perf(db): use encode_to in Scale implementations (#11297)

crates/storage/db-api/src/scale.rs

@@ -22,7 +22,7 @@ where
     }
 
     fn compress_to_buf<B: bytes::BufMut + AsMut<[u8]>>(self, buf: &mut B) {
-        buf.put_slice(&parity_scale_codec::Encode::encode(&self))
+        parity_scale_codec::Encode::encode_to(&self, OutputCompat::wrap_mut(buf));
     }
 }
 
@@ -50,3 +50,22 @@ impl sealed::Sealed for Vec<u8> {}
 
 impl_compression_for_scale!(U256);
 impl_compression_for_scale!(u8, u32, u16, u64);
+
+#[repr(transparent)]
+struct OutputCompat<B>(B);
+
+impl<B> OutputCompat<B> {
+    fn wrap_mut(buf: &mut B) -> &mut Self {
+        unsafe { std::mem::transmute(buf) }
+    }
+}
+
+impl<B: bytes::BufMut> parity_scale_codec::Output for OutputCompat<B> {
+    fn write(&mut self, bytes: &[u8]) {
+        self.0.put_slice(bytes);
+    }
+
+    fn push_byte(&mut self, byte: u8) {
+        self.0.put_u8(byte);
+    }
+}