From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from fhigh7-smtp.messagingengine.com (fhigh7-smtp.messagingengine.com [103.168.172.158]) (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 8F568145358 for ; Tue, 4 Jun 2024 12:37:09 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=103.168.172.158 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1717504631; cv=none; b=WTKNlUbZ7o96BUcdUKqf1UrLl5nJJWk0eBJ6mjGAYgwvCfy7NxlYaeqVHlHcJepPYzGxewDzMxj0vjp5YRA+QlqVSrzQ9tDREx63l8tQaMu/geRYr3cAq+Vdb13JT7PsrTa9qUCWEwMeJOkWgNEttTxArRm0DTDft8J9rppAkG8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1717504631; c=relaxed/simple; bh=lbi5wr0zHsn04kYVYgaP1e/qvWsoNcDNJSb7k/rl8Oc=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=GtfRz0IQFZZuu/hD8WrnDLpsliYa9TMAZZtakhmsuDYXqq8gf+KjMSuyD4CnslOhB93DrAE6NV3vO3oaWc2NQ5YRyuxvPUv2RAbgGsdQ1S2/86wIaD2b3Fyu8mbduGvszGlcIoAds0BGbgBZL01okM6amYXMm02aQS9yozoaUM4= 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=cbea6R2F; dkim=pass (2048-bit key) header.d=messagingengine.com header.i=@messagingengine.com header.b=Wv61xkqY; arc=none smtp.client-ip=103.168.172.158 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="cbea6R2F"; dkim=pass (2048-bit key) header.d=messagingengine.com header.i=@messagingengine.com header.b="Wv61xkqY" Received: from compute6.internal (compute6.nyi.internal [10.202.2.47]) by mailfhigh.nyi.internal (Postfix) with ESMTP id DB86911400C2; Tue, 4 Jun 2024 08:37:08 -0400 (EDT) Received: from mailfrontend1 ([10.202.2.162]) by compute6.internal (MEProxy); Tue, 04 Jun 2024 08:37:08 -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=1717504628; x=1717591028; bh=J4ibQ7qQUR af9UzmFendo09VM8PT0GswMpr0TwrjdF0=; b=cbea6R2FXbwls3ixBw9Dn3sbZ5 heQgDW14J8KhKL53mrq8UJENLCxToSMnSjEVMXXjHHl/7zLazC1mRhJfexmCML3e Eu40jQYqWDNj92NrIIZIWmYYPF9wUipq05EKEYdTikT1AnsqzqnjLTGFqlOkF5LG hm3lT7MSvWFAg4kRkKRhzDKE0jP29ywTLUxHRStyPv4zDVj6H14R3rx0f8aGTMsy KblB1OPnbTG2aX/abCmxVNy6LjtQ/+iNKuAPttXHdXxhaowjDEpyM/w8pVh/cG/7 m0SD65QcaNMjryMyP9JS5yd+Izks8VjT4HqJ3roz+V4l+L0/7FAqthg0yYbA== 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=1717504628; x=1717591028; bh=J4ibQ7qQURaf9UzmFendo09VM8PT 0GswMpr0TwrjdF0=; b=Wv61xkqYNwcofV0HeZIHA4MBQcNzgHf5B8COOp1Ip+vg 4gAxmwaKW5CyfMKQ3fo48FHcXAiQDWtgIrF8/2papCNtHH704my6AMfVb656tbgA cu5POrT8P5aaiirquD75m//90rlheLJebbcyohfjRSeobzYD6xaY5n9w6JwY+ISu TusOz4gXuXSZrouOOYd3eFKWXdaHwu2Ux+CwegRRlfJqQ0RApbOvJmWgeZboHBLX SMu3oNOnrrGpAWNzh2BofmNbITLRQOK2KWI4jsmpfMTba1IPQtBQZdWqBO0Cx8R6 AIfem7ZBYRTW+QrntG2H94YS036gxRHwDdR+69XAug== X-ME-Sender: X-ME-Received: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgedvledrvdelgedghedtucetufdoteggodetrfdotf fvucfrrhhofhhilhgvmecuhfgrshhtofgrihhlpdfqfgfvpdfurfetoffkrfgpnffqhgen uceurghilhhouhhtmecufedttdenucesvcftvggtihhpihgvnhhtshculddquddttddmne cujfgurhepfffhvfevuffkfhggtggujgesghdtreertddtvdenucfhrhhomheprfgrthhr ihgtkhcuufhtvghinhhhrghrughtuceophhssehpkhhsrdhimheqnecuggftrfgrthhtvg hrnhepgfffteefgeduvdekfedtheffgeefteeugeejiefhkeeukedttdefgfduvddtheeu necuffhomhgrihhnpehuphgurghtvgdrnhgrmhgvpdhuphgurghtvgdrvghmrghilhenuc evlhhushhtvghrufhiiigvpedtnecurfgrrhgrmhepmhgrihhlfhhrohhmpehpshesphhk shdrihhm X-ME-Proxy: Feedback-ID: i197146af:Fastmail Received: by mail.messagingengine.com (Postfix) with ESMTPA; Tue, 4 Jun 2024 08:37:07 -0400 (EDT) Received: by localhost (OpenSMTPD) with ESMTPSA id 63e280a5 (TLSv1.3:TLS_AES_256_GCM_SHA384:256:NO); Tue, 4 Jun 2024 12:36:40 +0000 (UTC) Date: Tue, 4 Jun 2024 14:37:04 +0200 From: Patrick Steinhardt To: git@vger.kernel.org Cc: Jeff King , Junio C Hamano , Eric Sunshine Subject: [PATCH v4 03/27] refs/reftable: stop micro-optimizing refname allocations on copy Message-ID: <379145478cbbf59387c799952a97abc16a528eab.1717504517.