libfuse/include/fuse_log.h
Stefan Hajnoczi d368dad2c8 log: move fuse_log() to the public header file
Applications may wish to call fuse_log() for unified logging.  This way
they don't need to define their own wrappers to invoke the log message
handler function installed by fuse_set_log_func().

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2019-09-10 14:25:15 +01:00

83 lines
1.9 KiB
C

/*
FUSE: Filesystem in Userspace
Copyright (C) 2019 Red Hat, Inc.
This program can be distributed under the terms of the GNU LGPLv2.
See the file COPYING.LIB.
*/
#ifndef FUSE_LOG_H_
#define FUSE_LOG_H_
/** @file
*
* This file defines the logging interface of FUSE
*/
#include <stdarg.h>
#ifdef __cplusplus
extern "C" {
#endif
/**
* Log severity level
*
* These levels correspond to syslog(2) log levels since they are widely used.
*/
enum fuse_log_level {
FUSE_LOG_EMERG,
FUSE_LOG_ALERT,
FUSE_LOG_CRIT,
FUSE_LOG_ERR,
FUSE_LOG_WARNING,
FUSE_LOG_NOTICE,
FUSE_LOG_INFO,
FUSE_LOG_DEBUG
};
/**
* Log message handler function.
*
* This function must be thread-safe. It may be called from any libfuse
* function, including fuse_parse_cmdline() and other functions invoked before
* a FUSE filesystem is created.
*
* Install a custom log message handler function using fuse_set_log_func().
*
* @param level log severity level
* @param fmt sprintf-style format string including newline
* @param ap format string arguments
*/
typedef void (*fuse_log_func_t)(enum fuse_log_level level,
const char *fmt, va_list ap);
/**
* Install a custom log handler function.
*
* Log messages are emitted by libfuse functions to report errors and debug
* information. Messages are printed to stderr by default but this can be
* overridden by installing a custom log message handler function.
*
* The log message handler function is global and affects all FUSE filesystems
* created within this process.
*
* @param func a custom log message handler function or NULL to revert to
* the default
*/
void fuse_set_log_func(fuse_log_func_t func);
/**
* Emit a log message
*
* @param level severity level (FUSE_LOG_ERR, FUSE_LOG_DEBUG, etc)
* @param fmt sprintf-style format string including newline
*/
void fuse_log(enum fuse_log_level level, const char *fmt, ...);
#ifdef __cplusplus
}
#endif
#endif /* FUSE_LOG_H_ */