harec

commit a57d77709b02bb6c39d33bdae1e9a85ea247abbd
parent 92912c78b5fd86669d51b2ea4cc0187b0c5973aa
Author: Eyal Sawady <ecs@d2evs.net>
Date:   Sun, 21 Feb 2021 18:06:19 -0500

Add rt::unensure

Diffstat:
M
rt/ensure.ha
 | 
16
++++++++++++++--

1 file changed, 14 insertions(+), 2 deletions(-)
diff --git a/rt/ensure.ha b/rt/ensure.ha
@@ -15,7 +15,19 @@ export fn ensure(s: *slice, membsz: size, length: size) void = {
 		};
 	};
 	s.capacity = cap;
-	let data = realloc(s.data, s.capacity * membsz);
-	assert(data != null);
+	const data = realloc(s.data, s.capacity * membsz);
+	assert(data != null || s.capacity * membsz == 0);
+	s.data = data;
+};
+
+export fn unensure(s: *slice, membsz: size, length: size) void = {
+	let cap = s.capacity;
+	for (cap > length) {
+		cap /= 2;
+	};
+	cap *= 2;
+	s.capacity = cap;
+	const data = realloc(s.data, s.capacity * membsz);
+	assert(data != null || s.capacity * membsz == 0);
 	s.data = data;
 };