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 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
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 *    notice, this list of conditions and the following disclaimer in
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 *    used to endorse or promote products derived from this software
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 *
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/**
 * @file mavlink_log.h
 * MAVLink text logging.
 *
 * @author Lorenz Meier <lorenz@px4.io>
 */

#ifndef MAVLINK_LOG
#define MAVLINK_LOG

/*
 * IOCTL interface for sending log messages.
 */
#include <sys/ioctl.h>

/**
 * The mavlink log device node; must be opened before messages
 * can be logged.
 */
#define MAVLINK_LOG_DEVICE			"/dev/mavlink"
/**
 * The maximum string length supported.
 */
#define MAVLINK_LOG_MAXLEN			50

#define MAVLINK_IOC_SEND_TEXT_INFO		_IOC(0x1100, 1)
#define MAVLINK_IOC_SEND_TEXT_CRITICAL		_IOC(0x1100, 2)
#define MAVLINK_IOC_SEND_TEXT_EMERGENCY		_IOC(0x1100, 3)

#ifdef __cplusplus
extern "C" {
#endif
__EXPORT void mavlink_vasprintf(int _fd, int severity, const char *fmt, ...);
#ifdef __cplusplus
}
#endif

/*
 * The va_args implementation here is not beautiful, but obviously we run into the same issues
 * the GCC devs saw, and are using their solution:
 *
 * http://gcc.gnu.org/onlinedocs/cpp/Variadic-Macros.html
 */

/**
 * Send a mavlink emergency message.
 *
 * @param _fd		A file descriptor returned from open(MAVLINK_LOG_DEVICE, 0);
 * @param _text		The text to log;
 */
#define mavlink_log_emergency(_fd, _text, ...)		mavlink_vasprintf(_fd, MAVLINK_IOC_SEND_TEXT_EMERGENCY, _text, ##__VA_ARGS__);

/**
 * Send a mavlink critical message.
 *
 * @param _fd		A file descriptor returned from open(MAVLINK_LOG_DEVICE, 0);
 * @param _text		The text to log;
 */
#define mavlink_log_critical(_fd, _text, ...)		mavlink_vasprintf(_fd, MAVLINK_IOC_SEND_TEXT_CRITICAL, _text, ##__VA_ARGS__);

/**
 * Send a mavlink info message.
 *
 * @param _fd		A file descriptor returned from open(MAVLINK_LOG_DEVICE, 0);
 * @param _text		The text to log;
 */
#define mavlink_log_info(_fd, _text, ...)		mavlink_vasprintf(_fd, MAVLINK_IOC_SEND_TEXT_INFO, _text, ##__VA_ARGS__);

/**
 * Send a mavlink emergency message and print to console.
 *
 * @param _fd		A file descriptor returned from open(MAVLINK_LOG_DEVICE, 0);
 * @param _text		The text to log;
 */
#define mavlink_and_console_log_emergency(_fd, _text, ...)		mavlink_vasprintf(_fd, MAVLINK_IOC_SEND_TEXT_EMERGENCY, _text, ##__VA_ARGS__); \
									fprintf(stderr, "telem> "); \
									fprintf(stderr, _text, ##__VA_ARGS__); \
									fprintf(stderr, "\n");

/**
 * Send a mavlink critical message and print to console.
 *
 * @param _fd		A file descriptor returned from open(MAVLINK_LOG_DEVICE, 0);
 * @param _text		The text to log;
 */
#define mavlink_and_console_log_critical(_fd, _text, ...)		mavlink_vasprintf(_fd, MAVLINK_IOC_SEND_TEXT_CRITICAL, _text, ##__VA_ARGS__); \
									fprintf(stderr, "telem> "); \
									fprintf(stderr, _text, ##__VA_ARGS__); \
									fprintf(stderr, "\n");

/**
 * Send a mavlink emergency message and print to console.
 *
 * @param _fd		A file descriptor returned from open(MAVLINK_LOG_DEVICE, 0);
 * @param _text		The text to log;
 */
#define mavlink_and_console_log_info(_fd, _text, ...)			mavlink_vasprintf(_fd, MAVLINK_IOC_SEND_TEXT_INFO, _text, ##__VA_ARGS__); \
									fprintf(stderr, "telem> "); \
									fprintf(stderr, _text, ##__VA_ARGS__); \
									fprintf(stderr, "\n");

struct mavlink_logmessage {
	char text[MAVLINK_LOG_MAXLEN + 1];
	unsigned char severity;
};

struct mavlink_logbuffer {
	unsigned int start;
	unsigned int size;
	int count;
	struct mavlink_logmessage *elems;
};

__BEGIN_DECLS
void mavlink_logbuffer_init(struct mavlink_logbuffer *lb, int size);

void mavlink_logbuffer_destroy(struct mavlink_logbuffer *lb);

int mavlink_logbuffer_is_full(struct mavlink_logbuffer *lb);

int mavlink_logbuffer_is_empty(struct mavlink_logbuffer *lb);

void mavlink_logbuffer_write(struct mavlink_logbuffer *lb, const struct mavlink_logmessage *elem);

int mavlink_logbuffer_read(struct mavlink_logbuffer *lb, struct mavlink_logmessage *elem);

void mavlink_logbuffer_vasprintf(struct mavlink_logbuffer *lb, int severity, const char *fmt, ...);
__END_DECLS

#endif