{"id":23487,"url":"https://patchwork.libcamera.org/api/patches/23487/?format=json","web_url":"https://patchwork.libcamera.org/patch/23487/","project":{"id":1,"url":"https://patchwork.libcamera.org/api/projects/1/?format=json","name":"libcamera","link_name":"libcamera","list_id":"libcamera_core","list_email":"libcamera-devel@lists.libcamera.org","web_url":"","scm_url":"","webscm_url":""},"msgid":"<20250606164156.1442682-7-barnabas.pocze@ideasonboard.com>","date":"2025-06-06T16:41:39","name":"[RFC,v1,06/23] libcamera: base: Add alignment utility functions","commit_ref":null,"pull_url":null,"state":"superseded","archived":false,"hash":"10222ba06391a82d6fddccb35f697c4f9bcebd04","submitter":{"id":216,"url":"https://patchwork.libcamera.org/api/people/216/?format=json","name":"Barnabás Pőcze","email":"barnabas.pocze@ideasonboard.com"},"delegate":null,"mbox":"https://patchwork.libcamera.org/patch/23487/mbox/","series":[{"id":5210,"url":"https://patchwork.libcamera.org/api/series/5210/?format=json","web_url":"https://patchwork.libcamera.org/project/libcamera/list/?series=5210","date":"2025-06-06T16:41:33","name":"libcamera: Add `MetadataList`","version":1,"mbox":"https://patchwork.libcamera.org/series/5210/mbox/"}],"comments":"https://patchwork.libcamera.org/api/patches/23487/comments/","check":"pending","checks":"https://patchwork.libcamera.org/api/patches/23487/checks/","tags":{},"headers":{"Return-Path":"","X-Original-To":"parsemail@patchwork.libcamera.org","Delivered-To":"parsemail@patchwork.libcamera.org","Received":["from lancelot.ideasonboard.com (lancelot.ideasonboard.com\n\t[92.243.16.209])\n\tby patchwork.libcamera.org (Postfix) with ESMTPS id 343EEC3326\n\tfor ;\n\tFri, 6 Jun 2025 16:42:37 +0000 (UTC)","from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id EAC2B68DB0;\n\tFri, 6 Jun 2025 18:42:34 +0200 (CEST)","from perceval.ideasonboard.com (perceval.ideasonboard.com\n\t[213.167.242.64])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id 95F6968DC1\n\tfor ;\n\tFri, 6 Jun 2025 18:42:16 +0200 (CEST)","from pb-laptop.local (185.182.215.79.nat.pool.zt.hu\n\t[185.182.215.79])\n\tby perceval.ideasonboard.com (Postfix) with ESMTPSA id 265238DB\n\tfor ;\n\tFri, 6 Jun 2025 18:42:12 +0200 (CEST)"],"Authentication-Results":"lancelot.ideasonboard.com; dkim=pass (1024-bit key;\n\tunprotected) header.d=ideasonboard.com header.i=@ideasonboard.com\n\theader.b=\"cd6uaOdL\"; dkim-atps=neutral","DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com;\n\ts=mail; t=1749228132;\n\tbh=iIDSatRfy0cQy+iqy8owgNdQ6BhWbHCC8Hz44BO/7ws=;\n\th=From:To:Subject:Date:In-Reply-To:References:From;\n\tb=cd6uaOdLn6JPFVaUnFs6GULk87r//6kq7Ft53pG5VqgDyd+D7nnt5LqPfxt9mDScS\n\tQQBKgX13GRHupeioGlD/FCcbs369jTNAKVT/DZzCWx97aiflR8AhAtJxB1XKlqplc6\n\tGYafglcV1LlcAv0XcnCz25oDbmPRR2/gWi6+ruiI=","From":"=?utf-8?q?Barnab=C3=A1s_P=C5=91cze?= ","To":"libcamera-devel@lists.libcamera.org","Subject":"[RFC PATCH v1 06/23] libcamera: base: Add alignment utility\n\tfunctions","Date":"Fri, 6 Jun 2025 18:41:39 +0200","Message-ID":"<20250606164156.1442682-7-barnabas.pocze@ideasonboard.com>","X-Mailer":"git-send-email 2.49.0","In-Reply-To":"<20250606164156.1442682-1-barnabas.pocze@ideasonboard.com>","References":"<20250606164156.1442682-1-barnabas.pocze@ideasonboard.com>","MIME-Version":"1.0","Content-Type":"text/plain; charset=UTF-8","Content-Transfer-Encoding":"8bit","X-BeenThere":"libcamera-devel@lists.libcamera.org","X-Mailman-Version":"2.1.29","Precedence":"list","List-Id":"","List-Unsubscribe":",\n\t","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n\t","Errors-To":"libcamera-devel-bounces@lists.libcamera.org","Sender":"\"libcamera-devel\" "},"content":"Add a couple internal functions to check alignment, and to\nalign integers, pointer up to a given alignment.\n\nSigned-off-by: Barnabás Pőcze \n---\n include/libcamera/base/details/align.h | 72 ++++++++++++++++++++++++++\n 1 file changed, 72 insertions(+)\n create mode 100644 include/libcamera/base/details/align.h","diff":"diff --git a/include/libcamera/base/details/align.h b/include/libcamera/base/details/align.h\nnew file mode 100644\nindex 000000000..e1c24c6e1\n--- /dev/null\n+++ b/include/libcamera/base/details/align.h\n@@ -0,0 +1,72 @@\n+#pragma once\n+\n+#include \n+#include \n+#include \n+\n+#include \n+\n+namespace libcamera::details::align {\n+\n+template\n+bool is(T *p, std::uintptr_t alignment)\n+{\n+\tassert(alignment > 0);\n+\n+\treturn reinterpret_cast(p) % alignment == 0;\n+}\n+\n+template\n+constexpr T up(T x, cxx20::type_identity_t alignment)\n+{\n+\tstatic_assert(std::is_unsigned_v);\n+\tassert(alignment > 0);\n+\n+\tconst auto padding = (alignment - (x % alignment)) % alignment;\n+\tassert(x + padding >= x);\n+\n+\treturn x + padding;\n+}\n+\n+template\n+auto *up(T *p, std::uintptr_t alignment)\n+{\n+\tusing U = std::conditional_t<\n+\t\tstd::is_const_v,\n+\t\tconst std::byte,\n+\t\tstd::byte\n+\t>;\n+\n+\treturn reinterpret_cast(up(reinterpret_cast(p), alignment));\n+}\n+\n+template\n+T *up(std::size_t size, std::size_t alignment, T *&ptr, std::size_t *avail = nullptr)\n+{\n+\tassert(alignment > 0);\n+\n+\tauto p = reinterpret_cast(ptr);\n+\tconst auto padding = (alignment - (p % alignment)) % alignment;\n+\n+\tif (avail) {\n+\t\tif (size > *avail || padding > *avail - size)\n+\t\t\treturn nullptr;\n+\n+\t\t*avail -= size + padding;\n+\t}\n+\n+\tp += padding;\n+\tptr = reinterpret_cast(p + size);\n+\n+\treturn reinterpret_cast(p);\n+}\n+\n+template\n+U *up(T *&ptr, std::size_t *avail = nullptr)\n+{\n+\treturn reinterpret_cast, const U, U> *>(\n+\t\tup(sizeof(U), alignof(U), ptr, avail)\n+\t);\n+}\n+\n+} /* namespace libcamera::details::align */\n","prefixes":["RFC","v1","06/23"]}