From 9692477a59c47b5fb6bd6d4702302859296db070 Mon Sep 17 00:00:00 2001
From: Filipe Brandenburger <filbranden@google.com>
Date: Wed, 23 Jan 2019 19:48:54 -0800
Subject: [PATCH] time-util: Introduce parse_sec_def_infinity

This works like parse_sec() but defaults to USEC_INFINITY when passed an
empty string or only whitespace.

Also introduce config_parse_sec_def_infinity, which can be used to parse
config options using this function.

This is useful for time options that use "infinity" for default and that
can be reset by unsetting them.

Introduce a test case to ensure it works as expected.

(cherry picked from commit 7b61ce3c44ef5908e817009ce4f9d2a7a37722be)

Related: #1770379
---
 src/basic/time-util.c     |  9 +++++++++
 src/basic/time-util.h     |  1 +
 src/shared/conf-parser.c  |  1 +
 src/shared/conf-parser.h  |  1 +
 src/test/test-time-util.c | 21 +++++++++++++++++++++
 5 files changed, 33 insertions(+)

diff --git a/src/basic/time-util.c b/src/basic/time-util.c
index fe201c398d..c36e462193 100644
--- a/src/basic/time-util.c
+++ b/src/basic/time-util.c
@@ -1072,6 +1072,15 @@ int parse_sec_fix_0(const char *t, usec_t *usec) {
         return parse_sec(t, usec);
 }
 
+int parse_sec_def_infinity(const char *t, usec_t *ret) {
+        t += strspn(t, WHITESPACE);
+        if (isempty(t)) {
+                *ret = USEC_INFINITY;
+                return 0;
+        }
+        return parse_sec(t, ret);
+}
+
 int parse_nsec(const char *t, nsec_t *nsec) {
         static const struct {
                 const char *suffix;
diff --git a/src/basic/time-util.h b/src/basic/time-util.h
index 344f2dc52e..f5c9ea6327 100644
--- a/src/basic/time-util.h
+++ b/src/basic/time-util.h
@@ -116,6 +116,7 @@ int parse_timestamp(const char *t, usec_t *usec);
 
 int parse_sec(const char *t, usec_t *usec);
 int parse_sec_fix_0(const char *t, usec_t *usec);
+int parse_sec_def_infinity(const char *t, usec_t *usec);
 int parse_time(const char *t, usec_t *usec, usec_t default_unit);
 int parse_nsec(const char *t, nsec_t *nsec);
 
diff --git a/src/shared/conf-parser.c b/src/shared/conf-parser.c
index 2d62fdf05d..246b7431e4 100644
--- a/src/shared/conf-parser.c
+++ b/src/shared/conf-parser.c
@@ -509,6 +509,7 @@ DEFINE_PARSER(unsigned, unsigned, safe_atou);
 DEFINE_PARSER(double, double, safe_atod);
 DEFINE_PARSER(nsec, nsec_t, parse_nsec);
 DEFINE_PARSER(sec, usec_t, parse_sec);
+DEFINE_PARSER(sec_def_infinity, usec_t, parse_sec_def_infinity);
 DEFINE_PARSER(mode, mode_t, parse_mode);
 
 int config_parse_iec_size(const char* unit,
diff --git a/src/shared/conf-parser.h b/src/shared/conf-parser.h
index 16f042d894..a0a5c89c27 100644
--- a/src/shared/conf-parser.h
+++ b/src/shared/conf-parser.h
@@ -127,6 +127,7 @@ CONFIG_PARSER_PROTOTYPE(config_parse_string);
 CONFIG_PARSER_PROTOTYPE(config_parse_path);
 CONFIG_PARSER_PROTOTYPE(config_parse_strv);
 CONFIG_PARSER_PROTOTYPE(config_parse_sec);
+CONFIG_PARSER_PROTOTYPE(config_parse_sec_def_infinity);
 CONFIG_PARSER_PROTOTYPE(config_parse_nsec);
 CONFIG_PARSER_PROTOTYPE(config_parse_mode);
 CONFIG_PARSER_PROTOTYPE(config_parse_warn_compat);
diff --git a/src/test/test-time-util.c b/src/test/test-time-util.c
index 87de8d172c..354a01dd1a 100644
--- a/src/test/test-time-util.c
+++ b/src/test/test-time-util.c
@@ -61,6 +61,26 @@ static void test_parse_sec_fix_0(void) {
         assert_se(u == USEC_INFINITY);
 }
 
+static void test_parse_sec_def_infinity(void) {
+        usec_t u;
+
+        log_info("/* %s */", __func__);
+
+        assert_se(parse_sec_def_infinity("5s", &u) >= 0);
+        assert_se(u == 5 * USEC_PER_SEC);
+        assert_se(parse_sec_def_infinity("", &u) >= 0);
+        assert_se(u == USEC_INFINITY);
+        assert_se(parse_sec_def_infinity("     ", &u) >= 0);
+        assert_se(u == USEC_INFINITY);
+        assert_se(parse_sec_def_infinity("0s", &u) >= 0);
+        assert_se(u == 0);
+        assert_se(parse_sec_def_infinity("0", &u) >= 0);
+        assert_se(u == 0);
+        assert_se(parse_sec_def_infinity(" 0", &u) >= 0);
+        assert_se(u == 0);
+        assert_se(parse_sec_def_infinity("-5s", &u) < 0);
+}
+
 static void test_parse_time(void) {
         usec_t u;
 
@@ -420,6 +440,7 @@ int main(int argc, char *argv[]) {
 
         test_parse_sec();
         test_parse_sec_fix_0();
+        test_parse_sec_def_infinity();
         test_parse_time();
         test_parse_nsec();
         test_format_timespan(1);