+/* copy constructor target <- source */
+void
+map_init_clone(Map *target, const Map *source)
+{
+ target->size = source->size;
+ if (source->size)
+ {
+ target->map = solv_malloc(source->size);
+ memcpy(target->map, source->map, source->size);
+ }
+ else
+ target->map = 0;
+}
+
+/* grow a map */
+void
+map_grow(Map *m, int n)
+{
+ n = (n + 7) >> 3;
+ if (m->size < n)
+ {
+ m->map = solv_realloc(m->map, n);
+ memset(m->map + m->size, 0, n - m->size);
+ m->size = n;
+ }
+}
+
+/* bitwise-ands maps t and s, stores the result in t. */
+void
+map_and(Map *t, const Map *s)
+{
+ unsigned char *ti, *si, *end;
+ ti = t->map;
+ si = s->map;
+ end = ti + (t->size < s->size ? t->size : s->size);
+ while (ti < end)
+ *ti++ &= *si++;
+}
+
+/* bitwise-ors maps t and s, stores the result in t. */
+void
+map_or(Map *t, const Map *s)
+{
+ unsigned char *ti, *si, *end;
+ if (t->size < s->size)
+ map_grow(t, s->size << 3);
+ ti = t->map;
+ si = s->map;
+ end = ti + (t->size < s->size ? t->size : s->size);
+ while (ti < end)
+ *ti++ |= *si++;
+}
+
+/* remove all set bits in s from t. */
+void
+map_subtract(Map *t, const Map *s)
+{
+ unsigned char *ti, *si, *end;
+ ti = t->map;
+ si = s->map;
+ end = ti + (t->size < s->size ? t->size : s->size);
+ while (ti < end)
+ *ti++ &= ~*si++;
+}
+