From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 97750C433DB for ; Mon, 8 Feb 2021 21:06:12 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 14EE064E7A for ; Mon, 8 Feb 2021 21:06:11 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 14EE064E7A Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:45836 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1l9DjW-0007d8-NF for qemu-devel@archiver.kernel.org; Mon, 08 Feb 2021 16:06:10 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:44848) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1l98hj-0007XD-Ix for qemu-devel@nongnu.org; Mon, 08 Feb 2021 10:43:59 -0500 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:26386) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1l98hd-0001O7-Nr for qemu-devel@nongnu.org; Mon, 08 Feb 2021 10:43:59 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1612799033; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=MkuSG80/9qXY+jIKePksbW68QVeNYyHpdem3YSEdxwY=; b=Ea0CtnA+6LGB7rDaLOIBowxyNNL4PbWzELp1fJYRRNdpxvHBz1ofVQRDyZNFJm+01Z2aQB w8Lke4lnq0gzq8MeyrOThA9F7w5Y85xzGx4BTAn9Q/k5wIe+g6dwEleT5Mg+oyQf7IIxdk x5j1C2Yl5/UzLuyYbe+m/23nzGvYUEA= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-559-zcopPFfuPm2mzVhdW1IVQg-1; Mon, 08 Feb 2021 10:43:48 -0500 X-MC-Unique: zcopPFfuPm2mzVhdW1IVQg-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id B29651966323 for ; Mon, 8 Feb 2021 15:43:47 +0000 (UTC) Received: from blackfin.pond.sub.org (ovpn-115-51.ams2.redhat.com [10.36.115.51]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 5DF2D6085D; Mon, 8 Feb 2021 15:43:47 +0000 (UTC) Received: by blackfin.pond.sub.org (Postfix, from userid 1000) id E9767113865F; Mon, 8 Feb 2021 16:43:45 +0100 (CET) From: Markus Armbruster To: John Snow Subject: Re: [PATCH v5 13/15] qapi/introspect.py: add introspect.json dummy types References: <20210204003207.2856909-1-jsnow@redhat.com> <20210204003207.2856909-14-jsnow@redhat.com> Date: Mon, 08 Feb 2021 16:43:45 +0100 In-Reply-To: <20210204003207.2856909-14-jsnow@redhat.com> (John Snow's message of "Wed, 3 Feb 2021 19:32:05 -0500") Message-ID: <87czxa36q6.fsf@dusky.pond.sub.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.1 (gnu/linux) MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=armbru@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain Received-SPF: pass client-ip=216.205.24.124; envelope-from=armbru@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -33 X-Spam_score: -3.4 X-Spam_bar: --- X-Spam_report: (-3.4 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.57, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Cleber Rosa , qemu-devel@nongnu.org, Eduardo Habkost Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" John Snow writes: > Add some aliases that declare intent for some of the "dictly-typed" > objects we pass around in introspect.py. > > Signed-off-by: John Snow > > --- > > This patch is optional, it can be dropped if desired. If it's taken, > it's probably best to squash it with the prior patch. It is purely for > the sake of demonstrating what the _DObject was meant to convey: a > Python Dict that represents some JSON Object. It does not add any type > safety in and of itself, but does have some (light) annotational > benefit. In this case, it's usually a specific data structure from the > QAPI Schema we are referencing, but do not have "compile-time" access to > in Python. > > These are loosely typed and don't bother reproducing the exact structure > of the real types. Python 3.6 does not have support for TypedDict > structures, so this is as good as we can do without involving a > third-party library (e.g. Pydantic), in which we might be able to say: > > > class SchemaMetaType(str, enum.Enum): > BUILTIN = "builtin" > ENUM = "enum" > ARRAY = "array" > OBJECT = "object" > ALTERNATE = "alternate" > COMMAND = "command" > EVENT = "event" > > > class SchemaInfo(pydantic.BaseModel): > name: str > meta-type: SchemaMetaType > features: Optional[List[str]] > data: Union[SchemaInfoBuiltin, SchemaInfoEnum, SchemaInfoArray, > SchemaInfoObject, SchemaInfoAlternate, SchemaInfoCommand, > SchemaInfoEvent] > > > However, the cost of reproducing and keeping these structure definitions > in-sync between the user-defined portion of the schema and the code > generator is likely not worth doing any such thing. However, it does > illustrate an interesting dependency the generator has on the > user-defined schema itself in terms of types. > > So, I settled on using some light types that suggest the form of the > object instead of enforcing the form. > > Signed-off-by: John Snow > --- > scripts/qapi/introspect.py | 51 +++++++++++++++++++++++--------------- > 1 file changed, 31 insertions(+), 20 deletions(-) > > diff --git