Bump unrolled/render to v1.1.0 (#15581)

v1.1.0 has improved buffer pooling

vendor/github.com/unrolled/render/sizedbufferpool.go

@@ -0,0 +1,62 @@
+package render
+
+import (
+	"bytes"
+)
+
+// Pulled from the github.com/oxtoacart/bpool package (Apache licensed).
+
+// SizedBufferPool implements a pool of bytes.Buffers in the form of a bounded
+// channel. Buffers are pre-allocated to the requested size.
+type SizedBufferPool struct {
+	c chan *bytes.Buffer
+	a int
+}
+
+// NewSizedBufferPool creates a new BufferPool bounded to the given size.
+// size defines the number of buffers to be retained in the pool and alloc sets
+// the initial capacity of new buffers to minimize calls to make().
+//
+// The value of alloc should seek to provide a buffer that is representative of
+// most data written to the the buffer (i.e. 95th percentile) without being
+// overly large (which will increase static memory consumption). You may wish to
+// track the capacity of your last N buffers (i.e. using an []int) prior to
+// returning them to the pool as input into calculating a suitable alloc value.
+func NewSizedBufferPool(size int, alloc int) (bp *SizedBufferPool) {
+	return &SizedBufferPool{
+		c: make(chan *bytes.Buffer, size),
+		a: alloc,
+	}
+}
+
+// Get gets a Buffer from the SizedBufferPool, or creates a new one if none are
+// available in the pool. Buffers have a pre-allocated capacity.
+func (bp *SizedBufferPool) Get() (b *bytes.Buffer) {
+	select {
+	case b = <-bp.c:
+		// reuse existing buffer
+	default:
+		// create new buffer
+		b = bytes.NewBuffer(make([]byte, 0, bp.a))
+	}
+	return
+}
+
+// Put returns the given Buffer to the SizedBufferPool.
+func (bp *SizedBufferPool) Put(b *bytes.Buffer) {
+	b.Reset()
+
+	// Release buffers over our maximum capacity and re-create a pre-sized
+	// buffer to replace it.
+	// Note that the cap(b.Bytes()) provides the capacity from the read off-set
+	// only, but as we've called b.Reset() the full capacity of the underlying
+	// byte slice is returned.
+	if cap(b.Bytes()) > bp.a {
+		b = bytes.NewBuffer(make([]byte, 0, bp.a))
+	}
+
+	select {
+	case bp.c <- b:
+	default: // Discard the buffer if the pool is full.
+	}
+}