serval-dna/xprintf.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

118 lines
3.9 KiB
C

/*
Serval extensible printf.
Copyright (C) 2012 Serval Project Inc.
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__XPRINTF_H
#define __SERVAL_DNA__XPRINTF_H
/* Generalised (extensible) printf framework.
*
* Instead of writing a function to send output to a <stdio.h> FILE stream,
* write it to send output to an extensible stream. Eg, this code:
*
* void print_something(FILE *fp, int something) {
* fprintf(fp, "%d (0x%08X)", something, something);
* }
*
* Becomes:
*
* void print_something(XPRINTF xpf, int something) {
* xprintf(xpf, "%d (0x%08X)", something, something);
* }
*
* Then, instead of writing this:
*
* print_something(stdout, 10);
*
* you write this:
*
* print_something(XPRINTF_STDIO(stdout), 10);
*
* But with the extensible version you can also do this:
*
* struct mallocbuf mb = STRUCT_MALLOCBUF_NULL;
* print_something(XPRINTF_MALLOCBUF(&mb), 10);
* if (mb.buffer)
* puts(mb.buffer);
*
* And this:
*
* void __log_vprintf(int level, const char *fmt, va_list);
*
* void log_vprintf(void *context, const char *fmt, va_list ap) {
* __log_vprintf((int)context, fmt, ap);
* }
*
* print_something(XPRINTF_GEN(log_vprintf, LOG_LEVEL_INFO), 10);
*/
#include <stdarg.h>
#include <unistd.h>
#include "lang.h"
typedef void CONTEXT_VPRINTF(void *context, const char *fmt, va_list);
typedef struct _xprintf {
CONTEXT_VPRINTF *func;
void *context;
} XPRINTF;
#define XPRINTF_IS_NULL(X) ((X).func == NULL)
#define _XPRINTF(F,C) ((XPRINTF){(F),(C)})
void xprintf(XPRINTF xpf, const char *fmt, ...) __attribute__ ((__ATTRIBUTE_format(printf,2,3)));
void vxprintf(XPRINTF xpf, const char *fmt, va_list);
void xputs(const char *str, XPRINTF xpf);
void xputc(char c, XPRINTF xpf);
size_t xhexdump_line(XPRINTF xpf, const unsigned char *addr, const size_t len, const size_t off);
void xhexdump(XPRINTF xpf, const unsigned char *addr, size_t len, const char *line_prefix);
#define XPRINTF_GEN(F,C) _XPRINTF((F),(void *)(C))
#define XPRINTF_NULL _XPRINTF(NULL, NULL)
/* Standard i/o adapter. An XPRINTF constructed with XPRINTF_STDIO(stream)
* will write all its output to stream using fprintf(stream,...).
*/
#define XPRINTF_STDIO(S) _XPRINTF(_cx_vprintf_stdio,(S))
CONTEXT_VPRINTF _cx_vprintf_stdio;
/* Malloc memory buffer adapter. An XPRINTF constructed with
* XPRINTF_MALLOCBUF(&mb) will use realloc() to allocate and grow a memory
* buffer and fill it using sprintf(), always with a nul terminator at the end.
* The caller must free() the buffer after use.
*/
struct mallocbuf {
char *buffer; // Start of buffer, NULL if not allocated yet
char *current; // Current position of terminating nul in buffer
size_t size; // Size of current allocated buffer
};
#define STRUCT_MALLOCBUF_NULL ((struct mallocbuf){NULL,NULL,0})
#define XPRINTF_MALLOCBUF(MB) _XPRINTF(_cx_vprintf_mallocbuf, (MB))
CONTEXT_VPRINTF _cx_vprintf_mallocbuf;
/* Strbuf adapter. An XPRINTF constructed with XPRINTF_STRBUF(sb) will write
* all its output to the give strbuf using strbuf_sprintf(sb,...).
*/
#define XPRINTF_STRBUF(SB) _XPRINTF(_cx_vprintf_strbuf,(SB))
CONTEXT_VPRINTF _cx_vprintf_strbuf;
#endif // __SERVAL_DNA__XPRINTF_H