Support time.Time (#100)

* Support time.Time as a uint64.

* Move tests to testcases directory.

* Add reference for time type.

* Use helpers for marshal and unmarshal.

* DRY

encode.go

@@ -4,6 +4,7 @@ import (
 	"encoding/binary"
 	"fmt"
 	"math/bits"
+	"time"
 )
 
 // MarshalSSZ marshals an object
@@ -66,6 +67,11 @@ func UnmarshalBool(src []byte) bool {
 	return false
 }
 
+// UnmarshalTime unmarshals a time.Time from the src input
+func UnmarshalTime(src []byte) time.Time {
+	return time.Unix(int64(UnmarshallUint64(src)), 0).UTC()
+}
+
 // ---- Marshal functions ----
 
 // MarshalUint64 marshals a little endian uint64 to dst
@@ -108,6 +114,11 @@ func MarshalBool(dst []byte, b bool) []byte {
 	return dst
 }
 
+// MarshalTime marshals a time to dst
+func MarshalTime(dst []byte, t time.Time) []byte {
+	return MarshalUint64(dst, uint64(t.Unix()))
+}
+
 // ---- offset functions ----
 
 // WriteOffset writes an offset to dst

sszgen/.gitignore

@@ -0,0 +1 @@
+sszgen

sszgen/generator/generator.go

@@ -209,6 +209,8 @@ const (
 	TypeContainer
 	// TypeReference is a SSZ reference
 	TypeReference
+	// TypeTime is a timestamp
+	TypeTime
 )
 
 func (t Type) String() string {
@@ -231,6 +233,8 @@ func (t Type) String() string {
 		return "container"
 	case TypeReference:
 		return "reference"
+	case TypeTime:
+		return "time.Time"
 	default:
 		panic("not found")
 	}
@@ -1056,7 +1060,9 @@ func (e *env) parseASTFieldType(name, tags string, expr ast.Expr) (*Value, error
 		name := obj.X.(*ast.Ident).Name
 		sel := obj.Sel.Name
 
-		if sel == "Bitlist" {
+		if name == "time" && sel == "Time" {
+			return &Value{t: TypeTime, s: 8}, nil
+		} else if sel == "Bitlist" {
 			// go-bitfield/Bitlist
 			maxSize, ok := getTagsInt(tags, "ssz-max")
 			if !ok {
@@ -1174,6 +1180,8 @@ func (v *Value) isFixed() bool {
 			return true
 		}
 		return false
+	case TypeTime:
+		return true
 	default:
 		// TypeUndefined should be the only type to fallthrough to this case
 		// TypeUndefined always means there is a fatal error in the parsing logic

sszgen/generator/hash.go

@@ -209,6 +209,9 @@ func (v *Value) hashTreeRoot(name string, appendBytes bool) string {
 			"htrCall": htrCall,
 		})
 
+	case TypeTime:
+		return fmt.Sprintf("hh.PutUint64(uint64(%s.Unix()))", name)
+
 	default:
 		panic(fmt.Errorf("hash not implemented for type %s", v.t.String()))
 	}

sszgen/generator/marshal.go

@@ -77,6 +77,9 @@ func (v *Value) marshal() string {
 	case TypeList:
 		return v.marshalList()
 
+	case TypeTime:
+		return fmt.Sprintf("dst = ssz.MarshalTime(dst, ::.%s)", v.name)
+
 	default:
 		panic(fmt.Errorf("marshal not implemented for type %s", v.t.String()))
 	}

sszgen/generator/unmarshal.go

@@ -104,6 +104,9 @@ func (v *Value) unmarshal(dst string) string {
 	case TypeBool:
 		return fmt.Sprintf("::.%s = ssz.UnmarshalBool(%s)", v.name, dst)
 
+	case TypeTime:
+		return fmt.Sprintf("::.%s = ssz.UnmarshalTime(%s)", v.name, dst)
+
 	default:
 		panic(fmt.Errorf("unmarshal not implemented for type %d", v.t))
 	}
@@ -352,6 +355,6 @@ func (v *Value) createSlice(useNumVariable bool) string {
 		return fmt.Sprintf("::.%s = make([][]byte, %s)", v.name, size)
 
 	default:
-		panic(fmt.Sprintf("create not implemented for type %s", v.e.t.String()))
+		panic(fmt.Sprintf("create not implemented for %s type %s", v.name, v.e.t.String()))
 	}
 }

sszgen/testcases/time.go

@@ -0,0 +1,13 @@
+package testcases
+
+import "time"
+
+type TimeType struct {
+	Timestamp time.Time
+	Int       uint64
+}
+
+type TimeRawType struct {
+	Timestamp uint64
+	Int       uint64
+}