From cfb344892209783a600e80053dba1cfeee4bd16a Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Wed, 25 May 2022 15:38:48 +0200 Subject: [PATCH] cutils: add functions for IEC and SI prefixes Extract the knowledge of IEC and SI prefixes out of size_to_str and freq_to_str, so that it can be reused when printing statistics. Signed-off-by: Paolo Bonzini --- include/qemu/cutils.h | 18 +++++++++++++++++ tests/unit/test-cutils.c | 52 ++++++++++++++++++++++++++++++++++++++++++++++++ util/cutils.c | 34 ++++++++++++++++++++++--------- 3 files changed, 95 insertions(+), 9 deletions(-) diff --git a/include/qemu/cutils.h b/include/qemu/cutils.h index 40e10e19a7..d3e532b64c 100644 --- a/include/qemu/cutils.h +++ b/include/qemu/cutils.h @@ -1,6 +1,24 @@ #ifndef QEMU_CUTILS_H #define QEMU_CUTILS_H +/* + * si_prefix: + * @exp10: exponent of 10, a multiple of 3 between -18 and 18 inclusive. + * + * Return a SI prefix (n, u, m, K, M, etc.) corresponding + * to the given exponent of 10. + */ +const char *si_prefix(unsigned int exp10); + +/* + * iec_binary_prefix: + * @exp2: exponent of 2, a multiple of 10 between 0 and 60 inclusive. + * + * Return an IEC binary prefix (Ki, Mi, etc.) corresponding + * to the given exponent of 2. + */ +const char *iec_binary_prefix(unsigned int exp2); + /** * pstrcpy: * @buf: buffer to copy string into diff --git a/tests/unit/test-cutils.c b/tests/unit/test-cutils.c index 98671f1ac3..f5b780f012 100644 --- a/tests/unit/test-cutils.c +++ b/tests/unit/test-cutils.c @@ -2450,6 +2450,50 @@ static void test_qemu_strtosz_metric(void) g_assert(endptr == str + 7); } +static void test_freq_to_str(void) +{ + g_assert_cmpstr(freq_to_str(999), ==, "999 Hz"); + g_assert_cmpstr(freq_to_str(1000), ==, "1 KHz"); + g_assert_cmpstr(freq_to_str(1010), ==, "1.01 KHz"); +} + +static void test_size_to_str(void) +{ + g_assert_cmpstr(size_to_str(0), ==, "0 B"); + g_assert_cmpstr(size_to_str(1), ==, "1 B"); + g_assert_cmpstr(size_to_str(1016), ==, "0.992 KiB"); + g_assert_cmpstr(size_to_str(1024), ==, "1 KiB"); + g_assert_cmpstr(size_to_str(512ull << 20), ==, "512 MiB"); +} + +static void test_iec_binary_prefix(void) +{ + g_assert_cmpstr(iec_binary_prefix(0), ==, ""); + g_assert_cmpstr(iec_binary_prefix(10), ==, "Ki"); + g_assert_cmpstr(iec_binary_prefix(20), ==, "Mi"); + g_assert_cmpstr(iec_binary_prefix(30), ==, "Gi"); + g_assert_cmpstr(iec_binary_prefix(40), ==, "Ti"); + g_assert_cmpstr(iec_binary_prefix(50), ==, "Pi"); + g_assert_cmpstr(iec_binary_prefix(60), ==, "Ei"); +} + +static void test_si_prefix(void) +{ + g_assert_cmpstr(si_prefix(-18), ==, "a"); + g_assert_cmpstr(si_prefix(-15), ==, "f"); + g_assert_cmpstr(si_prefix(-12), ==, "p"); + g_assert_cmpstr(si_prefix(-9), ==, "n"); + g_assert_cmpstr(si_prefix(-6), ==, "u"); + g_assert_cmpstr(si_prefix(-3), ==, "m"); + g_assert_cmpstr(si_prefix(0), ==, ""); + g_assert_cmpstr(si_prefix(3), ==, "K"); + g_assert_cmpstr(si_prefix(6), ==, "M"); + g_assert_cmpstr(si_prefix(9), ==, "G"); + g_assert_cmpstr(si_prefix(12), ==, "T"); + g_assert_cmpstr(si_prefix(15), ==, "P"); + g_assert_cmpstr(si_prefix(18), ==, "E"); +} + int main(int argc, char **argv) { g_test_init(&argc, &argv, NULL); @@ -2729,5 +2773,13 @@ int main(int argc, char **argv) g_test_add_func("/cutils/strtosz/metric", test_qemu_strtosz_metric); + g_test_add_func("/cutils/size_to_str", + test_size_to_str); + g_test_add_func("/cutils/freq_to_str", + test_freq_to_str); + g_test_add_func("/cutils/iec_binary_prefix", + test_iec_binary_prefix); + g_test_add_func("/cutils/si_prefix", + test_si_prefix); return g_test_run(); } diff --git a/util/cutils.c b/util/cutils.c index a58bcfd80e..6d04e52907 100644 --- a/util/cutils.c +++ b/util/cutils.c @@ -872,6 +872,25 @@ int parse_debug_env(const char *name, int max, int initial) return debug; } +const char *si_prefix(unsigned int exp10) +{ + static const char *prefixes[] = { + "a", "f", "p", "n", "u", "m", "", "K", "M", "G", "T", "P", "E" + }; + + exp10 += 18; + assert(exp10 % 3 == 0 && exp10 / 3 < ARRAY_SIZE(prefixes)); + return prefixes[exp10 / 3]; +} + +const char *iec_binary_prefix(unsigned int exp2) +{ + static const char *prefixes[] = { "", "Ki", "Mi", "Gi", "Ti", "Pi", "Ei" }; + + assert(exp2 % 10 == 0 && exp2 / 10 < ARRAY_SIZE(prefixes)); + return prefixes[exp2 / 10]; +} + /* * Return human readable string for size @val. * @val can be anything that uint64_t allows (no more than "16 EiB"). @@ -880,7 +899,6 @@ int parse_debug_env(const char *name, int max, int initial) */ char *size_to_str(uint64_t val) { - static const char *suffixes[] = { "", "Ki", "Mi", "Gi", "Ti", "Pi", "Ei" }; uint64_t div; int i; @@ -891,25 +909,23 @@ char *size_to_str(uint64_t val) * (see e41b509d68afb1f for more info) */ frexp(val / (1000.0 / 1024.0), &i); - i = (i - 1) / 10; - div = 1ULL << (i * 10); + i = (i - 1) / 10 * 10; + div = 1ULL << i; - return g_strdup_printf("%0.3g %sB", (double)val / div, suffixes[i]); + return g_strdup_printf("%0.3g %sB", (double)val / div, iec_binary_prefix(i)); } char *freq_to_str(uint64_t freq_hz) { - static const char *const suffixes[] = { "", "K", "M", "G", "T", "P", "E" }; double freq = freq_hz; - size_t idx = 0; + size_t exp10 = 0; while (freq >= 1000.0) { freq /= 1000.0; - idx++; + exp10 += 3; } - assert(idx < ARRAY_SIZE(suffixes)); - return g_strdup_printf("%0.3g %sHz", freq, suffixes[idx]); + return g_strdup_printf("%0.3g %sHz", freq, si_prefix(exp10)); } int qemu_pstrcmp0(const char **str1, const char **str2) -- 2.11.0