summaryrefslogtreecommitdiff
path: root/src/cam/buffer_writer.cpp
blob: e0374ffcb3199d30e01b02c7f203590518cbf94e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
 * Copyright (C) 2019, Google Inc.
 *
 * buffer_writer.cpp - Buffer writer
 */

#include <fcntl.h>
#include <iomanip>
#include <iostream>
#include <sstream>
#include <string.h>
#include <unistd.h>

#include "buffer_writer.h"

BufferWriter::BufferWriter(const std::string &pattern)
	: pattern_(pattern)
{
}

int BufferWriter::write(libcamera::Buffer *buffer,
			const std::string &streamName)
{
	std::string filename;
	size_t pos;
	int fd, ret = 0;

	filename = pattern_;
	pos = filename.find_first_of('#');
	if (pos != std::string::npos) {
		std::stringstream ss;
		ss << streamName << "-" << std::setw(6)
		   << std::setfill('0') << buffer->sequence();
		filename.replace(pos, 1, ss.str());
	}

	fd = open(filename.c_str(), O_CREAT | O_WRONLY |
		  (pos == std::string::npos ? O_APPEND : O_TRUNC),
		  S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH);
	if (fd == -1)
		return -errno;

	for (libcamera::Plane &plane : buffer->planes()) {
		void *data = plane.mem();
		unsigned int length = plane.length();

		ret = ::write(fd, data, length);
		if (ret < 0) {
			ret = -errno;
			std::cerr << "write error: " << strerror(-ret)
				  << std::endl;
			break;
		} else if (ret != (int)length) {
			std::cerr << "write error: only " << ret
				  << " bytes written instead of "
				  << length << std::endl;
			break;
		}
	}

	close(fd);

	return ret;
}
id='n303' href='#n303'>303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012
/* SPDX-License-Identifier: LGPL-2.1-or-later */
/*
 * Copyright (C) 2018, Google Inc.
 *
 * log.cpp - Logging infrastructure
 */

#include <libcamera/base/log.h>

#include <array>
#if HAVE_BACKTRACE
#include <execinfo.h>
#endif
#include <fstream>
#include <iostream>
#include <list>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <syslog.h>
#include <time.h>
#include <unordered_set>

#include <libcamera/logging.h>

#include <libcamera/base/thread.h>
#include <libcamera/base/utils.h>

/**
 * \file base/log.h
 * \brief Logging infrastructure
 *
 * libcamera includes a logging infrastructure used through the library that
 * allows inspection of internal operation in a user-configurable way. The log
 * messages are grouped in categories that represent areas of libcamera, and
 * output of messages for each category can be controlled by independent log
 * levels.
 *
 * The levels are configurable through the LIBCAMERA_LOG_LEVELS environment
 * variable that contains a comma-separated list of 'category:level' pairs.
 *
 * The category names are strings and can include a wildcard ('*') character at
 * the end to match multiple categories.
 *
 * The level are either numeric values, or strings containing the log level
 * name. The available log levels are DEBUG, INFO, WARN, ERROR and FATAL. Log
 * message with a level higher than or equal to the configured log level for
 * their category are output to the log, while other messages are silently
 * discarded.
 *
 * By default log messages are output to stderr. They can be redirected to a log
 * file by setting the LIBCAMERA_LOG_FILE environment variable to the name of
 * the file. The file must be writable and is truncated if it exists. If any
 * error occurs when opening the file, the file is ignored and the log is output
 * to stderr.
 */

/**
 * \file logging.h
 * \brief Logging management
 *
 * API to change the logging output destination and log levels programatically.
 */

namespace libcamera {

static int log_severity_to_syslog(LogSeverity severity)
{
	switch (severity) {
	case LogDebug:
		return LOG_DEBUG;
	case LogInfo:
		return LOG_INFO;
	case LogWarning:
		return LOG_WARNING;
	case LogError:
		return LOG_ERR;
	case LogFatal:
		return LOG_ALERT;
	default:
		return LOG_NOTICE;
	}
}

static const char *log_severity_name(LogSeverity severity)
{
	static const char *const names[] = {
		"DEBUG",
		" INFO",
		" WARN",
		"ERROR",
		"FATAL",
	};

	if (static_cast<unsigned int>(severity) < std::size(names))
		return names[severity];
	else
		return "UNKWN";
}

