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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id CABBBE71D36 for ; Fri, 29 Sep 2023 13:33:58 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qmDcQ-0003eH-1f; Fri, 29 Sep 2023 09:33:22 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qmDcO-0003ZE-MZ for qemu-devel@nongnu.org; Fri, 29 Sep 2023 09:33:20 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qmDcI-0001by-5j for qemu-devel@nongnu.org; Fri, 29 Sep 2023 09:33:20 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1695994393; h=from:from:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=w+7xgqJE1duQnFogGCbOhRpf4ZiPGJ0NJ2YmpPS1jTo=; b=Qb7rTaehDQGdCYsw5nPG3t2I8CZwwDVSYwUAjNo4KB0t3J5axXV6Ev1gwfdqm6Gb4Ozq7Q 5n8TgxYvDO1iuycwld19jMeo3HLIf8Kmten92eNEqb9qIlhONUiLG7+SDkGZyKwhlPUBUt M4svgFn+6vFAXcmXRKJJBVpw+hTLYXM= Received: from mimecast-mx02.redhat.com (mx-ext.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-73-e9LDS2dTP0uo7zmwcG_syA-1; Fri, 29 Sep 2023 09:33:11 -0400 X-MC-Unique: e9LDS2dTP0uo7zmwcG_syA-1 Received: from smtp.corp.redhat.com (int-mx09.intmail.prod.int.rdu2.redhat.com [10.11.54.9]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 7E6111C294C0 for ; Fri, 29 Sep 2023 13:33:11 +0000 (UTC) Received: from redhat.com (unknown [10.42.28.43]) by smtp.corp.redhat.com (Postfix) with ESMTPS id CD845492B16; Fri, 29 Sep 2023 13:33:10 +0000 (UTC) Date: Fri, 29 Sep 2023 14:33:08 +0100 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Victor Toso Cc: qemu-devel@nongnu.org, Markus Armbruster , John Snow Subject: Re: [PATCH v1 3/9] qapi: golang: Generate qapi's struct types in Go Message-ID: References: <20230927112544.85011-1-victortoso@redhat.com> <20230927112544.85011-4-victortoso@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: Mutt/2.2.9 (2022-11-12) X-Scanned-By: MIMEDefang 3.1 on 10.11.54.9 Received-SPF: pass client-ip=170.10.129.124; envelope-from=berrange@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: 12 X-Spam_score: 1.2 X-Spam_bar: + X-Spam_report: (1.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, RCVD_IN_SBL_CSS=3.335, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=no autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On Fri, Sep 29, 2023 at 03:29:34PM +0200, Victor Toso wrote: > Hi, > > On Thu, Sep 28, 2023 at 03:06:23PM +0100, Daniel P. Berrangé wrote: > > On Wed, Sep 27, 2023 at 01:25:38PM +0200, Victor Toso wrote: > > > This patch handles QAPI struct types and generates the equivalent > > > types in Go. The following patch adds extra logic when a member of the > > > struct has a Type that can take JSON Null value (e.g: StrOrNull in > > > QEMU) > > > > > > The highlights of this implementation are: > > > > > > 1. Generating an Go struct that requires a @base type, the @base type > > > fields are copied over to the Go struct. The advantage of this > > > approach is to not have embed structs in any of the QAPI types. > > > Note that embedding a @base type is recursive, that is, if the > > > @base type has a @base, all of those fields will be copied over. > > > > > > 2. About the Go struct's fields: > > > > > > i) They can be either by Value or Reference. > > > > > > ii) Every field that is marked as optional in the QAPI specification > > > are translated to Reference fields in its Go structure. This > > > design decision is the most straightforward way to check if a > > > given field was set or not. Exception only for types that can > > > take JSON Null value. > > > > > > iii) Mandatory fields are always by Value with the exception of QAPI > > > arrays, which are handled by Reference (to a block of memory) by > > > Go. > > > > > > iv) All the fields are named with Uppercase due Golang's export > > > convention. > > > > > > v) In order to avoid any kind of issues when encoding or decoding, > > > to or from JSON, we mark all fields with its @name and, when it is > > > optional, member, with @omitempty > > > > > > Example: > > > > > > qapi: > > > | { 'struct': 'BlockdevCreateOptionsFile', > > > | 'data': { 'filename': 'str', > > > | 'size': 'size', > > > | '*preallocation': 'PreallocMode', > > > | '*nocow': 'bool', > > > | '*extent-size-hint': 'size'} } > > > > > > go: > > > | type BlockdevCreateOptionsFile struct { > > > | Filename string `json:"filename"` > > > | Size uint64 `json:"size"` > > > | Preallocation *PreallocMode `json:"preallocation,omitempty"` > > > | Nocow *bool `json:"nocow,omitempty"` > > > | ExtentSizeHint *uint64 `json:"extent-size-hint,omitempty"` > > > | } > > > > Note, 'omitempty' shouldn't be used on pointer fields, only > > scalar fields. The pointer fields are always omitted when nil. > > 'omitempty' should be used with pointer fields unless you want to > Marshal JSON Null, which is not the expected output. Oh doh, did't notice that. With regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|