", "m", "a", "r"
 
@@ -101,12 +100,7 @@ class UnexpectedRPCDataFormatFromServer(Error):
 # In general the server is responsible for rejecting too old clients and the client it responsible for rejecting
 # too old servers. This ensures that the knowledge what is compatible is always held by the newer component.
 #
-# The server can do checks for the client version in RepositoryServer.negotiate. If the client_data is 2 then
-# client is in the version range [0.29.0, 1.0.x] inclusive. For newer clients client_data is a dict which contains
-# client_version.
-#
-# For the client the return of the negotiate method is either 2 if the server is in the version range [0.29.0, 1.0.x]
-# inclusive, or it is a dict which includes the server version.
+# For the client the return of the negotiate method is a dict which includes the server version.
 #
 # All method calls on the remote repository object must be allowlisted in RepositoryServer.rpc_methods and have api
 # stubs in RemoteRepository. The @api decorator on these stubs is used to set server version requirements.
@@ -118,25 +112,6 @@ class UnexpectedRPCDataFormatFromServer(Error):
 # servers still get compatible input.
 
 
-compatMap = {
-    "check": ("repair",),
-    "commit": (),
-    "rollback": (),
-    "destroy": (),
-    "__len__": (),
-    "list": ("limit", "marker"),
-    "put": ("id", "data"),
-    "get": ("id",),
-    "delete": ("id",),
-    "save_key": ("keydata",),
-    "load_key": (),
-    "break_lock": (),
-    "negotiate": ("client_data",),
-    "open": ("path", "create", "lock_wait", "lock", "exclusive", "append_only"),
-    "info": (),
-}
-
-
 class RepositoryServer:  # pragma: no cover
     rpc_methods = (
         "__len__",
@@ -170,21 +145,7 @@ class RepositoryServer:  # pragma: no cover
         # (see RepositoryServer.open below).
         self.append_only = append_only
         self.storage_quota = storage_quota
-        self.client_version = parse_version(
-            "1.0.8"
-        )  # fallback version if client is too old to send version information
-
-    def positional_to_named(self, method, argv):
-        """Translate from positional protocol to named protocol."""
-        try:
-            return {name: argv[pos] for pos, name in enumerate(compatMap[method])}
-        except IndexError:
-            if method == "open" and len(argv) == 4:
-                # borg clients < 1.0.7 use open() with 4 args
-                mapping = compatMap[method][:4]
-            else:
-                raise
-            return {name: argv[pos] for pos, name in enumerate(mapping)}
+        self.client_version = None  # we update this after client sends version information
 
