{"id":22606,"url":"https://patchwork.libcamera.org/api/1.1/patches/22606/?format=json","web_url":"https://patchwork.libcamera.org/patch/22606/","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":"<20250121185554.301901-3-pobrn@protonmail.com>","date":"2025-01-21T18:56:07","name":"[RFC,v1,5/7] libcamera: base: log: Use `std::string_view` to avoid some copies","commit_ref":null,"pull_url":null,"state":"superseded","archived":false,"hash":"6f0ae78c0101306d1fa70dec7b36ef0ad60151ea","submitter":{"id":133,"url":"https://patchwork.libcamera.org/api/1.1/people/133/?format=json","name":"Pőcze Barnabás","email":"pobrn@protonmail.com"},"delegate":null,"mbox":"https://patchwork.libcamera.org/patch/22606/mbox/","series":[{"id":4960,"url":"https://patchwork.libcamera.org/api/1.1/series/4960/?format=json","web_url":"https://patchwork.libcamera.org/project/libcamera/list/?series=4960","date":"2025-01-21T18:50:47","name":"libcamera: base: log: Misc. changes","version":1,"mbox":"https://patchwork.libcamera.org/series/4960/mbox/"}],"comments":"https://patchwork.libcamera.org/api/patches/22606/comments/","check":"pending","checks":"https://patchwork.libcamera.org/api/patches/22606/checks/","tags":{},"headers":{"Return-Path":"<libcamera-devel-bounces@lists.libcamera.org>","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 071F1BD160\n\tfor <parsemail@patchwork.libcamera.org>;\n\tTue, 21 Jan 2025 18:56:13 +0000 (UTC)","from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id A78D868551;\n\tTue, 21 Jan 2025 19:56:13 +0100 (CET)","from mail-10628.protonmail.ch (mail-10628.protonmail.ch\n\t[79.135.106.28])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id 4C97D68503\n\tfor <libcamera-devel@lists.libcamera.org>;\n\tTue, 21 Jan 2025 19:56:12 +0100 (CET)"],"Authentication-Results":"lancelot.ideasonboard.com;\n\tdkim=fail reason=\"signature verification failed\" (2048-bit key;\n\tunprotected) header.d=protonmail.com header.i=@protonmail.com\n\theader.b=\"rrxkpaBB\"; dkim-atps=neutral","DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/relaxed; d=protonmail.com;\n\ts=protonmail3; t=1737485771; x=1737744971;\n\tbh=mT1gGibnHhvJaaZgc3Zmplug3lJwxIgsUTRvF+/Boxk=;\n\th=Date:To:From:Subject:Message-ID:In-Reply-To:References:\n\tFeedback-ID:From:To:Cc:Date:Subject:Reply-To:Feedback-ID:\n\tMessage-ID:BIMI-Selector:List-Unsubscribe:List-Unsubscribe-Post;\n\tb=rrxkpaBB64WzVfCki3vnMVvjp5RBk6i8TERJEsToVO8JCY5q7LR5fXmUG8tocOZsl\n\tinahsLuk8yDdXkQyAd3qOrlOY3WxUWaAy6bawBQLy/uJ8V9bdlaGOXCnGIDzecJnUf\n\tNefYaZ43ORnK7K0gZT3F5aYSotHpdmNCDMDQCbKMAJT7RF8iRwa/Opn036skXaKl4t\n\tzpSUOR10jxkPtw6kTm7WfDep3BpdHWvNCMUjRSMXcRUUO5SNGutg5aMJEsWVZ6LZKY\n\tBstgvg8cXw44rMsVyCrwuE6708nOD4q72w7qim7GI/PS6ll0TlAD1LXEaa2ikWVZsX\n\tgLYpK9cyeX3Rw==","Date":"Tue, 21 Jan 2025 18:56:07 +0000","To":"libcamera-devel@lists.libcamera.org","From":"=?utf-8?q?Barnab=C3=A1s_P=C5=91cze?= <pobrn@protonmail.com>","Subject":"[RFC PATCH v1 5/7] libcamera: base: log: Use `std::string_view` to\n\tavoid some copies","Message-ID":"<20250121185554.301901-3-pobrn@protonmail.com>","In-Reply-To":"<20250121185554.301901-1-pobrn@protonmail.com>","References":"<20250121185554.301901-1-pobrn@protonmail.com>","Feedback-ID":"20568564:user:proton","X-Pm-Message-ID":"bfaf80448bcf3490e3d3578c10a70c849ee035ea","MIME-Version":"1.0","Content-Type":"text/plain; charset=utf-8","Content-Transfer-Encoding":"quoted-printable","X-BeenThere":"libcamera-devel@lists.libcamera.org","X-Mailman-Version":"2.1.29","Precedence":"list","List-Id":"<libcamera-devel.lists.libcamera.org>","List-Unsubscribe":"<https://lists.libcamera.org/options/libcamera-devel>,\n\t<mailto:libcamera-devel-request@lists.libcamera.org?subject=unsubscribe>","List-Archive":"<https://lists.libcamera.org/pipermail/libcamera-devel/>","List-Post":"<mailto:libcamera-devel@lists.libcamera.org>","List-Help":"<mailto:libcamera-devel-request@lists.libcamera.org?subject=help>","List-Subscribe":"<https://lists.libcamera.org/listinfo/libcamera-devel>,\n\t<mailto:libcamera-devel-request@lists.libcamera.org?subject=subscribe>","Errors-To":"libcamera-devel-bounces@lists.libcamera.org","Sender":"\"libcamera-devel\" <libcamera-devel-bounces@lists.libcamera.org>"},"content":"Use `std::string_view` to avoid some largely unnecessary copies, and\nto make string comparisong potentially faster by eliminating repeated\n`strlen()` calls.