a/scripts/qapi/introspect.py b/scripts/qapi/introspect.py > index 3afcdda7446..2a39726f40a 100644 > --- a/scripts/qapi/introspect.py > +++ b/scripts/qapi/introspect.py > @@ -66,10 +66,15 @@ > _value = Union[_scalar, _nonscalar] > TreeValue = Union[_value, 'Annotated[_value]'] > > -# This is an alias for an arbitrary JSON object, represented here as a Dict. > -# It is stricter on the value type than the recursive definition above. > -# It is used to represent SchemaInfo-related structures exclusively. > -_DObject = Dict[str, object] > +# These types are based on structures defined in QEMU's schema, so we lack > +# precise types for them here. Python 3.6 does not offer TypedDict constructs, > +# so they are broadly typed here as simple Python Dicts. > +SchemaInfo = Dict[str, object] > +SchemaInfoObject = Dict[str, object] > +SchemaInfoObjectVariant = Dict[str, object] > +SchemaInfoObjectMember = Dict[str, object] > +SchemaInfoCommand = Dict[str, object] > + > > _NodeT = TypeVar('_NodeT', bound=_value) > > @@ -162,7 +167,7 @@ def __init__(self, prefix: str, unmask: bool): > ' * QAPI/QMP schema introspection', __doc__) > self._unmask = unmask > self._schema: Optional[QAPISchema] = None > - self._trees: List[Annotated[_DObject]] = [] > + self._trees: List[Annotated[SchemaInfo]] = [] > self._used_types: List[QAPISchemaType] = [] > self._name_map: Dict[str, str] = {} > self._genc.add(mcgen(''' > @@ -234,9 +239,18 @@ def _gen_features(features: List[QAPISchemaFeature] > ) -> List[Annotated[str]]: > return [Annotated(f.name, f.ifcond) for f in features] > > - def _gen_tree(self, name: str, mtype: str, obj: _DObject, > + def _gen_tree(self, name: str, mtype: str, obj: Dict[str, object], > ifcond: List[str], > features: Optional[List[QAPISchemaFeature]]) -> None: > + """ > + Build and append a SchemaInfo object to self._trees. > + > + :param name: The entity's name. > + :param mtype: The entity's meta-type. > + :param obj: Additional entity fields, as appropriate for the meta-type. > + :param ifcond: List of conditionals that apply to this entire entity. > + :param features: Optional features field for SchemaInfo. > + """ > comment: Optional[str] = None > if mtype not in ('command', 'event', 'builtin', 'array'): > if not self._unmask: > @@ -251,8 +265,8 @@ def _gen_tree(self, name: str, mtype: str, obj: _DObject, > self._trees.append(Annotated(obj, ifcond, comment)) > > def _gen_member(self, member: QAPISchemaObjectTypeMember > - ) -> Annotated[_DObject]: > - obj: _DObject = { > + ) -> Annotated[SchemaInfoObjectMember]: > + obj: SchemaInfoObjectMember = { > 'name': member.name, > 'type': self._use_type(member.type) > } > @@ -262,13 +276,9 @@ def _gen_member(self, member: QAPISchemaObjectTypeMember > obj['features'] = self._gen_features(member.features) > return Annotated(obj, member.ifcond) > > - def _gen_variants(self, tag_name: str, > - variants: List[QAPISchemaVariant]) -> _DObject: > - return {'tag': tag_name, > - 'variants': [self._gen_variant(v) for v in variants]} > - > - def _gen_variant(self, variant: QAPISchemaVariant) -> Annotated[_DObject]: > - obj: _DObject = { > + def _gen_variant(self, variant: QAPISchemaVariant > + ) -> Annotated[SchemaInfoObjectVariant]: > + obj: SchemaInfoObjectVariant = { > 'case': variant.name, > 'type': self._use_type(variant.type) > } > @@ -300,11 +310,12 @@ def visit_object_type_flat(self, name: str, info: Optional[QAPISourceInfo], > features: List[QAPISchemaFeature], > members: List[QAPISchemaObjectTypeMember], > variants: Optional[QAPISchemaVariants]) -> None: > - obj: _DObject = {'members': [self._gen_member(m) for m in members]} > + obj: SchemaInfoObject = { > + 'members': [self._gen_member(m) for m in members] > + } > if variants: > - obj.update(self._gen_variants(variants.tag_member.name, > - variants.variants)) > - > + obj['tag'] = variants.tag_member.name > + obj['variants'] = [self._gen_variant(v) for v in variants.variants] > self._gen_tree(name, 'object', obj, ifcond, features) > > def visit_alternate_type(self, name: str, info: Optional[QAPISourceInfo], > @@ -329,7 +340,7 @@ def visit_command(self, name: str, info: Optional[QAPISourceInfo], > > arg_type = arg_type or self._schema.the_empty_object_type > ret_type = ret_type or self._schema.the_empty_object_type > - obj: _DObject = { > + obj: SchemaInfoCommand = { > 'arg-type': self._use_type(arg_type), > 'ret-type': self._use_type(ret_type) > } I see what you mean by "some (light) annotational benefit". I figure some of is simply due to going from _DObject, a name that tells me nothing, to SchemaInfo, which makes me go aha! The remainder is having the subtypes of SchemaInfo, too. albeit without actual type checking. Worthwhile? I agree it should be squashed if we want it, or parts of it.