From 7c74cd6f7af0a5b4ea25c7a480db0d1a564771ea Mon Sep 17 00:00:00 2001
From: Keenan Tims <ktims@gotroot.ca>
Date: Thu, 23 Mar 2023 11:17:58 -0700
Subject: [PATCH] Write using a BufWriter for +10% speed

---
 src/main.rs | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/src/main.rs b/src/main.rs
index fde5459..cc1afa4 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,16 +1,18 @@
 extern crate ipnet;
 extern crate iprange;
 
-use std::process::exit;
+use std::{process::exit, io};
 
 mod iputils;
 use iputils::{IpBothRange, IpOrNet, PrefixlenPair};
 
 use clio::*;
-use std::io::BufRead;
+use std::io::{Write, BufRead};
 
 use clap::Parser;
 
+const WRITER_BUFSIZE: usize = 32 * 1024;
+
 #[derive(Parser)]
 #[command(author, version, about, long_about=None)]
 struct Args {
@@ -123,7 +125,11 @@ impl App {
 
         self.simplify_inputs();
 
-        print!("{}", self.prefixes);
+        let stdout = io::stdout().lock();
+        let mut w = io::BufWriter::with_capacity(WRITER_BUFSIZE, stdout);
+
+        write!(&mut w, "{}", self.prefixes).unwrap();
+        w.flush().unwrap();
     }
 }