From: Petr Špaček <petr.spacek@nic.cz>
Date: Wed, 2 Jan 2019 13:56:53 +0000 (+0100)
Subject: utils: diff between two calendar times in strings
X-Git-Tag: v3.2.1~5^2~4
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=c487ecb5a3469b46e08e97c22d5eab749057da27;p=thirdparty%2Fknot-resolver.git

utils: diff between two calendar times in strings
---

diff --git a/daemon/lua/kres-gen.lua b/daemon/lua/kres-gen.lua
index a041ed603..eeb8ff7ca 100644
--- a/daemon/lua/kres-gen.lua
+++ b/daemon/lua/kres-gen.lua
@@ -315,6 +315,7 @@ int kr_zonecut_add(struct kr_zonecut *, const knot_dname_t *, const void *, int)
 _Bool kr_zonecut_is_empty(struct kr_zonecut *);
 void kr_zonecut_set(struct kr_zonecut *, const knot_dname_t *);
 uint64_t kr_now();
+const char *kr_strptime_diff(const char *, const char *, const char *, double *);
 void lru_free_items_impl(struct lru *);
 struct lru *lru_create_impl(unsigned int, knot_mm_t *, knot_mm_t *);
 void *lru_get_impl(struct lru *, const char *, unsigned int, unsigned int, _Bool, _Bool *);
diff --git a/daemon/lua/kres-gen.sh b/daemon/lua/kres-gen.sh
index 661a001f1..538fe239e 100755
--- a/daemon/lua/kres-gen.sh
+++ b/daemon/lua/kres-gen.sh
@@ -169,6 +169,7 @@ EOF
 	kr_zonecut_is_empty
 	kr_zonecut_set
 	kr_now
+	kr_strptime_diff
 	lru_free_items_impl
 	lru_create_impl
 	lru_get_impl
diff --git a/lib/utils.c b/lib/utils.c
index 1d4be296f..fe9ab03b5 100644
--- a/lib/utils.c
+++ b/lib/utils.c
@@ -948,6 +948,38 @@ uint64_t kr_now()
 	return uv_now(uv_default_loop());
 }
 
+const char *kr_strptime_diff(const char *format, const char *time1_str,
+		             const char *time0_str, double *diff) {
+	assert(format != NULL);
+	assert(time1_str != NULL);
+	assert(time0_str != NULL);
+	assert(diff != NULL);
+
+	struct tm time1_tm;
+	time_t time1_u;
+	struct tm time0_tm;
+	time_t time0_u;
+
+	char *err = strptime(time1_str, format, &time1_tm);
+	if (err == NULL || err != time1_str + strlen(time1_str))
+		return "strptime failed for time1";
+	time1_tm.tm_isdst = -1; /* determine if DST is active or not */
+	time1_u = mktime(&time1_tm);
+	if (time1_u == (time_t)-1)
+		return "mktime failed for time1";
+
+	err = strptime(time0_str, format, &time0_tm);
+	if (err == NULL || err != time0_str + strlen(time0_str))
+		return "strptime failed for time0";
+	time0_tm.tm_isdst = -1; /* determine if DST is active or not */
+	time0_u = mktime(&time0_tm);
+	if (time0_u == (time_t)-1)
+		return "mktime failed for time0";
+	*diff = difftime(time1_u, time0_u);
+
+	return NULL;
+}
+
 int knot_dname_lf2wire(knot_dname_t * const dst, uint8_t len, const uint8_t *lf)
 {
 	knot_dname_t *d = dst; /* moving "cursor" as we write it out */
diff --git a/lib/utils.h b/lib/utils.h
index 8e4e1ad4b..21eabac80 100644
--- a/lib/utils.h
+++ b/lib/utils.h
@@ -476,6 +476,15 @@ static inline int kr_dname_lf(uint8_t *dst, const knot_dname_t *src, bool add_wi
 	return KNOT_EOK;
 }
 
+/**
+ * Difference between two calendar times specified as strings.
+ * \param format[in] format for strptime
+ * \param diff[out] result from C difftime(time1, time0)
+ */
+KR_EXPORT
+const char *kr_strptime_diff(const char *format, const char *time1_str,
+		             const char *time0_str, double *diff);
+
 /* Trivial non-inline wrappers, to be used in lua. */
 KR_EXPORT void kr_rrset_init(knot_rrset_t *rrset, knot_dname_t *owner,
 				uint16_t type, uint16_t rclass, uint32_t ttl);
diff --git a/tests/test_utils.c b/tests/test_utils.c
index 07856560e..e6371c300 100644
--- a/tests/test_utils.c
+++ b/tests/test_utils.c
@@ -79,11 +79,44 @@ static void test_straddr(void **state)
 	assert_int_not_equal(test_bitcmp(ip6_sub, ip6_out, 4), 0);
 }
 
+static void test_strptime_diff(void **state)
+{
+	char *format = "%Y-%m-%dT%H:%M:%S";
+	const char *errmsg = NULL;
+	double output;
+
+	errmsg = kr_strptime_diff(format,
+		"2019-01-09T12:06:04",
+		"2019-01-09T12:06:04", &output);
+	assert_true(errmsg == NULL);
+	/* double type -> equality is not reliable */
+	assert_true(output > -0.01 && output < 0.01);
+
+	errmsg = kr_strptime_diff(format,
+		"2019-01-09T12:06:04",
+		"2019-01-09T11:06:04", &output);
+	assert_true(errmsg == NULL);
+	/* double type -> equality is not reliable */
+	assert_true(output > -3600.01 && output < 3600.01);
+
+	/* invalid inputs */
+	errmsg = kr_strptime_diff(format,
+		"2019-01-09T25:06:04",
+		"2019-01-09T11:06:04", &output);
+	assert_true(errmsg != NULL);
+
+	errmsg = kr_strptime_diff("fail",
+		"2019-01-09T23:06:04",
+		"2019-01-09T11:06:04", &output);
+	assert_true(errmsg != NULL);
+}
+
 int main(void)
 {
 	const UnitTest tests[] = {
 		unit_test(test_strcatdup),
 		unit_test(test_straddr),
+		unit_test(test_strptime_diff),
 	};
 
 	return run_tests(tests);