From a71b592ec524f97feda8947853092688cf1ffb63 Mon Sep 17 00:00:00 2001
From: cancaicai <2356672992@qq.com>
Date: Sat, 14 Feb 2026 22:57:18 +0800
Subject: [PATCH] perf(layout): add empty-range fast paths in chunked reader

Signed-off-by: cancaicai <2356672992@qq.com>
---
 vortex-layout/src/layouts/chunked/reader.rs | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/vortex-layout/src/layouts/chunked/reader.rs b/vortex-layout/src/layouts/chunked/reader.rs
index e4d26c7e808..9c23738d54c 100644
--- a/vortex-layout/src/layouts/chunked/reader.rs
+++ b/vortex-layout/src/layouts/chunked/reader.rs
@@ -166,6 +166,10 @@ impl LayoutReader for ChunkedReader {
         row_range: &Range<u64>,
         splits: &mut BTreeSet<u64>,
     ) -> VortexResult<()> {
+        if row_range.is_empty() {
+            return Ok(());
+        }
+
         for (index, (&start, &end)) in self
             .chunk_offsets
             .iter()
@@ -201,6 +205,10 @@ impl LayoutReader for ChunkedReader {
         expr: &Expression,
         mask: Mask,
     ) -> VortexResult<MaskFuture> {
+        if row_range.is_empty() {
+            return Ok(MaskFuture::ready(mask));
+        }
+
         let mut chunk_evals = vec![];
 
         for (chunk_idx, chunk_range, mask_range) in self.ranges(row_range) {
@@ -243,6 +251,10 @@ impl LayoutReader for ChunkedReader {
         expr: &Expression,
         mask: MaskFuture,
     ) -> VortexResult<MaskFuture> {
+        if row_range.is_empty() {
+            return Ok(mask);
+        }
+
         let mut chunk_evals = vec![];
 
         for (chunk_idx, chunk_range, mask_range) in self.ranges(row_range) {
@@ -279,6 +291,10 @@ impl LayoutReader for ChunkedReader {
         mask: MaskFuture,
     ) -> VortexResult<BoxFuture<'static, VortexResult<ArrayRef>>> {
         let dtype = expr.return_dtype(self.dtype())?;
+        if row_range.is_empty() {
+            return Ok(async move { Ok(ChunkedArray::try_new(vec![], dtype)?.to_array()) }.boxed());
+        }
+
         let mut chunk_evals = vec![];
 
         for (chunk_idx, chunk_range, mask_range) in self.ranges(row_range) {