     def filter_args(self, f, kwargs):
         """Remove unknown named parameters from call, because client did (implicitly) say it's ok."""
@@ -217,15 +178,9 @@ class RepositoryServer:  # pragma: no cover
                 unpacker.feed(data)
                 for unpacked in unpacker:
                     if isinstance(unpacked, dict):
-                        dictFormat = True
                         msgid = unpacked[MSGID]
                         method = unpacked[MSG]
                         args = unpacked[ARGS]
-                    elif isinstance(unpacked, tuple) and len(unpacked) == 4:
-                        dictFormat = False
-                        # The first field 'type' was always 1 and has always been ignored
-                        _, msgid, method, args = unpacked
-                        args = self.positional_to_named(method, args)
                     else:
                         if self.repository is not None:
                             self.repository.close()
@@ -240,82 +195,53 @@ class RepositoryServer:  # pragma: no cover
                         args = self.filter_args(f, args)
                         res = f(**args)
                     except BaseException as e:
-                        if dictFormat:
-                            ex_short = traceback.format_exception_only(e.__class__, e)
-                            ex_full = traceback.format_exception(*sys.exc_info())
-                            ex_trace = True
-                            if isinstance(e, Error):
-                                ex_short = [e.get_message()]
-                                ex_trace = e.traceback
-                            if isinstance(e, (Repository.DoesNotExist, Repository.AlreadyExists, PathNotAllowed)):
-                                # These exceptions are reconstructed on the client end in RemoteRepository.call_many(),
-                                # and will be handled just like locally raised exceptions. Suppress the remote traceback
-                                # for these, except ErrorWithTraceback, which should always display a traceback.
-                                pass
-                            else:
-                                logging.debug("\n".join(ex_full))
-
-                            try:
-                                msg = msgpack.packb(
-                                    {
-                                        MSGID: msgid,
-                                        "exception_class": e.__class__.__name__,
-                                        "exception_args": e.args,
-                                        "exception_full": ex_full,
-                                        "exception_short": ex_short,
-                                        "exception_trace": ex_trace,
-                                        "sysinfo": sysinfo(),
-                                    }
-                                )
-                            except TypeError:
-                                msg = msgpack.packb(
-                                    {
-                                        MSGID: msgid,
-                                        "exception_class": e.__class__.__name__,
-                                        "exception_args": [
-                                            x if isinstance(x, (str, bytes, int)) else None for x in e.args
-                                        ],
-                                        "exception_full": ex_full,
-                                        "exception_short": ex_short,
-                                        "exception_trace": ex_trace,
-                                        "sysinfo": sysinfo(),
-                                    }
-                                )
-
-                            os_write(stdout_fd, msg)
+                        ex_short = traceback.format_exception_only(e.__class__, e)
+                        ex_full = traceback.format_exception(*sys.exc_info())
+                        ex_trace = True
+                        if isinstance(e, Error):
+                            ex_short = [e.get_message()]
+                            ex_trace = e.traceback
+                        if isinstance(e, (Repository.DoesNotExist, Repository.AlreadyExists, PathNotAllowed)):
+                            # These exceptions are reconstructed on the client end in RemoteRepository.call_many(),
+                            # and will be handled just like locally raised exceptions. Suppress the remote traceback
+                            # for these, except ErrorWithTraceback, which should always display a traceback.
+                            pass
                         else:
-                            if isinstance(e, (Repository.DoesNotExist, Repository.AlreadyExists, PathNotAllowed)):
-                                # These exceptions are reconstructed on the client end in RemoteRepository.call_many(),
-                                # and will be handled just like locally raised exceptions. Suppress the remote traceback
-                                # for these, except ErrorWithTraceback, which should always display a traceback.
-                                pass
-                            else:
-                                if isinstance(e, Error):
-                                    tb_log_level = logging.ERROR if e.traceback else logging.DEBUG
-                                    msg = e.get_message()
-                                else:
-                                    tb_log_level = logging.ERROR
-                                    msg = "%s Exception in RPC call" % e.__class__.__name__
-                                tb = f"{traceback.format_exc()}\n{sysinfo()}"
-                                logging.error(msg)
-                                logging.log(tb_log_level, tb)
-                            exc = "Remote Exception (see remote log for the traceback)"
-                            os_write(stdout_fd, msgpack.packb((1, msgid, e.__class__.__name__, exc)))
+                            logging.debug("\n".join(ex_full))
+
+                        try:
+                            msg = msgpack.packb(
+                                {
+                                    MSGID: msgid,
+                                    "exception_class": e.__class__.__name__,
+                                    "exception_args": e.args,
+                                    "exception_full": ex_full,
+                                    "exception_short": ex_short,
+                                    "exception_trace": ex_trace,
+                                    "sysinfo": sysinfo(),
+                                }
+                            )
+                        except TypeError:
+                            msg = msgpack.packb(
+                                {
+                                    MSGID: msgid,
+                                    "exception_class": e.__class__.__name__,
+                                    "exception_args": [x if isinstance(x, (str, bytes, int)) else None for x in e.args],
+                                    "exception_full": ex_full,
+                                    "exception_short": ex_short,
+                                    "exception_trace": ex_trace,
+                                    "sysinfo": sysinfo(),
+                                }
+                            )
+
+                        os_write(stdout_fd, msg)
                     else:
-                        if dictFormat:
-                            os_write(stdout_fd, msgpack.packb({MSGID: msgid, RESULT: res}))
-                        else:
-                            os_write(stdout_fd, msgpack.packb((1, msgid, None, res)))
+                        os_write(stdout_fd, msgpack.packb({MSGID: msgid, RESULT: res}))
             if es:
                 self.repository.close()
                 return
 