/**
 * \brief Log output
 *
 * The LogOutput class models a log output destination
 */
class LogOutput
{
public:
	LogOutput(const char *path);
	LogOutput(std::ostream *stream);
	LogOutput();
	~LogOutput();

	bool isValid() const;
	void write(const LogMessage &msg);
	void write(const std::string &msg);

private:
	void writeSyslog(LogSeverity severity, const std::string &msg);
	void writeStream(const std::string &msg);

	std::ostream *stream_;
	LoggingTarget target_;
};

/**
 * \brief Construct a log output based on a file
 * \param[in] path Full path to log file
 */
LogOutput::LogOutput(const char *path)
	: target_(LoggingTargetFile)
{
	stream_ = new std::ofstream(path);
}

/**
 * \brief Construct a log output based on a stream
 * \param[in] stream Stream to send log output to
 */
LogOutput::LogOutput(std::ostream *stream)
	: stream_(stream), target_(LoggingTargetStream)
{
}

/**
 * \brief Construct a log output to syslog
 */
LogOutput::LogOutput()
	: stream_(nullptr), target_(LoggingTargetSyslog)
{
	openlog("libcamera", LOG_PID, 0);
}

LogOutput::~LogOutput()
{
	switch (target_) {
	case LoggingTargetFile:
		delete stream_;
		break;
	case LoggingTargetSyslog:
		closelog();
		break;
	default:
		break;
	}
}

/**
 * \brief Check if the log output is valid
 * \return True if the log output is valid
 */
bool LogOutput::isValid() const
{
	switch (target_) {
	case LoggingTargetFile:
		return stream_->good();
	case LoggingTargetStream:
		return stream_ != nullptr;
	default:
		return true;
	}
}

/**
 * \brief Write message to log output
 * \param[in] msg Message to write
 */
void LogOutput::write(const LogMessage &msg)
{
	std::string str;

	switch (target_) {
	case LoggingTargetSyslog:
		str = std::string(log_severity_name(msg.severity())) + " "
		    + msg.category().name() + " " + msg.fileInfo() + " "
		    + msg.msg();
		writeSyslog(msg.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();
		writeStream(str);
		break;
	default:
		break;
	}
}

/**
 * \brief Write string to log output
 * \param[in] str String to write
 */
void LogOutput::write(const std::string &str)
{
	switch (target_) {
	case LoggingTargetSyslog:
		writeSyslog(LogDebug, str);
		break;
	case LoggingTargetStream:
	case LoggingTargetFile:
		writeStream(str);
		break;
	default:
		break;
	}
}

void LogOutput::writeSyslog(LogSeverity severity, const std::string &str)
{
	syslog(log_severity_to_syslog(severity), "%s", str.c_str());
}

void LogOutput::writeStream(const std::string &str)
{
	stream_->write(str.c_str(), str.size());
	stream_->flush();
}

/**
 * \brief Message logger
 *
 * The Logger class handles log configuration.
 */
class Logger
{
public:
	~Logger();

	static Logger *instance();

	void write(const LogMessage &msg);
	void backtrace();

	int logSetFile(const char *path);
	int logSetStream(std::ostream *stream);
	int logSetTarget(LoggingTarget target);
	void logSetLevel(const char *category, const char *level);

private:
	Logger();

	void parseLogFile();
	void parseLogLevels();
	static LogSeverity parseLogLevel(const std::string &level);

	friend LogCategory;
	void registerCategory(LogCategory *category);

	static bool destroyed_;

	std::unordered_set<LogCategory *> categories_;
	std::list<std::pair<std::string, LogSeverity>> levels_;

	std::shared_ptr<LogOutput> output_;
};

bool Logger::destroyed_ = false;

/**
 * \enum LoggingTarget
 * \brief Log destination type
 * \var LoggingTargetNone
 * \brief No logging destination
 * \sa Logger::logSetTarget
 * \var LoggingTargetSyslog
 * \brief Log to syslog
 * \sa Logger::logSetTarget
 * \var LoggingTargetFile
 * \brief Log to file
 * \sa Logger::logSetFile
 * \var LoggingTargetStream
 * \brief Log to stream
 * \sa Logger::logSetStream
 */

