Make GnoAttribute an int derived enum

This change reduces on the key comparison
time (from hashing).

gnovm/pkg/gnolang/nodes.go

@@ -145,26 +145,58 @@ func (loc Location) IsZero() bool {
 // even after preprocessing.  Temporary attributes (e.g. those
 // for preprocessing) are stored in .data.
 
-type GnoAttribute string
+type GnoAttribute int
 
 const (
-	ATTR_PREPROCESSED    GnoAttribute = "ATTR_PREPROCESSED"
-	ATTR_PREDEFINED      GnoAttribute = "ATTR_PREDEFINED"
-	ATTR_TYPE_VALUE      GnoAttribute = "ATTR_TYPE_VALUE"
-	ATTR_TYPEOF_VALUE    GnoAttribute = "ATTR_TYPEOF_VALUE"
-	ATTR_IOTA            GnoAttribute = "ATTR_IOTA"
-	ATTR_LOOP_DEFINES    GnoAttribute = "ATTR_LOOP_DEFINES" // []Name defined within loops.
-	ATTR_LOOP_USES       GnoAttribute = "ATTR_LOOP_USES"    // []Name loop defines actually used.
-	ATTR_SHIFT_RHS       GnoAttribute = "ATTR_SHIFT_RHS"
-	ATTR_LAST_BLOCK_STMT GnoAttribute = "ATTR_LAST_BLOCK_STMT"
-	ATTR_GLOBAL          GnoAttribute = "ATTR_GLOBAL"
+	ATTR_PREPROCESSED GnoAttribute = iota
+	ATTR_PREDEFINED
+	ATTR_TYPE_VALUE
+	ATTR_TYPEOF_VALUE
+	ATTR_IOTA
+	ATTR_LOOP_DEFINES
+	ATTR_LOOP_USES
+	ATTR_SHIFT_RHS
+	ATTR_LAST_BLOCK_STMT
+	ATTR_GLOBAL
 )
 
+func (ga GnoAttribute) String() string {
+	switch ga {
+	case ATTR_PREPROCESSED:
+		return "ATTR_PREPROCESSED"
+	case ATTR_PREDEFINED:
+		return "ATTR_PREDEFINED"
+	case ATTR_TYPE_VALUE:
+		return "ATTR_TYPE_VALUE"
+	case ATTR_TYPEOF_VALUE:
+		return "ATTR_TYPEOF_VALUE"
+	case ATTR_IOTA:
+		return "ATTR_IOTA"
+	case ATTR_LOOP_DEFINES:
+		return "ATTR_LOOP_DEFINES" // []Name defined within loops.
+	case ATTR_LOOP_USES:
+		return "ATTR_LOOP_USES" // []Name loop defines actually used.
+	case ATTR_SHIFT_RHS:
+		return "ATTR_SHIFT_RHS"
+	case ATTR_LAST_BLOCK_STMT:
+		return "ATTR_LAST_BLOCK_STMT"
+	case ATTR_GLOBAL:
+		return "ATTR_GLOBAL"
+	default:
+		panic(fmt.Sprintf("Unknown attribute: %d", ga))
+	}
+}
+
 type Attributes struct {
 	Line   int
 	Column int
 	Label  Name
-	data   []*attrKV // not persisted
+
+	// TODO: if ever the number of attributes ATTR_* grows
+	// to say more than 100 (rough guess), you can then
+	// consider using a map for it instead of a slice
+	// Please see https://github.com/gnolang/gno/issues/3436
+	data []*attrKV // not persisted
 }
 
 func (attr *Attributes) GetLine() int {
@@ -218,10 +250,6 @@ type attrKV struct {
 }
 
 func (attr *Attributes) SetAttribute(key GnoAttribute, value interface{}) {
-	if attr.data == nil {
-		attr.data = make([]*attrKV, 0, 4)
-	}
-
 	for _, kv := range attr.data {
 		if kv.key == key {
 			kv.value = value
@@ -233,9 +261,6 @@ func (attr *Attributes) SetAttribute(key GnoAttribute, value interface{}) {
 }
 
 func (attr *Attributes) DelAttribute(key GnoAttribute) {
-	if debug && attr.data == nil {
-		panic("should not happen, attribute is expected to be non-empty.")
-	}
 	_, index, _ := attr.getAttribute(key)
 	if index < 0 {
 		return

gnovm/pkg/gnolang/nodes_test.go

@@ -1,7 +1,6 @@
 package gnolang_test
 
 import (
-	"fmt"
 	"math"
 	"testing"
 
@@ -46,19 +45,20 @@ func TestStaticBlock_Define2_MaxNames(t *testing.T) {
 
 func TestAttributesSetGetDel(t *testing.T) {
 	attrs := new(gnolang.Attributes)
-	if got, want := attrs.GetAttribute("a"), (any)(nil); got != want {
+	key := gnolang.ATTR_IOTA
+	if got, want := attrs.GetAttribute(key), (any)(nil); got != want {
 		t.Errorf(".Get returned an unexpected value=%v, want=%v", got, want)
 	}
-	attrs.SetAttribute("a", 10)
-	if got, want := attrs.GetAttribute("a"), 10; got != want {
+	attrs.SetAttribute(key, 10)
+	if got, want := attrs.GetAttribute(key), 10; got != want {
 		t.Errorf(".Get returned an unexpected value=%v, want=%v", got, want)
 	}
-	attrs.SetAttribute("a", 20)
-	if got, want := attrs.GetAttribute("a"), 20; got != want {
+	attrs.SetAttribute(key, 20)
+	if got, want := attrs.GetAttribute(key), 20; got != want {
 		t.Errorf(".Get returned an unexpected value=%v, want=%v", got, want)
 	}
-	attrs.DelAttribute("a")
-	if got, want := attrs.GetAttribute("a"), (any)(nil); got != want {
+	attrs.DelAttribute(key)
+	if got, want := attrs.GetAttribute(key), (any)(nil); got != want {
 		t.Errorf(".Get returned an unexpected value=%v, want=%v", got, want)
 	}
 }
@@ -69,20 +69,22 @@ func BenchmarkAttributesSetGetDel(b *testing.B) {
 	n := 100
 	keys := make([]gnolang.GnoAttribute, 0, n)
 	for i := 0; i < n; i++ {
-		keys = append(keys, gnolang.GnoAttribute(fmt.Sprintf("%d", i)))
+		keys = append(keys, gnolang.GnoAttribute(i))
 	}
 
+	attrCommon := gnolang.ATTR_TYPEOF_VALUE
+
 	b.ReportAllocs()
 	b.ResetTimer()
 
 	for i := 0; i < b.N; i++ {
 		attrs := new(gnolang.Attributes)
 		for j := 0; j < 100; j++ {
-			sink = attrs.GetAttribute("a")
+			sink = attrs.GetAttribute(attrCommon)
 		}
 		for j := 0; j < 100; j++ {
-			attrs.SetAttribute("a", j)
-			sink = attrs.GetAttribute("a")
+			attrs.SetAttribute(attrCommon, j)
+			sink = attrs.GetAttribute(attrCommon)
 		}
 
 		for j, key := range keys {