From patchwork Wed Aug 23 08:54:23 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mads Ynddal X-Patchwork-Id: 13361821 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 A7064EE49A0 for ; Wed, 23 Aug 2023 08:56:46 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qYjdj-0003vZ-O2; Wed, 23 Aug 2023 04:54:59 -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 1qYjdi-0003vF-Ia for qemu-devel@nongnu.org; Wed, 23 Aug 2023 04:54:58 -0400 Received: from pv50p00im-tydg10021701.me.com ([17.58.6.54]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qYjdh-0008Fi-5S for qemu-devel@nongnu.org; Wed, 23 Aug 2023 04:54:58 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ynddal.dk; s=sig1; t=1692780896; bh=zbUuQMImgFXI+shnIyEaHz7dPAc3pcIDgFyYbkPOa8A=; h=From:To:Subject:Date:Message-Id:MIME-Version; b=fW06zrHo7yluhE1CxpV4pu6CpB4OFieztqjAZXN6ticAg4xVPhHqvpVPWJCFPLmkb +NuPm53nOhAYylkbU15M7pEQarVkeRzewCyyGc5dXcccGTWBB38uDbgDLNeevWXnbM pIAd4T1KzeYwaZAX0w9KmVic0k6TVKQtCN303reD6jfi+0P9s84E3CpwSfMWWR0LLu uMsdv9TziI0bT4kzP4M6tntHxF/tGydRpaIHyvRsneufw5o/Oxxnt1mq1EKcNvtu5s 0hh0iNrydVIHHcpBWxSZsDnBf/yjktkf7gFUxXEGnDrp5qhlxXpFXSmXtSSR0TPl63 BL1NE/UBtZx/A== Received: from localhost.localdomain (pv50p00im-dlb-asmtp-mailmevip.me.com [17.56.9.10]) by pv50p00im-tydg10021701.me.com (Postfix) with ESMTPSA id 50C493A0A87; Wed, 23 Aug 2023 08:54:54 +0000 (UTC) From: Mads Ynddal To: qemu-devel@nongnu.org Cc: John Snow , Mads Ynddal , Stefan Hajnoczi , Cleber Rosa , Mads Ynddal Subject: [PATCH v4 08/14] simpletrace: made Analyzer into context-manager Date: Wed, 23 Aug 2023 10:54:23 +0200 Message-Id: <20230823085429.20519-9-mads@ynddal.dk> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20230823085429.20519-1-mads@ynddal.dk> References: <20230823085429.20519-1-mads@ynddal.dk> MIME-Version: 1.0 X-Proofpoint-ORIG-GUID: LodQfIG7zHL0lRsb6zQjP6kLAthaWsK9 X-Proofpoint-GUID: LodQfIG7zHL0lRsb6zQjP6kLAthaWsK9 X-Proofpoint-Virus-Version: =?utf-8?q?vendor=3Dfsecure_engine=3D1=2E1=2E170-?= =?utf-8?q?22c6f66c430a71ce266a39bfe25bc2903e8d5c8f=3A6=2E0=2E517=2C18=2E0?= =?utf-8?q?=2E883=2C17=2E11=2E64=2E514=2E0000000_definitions=3D2022-06-21=5F?= =?utf-8?q?08=3A2022-06-21=5F01=2C2022-06-21=5F08=2C2022-02-23=5F01_signatur?= =?utf-8?q?es=3D0?= X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 malwarescore=0 spamscore=0 mlxlogscore=800 clxscore=1030 bulkscore=0 adultscore=0 phishscore=0 suspectscore=0 mlxscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2212070000 definitions=main-2308230080 Received-SPF: pass client-ip=17.58.6.54; envelope-from=mads@ynddal.dk; helo=pv50p00im-tydg10021701.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 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 Reviewed-by: Stefan Hajnoczi --- scripts/simpletrace.py | 31 ++++++++++++++++++++----------- 1 file changed, 20 insertions(+), 11 deletions(-) diff --git a/scripts/simpletrace.py b/scripts/simpletrace.py index 229b10aa99..7f514d1577 100755 --- a/scripts/simpletrace.py +++ b/scripts/simpletrace.py @@ -122,12 +122,13 @@ 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. + is invoked. When Analyzer is used as a context-manager (using the `with` + statement), begin() and end() are called automatically. If a method matching a trace event name exists, it is invoked to process that trace record. Otherwise the catchall() method is invoked. @@ -165,6 +166,15 @@ def end(self): """Called at the end of the trace.""" pass + def __enter__(self): + self.begin() + return self + + def __exit__(self, exc_type, exc_val, exc_tb): + if exc_type is None: + self.end() + return False + def process(events, log, analyzer, read_header=True): """Invoke an analyzer on each event in a log. Args: @@ -226,15 +236,14 @@ 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: + 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) if close_log: log.close()