From 89cb16e93dfb26a550f08e34305286b3c932293d Mon Sep 17 00:00:00 2001
From: Moises Vega <moises@uber.com>
Date: Fri, 3 May 2024 15:35:48 -0700
Subject: [PATCH] feat: opt for concatenation instead of using fmt.Sprintf

---
 baggage/baggage.go      |  4 ++--
 baggage/baggage_test.go | 15 +++++++++++++++
 2 files changed, 17 insertions(+), 2 deletions(-)

diff --git a/baggage/baggage.go b/baggage/baggage.go
index 75773bc1ce9..f98c54a3cba 100644
--- a/baggage/baggage.go
+++ b/baggage/baggage.go
@@ -335,9 +335,9 @@ func (m Member) String() string {
 	// A key is just an ASCII string. A value is restricted to be
 	// US-ASCII characters excluding CTLs, whitespace,
 	// DQUOTE, comma, semicolon, and backslash.
-	s := fmt.Sprintf("%s%s%s", m.key, keyValueDelimiter, valueEscape(m.value))
+	s := m.key + keyValueDelimiter + valueEscape(m.value)
 	if len(m.properties) > 0 {
-		s = fmt.Sprintf("%s%s%s", s, propertyDelimiter, m.properties.String())
+		s += propertyDelimiter + m.properties.String()
 	}
 	return s
 }
diff --git a/baggage/baggage_test.go b/baggage/baggage_test.go
index e8f67761f0b..8acd149f48c 100644
--- a/baggage/baggage_test.go
+++ b/baggage/baggage_test.go
@@ -1027,3 +1027,18 @@ func BenchmarkValueEscape(b *testing.B) {
 		})
 	}
 }
+
+func BenchmarkMemberString(b *testing.B) {
+	b.ReportAllocs()
+	alphabet := "abcdefghijklmnopqrstuvwxyz"
+	props := make([]Property, len(alphabet))
+	for i, r := range alphabet {
+		props[i] = Property{key: string(r)}
+	}
+	member, err := NewMember(alphabet, alphabet, props...)
+	require.NoError(b, err)
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		_ = member.String()
+	}
+}