From 47c0edc3f6ded8bbf960aa0cee8eae77907b84ad Mon Sep 17 00:00:00 2001
From: Link Mauve <linkmauve@linkmauve.fr>
Date: Tue, 9 Jun 2026 00:08:52 +0200
Subject: [PATCH] xmpp-parsers: Optimize to_hex() a bit

Just one correctly-sized String allocation, instead of one String per
byte, a Vec<String>, and then a final String.

skip-changelog: Internal change.
---
 parsers/src/hashes.rs | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/parsers/src/hashes.rs b/parsers/src/hashes.rs
index f116a481..6f6592b6 100644
--- a/parsers/src/hashes.rs
+++ b/parsers/src/hashes.rs
@@ -6,6 +6,7 @@
 
 use alloc::borrow::Cow;
 use core::{
+    fmt::Write,
     num::ParseIntError,
     ops::{Deref, DerefMut},
     str::FromStr,
@@ -181,11 +182,11 @@ impl Hash {
 
     /// Formats this hash into hexadecimal.
     pub fn to_hex(&self) -> String {
-        self.hash
-            .iter()
-            .map(|byte| format!("{:02x}", byte))
-            .collect::<Vec<_>>()
-            .join("")
+        let mut hex = String::with_capacity(self.hash.len() * 2);
+        for byte in &self.hash {
+            write!(&mut hex, "{:02x}", byte).unwrap();
+        }
+        hex
     }
 
     /// Formats this hash into colon-separated hexadecimal.