From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Michael Heerdegen Newsgroups: gmane.emacs.help Subject: Re: [External] : Passing buffers to function in elisp Date: Sat, 25 Feb 2023 12:23:22 +0100 Message-ID: <87pm9yf0ph.fsf@web.de> References: <87mt56hg4e.fsf@iki.fi> <87bklihln8.fsf@iki.fi> Mime-Version: 1.0 Content-Type: text/plain Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="33356"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Gnus/5.13 (Gnus v5.13) To: help-gnu-emacs@gnu.org Cancel-Lock: sha1:O9h/VKgC/45M/uhPkeVwnILR9cg= Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane-mx.org@gnu.org Sat Feb 25 12:24:04 2023 Return-path: Envelope-to: geh-help-gnu-emacs@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 1pVsep-0008P2-04 for geh-help-gnu-emacs@m.gmane-mx.org; Sat, 25 Feb 2023 12:24:03 +0100 Original-Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1pVseN-0001m2-U9; Sat, 25 Feb 2023 06:23:36 -0500 Original-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 1pVseM-0001lp-B9 for help-gnu-emacs@gnu.org; Sat, 25 Feb 2023 06:23:34 -0500 Original-Received: from ciao.gmane.io ([116.202.254.214]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pVseK-0005tM-BB for help-gnu-emacs@gnu.org; Sat, 25 Feb 2023 06:23:34 -0500 Original-Received: from list by ciao.gmane.io with local (Exim 4.92) (envelope-from ) id 1pVseI-0007lu-2o for help-gnu-emacs@gnu.org; Sat, 25 Feb 2023 12:23:30 +0100 X-Injected-Via-Gmane: http://gmane.org/ Received-SPF: pass client-ip=116.202.254.214; envelope-from=geh-help-gnu-emacs@m.gmane-mx.org; helo=ciao.gmane.io X-Spam_score_int: -13 X-Spam_score: -1.4 X-Spam_bar: - X-Spam_report: (-1.4 / 5.0 requ) BAYES_00=-1.9, FREEMAIL_FORGED_FROMDOMAIN=0.25, FREEMAIL_FROM=0.001, HEADER_FROM_DIFFERENT_DOMAINS=0.25, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=no autolearn_force=no X-Spam_action: no action X-BeenThere: help-gnu-emacs@gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Users list for the GNU Emacs text editor List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane-mx.org@gnu.org Original-Sender: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane-mx.org@gnu.org Xref: news.gmane.io gmane.emacs.help:142832 Archived-At: Petteri Hintsanen writes: > (defun emms-info-native--read-and-decode-ogg-page (filename offset) > (with-temp-buffer > (set-buffer-multibyte nil) > (insert-file-contents-literally filename > nil > offset > (+ offset > emms-info-native--ogg-page-size)) > (emms-info-native--decode-ogg-page (buffer-string)))) > [...] > > (defun emms-info-native--decode-ogg-packets (filename packets) > (let ((num-packets 0) > (offset 0) > (stream (vector))) > (while (< num-packets packets) > (let ((page (emms-info-native--read-and-decode-ogg-page filename > offset))) > (cl-incf num-packets (or (plist-get page :num-packets) 0)) > (cl-incf offset (plist-get page :num-bytes)) > (setq stream (vconcat stream (plist-get page :stream))) > stream)) If `emms-info-native--read-and-decode-ogg-page' is called very often (hundreds of times or more), it's probably better to use one single buffer instead of a fresh temp buffer every single time. Using temp buffers creates quite a bunch of garbage IME. Michael.