diff rvinterf/ctracedec/decode.c @ 858:4c6e7ada647b

compressed trace decoder almost fully implemented
author Space Falcon <falcon@ivan.Harhan.ORG>
date Sat, 02 May 2015 08:08:26 +0000
parents
children
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--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/rvinterf/ctracedec/decode.c	Sat May 02 08:08:26 2015 +0000
@@ -0,0 +1,150 @@
+/*
+ * 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);
+}