serval-dna/log_prolog.h
Andrew Bettison 92fa6c196a Rewrite logging system
Rename the logging primitive functions and utility functions, prefixing
all with 'serval_log', eg: logMessage() -> serval_logf() etc.

Add an XPRINTF xhexdump() function and use it to implement the
serval_log_hexdump() utility, renamed from dump().  Add macros
WHY_dump(), WARN_dump(), HINT_dump() and DEBUG_dump(), and use them
everywhere.

Remove the 'log.console.dump_config' and 'log.file.dump_config'
configuration options; configuration is now dumped in every log prolog.

The logging system now constructs the log prolog by invoking the new
'log_prolog' trigger, so that it no longer depends on the version string
and configuration system.  Any system that wants to present a message in
the log prolog can define its own trigger, which calls standard log
primitives to print the message.

Split the logging system into a front-end (log.c) that provides the
logging primitives and is independent of the configuration system, and a
set of back-end "outputters" (log_output_console.c, log_output_file.c,
log_output_android.c) that may depend on the configuration system and
are decoupled from the front-end using the 'logoutput' link section.

These log outputters are explicitly linked into executables by the
Makefile rules, but could also be linked in using USE_FEATURE().  The
USE_FEATURE() calls have _not_ been added to servald_features.c, so that
different daemon executables can be built with the same feature set but
different log outputs.
2018-03-06 15:16:56 +10:30

43 lines
1.6 KiB
C

/*
Serval DNA log prolog
Copyright (C) 2017 Flinders University
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/
#ifndef __SERVAL_DNA__LOG_PROLOG_H
#define __SERVAL_DNA__LOG_PROLOG_H
#include "trigger.h"
/* Whenever a log output starts a new log, such as opening the console for the
* first time or rotating to a new log file, or even at a regular interval, it
* emits a "prolog" that starts with the current date/time, then a series of
* log messages generated by invoking all the log_prolog triggers.
*
* The log_prolog trigger functions call the standard logging API to produce
* their output, but the logging system uses an internal trick to ensure that
* the their messages only go to the log output that invoked them, so for
* example, when a log file rotates, the prolog only gets written into the new
* file, and not into the console log as well.
*/
DECLARE_TRIGGER(log_prolog);
struct log_output_iterator;
void serval_log_print_prolog(struct log_output_iterator *it);
#endif // __SERVAL_DNA__LOG_PROLOG_H