diff options
author | Laurent Pinchart <laurent.pinchart@ideasonboard.com> | 2019-02-08 16:40:57 +0200 |
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committer | Laurent Pinchart <laurent.pinchart@ideasonboard.com> | 2019-02-11 11:23:51 +0200 |
commit | 8a401ed4119aac4ca994f70cb5540bc1b2c6939a (patch) | |
tree | f14a6eecb27b8db376351c331cce40d1d410cc5d /src/libcamera/log.cpp | |
parent | d8f2ed7d0d7f0de7184916da59cd2097529bd1c9 (diff) |
libcamera: log: Allow extending log messages
Introduce a base Loggable class that can be inherited from by other
classes to support adding per-instance information to the log messages.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
Diffstat (limited to 'src/libcamera/log.cpp')
-rw-r--r-- | src/libcamera/log.cpp | 124 |
1 files changed, 124 insertions, 0 deletions
diff --git a/src/libcamera/log.cpp b/src/libcamera/log.cpp index edeb5eab..26ebf410 100644 --- a/src/libcamera/log.cpp +++ b/src/libcamera/log.cpp @@ -405,6 +405,25 @@ LogMessage::LogMessage(const char *fileName, unsigned int line, init(fileName, line); } +/** + * \brief Move-construct a log message + * \param[in] other The other message + * + * The move constructor is meant to support the _log() functions. Thanks to copy + * elision it will likely never be called, but C++11 only permits copy elision, + * it doesn't enforce it unlike C++17. To avoid potential link errors depending + * on the compiler type and version, and optimization level, the move + * constructor is defined even if it will likely never be called, and ensures + * that the destructor of the \a other message will not output anything to the + * log by setting the severity to -1. + */ +LogMessage::LogMessage(LogMessage &&other) + : msgStream_(std::move(other.msgStream_)), category_(other.category_), + severity_(other.severity_) +{ + other.severity_ = static_cast<LogSeverity>(-1); +} + void LogMessage::init(const char *fileName, unsigned int line) { /* Log the timestamp, severity and file information. */ @@ -424,6 +443,10 @@ void LogMessage::init(const char *fileName, unsigned int line) LogMessage::~LogMessage() { + /* Don't print anything if we have been moved to another LogMessage. */ + if (severity_ == -1) + return; + msgStream_ << std::endl; if (severity_ >= category_.severity()) { @@ -446,6 +469,107 @@ LogMessage::~LogMessage() */ /** + * \class Loggable + * \brief Base class to support log message extensions + * + * The Loggable class allows classes to extend log messages without any change + * to the way the LOG() macro is invoked. By inheriting from Loggable and + * implementing the logPrefix() virtual method, a class can specify extra + * information to be automatically added to messages logged from class member + * methods. + */ + +Loggable::~Loggable() +{ +} + +/** + * \fn Loggable::logPrefix() + * \brief Retrieve a string to be prefixed to the log message + * + * This method allows classes inheriting from the Loggable class to extend the + * logger with an object-specific prefix output right before the log message + * contents. + * + * \return A string to be prefixed to the log message + */ + +/** + * \brief Create a temporary LogMessage object to log a message + * \param[in] fileName The file name where the message is logged from + * \param[in] line The line number where the message is logged from + * \param[in] severity The log message severity + * + * This method is used as a backeng by the LOG() macro to create a log message + * for locations inheriting from the Loggable class. + * + * \return A log message + */ +LogMessage Loggable::_log(const char *fileName, unsigned int line, + LogSeverity severity) +{ + LogMessage msg(fileName, line, severity); + + msg.stream() << logPrefix() << ": "; + return msg; +} + +/** + * \brief Create a temporary LogMessage object to log a message + * \param[in] fileName The file name where the message is logged from + * \param[in] line The line number where the message is logged from + * \param[in] category The log message category + * \param[in] severity The log message severity + * + * This method is used as a backeng by the LOG() macro to create a log message + * for locations inheriting from the Loggable class. + * + * \return A log message + */ +LogMessage Loggable::_log(const char *fileName, unsigned int line, + const LogCategory &category, LogSeverity severity) +{ + LogMessage msg(fileName, line, category, severity); + + msg.stream() << logPrefix() << ": "; + return msg; +} + +/** + * \brief Create a temporary LogMessage object to log a message + * \param[in] fileName The file name where the message is logged from + * \param[in] line The line number where the message is logged from + * \param[in] severity The log message severity + * + * This function is used as a backeng by the LOG() macro to create a log + * message for locations not inheriting from the Loggable class. + * + * \return A log message + */ +LogMessage _log(const char *fileName, unsigned int line, LogSeverity severity) +{ + return LogMessage(fileName, line, severity); +} + +/** + * \brief Create a temporary LogMessage object to log a message + * \param[in] fileName The file name where the message is logged from + * \param[in] line The line number where the message is logged from + * \param[in] category The log message category + * \param[in] severity The log message severity + * + * This function is used as a backeng by the LOG() macro to create a log + * message for locations not inheriting from the Loggable class. + * + * \return A log message + */ +LogMessage _log(const char *fileName, unsigned int line, + const LogCategory &category, LogSeverity severity) +{ + return LogMessage(fileName, line, category, severity); +} + +/** * \def LOG_DECLARE_CATEGORY(name) * \hideinitializer * \brief Declare a category of log messages |