/**
 * \brief Direct logging to a file
 * \param[in] path Full path to the log file
 *
 * 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.
 *
 * 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)
{
	return Logger::instance()->logSetFile(path);
}

/**
 * \brief Direct logging to a stream
 * \param[in] stream Stream to send log output to
 *
 * 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.
 *
 * 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)
{
	return Logger::instance()->logSetStream(stream);
}

/**
 * \brief Set the logging target
 * \param[in] target Logging destination
 *
 * This function sets the logging output to the target specified by \a target.
 * The allowed values of \a target are LoggingTargetNone and
 * LoggingTargetSyslog. LoggingTargetNone will send the log output to nowhere,
 * and LoggingTargetSyslog will send the log output to syslog. The previous
 * log target, if any, is closed, and all new log messages will be written to
 * the new log destination.
 *
 * LoggingTargetFile and LoggingTargetStream are not valid values for \a target.
 * Use logSetFile() and logSetStream() instead, respectively.
 *
 * If the function returns an error, the log file is not changed.
 *
 * \return Zero on success, or a negative error code otherwise.
 */
int logSetTarget(LoggingTarget target)
{
	return Logger::instance()->logSetTarget(target);
}

/**
 * \brief Set the log level
 * \param[in] category Logging category
 * \param[in] level Log level
 *
 * This function sets the log level of \a category to \a level.
 * \a level shall be one of the following strings:
 * - "DEBUG"
 * - "INFO"
 * - "WARN"
 * - "ERROR"
 * - "FATAL"
 *
 * "*" is not a valid \a category for this function.
 */
void logSetLevel(const char *category, const char *level)
{
	Logger::instance()->logSetLevel(category, level);
}

Logger::~Logger()
{
	destroyed_ = true;

	for (LogCategory *category : categories_)
		delete category;
}

/**
 * \brief Retrieve the logger instance
 *
 * The Logger is a singleton and can't be constructed manually. This function
 * shall instead be used to retrieve the single global instance of the logger.
 *
 * \return The logger instance
 */
Logger *Logger::instance()
{
	static Logger instance;

	if (destroyed_)
		return nullptr;

	return &instance;
}

/**
 * \brief Write a message to the configured logger output
 * \param[in] msg The message object
 */
void Logger::write(const LogMessage &msg)
{
	std::shared_ptr<LogOutput> output = std::atomic_load(&output_);
	if (!output)
		return;

	output->write(msg);
}

/**
 * \brief Write a backtrace to the log
 */
void Logger::backtrace()
{
#if HAVE_BACKTRACE
	std::shared_ptr<LogOutput> output = std::atomic_load(&output_);
	if (!output)
		return;

	void *buffer[32];
	int num_entries = ::backtrace(buffer, std::size(buffer));
	char **strings = backtrace_symbols(buffer, num_entries);
	if (!strings)
		return;

	std::ostringstream msg;
	msg << "Backtrace:" << std::endl;

	/*
	 * Skip the first two entries that correspond to this function and
	 * ~LogMessage().
	 */
	for (int i = 2; i < num_entries; ++i)
		msg << strings[i] << std::endl;

	output->write(msg.str());

	free(strings);
#endif
}

/**
 * \brief Set the log file
 * \param[in] path Full path to the log file
 *
 * \sa libcamera::logSetFile()
 *
 * \return Zero on success, or a negative error code otherwise.
 */
int Logger::logSetFile(const char *path)
{
	std::shared_ptr<LogOutput> output = std::make_shared<LogOutput>(path);
	if (!output->isValid())
		return -EINVAL;

	std::atomic_store(&output_, output);
	return 0;
}

/**
 * \brief Set the log stream
 * \param[in] stream Stream to send log output to
 *
 * \sa libcamera::logSetStream()
 *
 * \return Zero on success, or a negative error code otherwise.
 */
int Logger::logSetStream(std::ostream *stream)
{
	std::shared_ptr<LogOutput> output = std::make_shared<LogOutput>(stream);
	std::atomic_store(&output_, output);
	return 0;
}

