perf(jsonutils): fixed Adapter's interface to reduce its overhead

* performance optimization (jsonutils):

The Adapter structurally requires to call functions that return an
interface.

> It is difficult to get such functions to work without extra memory
> allocations.
>
> By slightly modifying the interface, the Adapter now converts the
> concrete types without any extra allocation.
>
> I've been able to verify by profiling a benchmark execution that
> the overhead incurred by the adapter is very small compared
> to the json Marshaling/Unmarshaling workload, even for small payloads.

* benchmark results

The benchmarks for jsonutils have been updated with a run on go1.25
(also compared with the new experimental greenteagc) and presented
on a chart.

Signed-off-by: Frederic BIDON <fredbi@yahoo.com>

Author: fredbi

jsonutils/adapters/easyjson/json/adapter.go

@@ -144,10 +144,17 @@ func (a *Adapter) NewOrderedMap(capacity int) ifaces.OrderedMap {
 	return &m
 }
 
-func (a *Adapter) redeem() {
+func (a *Adapter) Redeem() {
+	if a == nil {
+		return
+	}
 	RedeemAdapter(a)
 }
 
+func (a *Adapter) Reset() {
+	a.options = options{}
+}
+
 func newJWriter() *jwriter.Writer {
 	return &jwriter.Writer{
 		Flags: jwriter.NilMapAsEmpty | jwriter.NilSliceAsEmpty,

jsonutils/adapters/easyjson/json/pool.go

@@ -17,6 +17,7 @@ package json
 import (
 	"sync"
 
+	"github.com/go-openapi/swag/jsonutils/adapters/ifaces"
 	"github.com/mailru/easyjson/buffer"
 	"github.com/mailru/easyjson/jlexer"
 	"github.com/mailru/easyjson/jwriter"
@@ -27,9 +28,11 @@ type adaptersPool struct {
 }
 
 func (p *adaptersPool) Borrow() *Adapter {
-	ptr := p.Get()
+	return p.Get().(*Adapter)
+}
 
-	return ptr.(*Adapter)
+func (p *adaptersPool) BorrowIface() ifaces.Adapter {
+	return p.Get().(*Adapter)
 }
 
 func (p *adaptersPool) Redeem(a *Adapter) {
@@ -107,11 +110,22 @@ func BorrowAdapter() *Adapter {
 	return poolOfAdapters.Borrow()
 }
 
+func BorrowAdapterIface() ifaces.Adapter {
+	return poolOfAdapters.BorrowIface()
+}
+
 // RedeemAdapter redeems an [Adapter] to the pool, so it may be recycled.
 func RedeemAdapter(a *Adapter) {
 	poolOfAdapters.Redeem(a)
 }
 
+func RedeemAdapterIface(a ifaces.Adapter) {
+	concrete, ok := a.(*Adapter)
+	if ok {
+		poolOfAdapters.Redeem(concrete)
+	}
+}
+
 // BorrowWriter borrows a [jwriter.Writer] from the pool, recycling already allocated instances.
 func BorrowWriter() *jwriter.Writer {
 	return poolOfWriters.Borrow()

jsonutils/adapters/easyjson/json/register.go

@@ -37,15 +37,10 @@ func Register(dispatcher ifaces.Registrar, opts ...Option) {
 
 	dispatcher.RegisterFor(
 		ifaces.RegistryEntry{
-			Who:  fmt.Sprintf("%s.%s", t.PkgPath(), t.Name()),
-			What: ifaces.AllCapabilities,
-			Constructor: func() (ifaces.Adapter, func()) {
-				a := BorrowAdapter()
-				a.options = o
-
-				return a, a.redeem // since we return an interface, we have an extra allocation here. There is not much we can do about it.
-			},
-			Support: support,
+			Who:         fmt.Sprintf("%s.%s", t.PkgPath(), t.Name()),
+			What:        ifaces.AllCapabilities,
+			Constructor: BorrowAdapterIface,
+			Support:     support,
 		})
 }
 

jsonutils/adapters/ifaces/ifaces.go

@@ -23,27 +23,36 @@ type SetOrdered interface {
 type OrderedMap interface {
 	Ordered
 	SetOrdered
+
 	OrderedMarshalJSON() ([]byte, error)
 	OrderedUnmarshalJSON([]byte) error
 }
 
 // MarshalAdapter behaves likes the standard library [json.Marshal].
 type MarshalAdapter interface {
+	Poolable
+
 	Marshal(any) ([]byte, error)
 }
 
 // OrderedMarshalAdapter behaves likes the standard library [json.Marshal], preserving the order of keys in objects.
 type OrderedMarshalAdapter interface {
+	Poolable
+
 	OrderedMarshal(Ordered) ([]byte, error)
 }
 
 // UnmarshalAdapter behaves likes the standard library [json.Unmarshal].
 type UnmarshalAdapter interface {
+	Poolable
+
 	Unmarshal([]byte, any) error
 }
 
 // OrderedUnmarshalAdapter behaves likes the standard library [json.Unmarshal], preserving the order of keys in objects.
 type OrderedUnmarshalAdapter interface {
+	Poolable
+
 	OrderedUnmarshal([]byte, SetOrdered) error
 }
 
@@ -61,3 +70,12 @@ type OrderedAdapter interface {
 	OrderedUnmarshalAdapter
 	NewOrderedMap(capacity int) OrderedMap
 }
+
+type Poolable interface {
+	// Self-redeem: for [Adapter] s that are allocated from a pool.
+	// The [Adapter] must not be used after calling [Redeem].
+	Redeem()
+
+	// Reset the state of the [Adapter], if any.
+	Reset()
+}