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=-5.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_2 autolearn=no 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 DD89BC48BE5 for ; Tue, 15 Jun 2021 15:58:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C01306148E for ; Tue, 15 Jun 2021 15:58:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232260AbhFOQAq (ORCPT ); Tue, 15 Jun 2021 12:00:46 -0400 Received: from mail.kernel.org ([198.145.29.99]:55328 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233170AbhFOP7p (ORCPT ); Tue, 15 Jun 2021 11:59:45 -0400 Received: from oasis.local.home (cpe-66-24-58-225.stny.res.rr.com [66.24.58.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 263A6608FE; Tue, 15 Jun 2021 15:57:40 +0000 (UTC) Date: Tue, 15 Jun 2021 11:57:38 -0400 From: Steven Rostedt To: Philippe Proulx Cc: Mathieu Desnoyers , Jeremie Galarneau , lttng-dev , "linux-trace-devel@vger.kernel.org" Subject: Re: [lttng-dev] Usage example of libbabeltrace (babeltrace2) to read CTF traces from a GUI Message-ID: <20210615115738.46818ace@oasis.local.home> In-Reply-To: References: <1119833442.5505.1623700847146.JavaMail.zimbra@efficios.com> X-Mailer: Claws Mail 3.17.3 (GTK+ 2.24.33; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-trace-devel@vger.kernel.org [ Adding linux-trace-devel too ] On Tue, 15 Jun 2021 11:13:41 -0400 Philippe Proulx wrote: > On Mon, Jun 14, 2021 at 4:01 PM Mathieu Desnoyers via lttng-dev > wrote: > > > > Hi Philippe, Hi Jeremie, > > > > Steven is interested to use libbabeltrace as a CTF trace reader in the KernelShark > > project. It's a GUI which shows Linux kernel traces. > > > > He notices that most of the documented usage examples of the libbabeltrace API > > focus on use-cases where a custom trace format is converted into CTF. > > > > I know that the babeltrace2 program is the main user of libbabeltrace at this > > point, and that it reads CTF as source. > > > > For using libbabeltrace as CTF reader for a GUI, what would be the best examples > > to look at as starting point ? Perhaps the babeltrace2 binary, or just adapt a > > smaller example program and change the custom trace format source to "ctf.fs" ? > > Or anything else ? > > Hello, > > Unfortunately, the Babeltrace 2 C API documentation [1] doesn't offer a > graph building example at the moment. > > Therefore, indeed, the "best" example would be the babeltrace2(1) CLI > (see `src/cli`), although I understand that it's a very generic example > which can be overwhelming to explore. > > However, note that instead of instantiating an existing sink component > class (as found in a plugin), you'll want to make your own sink > component class to get access to each event message while also > controlling the graph operations. Using > bt_graph_add_simple_sink_component() [2] would be a good start. > > I can cook a minimal working example in the following days. That would be great, thanks! -- Steve > > Phil > > [1]: https://babeltrace.org/docs/v2.0/libbabeltrace2/ > [2]: https://babeltrace.org/docs/v2.0/libbabeltrace2/group__api-graph.html#gaa8432f03a967d01b764fb1bc959c8e89 > > > > > Thanks, > > > > Mathieu > > > > -- > > Mathieu Desnoyers > > EfficiOS Inc. > > http://www.efficios.com > > _______________________________________________ > > lttng-dev mailing list > > lttng-dev@lists.lttng.org > > https://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev