From patchwork Fri Jun 7 06:37:48 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Patrick Steinhardt X-Patchwork-Id: 13689338 Received: from fout1-smtp.messagingengine.com (fout1-smtp.messagingengine.com [103.168.172.144]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 640A715278F for ; Fri, 7 Jun 2024 06:37:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=103.168.172.144 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1717742274; cv=none; b=vDtnC8gLa/ICFuYU3QvzchcIApoa79plBS8sbDr7BVzRTLcN2re8/+Rx5u/2dPkGYIyadkEP7tJoeJdQ6O8Vi9NV63JFc0d89Bku20UzKxKhVvoHy4ebIzEOKztx2+B23cuXNDjrtbjpJXEIdlhDTIyCFstLfZtbimjcMPhDn48= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1717742274; c=relaxed/simple; bh=qVRcKQAxquCRTLuauXmyH5CSPLge5NfM06E4iM3aNHE=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=IGV8XrZ/pUkfn97E/XT2T6Rh1kwgOSzxwHbqXS6pYpje2bGkz2xoA8+0dblizNa+kWGL2mRyhn79aroa1wvNuQUsMJb2/y7Cax9GfuMSBcsyVtsN++eCWdi4lpVTqmyUy+RPQoCAeAHEONwbYeZtxtVw/tEIsIBg80PmEXjVsrc= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=pks.im; spf=pass smtp.mailfrom=pks.im; dkim=pass (2048-bit key) header.d=pks.im header.i=@pks.im header.b=N8//Sqwi; dkim=pass (2048-bit key) header.d=messagingengine.com header.i=@messagingengine.com header.b=jSGML0WO; arc=none smtp.client-ip=103.168.172.144 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=pks.im Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=pks.im Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=pks.im header.i=@pks.im header.b="N8//Sqwi"; dkim=pass (2048-bit key) header.d=messagingengine.com header.i=@messagingengine.com header.b="jSGML0WO" Received: from compute6.internal (compute6.nyi.internal [10.202.2.47]) by mailfout.nyi.internal (Postfix) with ESMTP id 63FA113801DD; Fri, 7 Jun 2024 02:37:51 -0400 (EDT) Received: from mailfrontend1 ([10.202.2.162]) by compute6.internal (MEProxy); Fri, 07 Jun 2024 02:37:51 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=pks.im; h=cc:cc :content-type:content-type:date:date:from:from:in-reply-to :in-reply-to:message-id:mime-version:references:reply-to:subject :subject:to:to; s=fm1; t=1717742271; x=1717828671; bh=LauQLYedlz BYkGX6SSvhY4i8V0A3zSq0XU6k/Xe01jE=; b=N8//SqwiT+/OwrrPX/b5B2shre RlVpLFVqgivlbwbjzLajs1CKLdSgnNR23u9dl0XYppf9O3wp22VQ4bFK+CbcVtxh tgWjBJR8BaHTj36Dor8AwqJcYTZbXfA2+hZDwmt3nHhF76+nI/8UgcfoTNMNWMoj rgl/CuXmDJBNSTecvi8K/xkB0y0bn5ql3kIoqVbbfT9VQS/PVmB9ph+pjRWrJUHo ZkC0O3wvyZnSJs2RubgPCGsVNg63pjBaMtmvu/syXiIUSaGOZQ2ZNMI6KLSVjt+q jk88ZMEVGDgC5qMoM4XDNakpDpg2jTxHzW2MmWjI1JQfEnxErGIGLAOFNQuQ== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:cc:content-type:content-type:date:date :feedback-id:feedback-id:from:from:in-reply-to:in-reply-to :message-id:mime-version:references:reply-to:subject:subject:to :to:x-me-proxy:x-me-proxy:x-me-sender:x-me-sender:x-sasl-enc; s= fm1; t=1717742271; x=1717828671; bh=LauQLYedlzBYkGX6SSvhY4i8V0A3 zSq0XU6k/Xe01jE=; b=jSGML0WOQHbWs2zmAaDsnXy8OjyxcHf62aC1sefbgDpe sCK21wvXYGcbRFGdRdDABjq/L+JaaTFU9khnlQxKOd5mrt/Jq11ExTrOnZNEwcbk