Include a buffer pool to improve memory usage

internal/ingress/controller/template/buffer_pool.go

@@ -0,0 +1,51 @@
+/*
+Copyright 2017 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package template
+
+import (
+	"bytes"
+	"sync"
+)
+
+// BufferPool defines a Pool of Buffers
+type BufferPool struct {
+	sync.Pool
+}
+
+// NewBufferPool creates a new BufferPool with a custom buffer size
+func NewBufferPool(s int) *BufferPool {
+	return &BufferPool{
+		Pool: sync.Pool{
+			New: func() interface{} {
+				b := bytes.NewBuffer(make([]byte, s))
+				b.Reset()
+				return b
+			},
+		},
+	}
+}
+
+// Get returns a Buffer from the pool
+func (bp *BufferPool) Get() *bytes.Buffer {
+	return bp.Pool.Get().(*bytes.Buffer)
+}
+
+// Put resets ans returns a Buffer to the pool
+func (bp *BufferPool) Put(b *bytes.Buffer) {
+	b.Reset()
+	bp.Pool.Put(b)
+}