1 files changed, 105 insertions, 0 deletions
diff --git a/vendor/github.com/pquerna/ffjson/fflib/v1/buffer_pool.go b/vendor/github.com/pquerna/ffjson/fflib/v1/buffer_pool.go
new file mode 100644
index 000000000..a021c57cf
--- /dev/null
+++ b/vendor/github.com/pquerna/ffjson/fflib/v1/buffer_pool.go
@@ -0,0 +1,105 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build go1.3
+
+package v1
+
+// Allocation pools for Buffers.
+
+import "sync"
+
+var pools [14]sync.Pool
+var pool64 *sync.Pool
+
+func init() {
+	var i uint
+	// TODO(pquerna): add science here around actual pool sizes.
+	for i = 6; i < 20; i++ {
+		n := 1 << i
+		pools[poolNum(n)].New = func() interface{} { return make([]byte, 0, n) }
+	}
+	pool64 = &pools[0]
+}
+
+// This returns the pool number that will give a buffer of
+// at least 'i' bytes.
+func poolNum(i int) int {
+	// TODO(pquerna): convert to log2 w/ bsr asm instruction:
+	// 	<https://groups.google.com/forum/#!topic/golang-nuts/uAb5J1_y7ns>
+	if i <= 64 {
+		return 0
+	} else if i <= 128 {
+		return 1
+	} else if i <= 256 {
+		return 2
+	} else if i <= 512 {
+		return 3
+	} else if i <= 1024 {
+		return 4
+	} else if i <= 2048 {
+		return 5
+	} else if i <= 4096 {
+		return 6
+	} else if i <= 8192 {
+		return 7
+	} else if i <= 16384 {
+		return 8
+	} else if i <= 32768 {
+		return 9
+	} else if i <= 65536 {
+		return 10
+	} else if i <= 131072 {
+		return 11
+	} else if i <= 262144 {
+		return 12
+	} else if i <= 524288 {
+		return 13
+	} else {
+		return -1
+	}
+}
+
+// Send a buffer to the Pool to reuse for other instances.
+// You may no longer utilize the content of the buffer, since it may be used
+// by other goroutines.
+func Pool(b []byte) {
+	if b == nil {
+		return
+	}
+	c := cap(b)
+
+	// Our smallest buffer is 64 bytes, so we discard smaller buffers.
+	if c < 64 {
+		return
+	}
+
+	// We need to put the incoming buffer into the NEXT buffer,
+	// since a buffer guarantees AT LEAST the number of bytes available
+	// that is the top of this buffer.
+	// That is the reason for dividing the cap by 2, so it gets into the NEXT bucket.
+	// We add 2 to avoid rounding down if size is exactly power of 2.
+	pn := poolNum((c + 2) >> 1)
+	if pn != -1 {
+		pools[pn].Put(b[0:0])
+	}
+	// if we didn't have a slot for this []byte, we just drop it and let the GC
+	// take care of it.
+}
+
+// makeSlice allocates a slice of size n -- it will attempt to use a pool'ed
+// instance whenever possible.
+func makeSlice(n int) []byte {
+	if n <= 64 {
+		return pool64.Get().([]byte)[0:n]
+	}
+
+	pn := poolNum(n)
+
+	if pn != -1 {
+		return pools[pn].Get().([]byte)[0:n]
+	} else {
+		return make([]byte, n)
+	}
+}