From patchwork Tue May 2 09:23:32 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mads Ynddal X-Patchwork-Id: 13228619 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 16CD2C7EE21 for ; Tue, 2 May 2023 09:25:36 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ptmEs-00051F-M9; Tue, 02 May 2023 05:24:02 -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 1ptmEr-00050q-DF for qemu-devel@nongnu.org; Tue, 02 May 2023 05:24:01 -0400 Received: from mr85p00im-ztdg06021701.me.com ([17.58.23.196]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ptmEp-00040B-Kc for qemu-devel@nongnu.org; Tue, 02 May 2023 05:24:01 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ynddal.dk; s=sig1; t=1683019438; bh=truZGcf/836/sOv1LjrGTCJdJmzGnXZDDsKkr3nCFe0=; h=From:To:Subject:Date:Message-Id:MIME-Version; b=NXL1RNRvrxVYmIEtLSg8MnGCVLLXdGdIaEyfki4JKEZK0+CjATmwOd/8Ty+juEK6g hB7LOZZtAdQ4MjqYNALCgfmu5QlEjccLTj8Jd8ubqy9ny+3/pe9ep/q6+kiCPmo+7e wmuS/MTjT8eWKskg5+d1txZdoYR63Xh00V3PyhG0BONlqQ/3FQNaTQAzY8rdONzd7C zt0o0nFrJ323pjp5Qvbdo8hpPxsDffiEcmbGXG/AWIlOtPr5kESTXROoFzyPGLPhSv fFx7Il5MYHM4MKzxg+EZZk/YzZ1KPoBZLCUKdrVU3ZfFAgPqlz2bLLfCPTdmArRIPD IUKqFHsTcLnFg== Received: from localhost.localdomain (mr38p00im-dlb-asmtp-mailmevip.me.com [17.57.152.18]) by mr85p00im-ztdg06021701.me.com (Postfix) with ESMTPSA id DE1FB2633960; Tue, 2 May 2023 09:23:56 +0000 (UTC) From: Mads Ynddal To: qemu-devel@nongnu.org Cc: Cleber Rosa , Stefan Hajnoczi , John Snow , Mads Ynddal , Mads Ynddal Subject: [PATCH v2 05/12] simpletrace: Changed Analyzer class to become context-manager Date: Tue, 2 May 2023 11:23:32 +0200 Message-Id: <20230502092339.27341-6-mads@ynddal.dk> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20230502092339.27341-1-mads@ynddal.dk> References: <20230502092339.27341-1-mads@ynddal.dk> MIME-Version: 1.0 X-Proofpoint-GUID: NInfHy1XcRfCJWMxyUwC2BYIS5pibZQU X-Proofpoint-ORIG-GUID: NInfHy1XcRfCJWMxyUwC2BYIS5pibZQU X-Proofpoint-Virus-Version: =?utf-8?q?vendor=3Dfsecure_engine=3D1=2E1=2E170-?= =?utf-8?q?22c6f66c430a71ce266a39bfe25bc2903e8d5c8f=3A6=2E0=2E425=2C18=2E0?= =?utf-8?q?=2E816=2C17=2E11=2E62=2E513=2E0000000_definitions=3D2022-01-18=5F?= =?utf-8?q?01=3A2022-01-14=5F01=2C2022-01-18=5F01=2C2021-12-02=5F01_signatur?= =?utf-8?q?es=3D0?= X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=0 adultscore=0 spamscore=0 phishscore=0 clxscore=1030 mlxlogscore=999 bulkscore=0 malwarescore=0 mlxscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2212070000 definitions=main-2305020080 Received-SPF: pass client-ip=17.58.23.196; envelope-from=mads@ynddal.dk; helo=mr85p00im-ztdg06021701.me.com X-Spam_score_int: -27 X-Spam_score: -2.8 X-Spam_bar: -- X-Spam_report: (-2.8 / 5.0 requ) BAYES_00=-1.9, 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_H2=-0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham 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: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org From: Mads Ynddal Instead of explicitly calling `begin` and `end`, we can change the class to use the context-manager paradigm. This is mostly a styling choice, used in modern Python code. But it also allows for more advanced analyzers to handle exceptions gracefully in the `__exit__` method (not demonstrated here). Signed-off-by: Mads Ynddal --- scripts/simpletrace.py | 40 +++++++++++++++++++++++----------------- 1 file changed, 23 insertions(+), 17 deletions(-) diff --git a/scripts/simpletrace.py b/scripts/simpletrace.py index 7444a6e090..10ca093046 100755 --- a/scripts/simpletrace.py +++ b/scripts/simpletrace.py @@ -121,12 +121,12 @@ def read_trace_records(event_mapping, event_id_to_name, fobj): yield rec -class Analyzer(object): +class Analyzer: """A trace file analyzer which processes trace records. - An analyzer can be passed to run() or process(). The begin() method is - invoked, then each trace record is processed, and finally the end() method - is invoked. + An analyzer can be passed to run() or process(). The __enter__() method is + invoked when opening the analyzer using the `with` statement, then each trace + record is processed, and finally the __exit__() method is invoked. If a method matching a trace event name exists, it is invoked to process that trace record. Otherwise the catchall() method is invoked. @@ -152,19 +152,25 @@ def runstate_set(self, timestamp, pid, new_state): ... """ - def begin(self): + def __enter__(self): """Called at the start of the trace.""" - pass + return self def catchall(self, event, rec): """Called if no specific method for processing a trace event has been found.""" pass - def end(self): + def __exit__(self, _type, value, traceback): """Called at the end of the trace.""" pass -def process(events, log, analyzer, read_header=True): + def __call__(self): + """Fix for legacy use without context manager. + We call the provided object in `process` regardless of it being the object-type or instance. + With this function, it will work in both cases.""" + return self + +def process(events, log, analyzer_class, read_header=True): """Invoke an analyzer on each event in a log.""" if read_header: read_trace_header(log) @@ -203,15 +209,15 @@ def build_fn(analyzer, event): # Just arguments, no timestamp or pid return lambda _, rec: fn(*rec[3:3 + event_argcount]) - analyzer.begin() - fn_cache = {} - for rec in read_trace_records(event_mapping, event_id_to_name, log): - event_num = rec[0] - event = event_mapping[event_num] - if event_num not in fn_cache: - fn_cache[event_num] = build_fn(analyzer, event) - fn_cache[event_num](event, rec) - analyzer.end() + with analyzer_class() as analyzer: + fn_cache = {} + for rec in read_trace_records(event_mapping, event_id_to_name, log): + event_num = rec[0] + event = event_mapping[event_num] + if event_num not in fn_cache: + fn_cache[event_num] = build_fn(analyzer, event) + fn_cache[event_num](event, rec) + def run(analyzer): """Execute an analyzer on a trace file given on the command-line.