/**
 * \brief Set the log target
 * \param[in] target Log destination
 *
 * \sa libcamera::logSetTarget()
 *
 * \return Zero on success, or a negative error code otherwise.
 */
int Logger::logSetTarget(enum LoggingTarget target)
{
	std::shared_ptr<LogOutput> output;

	switch (target) {
	case LoggingTargetSyslog:
		output = std::make_shared<LogOutput>();
		std::atomic_store(&output_, output);
		break;
	case LoggingTargetNone:
		output = nullptr;
		std::atomic_store(&output_, std::shared_ptr<LogOutput>());
		break;
	default:
		return -EINVAL;
	}

	return 0;
}

/**
 * \brief Set the log level
 * \param[in] category Logging category
 * \param[in] level Log level
 *
 * \sa libcamera::logSetLevel()
 */
void Logger::logSetLevel(const char *category, const char *level)
{
	LogSeverity severity = parseLogLevel(level);
	if (severity == LogInvalid)
		return;

	for (LogCategory *c : categories_) {
		if (!strcmp(c->name(), category)) {
			c->setSeverity(severity);
			break;
		}
	}
}

/**
 * \brief Construct a logger
 */
Logger::Logger()
{
	parseLogFile();
	parseLogLevels();
}

/**
 * \brief Parse the log output file from the environment
 *
 * If the LIBCAMERA_LOG_FILE environment variable is set, open the file it
 * points to and redirect the logger output to it. If the environment variable
 * is set to "syslog", then the logger output will be directed to syslog. Errors
 * are silently ignored and don't affect the logger output (set to stderr).
 */
void Logger::parseLogFile()
{
	const char *file = utils::secure_getenv("LIBCAMERA_LOG_FILE");
	if (!file) {
		logSetStream(&std::cerr);
		return;
	}

	if (!strcmp(file, "syslog")) {
		logSetTarget(LoggingTargetSyslog);
		return;
	}

	logSetFile(file);
}

/**
 * \brief Parse the log levels from the environment
 *
 * The log levels are stored in the LIBCAMERA_LOG_LEVELS environment variable
 * as a list of "category:level" pairs, separated by commas (','). Parse the
 * variable and store the levels to configure all log categories.
 */
void Logger::parseLogLevels()
{
	const char *debug = utils::secure_getenv("LIBCAMERA_LOG_LEVELS");
	if (!debug)
		return;

	for (const char *pair = debug; *debug != '\0'; pair = debug) {
		const char *comma = strchrnul(debug, ',');
		size_t len = comma - pair;

		/* Skip over the comma. */
		debug = *comma == ',' ? comma + 1 : comma;

		/* Skip to the next pair if the pair is empty. */
		if (!len)
			continue;

		std::string category;
		std::string level;

		const char *colon = static_cast<const char *>(memchr(pair, ':', len));
		if (!colon) {
			/* 'x' is a shortcut for '*:x'. */
			category = "*";
			level = std::string(pair, len);
		} else {
			category = std::string(pair, colon - pair);
			level = std::string(colon + 1, comma - colon - 1);
		}

		/* Both the category and the level must be specified. */
		if (category.empty() || level.empty())
			continue;

		LogSeverity severity = parseLogLevel(level);
		if (severity == LogInvalid)
			continue;

		levels_.push_back({ category, severity });
	}
}

/**
 * \brief Parse a log level string into a LogSeverity
 * \param[in] level The log level string
 *
 * Log levels can be specified as an integer value in the range from LogDebug to
 * LogFatal, or as a string corresponding to the severity name in uppercase. Any
 * other value is invalid.
 *
 * \return The log severity, or LogInvalid if the string is invalid
 */
LogSeverity Logger::parseLogLevel(const std::string &level)
{
	static const char *const names[] = {
		"DEBUG",
		"INFO",
		"WARN",
		"ERROR",
		"FATAL",
	};

	int severity;

	if (std::isdigit(level[0])) {
		char *endptr;
		severity = strtoul(level.c_str(), &endptr, 10);
		if (*endptr != '\0' || severity > LogFatal)
			severity = LogInvalid;
	} else {
		severity = LogInvalid;
		for (unsigned int i = 0; i < std::size(names); ++i) {
			if (names[i] == level) {
				severity = i;
				break;
			}
		}
	}

	return static_cast<LogSeverity>(severity);
}

/**
 * \brief Register a log category with the logger
 * \param[in] category The log category
 *
 * Log categories must have unique names. If a category with the same name
 * already exists this function performs no operation.
 */
void Logger::registerCategory(LogCategory *category)
{
	categories_.insert(category);