     def negotiate(self, client_data):
-        # old format used in 1.0.x
-        if client_data == RPC_PROTOCOL_VERSION:
-            return RPC_PROTOCOL_VERSION
-        # clients since 1.1.0b3 use a dict as client_data
-        # clients since 1.1.0b6 support json log format from server
         if isinstance(client_data, dict):
             self.client_version = client_data["client_version"]
             level = logging.getLevelName(logging.getLogger("").level)
@@ -538,9 +464,6 @@ class RemoteRepository:
         def required_version(self):
             return self.args[1]
 
-    # If compatibility with 1.0.x is not longer needed, replace all checks of this with True and simplify the code
-    dictFormat = False  # outside of __init__ for testing of legacy free protocol
-
     def __init__(
         self,
         location,
@@ -567,9 +490,7 @@ class RemoteRepository:
         self.ratelimit = SleepingBandwidthLimiter(args.upload_ratelimit * 1024 if args and args.upload_ratelimit else 0)
         self.upload_buffer_size_limit = args.upload_buffer * 1024 * 1024 if args and args.upload_buffer else 0
         self.unpacker = get_limited_unpacker("client")
-        self.server_version = parse_version(
-            "1.0.8"
-        )  # fallback version if server is too old to send version information
+        self.server_version = None  # we update this after server sends its version
         self.p = None
         self._args = args
         testing = location.host == "__testsuite__"
@@ -597,51 +518,24 @@ class RemoteRepository:
                 version = self.call("negotiate", {"client_data": {"client_version": BORG_VERSION}})
             except ConnectionClosed:
                 raise ConnectionClosedWithHint("Is borg working on the server?") from None
-            if version == RPC_PROTOCOL_VERSION:
-                self.dictFormat = False
-            elif isinstance(version, dict) and "server_version" in version:
-                self.dictFormat = True
+            if isinstance(version, dict):
                 self.server_version = version["server_version"]
             else:
                 raise Exception("Server insisted on using unsupported protocol version %s" % version)
 
-            def do_open():
-                self.id = self.open(
-                    path=self.location.path,
-                    create=create,
-                    lock_wait=lock_wait,
-                    lock=lock,
-                    exclusive=exclusive,
-                    append_only=append_only,
-                    make_parent_dirs=make_parent_dirs,
-                )
-                info = self.info()
-                self.version = info["version"]
-                self.append_only = info["append_only"]
+            self.id = self.open(
+                path=self.location.path,
+                create=create,
+                lock_wait=lock_wait,
+                lock=lock,
+                exclusive=exclusive,
+                append_only=append_only,
+                make_parent_dirs=make_parent_dirs,
+            )
+            info = self.info()
+            self.version = info["version"]
+            self.append_only = info["append_only"]
 
-            if self.dictFormat:
-                do_open()
-            else:
-                # Ugly detection of versions prior to 1.0.7: If open throws it has to be 1.0.6 or lower
-                try:
-                    do_open()
-                except self.RPCError as err:
-                    if err.exception_class != "TypeError":
-                        raise
-                    msg = """\
-Please note:
-If you see a TypeError complaining about the number of positional arguments
-given to open(), you can ignore it if it comes from a borg version < 1.0.7.
-This TypeError is a cosmetic side effect of the compatibility code borg
-clients >= 1.0.7 have to support older borg servers.
-This problem will go away as soon as the server has been upgraded to 1.0.7+.
-"""
-                    # emit this msg in the same way as the 'Remote: ...' lines that show the remote TypeError
-                    sys.stderr.write(msg)
-                    self.server_version = parse_version("1.0.6")
-                    compatMap["open"] = ("path", "create", "lock_wait", "lock")
-                    # try again with corrected version and compatMap
-                    do_open()
         except Exception:
             self.close()
             raise
@@ -738,9 +632,6 @@ This problem will go away as soon as the server has been upgraded to 1.0.7+.
             args.append("%s" % location.host)
         return args
 
