{"id":2627,"url":"https://patchwork.libcamera.org/api/1.1/patches/2627/?format=json","web_url":"https://patchwork.libcamera.org/patch/2627/","project":{"id":1,"url":"https://patchwork.libcamera.org/api/1.1/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":"<20200113164245.52535-13-jacopo@jmondi.org>","date":"2020-01-13T16:42:34","name":"[libcamera-devel,12/23] libcamera: Add C++20 std::span<> implementation","commit_ref":null,"pull_url":null,"state":"superseded","archived":false,"hash":"b5352357208556b3904033cc081a3fed3359037a","submitter":{"id":3,"url":"https://patchwork.libcamera.org/api/1.1/people/3/?format=json","name":"Jacopo Mondi","email":"jacopo@jmondi.org"},"delegate":{"id":15,"url":"https://patchwork.libcamera.org/api/1.1/users/15/?format=json","username":"jmondi","first_name":"Jacopo","last_name":"Mondi","email":"jacopo@jmondi.org"},"mbox":"https://patchwork.libcamera.org/patch/2627/mbox/","series":[{"id":618,"url":"https://patchwork.libcamera.org/api/1.1/series/618/?format=json","web_url":"https://patchwork.libcamera.org/project/libcamera/list/?series=618","date":"2020-01-13T16:42:22","name":"Properties and compound controls","version":1,"mbox":"https://patchwork.libcamera.org/series/618/mbox/"}],"comments":"https://patchwork.libcamera.org/api/patches/2627/comments/","check":"pending","checks":"https://patchwork.libcamera.org/api/patches/2627/checks/","tags":{},"headers":{"Return-Path":"","Received":["from relay11.mail.gandi.net (relay11.mail.gandi.net\n\t[217.70.178.231])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id 1D258606EA\n\tfor ;\n\tMon, 13 Jan 2020 17:40:34 +0100 (CET)","from uno.lan (2-224-242-101.ip172.fastwebnet.it [2.224.242.101])\n\t(Authenticated sender: jacopo@jmondi.org)\n\tby relay11.mail.gandi.net (Postfix) with ESMTPSA id ABA0B100009;\n\tMon, 13 Jan 2020 16:40:33 +0000 (UTC)"],"From":"Jacopo Mondi ","To":"libcamera-devel@lists.libcamera.org","Date":"Mon, 13 Jan 2020 17:42:34 +0100","Message-Id":"<20200113164245.52535-13-jacopo@jmondi.org>","X-Mailer":"git-send-email 2.24.0","In-Reply-To":"<20200113164245.52535-1-jacopo@jmondi.org>","References":"<20200113164245.52535-1-jacopo@jmondi.org>","MIME-Version":"1.0","Content-Transfer-Encoding":"8bit","Subject":"[libcamera-devel] [PATCH 12/23] libcamera: Add C++20 std::span<>\n\timplementation","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","X-List-Received-Date":"Mon, 13 Jan 2020 16:40:34 -0000"},"content":"Add a simplified implementation of C++20 std::span<> class.\n\nSigned-off-by: Jacopo Mondi \n---\n Documentation/Doxyfile.in | 4 +-\n include/libcamera/meson.build | 1 +\n include/libcamera/span.h | 89 +++++++++++++++++++++++\n src/libcamera/meson.build | 1 +\n src/libcamera/span.cpp | 128 ++++++++++++++++++++++++++++++++++\n 5 files changed, 222 insertions(+), 1 deletion(-)\n create mode 100644 include/libcamera/span.h\n create mode 100644 src/libcamera/span.cpp","diff":"diff --git a/Documentation/Doxyfile.in b/Documentation/Doxyfile.in\nindex 8e6fbdbb92b6..6b08960a921f 100644\n--- a/Documentation/Doxyfile.in\n+++ b/Documentation/Doxyfile.in\n@@ -838,8 +838,10 @@ RECURSIVE = YES\n # Note that relative paths are relative to the directory from which doxygen is\n # run.