serialize: add serialize_string_set()

src/shared/serialize.c

@@ -219,6 +219,27 @@ int serialize_item_base64mem(FILE *f, const char *key, const void *p, size_t l)
         return 1;
 }
 
+int serialize_string_set(FILE *f, const char *key, Set *s) {
+        const char *e;
+        int r;
+
+        assert(f);
+        assert(key);
+
+        if (set_isempty(s))
+                return 0;
+
+        /* Serialize as individual items, as each element might contain separators and escapes */
+
+        SET_FOREACH(e, s) {
+                r = serialize_item(f, key, e);
+                if (r < 0)
+                        return r;
+        }
+
+        return 1;
+}
+
 int deserialize_read_line(FILE *f, char **ret) {
         _cleanup_free_ char *line = NULL;
         int r;

src/shared/serialize.h

@@ -6,6 +6,7 @@
 #include "fdset.h"
 #include "macro.h"
 #include "pidref.h"
+#include "set.h"
 #include "string-util.h"
 #include "time-util.h"
 
@@ -19,6 +20,7 @@ int serialize_usec(FILE *f, const char *key, usec_t usec);
 int serialize_dual_timestamp(FILE *f, const char *key, const dual_timestamp *t);
 int serialize_strv(FILE *f, const char *key, char **l);
 int serialize_pidref(FILE *f, FDSet *fds, const char *key, PidRef *pidref);
+int serialize_string_set(FILE *f, const char *key, Set *s);
 
 static inline int serialize_bool(FILE *f, const char *key, bool b) {
         return serialize_item(f, key, yes_no(b));

src/test/test-serialize.c

@@ -225,6 +225,37 @@ TEST(serialize_item_base64mem) {
         assert_se(streq(line, "a=////"));
 }
 
+TEST(serialize_string_set) {
+        _cleanup_(unlink_tempfilep) char fn[] = "/tmp/test-serialize.XXXXXX";
+        _cleanup_fclose_ FILE *f = NULL;
+        _cleanup_set_free_free_ Set *s = NULL;
+        _cleanup_free_ char *line1 = NULL, *line2 = NULL;
+        char *p, *q;
+
+        assert_se(fmkostemp_safe(fn, "r+", &f) == 0);
+        log_info("/* %s (%s) */", __func__, fn);
+
+        assert_se(set_ensure_allocated(&s, &string_hash_ops) >= 0);
+
+        assert_se(serialize_string_set(f, "a", s) == 0);
+
+        assert_se(set_put_strsplit(s, "abc def,ghi jkl", ",", 0) >= 0);
+
+        assert_se(serialize_string_set(f, "a", s) == 1);
+
+        rewind(f);
+
+        assert_se(read_line(f, LONG_LINE_MAX, &line1) > 0);
+        assert_se((p = startswith(line1, "a=")));
+
+        assert_se(read_line(f, LONG_LINE_MAX, &line2) > 0);
+        assert_se((q = startswith(line2, "a=")));
+
+        assert_se(!streq(p, q));
+        assert_se(STR_IN_SET(p, "abc def", "ghi jkl"));
+        assert_se(STR_IN_SET(q, "abc def", "ghi jkl"));
+}
+
 static int intro(void) {
         memset(long_string, 'x', sizeof(long_string)-1);
         char_array_0(long_string);