view rvinterf/ctracedec/decode.c @ 407:19e5a3e2f9c0

fcup-settime: moved time() retrieval a little closer to the output A fundamental problem with all simple time transfer tools is that there is always some delay between the time retrieval on the source system and that transmitted time being set on the destination, and the resulting time on the destination system is off by that delay amount. This delay cannot be fully eliminated when working in a simple environment like ours, but we should make our best effort to minimize it. In the present case, moving the atinterf_init() call before the time() retrieval should make a teensy-tiny improvement.
author Mychaela Falconia <falcon@freecalypso.org>
date Sat, 11 Aug 2018 21:52:17 +0000
parents e7502631a0f9
children
line wrap: on
line source

/*
 * This module implements the actual decoding of compressed traces.
 */

#include <sys/types.h>
#include <stdio.h>
#include <ctype.h>
#include <string.h>
#include <strings.h>
#include <stdlib.h>

extern char *str2ind_tab_filename;
extern int str2ind_array_size;
extern char **str2ind_orig_strings;
extern char **str2ind_param_strings;

#define	MAX_PRINTF_PARAMS	16

static int cindex, cindex_nchars;
static u_char param_bytes_array[256];
static int param_bytes_count;
static char *format_string, *param_type_string;
static int num_printf_params;
static u_long printf_params[MAX_PRINTF_PARAMS];
static char output_buf[2048];

decode_hex_digit(c)
{
	if (isdigit(c))
		return(c - '0');
	else if (isupper(c))
		return(c - 'A' + 10);
	else
		return(c - 'a' + 10);
}

static int
decode_idx_and_params(line)
	char *line;
{
	char *cp;
	u_char *dp;

	for (cp = line; isdigit(*cp); cp++)
		;
	if (*cp && *cp != ' ')
		return(-1);
	cindex = atoi(line);
	cindex_nchars = cp - line;
	for (dp = param_bytes_array; *cp; ) {
		if (*cp++ != ' ')
			return(-1);
		if (!isxdigit(cp[0]) || !isxdigit(cp[1]))
			return(-1);
		*dp++ = decode_hex_digit(cp[0]) << 4 | decode_hex_digit(cp[1]);
		cp += 2;
	}
	param_bytes_count = dp - param_bytes_array;
	return(0);
}

static void
decode_parameters(filename_for_errs, lineno_for_errs)
	char *filename_for_errs;
{
	int pi, type;
	u_char *bp, *endp;

	bp = param_bytes_array;
	endp = bp + param_bytes_count;
	for (pi = 0; pi < num_printf_params; pi++) {
		type = param_type_string[pi];
		switch (type) {
		case 'c':
			if (bp >= endp) {
wrong_param_byte_count:		fprintf(stderr,
	"%s line %d: wrong number of parameter bytes for %s entry #%d\n",
					filename_for_errs, lineno_for_errs,
					str2ind_tab_filename, cindex);
				exit(1);
			}
			printf_params[pi] = *bp++;
			continue;
		case 'i':
		case 'p':
		case '*':
			if (bp > endp - 4)
				goto wrong_param_byte_count;
			printf_params[pi] = (u_long) bp[0] |
					    (u_long) bp[1] << 8 |
					    (u_long) bp[2] << 16 |
					    (u_long) bp[3] << 24;
			bp += 4;
			continue;
		case 's':
			printf_params[pi] = (u_long) bp;
			for (;;) {
				if (bp >= endp) {
					fprintf(stderr,
	"%s line %d: unterminated string parameter in compressed trace\n",
						filename_for_errs,
						lineno_for_errs);
					exit(1);
				}
				if (!*bp++)
					break;
			}
			continue;
		default:
			fprintf(stderr,
			"%s entry #%d: parameter type \'%c\' not supported\n",
				str2ind_tab_filename, cindex, type);
			exit(1);
		}
	}
	if (bp != endp)
		goto wrong_param_byte_count;
}

process_ctrace_line(line, cindex_offset, filename_for_errs, lineno_for_errs)
	char *line, *filename_for_errs;
{
	if (decode_idx_and_params(line + cindex_offset) < 0) {
		fprintf(stderr,
			"%s line %d: unable to decode compressed trace line\n",
			filename_for_errs, lineno_for_errs);
		exit(1);
	}
	if (cindex >= str2ind_array_size) {
		fprintf(stderr,
			"%s line %d: index %d exceeds the range of %s\n",
			filename_for_errs, lineno_for_errs, cindex,
			str2ind_tab_filename);
		exit(1);
	}
	format_string = str2ind_orig_strings[cindex];
	param_type_string = str2ind_param_strings[cindex];
	num_printf_params = strlen(param_type_string);
	if (num_printf_params > MAX_PRINTF_PARAMS) {
		fprintf(stderr,
			"error: entry #%d in %s has too many parameters\n",
			cindex, str2ind_tab_filename);
		exit(1);
	}
	decode_parameters(filename_for_errs, lineno_for_errs);
	ind2str_doprnt(format_string, printf_params, output_buf);
	printf("%.*s \"%s\"\n", cindex_offset + cindex_nchars, line,
		output_buf);
	return(0);
}