\n \n-EXCLUDE = @TOP_SRCDIR@/src/libcamera/device_enumerator_sysfs.cpp \\\n+EXCLUDE = @TOP_SRCDIR@/include/libcamera/span.h \\\n+\t\t\t @TOP_SRCDIR@/src/libcamera/device_enumerator_sysfs.cpp \\\n \t\t\t @TOP_SRCDIR@/src/libcamera/device_enumerator_udev.cpp \\\n+\t\t\t @TOP_SRCDIR@/src/libcamera/span.cpp \\\n \t\t\t @TOP_SRCDIR@/src/libcamera/include/device_enumerator_sysfs.h \\\n \t\t\t @TOP_SRCDIR@/src/libcamera/include/device_enumerator_udev.h \\\n \t\t\t @TOP_SRCDIR@/src/libcamera/pipeline/ \\\ndiff --git a/include/libcamera/meson.build b/include/libcamera/meson.build\nindex f58c02d2cf35..f47c583cbbc0 100644\n--- a/include/libcamera/meson.build\n+++ b/include/libcamera/meson.build\n@@ -14,6 +14,7 @@ libcamera_api = files([\n 'pixelformats.h',\n 'request.h',\n 'signal.h',\n+ 'span.h',\n 'stream.h',\n 'timer.h',\n ])\ndiff --git a/include/libcamera/span.h b/include/libcamera/span.h\nnew file mode 100644\nindex 000000000000..3e63603f60ed\n--- /dev/null\n+++ b/include/libcamera/span.h\n@@ -0,0 +1,89 @@\n+/* SPDX-License-Identifier: LGPL-2.1-or-later */\n+/*\n+ * Copyright (C) 2020, Google Inc.\n+ *\n+ * span.h - C++20 std::span<> implementation for C++11\n+ */\n+\n+#ifndef __LIBCAMERA_SPAN_H__\n+#define __LIBCAMERA_SPAN_H__\n+\n+#include \n+#include \n+\n+namespace libcamera {\n+\n+template\n+class Span\n+{\n+private:\n+\tusing iterator = T *;\n+\tusing const_iterator = const T *;\n+\n+\tclass Storage\n+\t{\n+\tpublic:\n+\t\tStorage(T *ptr, size_t size)\n+\t\t\t: ptr_(ptr), size_(size)\n+\t\t{\n+\t\t}\n+\n+\t\tT *ptr() const { return ptr_; }\n+\t\tsize_t size() const { return size_; }\n+\n+\tprivate:\n+\t\tT *ptr_;\n+\t\tsize_t size_;\n+\t};\n+\n+public:\n+\tSpan(T &v)\n+\t\t: storage_(&v, 1)\n+\t{\n+\t}\n+\n+\tSpan(const T &v)\n+\t\t: storage_(const_cast(&v), 1)\n+\t{\n+\t}\n+\n+\tSpan(T *v, size_t s)\n+\t\t: storage_(v, s)\n+\t{\n+\t}\n+\n+\tSpan(const T *v, size_t s)\n+\t\t: storage_(const_cast(v), s)\n+\t{\n+\t}\n+\n+\tSpan(std::initializer_list list)\n+\t\t: storage_(const_cast(list.begin()), list.size())\n+\t{\n+\t}\n+\n+\tSpan(const Span &other) = default;\n+\tSpan &operator=(const Span &other) = default;\n+\n+\tT *data() const { return storage_.ptr(); }\n+\tsize_t size() const { return storage_.size(); }\n+\n+\tT &operator[](unsigned int index) const\n+\t{\n+\t\tif (index >= size())\n+\t\t\treturn *(end() - 1);\n+\t\treturn *(data() + index);\n+\t}\n+\n+\tconstexpr iterator begin() const { return data(); }\n+\tconstexpr iterator cbegin() const { return begin(); }\n+\tconstexpr iterator end() const { return data() + size(); }\n+\tconstexpr iterator cend() const { return end(); }\n+\n+private:\n+\tStorage storage_;\n+};\n+\n+}; /* namespace libcamera */\n+\n+#endif /* __LIBCAMERA_SPAN_H__ */\ndiff --git a/src/libcamera/meson.build b/src/libcamera/meson.build\nindex 1e5b54b34078..ecc5b5fe4023 100644\n--- a/src/libcamera/meson.build\n+++ b/src/libcamera/meson.build\n@@ -36,6 +36,7 @@ libcamera_sources = files([\n 'request.cpp',\n 'semaphore.cpp',\n 'signal.cpp',\n+ 'span.cpp',\n 'stream.cpp',\n 'thread.cpp',\n 'timer.cpp',\ndiff --git a/src/libcamera/span.cpp b/src/libcamera/span.cpp\nnew file mode 100644\nindex 000000000000..72ffdf7481c4\n--- /dev/null\n+++ b/src/libcamera/span.cpp\n@@ -0,0 +1,128 @@\n+/* SPDX-License-Identifier: LGPL-2.1-or-later */\n+/*\n+ * Copyright (C) 2020, Google Inc.\n+ *\n+ * span.h - C++20 std::span<> implementation for C++11\n+ */\n+\n+#include \n+\n+/**\n+ * \\file span.h\n+ * \\brief libcamera implementation of C++20 std::span<>\n+ */\n+\n+namespace libcamera {\n+\n+/**\n+ * \\class Span\n+ * \\brief Representation of a sequence of contiguous objects of type T\n+ *\n+ * This class represents a sequence of fixed size of contiguous objects of\n+ * template type T with the first object residing in position 0.