Add a signal-safe decimal formatting function

This commit is contained in:
Nick Mathewson 2013-07-19 13:03:23 -04:00
parent 8f0755fa85
commit 5343ee1a06
3 changed files with 85 additions and 0 deletions

View File

@ -3441,6 +3441,39 @@ format_hex_number_sigsafe(unsigned int x, char *buf, int buf_len)
return len;
}
/** As format_hex_number_sigsafe, but format the number in base 10. */
int
format_dec_number_sigsafe(unsigned long x, char *buf, int buf_len)
{
int len;
unsigned long tmp;
char *cp;
tmp = x;
len = 1;
while (tmp > 9) {
tmp /= 10;
++len;
}
if (len >= buf_len)
return 0;
cp = buf + len;
*cp = '\0';
do {
unsigned digit = x % 10;
tor_assert(cp > buf);
--cp;
*cp = '0' + digit;
x /= 10;
} while (x);
tor_assert(cp == buf);
return len;
}
#ifndef _WIN32
/** Format <b>child_state</b> and <b>saved_errno</b> as a hex string placed in
* <b>hex_errno</b>. Called between fork and _exit, so must be signal-handler

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@ -520,6 +520,7 @@ int32_t tor_weak_random_range(tor_weak_rng_t *rng, int32_t top);
#define tor_weak_random_one_in_n(rng, n) (0==tor_weak_random_range((rng),(n)))
int format_hex_number_sigsafe(unsigned int x, char *buf, int max_len);
int format_dec_number_sigsafe(unsigned long x, char *buf, int max_len);
#ifdef UTIL_PRIVATE
/* Prototypes for private functions only used by util.c (and unit tests) */

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@ -2670,6 +2670,56 @@ test_util_format_hex_number(void *ptr)
return;
}
/**
* Test for format_hex_number_sigsafe()
*/
static void
test_util_format_dec_number(void *ptr)
{
int i, len;
char buf[33];
const struct {
const char *str;
unsigned int x;
} test_data[] = {
{"0", 0},
{"1", 1},
{"1234", 1234},
{"12345678", 12345678},
{"99999999", 99999999},
{"100000000", 100000000},
{"4294967295", 4294967295u},
#if UINT_MAX > 0xffffffff
{"18446744073709551615", 18446744073709551615u },
#endif
{NULL, 0}
};
(void)ptr;
for (i = 0; test_data[i].str != NULL; ++i) {
len = format_dec_number_sigsafe(test_data[i].x, buf, sizeof(buf));
test_neq(len, 0);
test_eq(len, strlen(buf));
test_streq(buf, test_data[i].str);
len = format_dec_number_sigsafe(test_data[i].x, buf,
(int)(strlen(test_data[i].str) + 1));
test_eq(len, strlen(buf));
test_streq(buf, test_data[i].str);
}
test_eq(4, format_dec_number_sigsafe(7331, buf, 5));
test_streq(buf, "7331");
test_eq(0, format_dec_number_sigsafe(7331, buf, 4));
test_eq(1, format_dec_number_sigsafe(0, buf, 2));
test_eq(0, format_dec_number_sigsafe(0, buf, 1));
done:
return;
}
/**
* Test that we can properly format a Windows command line
*/
@ -3362,6 +3412,7 @@ struct testcase_t util_tests[] = {
UTIL_TEST(spawn_background_fail, 0),
UTIL_TEST(spawn_background_partial_read, 0),
UTIL_TEST(format_hex_number, 0),
UTIL_TEST(format_dec_number, 0),
UTIL_TEST(join_win_cmdline, 0),
UTIL_TEST(split_lines, 0),
UTIL_TEST(n_bits_set, 0),