	const std::string &name = category->name();
	for (const std::pair<std::string, LogSeverity> &level : levels_) {
		bool match = true;

		for (unsigned int i = 0; i < level.first.size(); ++i) {
			if (level.first[i] == '*')
				break;

			if (i >= name.size() ||
			    name[i] != level.first[i]) {
				match = false;
				break;
			}
		}

		if (match) {
			category->setSeverity(level.second);
			break;
		}
	}
}

/**
 * \enum LogSeverity
 * Log message severity
 * \var LogDebug
 * Debug message
 * \var LogInfo
 * Informational message
 * \var LogWarning
 * Warning message, signals a potential issue
 * \var LogError
 * Error message, signals an unrecoverable issue
 * \var LogFatal
 * Fatal message, signals an unrecoverable issue and aborts execution
 */

/**
 * \class LogCategory
 * \brief A category of log message
 *
 * The LogCategory class represents a category of log messages, related to an
 * area of the library. It groups all messages belonging to the same category,
 * and is used to control the log level per group.
 */

/**
 * \brief Construct a log category
 * \param[in] name The category name
 */
LogCategory::LogCategory(const char *name)
	: name_(name), severity_(LogSeverity::LogInfo)
{
	Logger::instance()->registerCategory(this);
}

/**
 * \fn LogCategory::name()
 * \brief Retrieve the log category name
 * \return The log category name
 */

/**
 * \fn LogCategory::severity()
 * \brief Retrieve the severity of the log category
 * \sa setSeverity()
 * \return Return the severity of the log category
 */

/**
 * \brief Set the severity of the log category
 *
 * Messages of severity higher than or equal to the severity of the log category
 * are printed, other messages are discarded.
 */
void LogCategory::setSeverity(LogSeverity severity)
{
	severity_ = severity;
}

/**
 * \brief Retrieve the default log category
 *
 * The default log category is named "default" and is used by the LOG() macro
 * when no log category is specified.
 *
 * \return A reference to the default log category
 */
const LogCategory &LogCategory::defaultCategory()
{
	static const LogCategory *category = new LogCategory("default");
	return *category;
}

/**
 * \class LogMessage
 * \brief Internal log message representation.
 *
 * The LogMessage class models a single message in the log. It serves as a
 * helper to provide the std::ostream API for logging, and must never be used
 * directly. Use the LOG() macro instead access the log infrastructure.
 */

/**
 * \brief Construct a log message for a given category
 * \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, controlling how the message
 * will be displayed
 * \param[in] severity The log message severity, controlling how the message
 * will be displayed
 *
 * Create a log message pertaining to line \a line of file \a fileName. The
 * \a severity argument sets the message severity to control whether it will be
 * output or dropped.
 */
LogMessage::LogMessage(const char *fileName, unsigned int line,
		       const LogCategory &category, LogSeverity severity)
	: category_(category), severity_(severity)
{
	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 LogInvalid.
 */
LogMessage::LogMessage(LogMessage &&other)
	: msgStream_(std::move(other.msgStream_)), category_(other.category_),
	  severity_(other.severity_)
{
	other.severity_ = LogInvalid;
}

void LogMessage::init(const char *fileName, unsigned int line)
{
	/* Log the timestamp, severity and file information. */
	timestamp_ = utils::clock::now();

	std::ostringstream ossFileInfo;
	ossFileInfo << utils::basename(fileName) << ":" << line;
	fileInfo_ = ossFileInfo.str();
}

LogMessage::~LogMessage()
{
	/* Don't print anything if we have been moved to another LogMessage. */
	if (severity_ == LogInvalid)
		return;

	Logger *logger = Logger::instance();
	if (!logger)
		return;

	msgStream_ << std::endl;

	if (severity_ >= category_.severity())
		logger->write(*this);

	if (severity_ == LogSeverity::LogFatal) {
		logger->backtrace();
		std::abort();
	}
}

/**
 * \fn std::ostream& LogMessage::stream()
 *
 * Data is added to a LogMessage through the stream returned by this function.
 * The stream implements the std::ostream API and can be used for logging as
 * std::cout.
 *
 * \return A reference to the log message stream
 */

/**
 * \fn LogMessage::timestamp()
 * \brief Retrieve the timestamp of the log message
 * \return The timestamp of the message
 */

