From 2ea960094ef3f440434612c1cc03ac97293bf5a5 Mon Sep 17 00:00:00 2001
From: Nicholas Gates <nick@nickgates.com>
Date: Sat, 9 May 2026 15:28:05 -0400
Subject: [PATCH] Faster Mask::from_slices

Signed-off-by: Nicholas Gates <nick@nickgates.com>
---
 vortex-mask/src/lib.rs | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/vortex-mask/src/lib.rs b/vortex-mask/src/lib.rs
index 29b2f5f83e4..339f9a12d74 100644
--- a/vortex-mask/src/lib.rs
+++ b/vortex-mask/src/lib.rs
@@ -281,10 +281,14 @@ impl Mask {
             return Self::AllTrue(len);
         }
 
-        let mut buf = BitBufferMut::new_unset(len);
+        let mut buf = BitBufferMut::with_capacity(len);
+        let mut cursor = 0;
         for (start, end) in slices.iter().copied() {
-            (start..end).for_each(|idx| buf.set(idx));
+            buf.append_n(false, start - cursor);
+            buf.append_n(true, end - start);
+            cursor = end;
         }
+        buf.append_n(false, len - cursor);
         debug_assert_eq!(buf.len(), len);
 
         Self::Values(Arc::new(MaskValues {