Initial commit

Proof-of-concept implementation. Bugs will occur.

vendor/github.com/hanwen/go-fuse/v2/splice/pool.go

@@ -0,0 +1,107 @@
+//go:build linux
+
+// Copyright 2016 the Go-FUSE Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package splice
+
+import (
+	"sync"
+)
+
+var splicePool *pairPool
+
+type pairPool struct {
+	sync.Mutex
+	unused    []*Pair
+	usedCount int
+}
+
+func ClearSplicePool() {
+	splicePool.clear()
+}
+
+func Get() (*Pair, error) {
+	return splicePool.get()
+}
+
+func Total() int {
+	return splicePool.total()
+}
+
+func Used() int {
+	return splicePool.used()
+}
+
+// Done returns the pipe pair to pool.
+func Done(p *Pair) {
+	splicePool.done(p)
+}
+
+// Closes and discards pipe pair.
+func Drop(p *Pair) {
+	splicePool.drop(p)
+}
+
+func newSplicePairPool() *pairPool {
+	return &pairPool{}
+}
+
+func (pp *pairPool) clear() {
+	pp.Lock()
+	for _, p := range pp.unused {
+		p.Close()
+	}
+	pp.unused = pp.unused[:0]
+	pp.Unlock()
+}
+
+func (pp *pairPool) used() (n int) {
+	pp.Lock()
+	n = pp.usedCount
+	pp.Unlock()
+
+	return n
+}
+
+func (pp *pairPool) total() int {
+	pp.Lock()
+	n := pp.usedCount + len(pp.unused)
+	pp.Unlock()
+	return n
+}
+
+func (pp *pairPool) drop(p *Pair) {
+	p.Close()
+	pp.Lock()
+	pp.usedCount--
+	pp.Unlock()
+}
+
+func (pp *pairPool) get() (p *Pair, err error) {
+	pp.Lock()
+	defer pp.Unlock()
+
+	pp.usedCount++
+	l := len(pp.unused)
+	if l > 0 {
+		p := pp.unused[l-1]
+		pp.unused = pp.unused[:l-1]
+		return p, nil
+	}
+
+	return newSplicePair()
+}
+
+func (pp *pairPool) done(p *Pair) {
+	p.discard()
+	pp.Lock()
+	pp.usedCount--
+	pp.unused = append(pp.unused, p)
+	pp.Unlock()
+}
+
+func init() {
+	splicePool = newSplicePairPool()
+}