[libcamera-devel] [PATCH 4/5] libcamera: base: log: Add coloring to the log output
Laurent Pinchart
laurent.pinchart at ideasonboard.com
Thu May 26 11:09:17 CEST 2022
On Thu, May 26, 2022 at 01:25:02AM +0300, Laurent Pinchart via libcamera-devel wrote:
> Extend the logger to support coloring messages. The log level is
> colorized with per-level colors, and the category with a fixed color.
> This makes the log output more readable.
>
> Coloring is enabled by default when logging to std::cerr, and can be
> disabled by setting the LIBCAMERA_LOG_NO_COLOR environment variable.
> When logging to a file with LIBCAMERA_LOG_FILE, coloring is disabled. It
> can be enabled for file logging using the logSetFile() function.
>
> Signed-off-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
> ---
> Documentation/environment_variables.rst | 21 +++--
> include/libcamera/logging.h | 4 +-
> src/libcamera/base/log.cpp | 114 +++++++++++++++++++-----
> src/libcamera/camera_manager.cpp | 2 +-
> 4 files changed, 109 insertions(+), 32 deletions(-)
>
> diff --git a/Documentation/environment_variables.rst b/Documentation/environment_variables.rst
> index fa703a726845..7028c024b14e 100644
> --- a/Documentation/environment_variables.rst
> +++ b/Documentation/environment_variables.rst
> @@ -19,6 +19,9 @@ LIBCAMERA_LOG_LEVELS
>
> Example value: ``*:DEBUG``
>
> +LIBCAMERA_LOG_NO_COLOR
> + Disable coloring of log messages (`more <Notes about debugging_>`__).
> +
> LIBCAMERA_IPA_CONFIG_PATH
> Define custom search locations for IPA configurations (`more <IPA configuration_>`__).
>
> @@ -40,12 +43,20 @@ Further details
> Notes about debugging
> ~~~~~~~~~~~~~~~~~~~~~
>
> -The environment variables ``LIBCAMERA_LOG_FILE`` and ``LIBCAMERA_LOG_LEVELS``
> -are used to modify the destination and verbosity of messages provided by
> -libcamera.
> +The environment variables ``LIBCAMERA_LOG_FILE``, ``LIBCAMERA_LOG_LEVELS`` and
> +``LIBCAMERA_LOG_NO_COLOR`` are used to modify the degault configuration of the
> +libcamera logger.
>
> -The ``LIBCAMERA_LOG_LEVELS`` variable accepts a comma-separated list of
> -'category:level' pairs.
> +By default, libcamera logs all messages to the standard error (std::cerr).
> +Messages are colored by default depending on the log level. Coloring can be
> +disabled by setting the ``LIBCAMERA_LOG_NO_COLOR`` environment variable.
> +
> +The default log destination can also be directed to a file by setting the
> +``LIBCAMERA_LOG_FILE`` environment variable to the log file name. This also
> +disables coloring.
> +
> +Log levels are controlled through the ``LIBCAMERA_LOG_LEVELS`` variable, which
> +accepts a comma-separated list of 'category:level' pairs.
>
> The `level <Log levels_>`__ part is mandatory and can either be specified by
> name or by numerical index associated with each level.
> diff --git a/include/libcamera/logging.h b/include/libcamera/logging.h
> index c36882b91974..cd842f67d553 100644
> --- a/include/libcamera/logging.h
> +++ b/include/libcamera/logging.h
> @@ -16,8 +16,8 @@ enum LoggingTarget {
> LoggingTargetStream,
> };
>
> -int logSetFile(const char *path);
> -int logSetStream(std::ostream *stream);
> +int logSetFile(const char *path, bool color = false);
> +int logSetStream(std::ostream *stream, bool color = false);
> int logSetTarget(LoggingTarget target);
> void logSetLevel(const char *category, const char *level);
>
> diff --git a/src/libcamera/base/log.cpp b/src/libcamera/base/log.cpp
> index 26f1420703b9..a9f5bbbd36f7 100644
> --- a/src/libcamera/base/log.cpp
> +++ b/src/libcamera/base/log.cpp
> @@ -104,8 +104,8 @@ static const char *log_severity_name(LogSeverity severity)
> class LogOutput
> {
> public:
> - LogOutput(const char *path);
> - LogOutput(std::ostream *stream);
> + LogOutput(const char *path, bool color);
> + LogOutput(std::ostream *stream, bool color);
> LogOutput();
> ~LogOutput();
>
> @@ -119,14 +119,16 @@ private:
>
> std::ostream *stream_;
> LoggingTarget target_;
> + bool color_;
> };
>
> /**
> * \brief Construct a log output based on a file
> * \param[in] path Full path to log file
> + * \param[in] color True to output colored messages
> */
> -LogOutput::LogOutput(const char *path)
> - : target_(LoggingTargetFile)
> +LogOutput::LogOutput(const char *path, bool color)
> + : target_(LoggingTargetFile), color_(color)
