Use freelists instead of sync.Pool for value object recycling

fieldpath/fromvalue.go

@@ -25,18 +25,20 @@ func SetFromValue(v value.Value) *Set {
 	s := NewSet()
 
 	w := objectWalker{
-		path:  Path{},
-		value: v,
-		do:    func(p Path) { s.Insert(p) },
+		path:      Path{},
+		value:     v,
+		allocator: value.NewFreelistAllocator(),
+		do:        func(p Path) { s.Insert(p) },
 	}
 
 	w.walk()
 	return s
 }
 
 type objectWalker struct {
-	path  Path
-	value value.Value
+	path      Path
+	value     value.Value
+	allocator value.Allocator
 
 	do func(Path)
 }
@@ -55,14 +57,14 @@ func (w *objectWalker) walk() {
 	case w.value.IsList():
 		// If the list were atomic, we'd break here, but we don't have
 		// a schema, so we can't tell.
-		l := w.value.AsList()
-		defer l.Recycle()
-		iter := l.Range()
-		defer iter.Recycle()
+		l := w.value.AsListUsing(w.allocator)
+		defer w.allocator.Free(l)
+		iter := l.RangeUsing(w.allocator)
+		defer w.allocator.Free(iter)
 		for iter.Next() {
 			i, value := iter.Item()
 			w2 := *w
-			w2.path = append(w.path, GuessBestListPathElement(i, value))
+			w2.path = append(w.path, w.GuessBestListPathElement(i, value))
 			w2.value = value
 			w2.walk()
 		}
@@ -71,9 +73,9 @@ func (w *objectWalker) walk() {
 		// If the map/struct were atomic, we'd break here, but we don't
 		// have a schema, so we can't tell.
 
-		m := w.value.AsMap()
-		defer m.Recycle()
-		m.Iterate(func(k string, val value.Value) bool {
+		m := w.value.AsMapUsing(w.allocator)
+		defer w.allocator.Free(m)
+		m.IterateUsing(w.allocator, func(k string, val value.Value) bool {
 			w2 := *w
 			w2.path = append(w.path, PathElement{FieldName: &k})
 			w2.value = val
@@ -102,16 +104,16 @@ var AssociativeListCandidateFieldNames = []string{
 // referencing by index is acceptable. Currently this is done by checking
 // whether item has any of the fields listed in
 // AssociativeListCandidateFieldNames which have scalar values.
-func GuessBestListPathElement(index int, item value.Value) PathElement {
+func (w *objectWalker) GuessBestListPathElement(index int, item value.Value) PathElement {
 	if !item.IsMap() {
 		// Non map items could be parts of sets or regular "atomic"
 		// lists. We won't try to guess whether something should be a
 		// set or not.
 		return PathElement{Index: &index}
 	}
 
-	m := item.AsMap()
-	defer m.Recycle()
+	m := item.AsMapUsing(w.allocator)
+	defer w.allocator.Free(m)
 	var keys value.FieldList
 	for _, name := range AssociativeListCandidateFieldNames {
 		f, ok := m.Get(name)

typed/helpers.go

@@ -154,19 +154,19 @@ func handleAtom(a schema.Atom, tr schema.TypeRef, ah atomHandler) ValidationErro
 }
 
 // Returns the list, or an error. Reminder: nil is a valid list and might be returned.
-func listValue(val value.Value) (value.List, error) {
+func listValue(a value.Allocator, val value.Value) (value.List, error) {
 	if val.IsNull() {
 		// Null is a valid list.
 		return nil, nil
 	}
 	if !val.IsList() {
 		return nil, fmt.Errorf("expected list, got %v", val)
 	}
-	return val.AsList(), nil
+	return val.AsListUsing(a), nil
 }
 
