New custom trace output interface.

[mLib] / trace.c

/* -*-c-*-
 *
 * $Id: trace.c,v 1.6 2001/02/03 16:23:55 mdw Exp $
 *
 * Tracing functions for debugging
 *
 * (c) 1998 Straylight/Edgeware
 */

/*----- Licensing notice --------------------------------------------------* 
 *
 * This file is part of the mLib utilities library.
 *
 * mLib is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Library General Public License as
 * published by the Free Software Foundation; either version 2 of the
 * License, or (at your option) any later version.
 * 
 * mLib 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 Library General Public License for more details.
 * 
 * You should have received a copy of the GNU Library General Public
 * License along with mLib; if not, write to the Free
 * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
 * MA 02111-1307, USA.
 */

/*----- Revision history --------------------------------------------------*
 *
 * $Log: trace.c,v $
 * Revision 1.6  2001/02/03 16:23:55  mdw
 * New custom trace output interface.
 *
 * Revision 1.5  1999/10/22 22:39:52  mdw
 * New documented interface for tracing.
 *
 * Revision 1.4  1999/05/19 20:27:11  mdw
 * Change naming to match newer mLib conventions.
 *
 * Revision 1.3  1999/05/06 19:51:35  mdw
 * Reformatted the LGPL notice a little bit.
 *
 * Revision 1.2  1999/05/05 18:50:31  mdw
 * Change licensing conditions to LGPL.
 *
 * Revision 1.1.1.1  1998/06/17 23:44:42  mdw
 * Initial version of mLib
 *
 */

/*----- Header files ------------------------------------------------------*/

/* --- ANSI headers --- */

#include <ctype.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

/* --- Local headers --- */

#include "dstr.h"
#include "quis.h"
#include "trace.h"

/*----- Private state information -----------------------------------------*/

static void (*tracefunc)(const char *buf, size_t sz, void *v) = 0;
static void *tracearg;
static unsigned tracelvl = 0;		/* How much tracing gets done? */

/*----- Functions provided ------------------------------------------------*/

/* --- @t_file@ --- *
 *
 * Arguments:	@const char *buf@ = buffer to print
 *		@size_t sz@ = buffer size
 *		@void *v@ = file handle
 *
 * Returns:	---
 *
 * Use:		Dumps tracing information to a file.
 */

static void t_file(const char *buf, size_t sz, void *v)
{
  FILE *fp = v;
  fprintf(fp, "+ %s: ", QUIS);
  fwrite(buf, 1, sz, fp);
  fputc('\n', fp);
}

/* --- @trace@ --- *
 *
 * Arguments:	@unsigned l@ = trace level for output
 *		@const char *f@ = a @printf@-style format string
 *		@...@ = other arguments
 *
 * Returns:	---
 *
 * Use:		Reports a message to the trace output.
 */

void trace(unsigned l, const char *f, ...)
{
  va_list ap;
  dstr d = DSTR_INIT;
  if ((l & tracing()) == 0)
    return;
  va_start(ap, f);
  dstr_vputf(&d, f, ap);
  va_end(ap);
  tracefunc(d.buf, d.len, tracearg);
  dstr_destroy(&d);
}

/* --- @trace_block@ --- *
 *
 * Arguments:	@unsigned l@ = trace level for output
 *		@const char *s@ = some header string to write
 *		@const void *b@ = pointer to a block of memory to dump
 *		@size_t sz@ = size of the block of memory
 *
 * Returns:	---
 *
 * Use:		Dumps the contents of a block to the trace output.
 */

void trace_block(unsigned l, const char *s, const void *b, size_t sz)
{
  const unsigned char *p = b;
  size_t i;
  unsigned long o = 0;
  dstr d = DSTR_INIT;
  size_t c;

  /* --- Skip if the trace level is too high --- */

  if ((l & tracing()) == 0)
    return;

  /* --- Now start work --- */

  tracefunc(s, strlen(s), tracearg);
  while (sz) {
    dstr_reset(&d);
    dstr_putf(&d, "   %08lx : ", o);
    for (i = 0; i < 8; i++) {
      if (i < sz)
	dstr_putf(&d, "%02x ", p[i]);
      else
	dstr_puts(&d, "** ");
    }
    dstr_puts(&d, ": ");
    for (i = 0; i < 8; i++) {
      if (i < sz)
	dstr_putc(&d, isprint(p[i]) ? p[i] : '.');
      else
	dstr_putc(&d, '*');
    }
    dstr_putz(&d);
    tracefunc(d.buf, d.len, tracearg);
    c = (sz >= 8) ? 8 : sz;
    sz -= c, p += c, o += c;
  }
  dstr_destroy(&d);
}

/* --- @trace_on@ --- *
 *
 * Arguments:	@FILE *fp@ = a file to trace on
 *		@unsigned l@ = trace level to set
 *
 * Returns:	---
 *
 * Use:		Enables tracing to a file.
 */

void trace_on(FILE *fp, unsigned l)
{
  tracefunc = t_file;
  tracearg = fp;
  if (!tracelvl)
    tracelvl = l;
}

/* --- @trace_custom@ --- *
 *
 * Arguments:	@void (*func)(const char *buf, size_t sz, void *v)@ =
 *			output function
 *		@void *v@ = magic handle to give to function
 *
 * Returns:	---
 *
 * Use:		Sets up a custom trace handler.
 */

void trace_custom(void (*func)(const char */*buf*/,
			       size_t /*sz*/, void */*v*/),
		  void *v)
{
  tracefunc = func;
  tracearg = v;
}

/* --- @trace_level@ --- *
 *
 * Arguments:	@unsigned l@ = trace level to set
 *
 * Returns:	---
 *
 * Use:		Sets the tracing level.
 */

void trace_level(unsigned l)
{
  tracelvl = l;
}

/* --- @tracing@ --- *
 *
 * Arguments:	---
 *
 * Returns:	Zero if not tracing, tracing level if tracing.
 *
 * Use:		Informs the caller whether tracing is enabled.
 */

unsigned tracing(void)
{
  return (tracefunc ? tracelvl : 0u);
}

/*----- That's all, folks -------------------------------------------------*/