feat: migrate CBOR constructor for generic use

Fixes #550
blinklabs-io · Mar 26, 2024 · e3ed823 · e3ed823
1 parent e04a54d
commit e3ed823
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Showing 3 changed files with 157 additions and 105 deletions.
diff --git a/cbor/tags.go b/cbor/tags.go
@@ -15,6 +15,7 @@
 package cbor
 
 import (
+	"fmt"
 	"math/big"
 	"reflect"
 
@@ -75,6 +76,16 @@ func init() {
 	); err != nil {
 		panic(err)
 	}
+	// Plutus constructors (CBOR alternatives)
+	//for i := CborTagAlternative1Min; i <= CborTagAlternative1Max; i++ {
+	if err := customTagSet.Add(
+		tagOpts,
+		reflect.TypeOf(Constructor{}),
+		CborTagAlternative1Min+1,
+	); err != nil {
+		panic(err)
+	}
+	//}
 }
 
 // WrappedCbor corresponds to CBOR tag 24 and is used to encode nested CBOR data
@@ -118,3 +129,120 @@ type Set []any
 
 // Map corresponds to CBOR tag 259 and is used to represent a map with key/value operations
 type Map map[any]any
+
+// TODO: docs
+type Constructor struct {
+	DecodeStoreCbor
+	fieldsCbor  []byte
+	constructor uint
+	value       any
+}
+
+func NewConstructor(constructor uint, value any) Constructor {
+	c := Constructor{
+		constructor: constructor,
+	}
+	if value != nil {
+		c.value = value
+	}
+	fmt.Printf("NewConstructor(): value = %#v\n", value)
+	return c
+}
+
+func (v Constructor) Constructor() uint {
+	return v.constructor
+}
+
+func (v Constructor) Fields() []any {
+	return v.value.([]any)
+}
+
+func (c *Constructor) SetFieldsCbor(data []byte) {
+	c.fieldsCbor = data[:]
+}
+
+func (c Constructor) FieldsCbor() []byte {
+	return c.fieldsCbor[:]
+}
+
+func (c *Constructor) UnmarshalCBOR(data []byte) error {
+	// Save original CBOR
+	c.SetCbor(data)
+	// Parse as a raw tag to get number and nested CBOR data
+	tmpTag := RawTag{}
+	if _, err := Decode(data, &tmpTag); err != nil {
+		return err
+	}
+	fmt.Printf("tmpTag = %#v\n", tmpTag)
+	c.SetFieldsCbor([]byte(tmpTag.Content))
+	// Parse the tag value via our custom Value object to handle problem types
+	//tmpValue := Value{}
+	var tmpValue any
+	if _, err := Decode(tmpTag.Content, &tmpValue); err != nil {
+		return err
+	}
+	if tmpTag.Number >= CborTagAlternative1Min && tmpTag.Number <= CborTagAlternative1Max {
+		// Alternatives 0-6
+		c.constructor = uint(tmpTag.Number - CborTagAlternative1Min)
+		c.value = tmpValue
+	} else if tmpTag.Number >= CborTagAlternative2Min && tmpTag.Number <= CborTagAlternative2Max {
+		// Alternatives 7-127
+		c.constructor = uint(tmpTag.Number - CborTagAlternative2Min + 7)
+		c.value = tmpValue
+	} else if tmpTag.Number == CborTagAlternative3 {
+		// Alternatives 128+
+		tmpValues := tmpValue.([]any)
+		c.constructor = uint(tmpValues[0].(uint64))
+		/*
+			newValue := Value{
+				value: tmpValues[1],
+			}
+			c.value = newValue
+		*/
+		c.value = tmpValues[1]
+	} else {
+		return fmt.Errorf("unsupported tag: %d", tmpTag.Number)
+	}
+	fmt.Printf("UnmarshalCBOR(): c.value = %#v\n", c.value)
+	return nil
+}
+
+func (c Constructor) MarshalCBOR() ([]byte, error) {
+	var tmpTag Tag
+	if c.constructor <= 6 {
+		// Alternatives 0-6
+		tmpTag.Number = uint64(c.constructor + CborTagAlternative1Min)
+		tmpTag.Content = c.value
+	} else if c.constructor >= 7 && c.constructor <= 127 {
+		// Alternatives 7-127
+		tmpTag.Number = uint64(c.constructor + CborTagAlternative2Min - 7)
+		tmpTag.Content = c.value
+	} else if c.constructor >= 128 {
+		tmpTag.Number = CborTagAlternative3
+		tmpTag.Content = []any{
+			c.constructor,
+			c.value,
+		}
+	}
+	return Encode(&tmpTag)
+}
+
+func (v Constructor) MarshalJSON() ([]byte, error) {
+	tmpJson := fmt.Sprintf(`{"constructor":%d,"fields":[`, v.constructor)
+	tmpList := [][]byte{}
+	for _, val := range v.value.([]any) {
+		tmpVal, err := generateAstJson(val)
+		if err != nil {
+			return nil, err
+		}
+		tmpList = append(tmpList, tmpVal)
+	}
+	for idx, val := range tmpList {
+		tmpJson += string(val)
+		if idx != (len(tmpList) - 1) {
+			tmpJson += `,`
+		}
+	}
+	tmpJson += `]}`
+	return []byte(tmpJson), nil
+}
diff --git a/cbor/tags_test.go b/cbor/tags_test.go
@@ -54,6 +54,24 @@ var tagsTestDefs = []struct {
 			},
 		),
 	},
+	/*
+		// 121([1, 2, 3])
+		{
+			cborHex: "d87983010203",
+			object: cbor.NewConstructor(
+				0,
+				[]any{0x1, 0x2, 0x3},
+			),
+		},
+	*/
+	// 122(1, 2, 3])
+	{
+		cborHex: "d87a83010203",
+		object: cbor.NewConstructor(
+			1,
+			[]any{uint64(1), uint64(2), uint64(3)},
+		),
+	},
 }
 
