fix: use HTTP compression when requesting Lz4 for result sets

CHANGELOG.md

@@ -8,6 +8,14 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased] - ReleaseDate
 
+### Fixed
+
+* Switched Lz4 compression to use HTTP standard `Accept-Encoding` negotiation, fixing a regression in ClickHouse 26.9. ([#482], [issue #468])
+
+[#482]: https://github.com/ClickHouse/clickhouse-rs/pull/482
+
+[issue #468]: https://github.com/ClickHouse/clickhouse-rs/issues/468
+
 ## [0.15.2] - 2026-08-24
 
 ### Added

Cargo.toml

@@ -100,7 +100,7 @@ test-util = ["hyper/server"]
 inserter = ["dep:quanta"]
 uuid = ["dep:uuid"]
 time = ["dep:time"]
-lz4 = ["dep:lz4_flex", "dep:cityhash-rs"]
+lz4 = ["dep:lz4_flex", "dep:cityhash-rs", "dep:twox-hash"]
 zstd = ["dep:zstd", "dep:cityhash-rs"]
 chrono = ["dep:chrono"]
 futures03 = []
@@ -152,9 +152,8 @@ hyper-rustls = { version = "0.27.3", default-features = false, features = [
 url = "2.1.1"
 futures-util = { version = "0.3.5", default-features = false, features = ["sink", "io"] }
 futures-channel = { version = "0.3.30", features = ["sink"] }
-lz4_flex = { version = "0.11.6", default-features = false, features = [
-    "std",
-], optional = true }
+twox-hash = { version = "2.1.4", optional = true }
+lz4_flex = { version = "0.14.0", optional = true, default-features = false, features = ["std"] }
 cityhash-rs = { version = "=1.0.1", optional = true } # exact version for safety, this package has been stable for years
 zstd = { version = "0.13", default-features = false, optional = true }
 uuid = { version = "1", optional = true }

src/bytes_ext.rs

@@ -38,6 +38,11 @@ impl BytesExt {
         *self.cursor.get_mut() += n;
     }
 
+    pub(crate) fn clear(&mut self) {
+        *self.cursor.get_mut() = 0;
+        self.bytes.clear();
+    }
+
     /// Adds the provided chunk into available bytes.
     #[inline(always)]
     pub(crate) fn extend(&mut self, chunk: Bytes) {
@@ -79,6 +84,14 @@ impl Buf for BytesExt {
     fn advance(&mut self, cnt: usize) {
         self.advance(cnt);
     }
+
+    fn copy_to_bytes(&mut self, len: usize) -> Bytes {
+        let start = self.cursor.get();
+        self.advance(len);
+        let end = self.cursor.get();
+
+        self.bytes.slice(start..end)
+    }
 }
 
 #[cfg(test)]