From b4b3b41989522a455198514a8a6f3c6df04dfd06 Mon Sep 17 00:00:00 2001
From: Timo Sirainen <timo.sirainen@open-xchange.com>
Date: Mon, 17 Aug 2020 15:28:00 +0300
Subject: [PATCH] lib: Add str_to_timeval()

---
 src/lib/test-time-util.c | 39 +++++++++++++++++++++++++++++++++++++++
 src/lib/time-util.c      | 28 ++++++++++++++++++++++++++++
 src/lib/time-util.h      |  7 +++++++
 3 files changed, 74 insertions(+)

diff --git a/src/lib/test-time-util.c b/src/lib/test-time-util.c
index 823f76d880..cfa322048e 100644
--- a/src/lib/test-time-util.c
+++ b/src/lib/test-time-util.c
@@ -354,6 +354,44 @@ static void test_micro_nanoseconds(void)
 	test_end();
 }
 
+static void test_str_to_timeval(void)
+{
+	struct {
+		const char *str;
+		unsigned int tv_sec, tv_usec;
+	} tests[] = {
+		{ "0", 0, 0 },
+		{ "0.0", 0, 0 },
+		{ "0.000000", 0, 0 },
+		{ "0.1", 0, 100000 },
+		{ "0.100000", 0, 100000 },
+		{ "0.000001", 0, 1 },
+		{ "0.100000", 0, 100000 },
+		{ "2147483647", 2147483647, 0 },
+		{ "2147483647.999999", 2147483647, 999999 },
+	};
+	const char *test_failures[] = {
+		"",
+		"0.",
+		"0.0000000",
+		"1234.-1",
+		"1234.x",
+		"x",
+		"x.100",
+	};
+	struct timeval tv;
+
+	test_begin("str_to_timeval");
+	for (unsigned int i = 0; i < N_ELEMENTS(tests); i++) {
+		test_assert_idx(str_to_timeval(tests[i].str, &tv) == 0, i);
+		test_assert_idx(tv.tv_sec == tests[i].tv_sec, i);
+		test_assert_idx(tv.tv_usec == tests[i].tv_usec, i);
+	}
+	for (unsigned int i = 0; i < N_ELEMENTS(test_failures); i++)
+		test_assert_idx(str_to_timeval(test_failures[i], &tv) == -1, i);
+	test_end();
+}
+
 void test_time_util(void)
 {
 	test_timeval_cmp();
@@ -363,4 +401,5 @@ void test_time_util(void)
 	test_strftime_now();
 	test_strftime_fixed();
 	test_micro_nanoseconds();
+	test_str_to_timeval();
 }
diff --git a/src/lib/time-util.c b/src/lib/time-util.c
index 7e269cd38b..3168c6df8e 100644
--- a/src/lib/time-util.c
+++ b/src/lib/time-util.c
@@ -131,3 +131,31 @@ const char *t_strfgmtime(const char *fmt, time_t t)
 {
 	return strftime_real(fmt, gmtime(&t));
 }
+
+int str_to_timeval(const char *str, struct timeval *tv_r)
+{
+	tv_r->tv_usec = 0;
+
+	const char *p = strchr(str, '.');
+	if (p == NULL)
+		return str_to_time(str, &tv_r->tv_sec);
+
+	int ret;
+	T_BEGIN {
+		ret = str_to_time(t_strdup_until(str, p++), &tv_r->tv_sec);
+	} T_END;
+	if (ret < 0 || p[0] == '\0')
+		return -1;
+
+	unsigned int len = strlen(p);
+	if (len > 6)
+		return -1; /* we don't support sub-microseconds */
+	char usecs_str[7] = "000000";
+	memcpy(usecs_str, p, len);
+
+	unsigned int usec;
+	if (str_to_uint(usecs_str, &usec) < 0)
+		return -1;
+	tv_r->tv_usec = usec;
+	return 0;
+}
diff --git a/src/lib/time-util.h b/src/lib/time-util.h
index d872158527..31bf9ecd78 100644
--- a/src/lib/time-util.h
+++ b/src/lib/time-util.h
@@ -77,4 +77,11 @@ const char *t_strftime(const char *fmt, const struct tm *tm) ATTR_STRFTIME(1);
 const char *t_strflocaltime(const char *fmt, time_t t) ATTR_STRFTIME(1);
 const char *t_strfgmtime(const char *fmt, time_t t) ATTR_STRFTIME(1);
 
+/* Parse string as <unix timestamp>[.<usecs>] into timeval. <usecs> must not
+   have higher precision time, i.e. a maximum of 6 digits is allowed. Note that
+   ".1" is handled as ".1000000" so the string should have been written using
+   "%06u" printf format. */
+int str_to_timeval(const char *str, struct timeval *tv_r)
+	ATTR_WARN_UNUSED_RESULT;
+
 #endif
-- 
2.47.3