 // Returns the map, or an error. Reminder: nil is a valid map and might be returned.
-func mapValue(val value.Value) (value.Map, error) {
+func mapValue(a value.Allocator, val value.Value) (value.Map, error) {
 	if val == nil {
 		return nil, fmt.Errorf("expected map, got nil")
 	}
@@ -177,10 +177,10 @@ func mapValue(val value.Value) (value.Map, error) {
 	if !val.IsMap() {
 		return nil, fmt.Errorf("expected map, got %v", val)
 	}
-	return val.AsMap(), nil
+	return val.AsMapUsing(a), nil
 }
 
-func keyedAssociativeListItemToPathElement(list *schema.List, index int, child value.Value) (fieldpath.PathElement, error) {
+func keyedAssociativeListItemToPathElement(a value.Allocator, list *schema.List, index int, child value.Value) (fieldpath.PathElement, error) {
 	pe := fieldpath.PathElement{}
 	if child.IsNull() {
 		// For now, the keys are required which means that null entries
@@ -191,8 +191,8 @@ func keyedAssociativeListItemToPathElement(list *schema.List, index int, child v
 		return pe, errors.New("associative list with keys may not have non-map elements")
 	}
 	keyMap := value.FieldList{}
-	m := child.AsMap()
-	defer m.Recycle()
+	m := child.AsMapUsing(a)
+	defer a.Free(m)
 	for _, fieldName := range list.Keys {
 		if val, ok := m.Get(fieldName); ok {
 			keyMap = append(keyMap, value.Field{Name: fieldName, Value: val})
@@ -225,10 +225,10 @@ func setItemToPathElement(list *schema.List, index int, child value.Value) (fiel
 	}
 }
 
-func listItemToPathElement(list *schema.List, index int, child value.Value) (fieldpath.PathElement, error) {
+func listItemToPathElement(a value.Allocator, list *schema.List, index int, child value.Value) (fieldpath.PathElement, error) {
 	if list.ElementRelationship == schema.Associative {
 		if len(list.Keys) > 0 {
-			return keyedAssociativeListItemToPathElement(list, index, child)
+			return keyedAssociativeListItemToPathElement(a, list, index, child)
 		}
 
 		// If there's no keys, then we must be a set of primitives.

typed/merge.go

@@ -48,6 +48,8 @@ type mergingWalker struct {
 
 	// Allocate only as many walkers as needed for the depth by storing them here.
 	spareWalkers *[]*mergingWalker
+
+	allocator value.Allocator
 }
 
 // merge rules examine w.lhs and w.rhs (up to one of which may be nil) and
@@ -152,7 +154,7 @@ func (w *mergingWalker) derefMap(prefix string, v value.Value) (value.Map, Valid
 	if v == nil {
 		return nil, nil
 	}
-	m, err := mapValue(v)
+	m, err := mapValue(w.allocator, v)
 	if err != nil {
 		return nil, errorf("%v: %v", prefix, err)
 	}
@@ -181,7 +183,7 @@ func (w *mergingWalker) visitListItems(t *schema.List, lhs, rhs value.List) (err
 	if rhs != nil {
 		for i := 0; i < rhs.Length(); i++ {
 			child := rhs.At(i)
-			pe, err := listItemToPathElement(t, i, child)
+			pe, err := listItemToPathElement(w.allocator, t, i, child)
 			if err != nil {
 				errs = append(errs, errorf("rhs: element %v: %v", i, err.Error())...)
 				// If we can't construct the path element, we can't
@@ -202,7 +204,7 @@ func (w *mergingWalker) visitListItems(t *schema.List, lhs, rhs value.List) (err
 	if lhs != nil {
 		for i := 0; i < lhs.Length(); i++ {
 			child := lhs.At(i)
-			pe, err := listItemToPathElement(t, i, child)
+			pe, err := listItemToPathElement(w.allocator, t, i, child)
 			if err != nil {
 				errs = append(errs, errorf("lhs: element %v: %v", i, err.Error())...)
 				// If we can't construct the path element, we can't
@@ -254,7 +256,7 @@ func (w *mergingWalker) derefList(prefix string, v value.Value) (value.List, Val
 	if v == nil {
 		return nil, nil
 	}
-	l, err := listValue(v)
+	l, err := listValue(w.allocator, v)
 	if err != nil {
 		return nil, errorf("%v: %v", prefix, err)
 	}
@@ -264,11 +266,11 @@ func (w *mergingWalker) derefList(prefix string, v value.Value) (value.List, Val
 func (w *mergingWalker) doList(t *schema.List) (errs ValidationErrors) {
 	lhs, _ := w.derefList("lhs: ", w.lhs)
 	if lhs != nil {
-		defer lhs.Recycle()
+		defer w.allocator.Free(lhs)
 	}
 	rhs, _ := w.derefList("rhs: ", w.rhs)
 	if rhs != nil {
-		defer rhs.Recycle()
+		defer w.allocator.Free(rhs)
 	}
 
