From d861261a5dd78e11fb56d21e1c6c22fd0099df03 Mon Sep 17 00:00:00 2001
From: Faerbit <faerbit@posteo.net>
Date: Sun, 4 Aug 2024 23:07:38 +0200
Subject: [PATCH] [bencode/ser] "Optimize" performance

---
 src/bencode/ser.rs | 16 +++++++++++-----
 1 file changed, 11 insertions(+), 5 deletions(-)

diff --git a/src/bencode/ser.rs b/src/bencode/ser.rs
index b730e7c..0ab694d 100644
--- a/src/bencode/ser.rs
+++ b/src/bencode/ser.rs
@@ -1,5 +1,5 @@
 use std::collections::BTreeMap;
-
+use std::mem::swap;
 use serde::{ser, Serialize};
 
 use crate::bencode::error::{Error, Result};
@@ -280,8 +280,9 @@ impl <'a> ser::SerializeMap for MapSerializer<'a> {
     {
         key.serialize(&mut self.value_serializer)?;
         self.last_inserted_key = self.value_serializer.output.clone();
-        self.sorted_map.insert(self.value_serializer.output.clone(), Vec::new());
-        self.value_serializer.output.clear();
+        let mut key_to_insert = Vec::new();
+        swap(&mut self.value_serializer.output, &mut key_to_insert);
+        self.sorted_map.insert(key_to_insert, Vec::new());
         Ok(())
     }
 
@@ -290,8 +291,13 @@ impl <'a> ser::SerializeMap for MapSerializer<'a> {
         T: ?Sized + Serialize
     {
         value.serialize(&mut self.value_serializer)?;
-        self.sorted_map.insert(self.last_inserted_key.clone(), self.value_serializer.output.clone());
-        self.value_serializer.output.clear();
+        let mut value_to_insert = Vec::new();
+        swap(&mut self.value_serializer.output, &mut value_to_insert);
+        if let Some(x) = self.sorted_map.get_mut(&self.last_inserted_key) {
+            *x = value_to_insert;
+        } else {
+            unreachable!()
+        }
         self.last_inserted_key.clear();
         Ok(())
     }