Initial QSfera import

Server/vendor/github.com/open-policy-agent/opa/v1/ast/syncpools.go

@@ -0,0 +1,38 @@
+package ast
+
+import (
+	"bytes"
+	"sync"
+
+	"github.com/open-policy-agent/opa/v1/util"
+)
+
+var (
+	TermPtrPool     = util.NewSyncPool[Term]()
+	BytesReaderPool = util.NewSyncPool[bytes.Reader]()
+	IndexResultPool = util.NewSyncPool[IndexResult]()
+
+	// Needs custom pool because of custom Put logic.
+	varVisitorPool = &vvPool{
+		pool: sync.Pool{
+			New: func() any {
+				return NewVarVisitor()
+			},
+		},
+	}
+)
+
+type vvPool struct {
+	pool sync.Pool
+}
+
+func (p *vvPool) Get() *VarVisitor {
+	return p.pool.Get().(*VarVisitor)
+}
+
+func (p *vvPool) Put(vv *VarVisitor) {
+	if vv != nil {
+		vv.Clear()
+		p.pool.Put(vv)
+	}
+}