Allow to access io write destination buffer (#504)

ntex-io/CHANGES.md

@@ -1,5 +1,9 @@
 # Changes
 
+## [2.9.3] - 2025-01-21
+
+* Allow to access io write destination buffer
+
 ## [2.9.2] - 2024-12-05
 
 * Better error handling

ntex-io/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "ntex-io"
-version = "2.9.2"
+version = "2.9.3"
 authors = ["ntex contributors <team@ntex.rs>"]
 description = "Utilities for encoding and decoding frames"
 keywords = ["network", "framework", "async", "futures"]

ntex-io/src/buf.rs

@@ -218,12 +218,12 @@ impl Stack {
 
     pub(crate) fn with_write_destination<F, R>(&self, io: &IoRef, f: F) -> R
     where
-        F: FnOnce(&mut Option<BytesVec>) -> R,
+        F: FnOnce(Option<&mut BytesVec>) -> R,
     {
         let item = self.get_last_level();
         let mut wb = item.1.take();
 
-        let result = f(&mut wb);
+        let result = f(wb.as_mut());
 
         // check nested updates
         if item.1.take().is_some() {

ntex-io/src/ioref.rs

@@ -199,6 +199,16 @@ impl IoRef {
         }
     }
 
+    #[doc(hidden)]
+    #[inline]
+    /// Get mut access to destination write buffer
+    pub fn with_write_dest_buf<F, R>(&self, f: F) -> R
+    where
+        F: FnOnce(Option<&mut BytesVec>) -> R,
+    {
+        self.0.buffer.with_write_destination(self, f)
+    }
+
     #[inline]
     /// Get mut access to source read buffer
     pub fn with_read_buf<F, R>(&self, f: F) -> R
@@ -559,6 +569,10 @@ mod tests {
 
         assert_eq!(in_bytes.get(), BIN.len() * 2);
         assert_eq!(out_bytes.get(), 8);
+        assert_eq!(
+            state.with_write_dest_buf(|b| b.map(|b| b.len()).unwrap_or(0)),
+            0
+        );
 
         // refs
         assert_eq!(Rc::strong_count(&in_bytes), 3);