\n\nSigned-off-by: Barnabás Pőcze <pobrn@protonmail.com>\n---\n include/libcamera/base/log.h |  5 +++--\n src/libcamera/base/log.cpp   | 25 +++++++++++++------------\n 2 files changed, 16 insertions(+), 14 deletions(-)","diff":"diff --git a/include/libcamera/base/log.h b/include/libcamera/base/log.h\nindex 89f707e54..9c7775660 100644\n--- a/include/libcamera/base/log.h\n+++ b/include/libcamera/base/log.h\n@@ -9,6 +9,7 @@\n \n #include <atomic>\n #include <sstream>\n+#include <string_view>\n \n #include <libcamera/base/private.h>\n \n@@ -29,7 +30,7 @@ enum LogSeverity {\n class LogCategory\n {\n public:\n-\tstatic LogCategory *create(const char *name);\n+\tstatic LogCategory *create(std::string_view name);\n \n \tconst std::string &name() const { return name_; }\n \tLogSeverity severity() const { return severity_.load(std::memory_order_relaxed); }\n@@ -38,7 +39,7 @@ public:\n \tstatic const LogCategory &defaultCategory();\n \n private:\n-\texplicit LogCategory(const char *name);\n+\texplicit LogCategory(std::string_view name);\n \n \tconst std::string name_;\n \ndiff --git a/src/libcamera/base/log.cpp b/src/libcamera/base/log.cpp\nindex 795260b0a..78db4990c 100644\n--- a/src/libcamera/base/log.cpp\n+++ b/src/libcamera/base/log.cpp\n@@ -15,6 +15,7 @@\n #include <stdio.h>\n #include <stdlib.h>\n #include <string.h>\n+#include <string_view>\n #include <syslog.h>\n #include <time.h>\n #include <unordered_set>\n@@ -313,11 +314,11 @@ private:\n \n \tvoid parseLogFile();\n \tvoid parseLogLevels();\n-\tstatic LogSeverity parseLogLevel(const std::string &level);\n+\tstatic LogSeverity parseLogLevel(std::string_view level);\n \n \tfriend LogCategory;\n \tvoid registerCategory(LogCategory *category);\n-\tLogCategory *findCategory(const char *name) const;\n+\tLogCategory *findCategory(std::string_view name) const;\n \n \tstatic bool destroyed_;\n \n@@ -642,17 +643,17 @@ void Logger::parseLogLevels()\n \t\tif (!len)\n \t\t\tcontinue;\n \n-\t\tstd::string category;\n-\t\tstd::string level;\n+\t\tstd::string_view category;\n+\t\tstd::string_view level;\n \n \t\tconst char *colon = static_cast<const char *>(memchr(pair, ':', len));\n \t\tif (!colon) {\n \t\t\t/* 'x' is a shortcut for '*:x'. */\n \t\t\tcategory = \"*\";\n-\t\t\tlevel = std::string(pair, len);\n+\t\t\tlevel = std::string_view(pair, len);\n \t\t} else {\n-\t\t\tcategory = std::string(pair, colon - pair);\n-\t\t\tlevel = std::string(colon + 1, comma - colon - 1);\n+\t\t\tcategory = std::string_view(pair, colon - pair);\n+\t\t\tlevel = std::string_view(colon + 1, comma - colon - 1);\n \t\t}\n \n \t\t/* Both the category and the level must be specified. */\n@@ -663,7 +664,7 @@ void Logger::parseLogLevels()\n \t\tif (severity == LogInvalid)\n \t\t\tcontinue;\n \n-\t\tlevels_.push_back({ category, severity });\n+\t\tlevels_.emplace_back(category, severity);\n \t}\n }\n \n@@ -677,7 +678,7 @@ void Logger::parseLogLevels()\n  *\n  * \\return The log severity, or LogInvalid if the string is invalid\n  */\n-LogSeverity Logger::parseLogLevel(const std::string &level)\n+LogSeverity Logger::parseLogLevel(std::string_view level)\n {\n \tstatic const char *const names[] = {\n \t\t\"DEBUG\",\n@@ -744,7 +745,7 @@ void Logger::registerCategory(LogCategory *category)\n  * \\param[in] name Name of the log category\n  * \\return The pointer to the found log category or nullptr if not found\n  */\n-LogCategory *Logger::findCategory(const char *name) const\n+LogCategory *Logger::findCategory(std::string_view name) const\n {\n \tif (auto it = std::find_if(categories_.begin(), categories_.end(),\n \t\t\t\t   [name](auto c) { return c->name() == name; });\n@@ -788,7 +789,7 @@ LogCategory *Logger::findCategory(const char *name) const\n  *\n  * \\return The pointer to the LogCategory\n  */\n-LogCategory *LogCategory::create(const char *name)\n+LogCategory *LogCategory::create(std::string_view name)\n {\n \tstatic Mutex mutex_;\n \tMutexLocker locker(mutex_);\n@@ -806,7 +807,7 @@ LogCategory *LogCategory::create(const char *name)\n  * \\brief Construct a log category\n  * \\param[in] name The category name\n  */\n-LogCategory::LogCategory(const char *name)\n+LogCategory::LogCategory(std::string_view name)\n \t: name_(name), severity_(LogSeverity::LogInfo)\n {\n }\n","prefixes":["RFC","v1","5/7"]}