From bfc54b97b1ae0e5cc3b8032a0558dbc8079d5d52 Mon Sep 17 00:00:00 2001
From: delthas <delthas@dille.cc>
Date: Fri, 18 Feb 2022 17:16:22 +0100
Subject: Optimize URL parsing performance

According to a CPU profiling I meade, the regex applied on each incoming
message took a substantial part of the CPU time. The slowdown it caused
was noticable at startup.

This optimizes the URL parsing by eliminating fast-path cases where no
dot appears to avoid parsing the line with a regex in those cases.
---
 ui/style.go | 5 +++++
 1 file changed, 5 insertions(+)

(limited to 'ui')

diff --git a/ui/style.go b/ui/style.go
index 91cd2e1..4552020 100644
--- a/ui/style.go
+++ b/ui/style.go
@@ -120,6 +120,11 @@ func (s StyledString) Truncate(w int, tail StyledString) StyledString {
 var urlRegex = xurls.Relaxed()
 
 func (s StyledString) ParseURLs() StyledString {
+	if !strings.ContainsRune(s.string, '.') {
+		// fast path: no dot means no URL
+		return s
+	}
+
 	styles := make([]rangedStyle, 0, len(s.styles))
 
 	urls := urlRegex.FindAllStringIndex(s.string, -1)
-- 
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