From 6f81292b372a4f63213763bca66a7211a26ec88b Mon Sep 17 00:00:00 2001
From: Carlo Alberto Ferraris <cafxx@mercari.com>
Date: Fri, 28 Feb 2020 19:33:23 +0900
Subject: [PATCH] wip

---
 buffer/pool.go      | 18 +++++++++++++++++-
 buffer/pool_test.go |  2 +-
 2 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/buffer/pool.go b/buffer/pool.go
index 07fb4bc..5e97991 100644
--- a/buffer/pool.go
+++ b/buffer/pool.go
@@ -113,6 +113,14 @@ func (b *Buffer) AppendByte(data byte) {
 
 // AppendBytes appends a byte slice to buffer.
 func (b *Buffer) AppendBytes(data []byte) {
+	if len(data) <= cap(b.Buf)-len(b.Buf) {
+		b.Buf = append(b.Buf, data...) // fast path
+	} else {
+		b.appendBytesSlow(data)
+	}
+}
+
+func (b *Buffer) appendBytesSlow(data []byte) {
 	for len(data) > 0 {
 		if cap(b.Buf) == len(b.Buf) { // EnsureSpace won't be inlined.
 			b.EnsureSpace(1)
@@ -128,8 +136,16 @@ func (b *Buffer) AppendBytes(data []byte) {
 	}
 }
 
-// AppendBytes appends a string to buffer.
+// AppendString appends a string to buffer.
 func (b *Buffer) AppendString(data string) {
+	if len(data) <= cap(b.Buf)-len(b.Buf) {
+		b.Buf = append(b.Buf, data...) // fast path
+	} else {
+		b.appendStringSlow(data)
+	}
+}
+
+func (b *Buffer) appendStringSlow(data string) {
 	for len(data) > 0 {
 		if cap(b.Buf) == len(b.Buf) { // EnsureSpace won't be inlined.
 			b.EnsureSpace(1)
diff --git a/buffer/pool_test.go b/buffer/pool_test.go
index 680623a..1f321d3 100644
--- a/buffer/pool_test.go
+++ b/buffer/pool_test.go
@@ -42,7 +42,7 @@ func TestAppendString(t *testing.T) {
 
 	s := "test"
 	for i := 0; i < 1000; i++ {
-		b.AppendBytes([]byte(s))
+		b.AppendString(s)
 		want = append(want, s...)
 	}