\n+ *\n+ * A Span internally consists of a pointer to raw memory and an associated\n+ * number of elements there located. It does not enforce any ownership on the\n+ * memory it represents, but it only provides a convenient, lightweight and\n+ * easily transportable view on such memory area.\n+ *\n+ * A Span can be constructed from a single element as well as from raw memory\n+ * by providing an associated size. It can be accessed by index and iterated\n+ * as a regular standard library container. As Span does not enforce any memory\n+ * ownership, destroying a Span instance does not invalidate the memory it\n+ * represents.\n+ *\n+ * The libcamera implementation of Span it's a simplified implementation of\n+ * C++20 the std::span<> class and it is no 1-to-1 compatible with it. Care\n+ * should be taken in not mixing usage of the two classes.\n+ */\n+\n+/**\n+ * \\fn Span::Span(T &v)\n+ * \\brief Contruct a Span of size 1 representing element \\a v\n+ * \\param[in] v The element represented by the Span\n+ */\n+\n+/**\n+ * \\fn Span::Span(const T &v)\n+ * \\brief Contruct a Span of size 1 representing the constant element \\a v\n+ * \\param[in] v The constant element represented by the Span\n+ */\n+\n+/**\n+ * \\fn Span::Span(T *v, size_t s)\n+ * \\brief Contruct a Span of size \\a s representing elements in memory \\a v\n+ * \\param[in] v The memory area represeted by the Span\n+ * \\param[in] s The number of elements in memory area \\a v\n+ */\n+\n+/**\n+ * \\fn Span::Span(const T *v, size_t s)\n+ * \\brief Contruct a Span of size \\a s representing elements in constant memory \\a v\n+ * \\param[in] v The constant memory area represeted by the Span\n+ * \\param[in] s The number of elements in memory area \\a v\n+ */\n+\n+/**\n+ * \\fn Span::Span(std::initializer_list list)\n+ * \\brief Contruct a Span with an initialier list of elements\n+ * \\param[in] list The initializer list\n+ */\n+\n+/**\n+ * \\fn Span::Span(const Span &other)\n+ * \\brief Contruct a Span with the content of \\a other\n+ * \\param[in] other The other Span\n+ */\n+\n+/**\n+ * \\fn Span::operator=(const Span &other)\n+ * \\brief Replace the content of the Span with the one from \\a other\n+ * \\param[in] other The other Span\n+ */\n+\n+/**\n+ * \\fn Span::data()\n+ * \\brief Retrieve a pointer to the beginning of the memory area represented by\n+ * the Span\n+ * \\return A pointer to the raw memory area\n+ */\n+\n+/**\n+ * \\fn Span::size()\n+ * \\brief Retrieve the number of elements in the Span\n+ * \\return The number of elements in the Span\n+ */\n+\n+/**\n+ * \\fn Span::operator[](unsigned int index)\n+ * \\brief Retrieve element in position \\a index\n+ * \\param[in] index\n+ *\n+ * If \\a index is larger than the number of elements in the Span, the last\n+ * element is returned.\n+ *\n+ * \\return The element at position \\a index\n+ */\n+\n+/**\n+ * \\fn iterator Span::begin()\n+ * \\brief Retrieve an iterator to the first element in the Span\n+ */\n+\n+/**\n+ * \\fn const_iterator Span::cbegin()\n+ * \\brief Retrieve a constant iterator to the first element in the Span\n+ */\n+\n+/**\n+ * \\fn iterator Span::end()\n+ * \\brief Retrieve an iterator pointing to the past-the-end element in the Span\n+ */\n+\n+/**\n+ * \\fn const_iterator Span::cend()\n+ * \\brief Retrieve a constant iterator pointing to the past-the-end element in the Span\n+ */\n+\n+} /* namespace libcamera */\n","prefixes":["libcamera-devel","12/23"]}