add dynamic-ssz prototype from attestantio/go-eth2-client#123

const.go

@@ -0,0 +1,11 @@
+package ssz
+
+import (
+	"reflect"
+
+	fastssz "github.com/ferranbt/fastssz"
+)
+
+var byteType = reflect.TypeOf(byte(0))
+var sszMarshallerType = reflect.TypeOf((*fastssz.Marshaler)(nil)).Elem()
+var sszUnmarshallerType = reflect.TypeOf((*fastssz.Unmarshaler)(nil)).Elem()

debug.go

@@ -0,0 +1,7 @@
+package ssz
+
+import "strings"
+
+func indent(c int) string {
+	return strings.Repeat(" ", c)
+}

dynssz.go

@@ -0,0 +1,85 @@
+package ssz
+
+import (
+	"fmt"
+	"reflect"
+)
+
+type DynSsz struct {
+	typesWithSpecVals map[reflect.Type]uint8
+	SpecValues        map[string]any
+	NoFastSsz         bool
+}
+
+const (
+	unknownSpecValued uint8 = iota
+	noSpecValues
+	hasSpecValues
+)
+
+func NewDynSsz(specs map[string]any) *DynSsz {
+	if specs == nil {
+		specs = map[string]any{}
+	}
+	return &DynSsz{
+		typesWithSpecVals: map[reflect.Type]uint8{},
+		SpecValues:        specs,
+	}
+}
+
+func (d *DynSsz) MarshalSSZ(source any) ([]byte, error) {
+	sourceType := reflect.TypeOf(source)
+	sourceValue := reflect.ValueOf(source)
+
+	size, err := d.getSszValueSize(sourceType, sourceValue)
+	if err != nil {
+		return nil, err
+	}
+
+	buf := make([]byte, size)
+	newBuf, err := d.marshalType(sourceType, sourceValue, buf[:0], []sszSizeHint{}, 0)
+	if err != nil {
+		return nil, err
+	}
+
+	if len(newBuf) != size {
+		return nil, fmt.Errorf("ssz length does not match expected length (expected: %v, got: %v)", size, len(newBuf))
+	}
+
+	return newBuf, nil
+}
+
+func (d *DynSsz) MarshalSSZTo(source any, buf []byte) ([]byte, error) {
+	sourceType := reflect.TypeOf(source)
+	sourceValue := reflect.ValueOf(source)
+
+	newBuf, err := d.marshalType(sourceType, sourceValue, buf, []sszSizeHint{}, 0)
+	if err != nil {
+		return nil, err
+	}
+
+	return newBuf, nil
+}
+
+func (d *DynSsz) SizeSSZ(source any) (int, error) {
+	sourceType := reflect.TypeOf(source)
+	sourceValue := reflect.ValueOf(source)
+
+	return d.getSszValueSize(sourceType, sourceValue)
+}
+
+func (d *DynSsz) UnmarshalSSZ(target any, ssz []byte) error {
+	targetType := reflect.TypeOf(target)
+	targetValue := reflect.ValueOf(target)
+
+	consumedBytes, err := d.unmarshalType(targetType, targetValue, ssz, []sszSizeHint{}, 0)
+	if err != nil {
+		return err
+	}
+
+	if consumedBytes != len(ssz) {
+		return fmt.Errorf("did not consume full ssz range (consumed: %v, ssz size: %v)", consumedBytes, len(ssz))
+	}
+
+	return nil
+}

go.mod

@@ -1,3 +1,11 @@
 module github.com/pk910/dynamic-ssz
 
 go 1.21.1
+
+require (
+	github.com/ferranbt/fastssz v0.1.3 // indirect
+	github.com/klauspost/cpuid/v2 v2.0.9 // indirect
+	github.com/minio/sha256-simd v1.0.0 // indirect
+	github.com/mitchellh/mapstructure v1.3.2 // indirect
+	gopkg.in/yaml.v2 v2.3.0 // indirect
+)

go.sum

@@ -0,0 +1,12 @@
+github.com/ferranbt/fastssz v0.1.3 h1:ZI+z3JH05h4kgmFXdHuR1aWYsgrg7o+Fw7/NCzM16Mo=
+github.com/ferranbt/fastssz v0.1.3/go.mod h1:0Y9TEd/9XuFlh7mskMPfXiI2Dkw4Ddg9EyXt1W7MRvE=
+github.com/klauspost/cpuid/v2 v2.0.4/go.mod h1:FInQzS24/EEf25PyTYn52gqo7WaD8xa0213Md/qVLRg=
+github.com/klauspost/cpuid/v2 v2.0.9 h1:lgaqFMSdTdQYdZ04uHyN2d/eKdOMyi2YLSvlQIBFYa4=
+github.com/klauspost/cpuid/v2 v2.0.9/go.mod h1:FInQzS24/EEf25PyTYn52gqo7WaD8xa0213Md/qVLRg=
+github.com/minio/sha256-simd v1.0.0 h1:v1ta+49hkWZyvaKwrQB8elexRqm6Y0aMLjCNsrYxo6g=
+github.com/minio/sha256-simd v1.0.0/go.mod h1:OuYzVNI5vcoYIAmbIvHPl3N3jUzVedXbKy5RFepssQM=
+github.com/mitchellh/mapstructure v1.3.2 h1:mRS76wmkOn3KkKAyXDu42V+6ebnXWIztFSYGN7GeoRg=
+github.com/mitchellh/mapstructure v1.3.2/go.mod h1:bFUtVrKA4DC2yAKiSyO/QUcy7e+RRV2QTWOzhPopBRo=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v2 v2.3.0 h1:clyUAQHOM3G0M3f5vQj7LuJrETvjVot3Z5el9nffUtU=
+gopkg.in/yaml.v2 v2.3.0/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=