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-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="V8lP1NVa7W/pGWjO" Content-Disposition: inline In-Reply-To: --V8lP1NVa7W/pGWjO Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable 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] =3D old_ref; - refs[0].refname =3D (char *)arg->newname; + refs[0].refname =3D xstrdup(arg->newname); refs[0].update_index =3D creation_ts; if (arg->delete_old) { - refs[1].refname =3D (char *)arg->oldname; + refs[1].refname =3D xstrdup(arg->oldname); refs[1].value_type =3D REFTABLE_REF_DELETION; refs[1].update_index =3D deletion_ts; } @@ -1366,7 +1366,7 @@ static int write_copy_table(struct reftable_writer *w= riter, 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 =3D (char *)arg->newname; + logs[logs_nr].refname =3D xstrdup(arg->newname); logs[logs_nr].update_index =3D deletion_ts; logs[logs_nr].value.update.message =3D 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] =3D logs[logs_nr - 1]; - logs[logs_nr].refname =3D "HEAD"; + logs[logs_nr].refname =3D xstrdup("HEAD"); + logs[logs_nr].value.update.name =3D + xstrdup(logs[logs_nr].value.update.name); + logs[logs_nr].value.update.email =3D + xstrdup(logs[logs_nr].value.update.email); + logs[logs_nr].value.update.message =3D + xstrdup(logs[logs_nr].value.update.message); logs_nr++; } } @@ -1398,7 +1404,7 @@ static int write_copy_table(struct reftable_writer *w= riter, 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 =3D (char *)arg->newname; + logs[logs_nr].refname =3D xstrdup(arg->newname); logs[logs_nr].update_index =3D creation_ts; logs[logs_nr].value.update.message =3D xstrndup(arg->logmsg, arg->refs->write_options.block_size / 2); @@ -1430,7 +1436,7 @@ static int write_copy_table(struct reftable_writer *w= riter, void *cb_data) */ ALLOC_GROW(logs, logs_nr + 1, logs_alloc); logs[logs_nr] =3D old_log; - logs[logs_nr].refname =3D (char *)arg->newname; + logs[logs_nr].refname =3D xstrdup(arg->newname); logs_nr++; =20 /* @@ -1439,7 +1445,7 @@ static int write_copy_table(struct reftable_writer *w= riter, 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 =3D (char *)arg->oldname; + logs[logs_nr].refname =3D xstrdup(arg->oldname); logs[logs_nr].value_type =3D REFTABLE_LOG_DELETION; logs[logs_nr].update_index =3D 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 =3D 0; i < logs_nr; i++) { - if (!strcmp(logs[i].refname, "HEAD")) - continue; - logs[i].refname =3D NULL; + for (i =3D 0; i < logs_nr; i++) reftable_log_record_release(&logs[i]); - } free(logs); + for (i =3D 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; --=20 2.45.1.410.g58bac47f8e.dirty --V8lP1NVa7W/pGWjO Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEF9hrgiFbCdvenl/rVbJhu7ckPpQFAmZfCm8ACgkQVbJhu7ck PpSuaRAAlHodVo0MDMtnon2Zzp3MK68EOrBqYa9JhI4VUw5jGD5GmZvWebqN8x/5 dei73z3eiOZapPQK6B2QArXFGPNz+20bDx+1+/P4aWm0liHLK0D8MSgLeUbxzy2W 2h+fezvDAg0MYfqrNQZFeVNjvDphZoFjh4uKOqHhtLdEMhxTtzKjRbKJdzZP2s/r q/3JsGeFpbByFTNASvjVwQ6ZpIEPNnAKQ+eYl0B27JXVH7Zx+uV2IVRNTuiX5TdW oWTqooXXIhpw1nU65C0LJU4utMRdBjxDwFGmKZcaPkYzTjTwsPmfQ7fdn5MeNxvU NHOOsmAIYcs/E413YBjm008swUC/rQCrom+aYBFfnAXj7OCLyCD15PsFnDzyxD8z rlXyKlXYg0mn4UXD/2NR4heQOvQKCW+l/Pg8BMf8us304QZnN885v+iOg+TQuEKL fKLcW9GfXiSqJpqjygFlkCU+y/gc0g4blj8CWJGq46xI7e6nQgIO8z3HZns2hn0O cjS7vEovLUg14eiG0LZ9K0CfcNPcZkkOGVdp/WgcnpkSPUef8JGnVPu59mGUBAhK SA+wYrZ/mbL+fqi5lz4vN1u9FSDXSvGmqLRGQg2UKbmnjktOEQB5oWHPaQc4jq8E j+TFr1qEvFc4HFQC5l0IfFAJRoWLkl7Xnjs3oWmRFvSyo4S1XMU= =XJrl -----END PGP SIGNATURE----- --V8lP1NVa7W/pGWjO--