e3sORawh/sBWGFyZHsLqQGRyxbnFUdDaBdiVOw+5gAX+IRm80/NVKV/skMGX2wH+ y+r1Ofn7KXDt7RWIFC2f1QttjWRWM6Rn39aROMXCVKa3AmthynIYU1qA9asVdNuy k+qu7/Fr7IU31XLPIFppSRX8KjcMA0WIwBlLBjA1PFtg4XNhD7in1ikYKeQg1cqe ONSBdASY86C64sW20u0HALxPj3yaq97UzCUzs3PBlA== X-ME-Sender: X-ME-Received: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgedvledrvdelledguddtkecutefuodetggdotefrod ftvfcurfhrohhfihhlvgemucfhrghsthforghilhdpqfgfvfdpuffrtefokffrpgfnqfgh necuuegrihhlohhuthemuceftddtnecusecvtfgvtghiphhivghnthhsucdlqddutddtmd enucfjughrpeffhffvvefukfhfgggtuggjsehgtderredttddvnecuhfhrohhmpefrrght rhhitghkucfuthgvihhnhhgrrhguthcuoehpshesphhkshdrihhmqeenucggtffrrghtth gvrhhnpefgffetfeeguddvkeeftdehffegfeetueegjeeihfekueektddtfefguddvtdeh ueenucffohhmrghinhepuhhpuggrthgvrdhnrghmvgdpuhhpuggrthgvrdgvmhgrihhlne cuvehluhhsthgvrhfuihiivgeptdenucfrrghrrghmpehmrghilhhfrhhomhepphhssehp khhsrdhimh X-ME-Proxy: Feedback-ID: i197146af:Fastmail Received: by mail.messagingengine.com (Postfix) with ESMTPA; Fri, 7 Jun 2024 02:37:50 -0400 (EDT) Received: by localhost (OpenSMTPD) with ESMTPSA id 0154d6c6 (TLSv1.3:TLS_AES_256_GCM_SHA384:256:NO); Fri, 7 Jun 2024 06:37:49 +0000 (UTC) Date: Fri, 7 Jun 2024 08:37:48 +0200 From: Patrick Steinhardt To: git@vger.kernel.org Cc: Jeff King , Junio C Hamano , Eric Sunshine Subject: [PATCH v6 03/27] refs/reftable: stop micro-optimizing refname allocations on copy Message-ID: <90613bd58285553a406d447fa41d4b86cacb605b.1717740366.git.ps@pks.im> References: Precedence: bulk X-Mailing-List: git@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: When copying refs, we execute `write_copy_table()` to write the new table. As the names are given to us via `arg->newname` and `arg->oldname`, respectively, we optimize away some allocations by assigning those fields to the reftable records we are about to write directly, without duplicating them. This requires us to cast the input to `char *` pointers as they are in fact constant strings. Later on, we then unset the refname for all of the records before calling `reftable_log_record_release()` on them. We also do this when assigning the "HEAD" constant, but here we do not cast because its type is `char[]` by default. It's about to be turned into `const char *` though once we enable `-Wwrite-strings` and will thus cause another warning. It's quite dubious whether this micro-optimization really helps. We're about to write to disk anyway, which is going to be way slower than a small handful of allocations. Let's drop the optimization altogther and instead copy arguments to simplify the code and avoid the future warning with `-Wwrite-strings`. Signed-off-by: Patrick Steinhardt --- refs/reftable-backend.c | 28 ++++++++++++++++------------ 1 file changed, 16 insertions(+), 12 deletions(-) diff --git a/refs/reftable-backend.c b/refs/reftable-backend.c index 1af86bbdec..e77faa2b9d 100644 --- a/refs/reftable-backend.c +++ b/refs/reftable-backend.c @@ -1340,10 +1340,10 @@ static int write_copy_table(struct reftable_writer *writer, void *cb_data) * old reference. */ refs[0] = old_ref; - refs[0].refname = (char *)arg->newname; + refs[0].refname = xstrdup(arg->newname); refs[0].update_index = creation_ts; if (arg->delete_old) { - refs[1].refname = (char *)arg->oldname; + refs[1].refname = xstrdup(arg->oldname); refs[1].value_type = REFTABLE_REF_DELETION; refs[1].update_index = deletion_ts; } @@ -1366,7 +1366,7 @@ static int write_copy_table(struct reftable_writer *writer, void *cb_data) ALLOC_GROW(logs, logs_nr + 1, logs_alloc); memset(&logs[logs_nr], 0, sizeof(logs[logs_nr])); fill_reftable_log_record(&logs[logs_nr], &committer_ident); - logs[logs_nr].refname = (char *)arg->newname; + logs[logs_nr].refname = xstrdup(arg->newname); logs[logs_nr].update_index = deletion_ts; logs[logs_nr].value.update.message = xstrndup(arg->logmsg, arg->refs->write_options.block_size / 2); @@ -1387,7 +1387,13 @@ static int write_copy_table(struct reftable_writer *writer, void *cb_data) if (append_head_reflog) { ALLOC_GROW(logs, logs_nr + 1, logs_alloc); logs[logs_nr] = logs[logs_nr - 1]; - logs[logs_nr].refname = "HEAD"; + logs[logs_nr].refname = xstrdup("HEAD"); + logs[logs_nr].value.update.name = + xstrdup(logs[logs_nr].value.update.name); + logs[logs_nr].value.update.email = + xstrdup(logs[logs_nr].value.update.email); + logs[logs_nr].value.update.message = + xstrdup(logs[logs_nr].value.update.message); logs_nr++; } } @@ -1398,7 +1404,7 @@ static int write_copy_table(struct reftable_writer *writer, void *cb_data) ALLOC_GROW(logs, logs_nr + 1, logs_alloc); memset(&logs[logs_nr], 0, sizeof(logs[logs_nr])); fill_reftable_log_record(&logs[logs_nr], &committer_ident); - logs[logs_nr].refname = (char *)arg->newname; + logs[logs_nr].refname = xstrdup(arg->newname); logs[logs_nr].update_index = creation_ts; logs[logs_nr].value.update.message = xstrndup(arg->logmsg, arg->refs->write_options.block_size / 2); @@ -1430,7 +1436,7 @@ static int write_copy_table(struct reftable_writer *writer, void *cb_data) */ ALLOC_GROW(logs, logs_nr + 1, logs_alloc); logs[logs_nr] = old_log; - logs[logs_nr].refname = (char *)arg->newname; + logs[logs_nr].refname = xstrdup(arg->newname); logs_nr++; /* @@ -1439,7 +1445,7 @@ static int write_copy_table(struct reftable_writer *writer, void *cb_data) if (arg->delete_old) { ALLOC_GROW(logs, logs_nr + 1, logs_alloc); memset(&logs[logs_nr], 0, sizeof(logs[logs_nr])); - logs[logs_nr].refname = (char *)arg->oldname; + logs[logs_nr].refname = xstrdup(arg->oldname); logs[logs_nr].value_type = REFTABLE_LOG_DELETION; logs[logs_nr].update_index = old_log.update_index; logs_nr++; @@ -1462,13 +1468,11 @@ static int write_copy_table(struct reftable_writer *writer, void *cb_data) reftable_iterator_destroy(&it); string_list_clear(&skip, 0); strbuf_release(&errbuf); - for (i = 0; i < logs_nr; i++) { - if (!strcmp(logs[i].refname, "HEAD")) - continue; - logs[i].refname = NULL; + for (i = 0; i < logs_nr; i++) reftable_log_record_release(&logs[i]); - } free(logs); + for (i = 0; i < ARRAY_SIZE(refs); i++) + reftable_ref_record_release(&refs[i]); reftable_ref_record_release(&old_ref); reftable_log_record_release(&old_log); return ret;