> {
> stream_ = new std::ofstream(path);
> }
> @@ -134,9 +136,10 @@ LogOutput::LogOutput(const char *path)
> /**
> * \brief Construct a log output based on a stream
> * \param[in] stream Stream to send log output to
> + * \param[in] color True to output colored messages
> */
> -LogOutput::LogOutput(std::ostream *stream)
> - : stream_(stream), target_(LoggingTargetStream)
> +LogOutput::LogOutput(std::ostream *stream, bool color)
> + : stream_(stream), target_(LoggingTargetStream), color_(color)
> {
> }
>
> @@ -144,7 +147,7 @@ LogOutput::LogOutput(std::ostream *stream)
> * \brief Construct a log output to syslog
> */
> LogOutput::LogOutput()
> - : stream_(nullptr), target_(LoggingTargetSyslog)
> + : stream_(nullptr), target_(LoggingTargetSyslog), color_(false)
> {
> openlog("libcamera", LOG_PID, 0);
> }
> @@ -179,28 +182,70 @@ bool LogOutput::isValid() const
> }
> }
>
> +namespace {
> +
> +constexpr const char *kColorReset = "\033[0m";
> +constexpr const char *kColorRed = "\033[31m";
clang complains about unused variables, so I'll have to drop a few, or
add [[maybe_unused]]. I think I'll go for the former in this case.
> +constexpr const char *kColorGreen = "\033[32m";
> +constexpr const char *kColorYellow = "\033[33m";
> +constexpr const char *kColorBlue = "\033[34m";
> +constexpr const char *kColorMagenta = "\033[35m";
> +constexpr const char *kColorCyan = "\033[36m";
> +constexpr const char *kColorWhite = "\033[37m";
> +constexpr const char *kColorGrey = "\033[90m";
> +constexpr const char *kColorBrightRed = "\033[91m";
> +constexpr const char *kColorBrightGreen = "\033[92m";
> +constexpr const char *kColorBrightYellow = "\033[93m";
> +constexpr const char *kColorBrightBlue = "\033[94m";
> +constexpr const char *kColorBrightMagenta = "\033[95m";
> +constexpr const char *kColorBrightCyan = "\033[96m";
> +constexpr const char *kColorBrightWhite = "\033[97m";
> +
> +} /* namespace */
> +
> /**
> * \brief Write message to log output
> * \param[in] msg Message to write
> */
> void LogOutput::write(const LogMessage &msg)
> {
> + static const char *const severityColors[] = {
> + kColorBrightCyan,
> + kColorBrightGreen,
> + kColorBrightYellow,
> + kColorBrightRed,
> + kColorBrightMagenta,
> + };
> +
> + const char *categoryColor = color_ ? kColorBrightWhite : "";
> + const char *fileColor = color_ ? kColorBrightBlue : "";
> + const char *msgColor = color_ ? kColorReset : "";
> + const char *severityColor = "";
> + LogSeverity severity = msg.severity();
> std::string str;
>
> + if (color_) {
> + if (static_cast<unsigned int>(severity) < std::size(severityColors))
> + severityColor = severityColors[severity];
> + else
> + severityColor = kColorBrightWhite;
> + }
> +
> switch (target_) {
> case LoggingTargetSyslog:
> - str = std::string(log_severity_name(msg.severity())) + " "
> + str = std::string(log_severity_name(severity)) + " "
> + msg.category().name() + " " + msg.fileInfo() + " "
> + msg.msg();
> - writeSyslog(msg.severity(), str);
> + writeSyslog(severity, str);
> break;
> case LoggingTargetStream:
> case LoggingTargetFile:
> str = "[" + utils::time_point_to_string(msg.timestamp()) + "] ["
> + std::to_string(Thread::currentId()) + "] "
> - + log_severity_name(msg.severity()) + " "
> - + msg.category().name() + " " + msg.fileInfo() + " "
> - + msg.msg();
> + + severityColor + log_severity_name(severity) + " "
> + + categoryColor + msg.category().name() + " "
> + + fileColor + msg.fileInfo() + " "
> + + msgColor + msg.msg();
> writeStream(str);
> break;
> default:
> @@ -253,8 +298,8 @@ public:
> void write(const LogMessage &msg);
> void backtrace();
>
> - int logSetFile(const char *path);
> - int logSetStream(std::ostream *stream);
> + int logSetFile(const char *path, bool color);
> + int logSetStream(std::ostream *stream, bool color);
> int logSetTarget(LoggingTarget target);
> void logSetLevel(const char *category, const char *level);
>
> @@ -298,35 +343,47 @@ bool Logger::destroyed_ = false;
> /**
> * \brief Direct logging to a file
> * \param[in] path Full path to the log file
> + * \param[in] color True to output colored messages
> *
> * This function directs the log output to the file identified by \a path. The
> * previous log target, if any, is closed, and all new log messages will be
> * written to the new log file.
