From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Stefan Monnier Newsgroups: gmane.emacs.devel Subject: Re: master daea9b3 1/2: Read mailcaps again only when necessary Date: Mon, 01 Nov 2021 12:56:37 -0400 Message-ID: References: <20211101135344.25800.81476@vcs0.savannah.gnu.org> <20211101135346.2EBEB20B72@vcs0.savannah.gnu.org> Mime-Version: 1.0 Content-Type: text/plain Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="18277"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/28.0.50 (gnu/linux) Cc: Gregory Heytings To: emacs-devel@gnu.org Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Mon Nov 01 17:57:30 2021 Return-path: Envelope-to: ged-emacs-devel@m.gmane-mx.org Original-Received: from lists.gnu.org ([209.51.188.17]) by ciao.gmane.io with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1mhack-0004ZH-L8 for ged-emacs-devel@m.gmane-mx.org; Mon, 01 Nov 2021 17:57:30 +0100 Original-Received: from localhost ([::1]:57844 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1mhaci-0007i9-OS for ged-emacs-devel@m.gmane-mx.org; Mon, 01 Nov 2021 12:57:28 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:50084) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mhac2-000715-Bw for emacs-devel@gnu.org; Mon, 01 Nov 2021 12:56:46 -0400 Original-Received: from mailscanner.iro.umontreal.ca ([132.204.25.50]:19441) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mhabz-0007u9-91 for emacs-devel@gnu.org; Mon, 01 Nov 2021 12:56:45 -0400 Original-Received: from pmg3.iro.umontreal.ca (localhost [127.0.0.1]) by pmg3.iro.umontreal.ca (Proxmox) with ESMTP id 823DF440FE0; Mon, 1 Nov 2021 12:56:40 -0400 (EDT) Original-Received: from mail01.iro.umontreal.ca (unknown [172.31.2.1]) by pmg3.iro.umontreal.ca (Proxmox) with ESMTP id CF81D440C8B; Mon, 1 Nov 2021 12:56:38 -0400 (EDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=iro.umontreal.ca; s=mail; t=1635785798; bh=2cP6+4XSyyN3PPek9f8M2EfZxiS5isHb5cQKz1mDX3A=; h=From:To:Cc:Subject:References:Date:In-Reply-To:From; b=aZWwjuVAviRqabduebYzoAdHpDb0y98rMxgBBdysNGBTLlGYktoCCUeD6U4KwTyzK wOHKYMEVa6rQN4pwqSz4/MwvCKworwXKGq8HPhuSV3ON9c9cqq+GuKDLK7srQdKiJW Ve80TgjAg+5MCiKT8AQfJMlzDJqNvzW7SVPz6EnhLS/ZETmx7euAGGbMsAPXYWvC+d T6/3ibmTi6Vumm0oGYlcRLEORtaTLAC4gyTzcaY4Ino8Yai/2AjUgHBlOqsWwIHi+l Vv84gDXCLhSa1GDZp//pmzCPHwODtrWuzrO2+Lj/Fe8Ajv0FJ1Rtf8JkvBjTdM0htP 5jMDPCgP/AbrA== Original-Received: from alfajor (lechon.iro.umontreal.ca [132.204.27.242]) by mail01.iro.umontreal.ca (Postfix) with ESMTPSA id 968701204FE; Mon, 1 Nov 2021 12:56:38 -0400 (EDT) In-Reply-To: <20211101135346.2EBEB20B72@vcs0.savannah.gnu.org> (Lars Ingebrigtsen's message of "Mon, 1 Nov 2021 09:53:46 -0400 (EDT)") Received-SPF: pass client-ip=132.204.25.50; envelope-from=monnier@iro.umontreal.ca; helo=mailscanner.iro.umontreal.ca X-Spam_score_int: -42 X-Spam_score: -4.3 X-Spam_bar: ---- X-Spam_report: (-4.3 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, RCVD_IN_DNSWL_MED=-2.3, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: "Emacs development discussions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Original-Sender: "Emacs-devel" Xref: news.gmane.io gmane.emacs.devel:278400 Archived-At: > +(defun file-has-changed-p (file) > + "Return non-nil if FILE has changed. > +The modification time of FILE is compared to the modification > +time of FILE during a previous invocation of `file-has-changed-p'. > +Therefore the first invocation of `file-has-changed-p' always > +returns non-nil." > + (let* ((attr (file-attributes file 'integer)) > + (mtime (file-attribute-modification-time attr)) > + (saved-mtime (gethash (intern file) > + file-has-changed-p--hash-table))) > + (when (not (equal mtime saved-mtime)) > + (puthash (intern file) mtime file-has-changed-p--hash-table)))) This API doesn't seem safe. If two packages read&parse the same file and both rely on this function to decide when to reparse, the second package can get a nil value (because the first has caused the mtime to be reset in the hash table) even though the file has changed since it last parsed it. So I think the function needs a second argument which represents the "since when". It could be the hash-table. Side question: why use `intern`? Why not just pass `:test #'equal` to the `make-hash-table`? Stefan