/**
 * \fn LogMessage::severity()
 * \brief Retrieve the severity of the log message
 * \return The severity of the message
 */

/**
 * \fn LogMessage::category()
 * \brief Retrieve the category of the log message
 * \return The category of the message
 */

/**
 * \fn LogMessage::fileInfo()
 * \brief Retrieve the file info of the log message
 * \return The file info of the message
 */

/**
 * \fn LogMessage::msg()
 * \brief Retrieve the message text of the log message
 * \return The message text of the message, as a string
 */

/**
 * \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 function, a class can specify extra
 * information to be automatically added to messages logged from class member
 * function.
 */

Loggable::~Loggable()
{
}

/**
 * \fn Loggable::logPrefix()
 * \brief Retrieve a string to be prefixed to the log message
 *
 * This function 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] category The log message category
 * \param[in] severity The log message severity
 * \param[in] fileName The file name where the message is logged from
 * \param[in] line The line number where the message is logged from
 *
 * This function is used as a backend by the LOG() macro to create a log message
 * for locations inheriting from the Loggable class.
 *
 * \return A log message
 */
LogMessage Loggable::_log(const LogCategory *category, LogSeverity severity,
			  const char *fileName, unsigned int line) const
{
	LogMessage msg(fileName, line,
		       category ? *category : LogCategory::defaultCategory(),
		       severity);

	msg.stream() << logPrefix() << ": ";
	return msg;
}

/**
 * \brief Create a temporary LogMessage object to log a message
 * \param[in] category The log message category
 * \param[in] severity The log message severity
 * \param[in] fileName The file name where the message is logged from
 * \param[in] line The line number where the message is logged from
 *
 * This function is used as a backend by the LOG() macro to create a log
 * message for locations not inheriting from the Loggable class.
 *
 * \return A log message
 */
LogMessage _log(const LogCategory *category, LogSeverity severity,
		const char *fileName, unsigned int line)
{
	return LogMessage(fileName, line,
			  category ? *category : LogCategory::defaultCategory(),
			  severity);
}

/**
 * \def LOG_DECLARE_CATEGORY(name)
 * \hideinitializer
 * \brief Declare a category of log messages
 *
 * This macro is used to declare a log category defined in another compilation
 * unit by the LOG_DEFINE_CATEGORY() macro.
 *
 * The LOG_DECLARE_CATEGORY() macro must be used in the libcamera namespace.
 *
 * \sa LogCategory
 */

/**
 * \def LOG_DEFINE_CATEGORY(name)
 * \hideinitializer
 * \brief Define a category of log messages
 *
 * This macro is used to define a log category that can then be used with the
 * LOGC() macro. Category names shall be unique, if a category is shared between
 * compilation units, it shall be defined in one compilation unit only and
 * declared with LOG_DECLARE_CATEGORY() in the other compilation units.
 *
 * The LOG_DEFINE_CATEGORY() macro must be used in the libcamera namespace.
 *
 * \sa LogCategory
 */

/**
 * \def LOG(category, severity)
 * \hideinitializer
 * \brief Log a message
 * \param[in] category Category (optional)
 * \param[in] severity Severity
 *
 * Return an std::ostream reference to which a message can be logged using the
 * iostream API. The \a category, if specified, sets the message category. When
 * absent the default category is used. The  \a severity controls whether the
 * message is printed or discarded, depending on the log level for the category.
 *
 * If the severity is set to Fatal, execution is aborted and the program
 * terminates immediately after printing the message.
 *
 * \warning Logging from the destructor of a global object, either directly or
 * indirectly, results in undefined behaviour.
 *
 * \todo Allow logging from destructors of global objects to the largest
 * possible extent
 */

/**
 * \def ASSERT(condition)
 * \hideinitializer
 * \brief Abort program execution if assertion fails
 *
 * If \a condition is false, ASSERT() logs an error message with the Fatal log
 * level and aborts program execution.
 *
 * If the macro NDEBUG is defined before including log.h, ASSERT() generates no
 * code.
 *
 * Using conditions that have side effects with ASSERT() is not recommended, as
 * these effects would depend on whether NDEBUG is defined or not. Similarly,
 * ASSERT() should not be used to check for errors that can occur under normal
 * conditions as those checks would then be removed when compiling with NDEBUG.
 */

} /* namespace libcamera */