> *
> + * \a color controls whether or not the messages will be colored with standard
> + * ANSI escape codes. This is done regardless of whether \a path refers to a
> + * standard file or a TTY, the caller is responsible for disabling coloring when
> + * not suitable for the log target.
> + *
> * If the function returns an error, the log target is not changed.
> *
> * \return Zero on success, or a negative error code otherwise
> */
> -int logSetFile(const char *path)
> +int logSetFile(const char *path, bool color)
> {
> - return Logger::instance()->logSetFile(path);
> + return Logger::instance()->logSetFile(path, color);
> }
>
> /**
> * \brief Direct logging to a stream
> * \param[in] stream Stream to send log output to
> + * \param[in] color True to output colored messages
> *
> * This function directs the log output to \a stream. The previous log target,
> * if any, is closed, and all new log messages will be written to the new log
> * stream.
> *
> + * \a color controls whether or not the messages will be colored with standard
> + * ANSI escape codes. This is done regardless of whether \a stream refers to a
> + * standard file or a TTY, the caller is responsible for disabling coloring when
> + * not suitable for the log target.
> + *
> * If the function returns an error, the log file is not changed
> *
> * \return Zero on success, or a negative error code otherwise.
> */
> -int logSetStream(std::ostream *stream)
> +int logSetStream(std::ostream *stream, bool color)
> {
> - return Logger::instance()->logSetStream(stream);
> + return Logger::instance()->logSetStream(stream, color);
> }
>
> /**
> @@ -437,14 +494,16 @@ void Logger::backtrace()
> /**
> * \brief Set the log file
> * \param[in] path Full path to the log file
> + * \param[in] color True to output colored messages
> *
> * \sa libcamera::logSetFile()
> *
> * \return Zero on success, or a negative error code otherwise.
> */
> -int Logger::logSetFile(const char *path)
> +int Logger::logSetFile(const char *path, bool color)
> {
> - std::shared_ptr<LogOutput> output = std::make_shared<LogOutput>(path);
> + std::shared_ptr<LogOutput> output =
> + std::make_shared<LogOutput>(path, color);
> if (!output->isValid())
> return -EINVAL;
>
> @@ -455,14 +514,16 @@ int Logger::logSetFile(const char *path)
> /**
> * \brief Set the log stream
> * \param[in] stream Stream to send log output to
> + * \param[in] color True to output colored messages
> *
> * \sa libcamera::logSetStream()
> *
> * \return Zero on success, or a negative error code otherwise.
> */
> -int Logger::logSetStream(std::ostream *stream)
> +int Logger::logSetStream(std::ostream *stream, bool color)
> {
> - std::shared_ptr<LogOutput> output = std::make_shared<LogOutput>(stream);
> + std::shared_ptr<LogOutput> output =
> + std::make_shared<LogOutput>(stream, color);
> std::atomic_store(&output_, output);
> return 0;
> }
> @@ -514,10 +575,15 @@ void Logger::logSetLevel(const char *category, const char *level)
>
> /**
> * \brief Construct a logger
> + *
> + * If the environment variable is not set, log to std::cerr. The log messages
> + * are then colored by default. This can be overridden by setting the
> + * LIBCAMERA_LOG_NO_COLOR environment variable to disabled coloring.
> */
> Logger::Logger()
> {
> - logSetStream(&std::cerr);
> + bool color = !utils::secure_getenv("LIBCAMERA_LOG_NO_COLOR");
> + logSetStream(&std::cerr, color);
>
> parseLogFile();
> parseLogLevels();
> @@ -543,7 +609,7 @@ void Logger::parseLogFile()
> return;
> }
>
> - logSetFile(file);
> + logSetFile(file, false);
> }
>
> /**
> diff --git a/src/libcamera/camera_manager.cpp b/src/libcamera/camera_manager.cpp
> index 70d73822193b..d934596e4145 100644
> --- a/src/libcamera/camera_manager.cpp
> +++ b/src/libcamera/camera_manager.cpp
> @@ -290,7 +290,7 @@ CameraManager::~CameraManager()
> */
> int CameraManager::start()
> {
> - LOG(Camera, Info) << "libcamera " << version_;
> + LOG(Camera, Debug) << "libcamera " << version_;
>
> int ret = _d()->start();
--
Regards,
Laurent Pinchart
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