uid-range: add some basic operations on UidRange objects

Helpers to compare and get size, and whether the object is empty.

src/basic/uid-range.c

@@ -340,3 +340,23 @@ bool uid_range_overlaps(const UIDRange *range, uid_t start, uid_t nr) {
 
         return false;
 }
+
+bool uid_range_equal(const UIDRange *a, const UIDRange *b) {
+        if (a == b)
+                return true;
+
+        if (!a || !b)
+                return false;
+
+        if (a->n_entries != b->n_entries)
+                return false;
+
+        for (size_t i = 0; i < a->n_entries; i++) {
+                if (a->entries[i].start != b->entries[i].start)
+                        return false;
+                if (a->entries[i].nr != b->entries[i].nr)
+                        return false;
+        }
+
+        return true;
+}

src/basic/uid-range.h

@@ -33,6 +33,36 @@ static inline bool uid_range_contains(const UIDRange *range, uid_t uid) {
 
 int uid_map_read_one(FILE *f, uid_t *ret_base, uid_t *ret_shift, uid_t *ret_range);
 
+static inline size_t uid_range_entries(const UIDRange *range) {
+        return range ? range->n_entries : 0;
+}
+
+static inline unsigned uid_range_size(const UIDRange *range) {
+        if (!range)
+                return 0;
+
+        unsigned n = 0;
+
+        FOREACH_ARRAY(e, range->entries, range->n_entries)
+                n += e->nr;
+
+        return n;
+}
+
+static inline bool uid_range_is_empty(const UIDRange *range) {
+
+        if (!range)
+                return true;
+
+        FOREACH_ARRAY(e, range->entries, range->n_entries)
+                if (e->nr > 0)
+                        return false;
+
+        return true;
+}
+
+bool uid_range_equal(const UIDRange *a, const UIDRange *b);
+
 typedef enum UIDRangeUsernsMode {
         UID_RANGE_USERNS_INSIDE,
         UID_RANGE_USERNS_OUTSIDE,