 	// If both lhs and rhs are empty/null, treat it as a
@@ -310,7 +312,7 @@ func (w *mergingWalker) visitMapItem(t *schema.Map, out map[string]interface{},
 func (w *mergingWalker) visitMapItems(t *schema.Map, lhs, rhs value.Map) (errs ValidationErrors) {
 	out := map[string]interface{}{}
 
-	value.MapZip(lhs, rhs, value.Unordered, func(key string, lhsValue, rhsValue value.Value) bool {
+	value.MapZipUsing(w.allocator, lhs, rhs, value.Unordered, func(key string, lhsValue, rhsValue value.Value) bool {
 		errs = append(errs, w.visitMapItem(t, out, key, lhsValue, rhsValue)...)
 		return true
 	})
@@ -325,11 +327,11 @@ func (w *mergingWalker) visitMapItems(t *schema.Map, lhs, rhs value.Map) (errs V
 func (w *mergingWalker) doMap(t *schema.Map) (errs ValidationErrors) {
 	lhs, _ := w.derefMap("lhs: ", w.lhs)
 	if lhs != nil {
-		defer lhs.Recycle()
+		defer w.allocator.Free(lhs)
 	}
 	rhs, _ := w.derefMap("rhs: ", w.rhs)
 	if rhs != nil {
-		defer rhs.Recycle()
+		defer w.allocator.Free(rhs)
 	}
 	// If both lhs and rhs are empty/null, treat it as a
 	// leaf: this helps preserve the empty/null

typed/remove.go

@@ -20,17 +20,19 @@ import (
 )
 
 type removingWalker struct {
-	value    value.Value
-	out      interface{}
-	schema   *schema.Schema
-	toRemove *fieldpath.Set
+	value     value.Value
+	out       interface{}
+	schema    *schema.Schema
+	toRemove  *fieldpath.Set
+	allocator value.Allocator
 }
 
 func removeItemsWithSchema(val value.Value, toRemove *fieldpath.Set, schema *schema.Schema, typeRef schema.TypeRef) value.Value {
 	w := &removingWalker{
-		value:    val,
-		schema:   schema,
-		toRemove: toRemove,
+		value:     val,
+		schema:    schema,
+		toRemove:  toRemove,
+		allocator: value.NewFreelistAllocator(),
 	}
 	resolveSchema(schema, typeRef, val, w)
 	return value.NewValueInterface(w.out)
@@ -42,20 +44,20 @@ func (w *removingWalker) doScalar(t *schema.Scalar) ValidationErrors {
 }
 
 func (w *removingWalker) doList(t *schema.List) (errs ValidationErrors) {
-	l := w.value.AsList()
-	defer l.Recycle()
+	l := w.value.AsListUsing(w.allocator)
+	defer w.allocator.Free(l)
 	// If list is null, empty, or atomic just return
 	if l == nil || l.Length() == 0 || t.ElementRelationship == schema.Atomic {
 		return nil
 	}
 
