view rvinterf/ctracedec/decode.c @ 619:f82551c77e58

libserial-newlnx: ASYNC_LOW_LATENCY patch reverted Reports from Das Signal indicate that loadtools performance on Debian is about the same as on Slackware, and that including or omitting the ASYNC_LOW_LATENCY patch from Serg makes no difference. Because the patch in question does not appear to be necessary, it is being reverted until and unless someone other than Serg reports an actual real-world system on which loadtools operation times are slowed compared to the Mother's Slackware reference and on which Slackware-like performance can be restored by setting the ASYNC_LOW_LATENCY flag.
author Mychaela Falconia <falcon@freecalypso.org>
date Thu, 27 Feb 2020 01:09:48 +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);
}