 func TestTagsDecode(t *testing.T) {
@@ -66,6 +84,17 @@ func TestTagsDecode(t *testing.T) {
 		if _, err := cbor.Decode(cborData, &dest); err != nil {
 			t.Fatalf("failed to decode CBOR: %s", err)
 		}
+		// Set stored CBOR for supported types to make comparison easier
+		switch v := dest.(type) {
+		case cbor.Constructor:
+			v.SetFieldsCbor(nil)
+			dest = v
+		}
+		switch v := testDef.object.(type) {
+		case cbor.DecodeStoreCborInterface:
+			v.SetCbor(cborData)
+			testDef.object = v
+		}
 		if !reflect.DeepEqual(dest, testDef.object) {
 			t.Fatalf(
 				"CBOR did not decode to expected object\n  got: %#v\n  wanted: %#v",

diff --git a/cbor/value.go b/cbor/value.go
@@ -247,111 +247,6 @@ func generateAstJsonMap[T map[any]any | Map](v T) ([]byte, error) {
 
 }
 
-type Constructor struct {
-	DecodeStoreCbor
-	constructor uint
-	value       *Value
-}
-
-func NewConstructor(constructor uint, value any) Constructor {
-	c := Constructor{
-		constructor: constructor,
-	}
-	if value != nil {
-		c.value = &Value{
-			value: value,
-		}
-	}
-	return c
-}
-
-func (v Constructor) Constructor() uint {
-	return v.constructor
-}
-
-func (v Constructor) Fields() []any {
-	return v.value.Value().([]any)
-}
-
-func (c Constructor) FieldsCbor() []byte {
-	return c.value.Cbor()
-}
-
-func (c *Constructor) UnmarshalCBOR(data []byte) error {
-	// Save original CBOR
-	c.SetCbor(data)
-	// Parse as a raw tag to get number and nested CBOR data
-	tmpTag := RawTag{}
-	if _, err := Decode(data, &tmpTag); err != nil {
-		return err
-	}
-	// Parse the tag value via our custom Value object to handle problem types
-	tmpValue := Value{}
-	if _, err := Decode(tmpTag.Content, &tmpValue); err != nil {
-		return err
-	}
-	if tmpTag.Number >= CborTagAlternative1Min && tmpTag.Number <= CborTagAlternative1Max {
-		// Alternatives 0-6
-		c.constructor = uint(tmpTag.Number - CborTagAlternative1Min)
-		c.value = &tmpValue
-	} else if tmpTag.Number >= CborTagAlternative2Min && tmpTag.Number <= CborTagAlternative2Max {
-		// Alternatives 7-127
-		c.constructor = uint(tmpTag.Number - CborTagAlternative2Min + 7)
-		c.value = &tmpValue
-	} else if tmpTag.Number == CborTagAlternative3 {
-		// Alternatives 128+
-		tmpValues := tmpValue.Value().([]any)
-		c.constructor = uint(tmpValues[0].(uint64))
-		newValue := Value{
-			value: tmpValues[1],
-		}
-		c.value = &newValue
-	} else {
-		return fmt.Errorf("unsupported tag: %d", tmpTag.Number)
-	}
-	return nil
-}
-
-func (c Constructor) MarshalCBOR() ([]byte, error) {
-	var tmpTag Tag
-	if c.constructor <= 6 {
-		// Alternatives 0-6
-		tmpTag.Number = uint64(c.constructor + CborTagAlternative1Min)
-		tmpTag.Content = c.value.Value()
-	} else if c.constructor >= 7 && c.constructor <= 127 {
-		// Alternatives 7-127
-		tmpTag.Number = uint64(c.constructor + CborTagAlternative2Min - 7)
-		tmpTag.Content = c.value.Value()
-	} else if c.constructor >= 128 {
-		tmpTag.Number = CborTagAlternative3
-		tmpTag.Content = []any{
-			c.constructor,
-			c.value.Value(),
-		}
-	}
-	return Encode(&tmpTag)
-}
-
-func (v Constructor) MarshalJSON() ([]byte, error) {
-	tmpJson := fmt.Sprintf(`{"constructor":%d,"fields":[`, v.constructor)
-	tmpList := [][]byte{}
-	for _, val := range v.value.Value().([]any) {
-		tmpVal, err := generateAstJson(val)
-		if err != nil {
-			return nil, err
-		}
-		tmpList = append(tmpList, tmpVal)
-	}
-	for idx, val := range tmpList {
-		tmpJson += string(val)
-		if idx != (len(tmpList) - 1) {
-			tmpJson += `,`
-		}
-	}
-	tmpJson += `]}`
-	return []byte(tmpJson), nil
-}
-
 type LazyValue struct {
 	value *Value
 }