 	var newItems []interface{}
-	iter := l.Range()
-	defer iter.Recycle()
+	iter := l.RangeUsing(w.allocator)
+	defer w.allocator.Free(iter)
 	for iter.Next() {
 		i, item := iter.Item()
 		// Ignore error because we have already validated this list
-		pe, _ := listItemToPathElement(t, i, item)
+		pe, _ := listItemToPathElement(w.allocator, t, i, item)
 		path, _ := fieldpath.MakePath(pe)
 		if w.toRemove.Has(path) {
 			continue
@@ -72,9 +74,9 @@ func (w *removingWalker) doList(t *schema.List) (errs ValidationErrors) {
 }
 
 func (w *removingWalker) doMap(t *schema.Map) ValidationErrors {
-	m := w.value.AsMap()
+	m := w.value.AsMapUsing(w.allocator)
 	if m != nil {
-		defer m.Recycle()
+		defer w.allocator.Free(m)
 	}
 	// If map is null, empty, or atomic just return
 	if m == nil || m.Empty() || t.ElementRelationship == schema.Atomic {

typed/tofieldset.go

@@ -34,6 +34,7 @@ func (tv TypedValue) toFieldSetWalker() *toFieldSetWalker {
 	v.schema = tv.schema
 	v.typeRef = tv.typeRef
 	v.set = &fieldpath.Set{}
+	v.allocator = value.NewFreelistAllocator()
 	return v
 }
 
@@ -55,6 +56,7 @@ type toFieldSetWalker struct {
 
 	// Allocate only as many walkers as needed for the depth by storing them here.
 	spareWalkers *[]*toFieldSetWalker
+	allocator    value.Allocator
 }
 
 func (v *toFieldSetWalker) prepareDescent(pe fieldpath.PathElement, tr schema.TypeRef) *toFieldSetWalker {
@@ -94,7 +96,7 @@ func (v *toFieldSetWalker) doScalar(t *schema.Scalar) ValidationErrors {
 func (v *toFieldSetWalker) visitListItems(t *schema.List, list value.List) (errs ValidationErrors) {
 	for i := 0; i < list.Length(); i++ {
 		child := list.At(i)
-		pe, _ := listItemToPathElement(t, i, child)
+		pe, _ := listItemToPathElement(v.allocator, t, i, child)
 		v2 := v.prepareDescent(pe, t.ElementType)
 		v2.value = child
 		errs = append(errs, v2.toFieldSet()...)
@@ -106,8 +108,10 @@ func (v *toFieldSetWalker) visitListItems(t *schema.List, list value.List) (errs
 }
 
 func (v *toFieldSetWalker) doList(t *schema.List) (errs ValidationErrors) {
-	list, _ := listValue(v.value)
-
+	list, _ := listValue(v.allocator, v.value)
+	if list != nil {
+		defer v.allocator.Free(list)
+	}
 	if t.ElementRelationship == schema.Atomic {
 		v.set.Insert(v.path)
 		return nil
@@ -143,9 +147,9 @@ func (v *toFieldSetWalker) visitMapItems(t *schema.Map, m value.Map) (errs Valid
 }
 
 func (v *toFieldSetWalker) doMap(t *schema.Map) (errs ValidationErrors) {
-	m, _ := mapValue(v.value)
+	m, _ := mapValue(v.allocator, v.value)
 	if m != nil {
-		defer m.Recycle()
+		defer v.allocator.Free(m)
 	}
 	if t.ElementRelationship == schema.Atomic {
 		v.set.Insert(v.path)

typed/typed.go

@@ -238,6 +238,9 @@ func merge(lhs, rhs *TypedValue, rule, postRule mergeRule) (*TypedValue, error)
 	mw.typeRef = lhs.typeRef
 	mw.rule = rule
 	mw.postItemHook = postRule
+	if mw.allocator == nil {
+		mw.allocator = value.NewFreelistAllocator()
+	}
 
 	errs := mw.merge(nil)
 	if len(errs) > 0 {