-    def named_to_positional(self, method, kwargs):
-        return [kwargs[name] for name in compatMap[method]]
-
     def call(self, cmd, args, **kw):
         for resp in self.call_many(cmd, [args], **kw):
             return resp
@@ -863,14 +754,6 @@ This problem will go away as soon as the server has been upgraded to 1.0.7+.
                     for unpacked in self.unpacker:
                         if isinstance(unpacked, dict):
                             msgid = unpacked[MSGID]
-                        elif isinstance(unpacked, tuple) and len(unpacked) == 4:
-                            # The first field 'type' was always 1 and has always been ignored
-                            _, msgid, error, res = unpacked
-                            if error:
-                                # ignore res, because it is only a fixed string anyway.
-                                unpacked = {MSGID: msgid, "exception_class": error}
-                            else:
-                                unpacked = {MSGID: msgid, RESULT: res}
                         else:
                             raise UnexpectedRPCDataFormatFromServer(data)
                         if msgid in self.ignore_responses:
@@ -918,23 +801,13 @@ This problem will go away as soon as the server has been upgraded to 1.0.7+.
                             else:
                                 self.msgid += 1
                                 waiting_for.append(self.msgid)
-                                if self.dictFormat:
-                                    self.to_send.push_back(msgpack.packb({MSGID: self.msgid, MSG: cmd, ARGS: args}))
-                                else:
-                                    self.to_send.push_back(
-                                        msgpack.packb((1, self.msgid, cmd, self.named_to_positional(cmd, args)))
-                                    )
+                                self.to_send.push_back(msgpack.packb({MSGID: self.msgid, MSG: cmd, ARGS: args}))
                     if not self.to_send and self.preload_ids:
                         chunk_id = self.preload_ids.pop(0)
                         args = {"id": chunk_id}
                         self.msgid += 1
                         self.chunkid_to_msgids.setdefault(chunk_id, []).append(self.msgid)
-                        if self.dictFormat:
-                            self.to_send.push_back(msgpack.packb({MSGID: self.msgid, MSG: "get", ARGS: args}))
-                        else:
-                            self.to_send.push_back(
-                                msgpack.packb((1, self.msgid, "get", self.named_to_positional("get", args)))
-                            )
+                        self.to_send.push_back(msgpack.packb({MSGID: self.msgid, MSG: "get", ARGS: args}))
 
                 send_buffer()
         self.ignore_responses |= set(waiting_for)  # we lose order here

src/borg/testsuite/repository.py

@@ -1047,34 +1047,6 @@ class RemoteRepositoryTestCase(RepositoryTestCase):
         assert self.repository.ssh_cmd(Location("ssh://example.com/foo")) == ["ssh", "-i", "foo", "example.com"]
 
 
-class RemoteLegacyFree(RepositoryTestCaseBase):
-    # Keep testing this so we can someday safely remove the legacy tuple format.
-
-    def open(self, create=False):
-        with patch.object(RemoteRepository, "dictFormat", True):
-            return RemoteRepository(
-                Location("ssh://__testsuite__" + os.path.join(self.tmppath, "repository")),
-                exclusive=True,
-                create=create,
-            )
-
-    def test_legacy_free(self):
-        # put
-        self.repository.put(H(0), fchunk(b"foo"))
-        self.repository.commit(compact=False)
-        self.repository.close()
-        # replace
-        self.repository = self.open()
-        with self.repository:
-            self.repository.put(H(0), fchunk(b"bar"))
-            self.repository.commit(compact=False)
-        # delete
-        self.repository = self.open()
-        with self.repository:
-            self.repository.delete(H(0))
-            self.repository.commit(compact=False)
-
-
 class RemoteRepositoryCheckTestCase(RepositoryCheckTestCase):
     def open(self, create=False):
         return RemoteRepository(