[libcamera-devel] [PATCH 2/3] libcamera: Add initial logger

[Kieran Bingham]

Hi Laurent,

On 04/12/2018 22:11, Laurent Pinchart wrote:
> The logger is based on the ostream API, allowing code to log messages in
> a native way. It automatically logs the time stamp, severity level, file
> name and line number.
> 
> Many important features are missing, such as logging to file, logging
> classes, and log filtering based on the severity level, file name and
> class.
> 
> Signed-off-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>

Great - I like that it builds in the timestamping and file/line
tracking, (which we might want to have as a verbosity option later).

It's better than not having anything... so lets get it in and let it
develop as we go.

Acked-by: Kieran Bingham <kieran.bingham at ideasonboard.com>


> ---
>  src/libcamera/include/.keep_empty |  0
>  src/libcamera/include/log.h       | 38 +++++++++++++++
>  src/libcamera/include/utils.h     | 12 +++++
>  src/libcamera/log.cpp             | 81 +++++++++++++++++++++++++++++++
>  src/libcamera/meson.build         |  5 +-
>  5 files changed, 135 insertions(+), 1 deletion(-)
>  delete mode 100644 src/libcamera/include/.keep_empty
>  create mode 100644 src/libcamera/include/log.h
>  create mode 100644 src/libcamera/include/utils.h
>  create mode 100644 src/libcamera/log.cpp
> 
> diff --git a/src/libcamera/include/.keep_empty b/src/libcamera/include/.keep_empty
> deleted file mode 100644
> index e69de29bb2d1..000000000000
> diff --git a/src/libcamera/include/log.h b/src/libcamera/include/log.h
> new file mode 100644
> index 000000000000..76acd1520868
> --- /dev/null
> +++ b/src/libcamera/include/log.h
> @@ -0,0 +1,38 @@
> +/* SPDX-License-Identifier: LGPL-2.1-or-later */
> +/*
> + * Copyright (C) 2018, Google Inc.
> + *
> + * log.h - Logging infrastructure
> + */
> +#ifndef __LIBCAMERA_LOG_H__
> +#define __LIBCAMERA_LOG_H__
> +
> +#include <sstream>
> +
> +namespace libcamera {
> +
> +enum LogSeverity {
> +	LogInfo,
> +	LogWarning,
> +	LogError,
> +};
> +
> +class LogMessage
> +{
> +public:
> +	LogMessage(const char *fileName, unsigned int line,
> +		  LogSeverity severity);
> +	LogMessage(const LogMessage&) = delete;
> +	~LogMessage();
> +
> +	std::ostream& stream() { return msgStream; }
> +
> +private:
> +	std::ostringstream msgStream;
> +};
> +
> +#define LOG(severity) LogMessage(__FILE__, __LINE__, Log##severity).stream()
> +
> +};
> +
> +#endif /* __LIBCAMERA_LOG_H__ */
> diff --git a/src/libcamera/include/utils.h b/src/libcamera/include/utils.h
> new file mode 100644
> index 000000000000..3ffa6f4ea591
> --- /dev/null
> +++ b/src/libcamera/include/utils.h
> @@ -0,0 +1,12 @@
> +/* SPDX-License-Identifier: LGPL-2.1-or-later */
> +/*
> + * Copyright (C) 2018, Google Inc.
> + *
> + * utils.h - Miscellaneous utility functions
> + */
> +#ifndef __LIBCAMERA_UTILS_H__
> +#define __LIBCAMERA_UTILS_H__
> +
> +#define ARRAY_SIZE(a)	(sizeof(a) / sizeof(a[0]))
> +
> +#endif /* __LIBCAMERA_UTILS_H__ */
> diff --git a/src/libcamera/log.cpp b/src/libcamera/log.cpp
> new file mode 100644
> index 000000000000..18ccfa32d8b4
> --- /dev/null
> +++ b/src/libcamera/log.cpp
> @@ -0,0 +1,81 @@
> +/* SPDX-License-Identifier: LGPL-2.1-or-later */
> +/*
> + * Copyright (C) 2018, Google Inc.
> + *
> + * log.h - Logging infrastructure
> + */
> +
> +#include <cstdio>
> +#include <ctime>
> +#include <iomanip>
> +#include <string.h>
> +
> +#include "log.h"
> +#include "utils.h"
> +
> +/**
> + * \file log.h
> + * \brief Logging infrastructure
> + */
> +
> +namespace libcamera {
> +
> +/**
> + * \enum LogSeverity
> + * Log message severity
> + * \var Info
> + * Informational message
> + * \var Warning
> + * Warning message, signals a potential issue
> + * \var Error
> + * Error message, signals an unrecoverable issue
> + */
> +
> +/**
> + * \def LOG(severity)
> + * \brief Log a message
> + *
> + * Return an std::ostream reference to which a message can be logged using the
> + * iostream API. The \a severity controls whether the message is printed or
> + * dropped, depending on the global log level.
> + */
> +
> +static const char *log_severity_name(LogSeverity severity)
> +{
> +	static const char * const names[] = {
> +		"INFO",
> +		"WARN",
> +		" ERR",
> +	};
> +
> +	if ((unsigned int)severity < ARRAY_SIZE(names))
> +		return names[severity];
> +	else
> +		return "UNKN";
> +}
> +
> +LogMessage::LogMessage(const char *fileName, unsigned int line,
> +		       LogSeverity severity)
> +{
> +	/* Log the timestamp, severity and file information. */
> +	struct timespec timestamp;
> +	clock_gettime(CLOCK_MONOTONIC, &timestamp);
> +	msgStream << "[" << timestamp.tv_sec / (60 * 60) << ":"
> +		  << std::setw(2) << (timestamp.tv_sec / 60) % 60 << ":"
> +		  << std::setw(2) << timestamp.tv_sec % 60 << "."
> +		  << std::setw(9) << timestamp.tv_nsec << "]";
> +
> +	msgStream << " " << log_severity_name(severity);
> +	msgStream << " " << basename(fileName) << ":" << line << " ";
> +}
> +
> +LogMessage::~LogMessage()
> +{
> +	msgStream << std::endl;
> +
> +	std::string msg(msgStream.str());
> +	fwrite(msg.data(), msg.size(), 1, stderr);
> +	fflush(stderr);
> +}
> +
> +};
> diff --git a/src/libcamera/meson.build b/src/libcamera/meson.build
> index 07d9cd448342..fe38f8b2b5b4 100644
> --- a/src/libcamera/meson.build
> +++ b/src/libcamera/meson.build
> @@ -1,4 +1,7 @@
> -sources = ['main.cpp']
> +sources = files([
> +    'log.cpp',
> +    'main.cpp',
> +])
>  
>  includes = [
>      libcamera_includes,
> 

-- 
Regards
--
Kieran