bug fixes (TCP + uint256) and started core part (#14)

* Fixed TCP read + Uint256 reversed array + started on some core pieces

* Disabled some debug output + muted test

* 0.5.0

pkg/util/uint256.go

@@ -0,0 +1,82 @@
+package util
+
+import (
+	"encoding/hex"
+	"fmt"
+)
+
+const uint256Size = 32
+
+// Uint256 is a 32 byte long unsigned integer.
+type Uint256 [uint256Size]uint8
+
+// Uint256DecodeFromString returns an Uint256 from a (hex) string.
+func Uint256DecodeFromString(s string) (Uint256, error) {
+	var val Uint256
+
+	if len(s) != uint256Size*2 {
+		return val, fmt.Errorf("expected string size of %d got %d", uint256Size*2, len(s))
+	}
+
+	b, err := hex.DecodeString(s)
+	if err != nil {
+		return val, err
+	}
+
+	b = ReverseByteSlice(b)
+
+	return Uint256DecodeFromBytes(b)
+}
+
+// Uint256DecodeFromBytes return an Uint256 from a byte slice.
+func Uint256DecodeFromBytes(b []byte) (Uint256, error) {
+	var val Uint256
+
+	if len(b) != uint256Size {
+		return val, fmt.Errorf("expected []byte of size %d got %d", uint256Size, len(b))
+	}
+
+	for i := 0; i < uint256Size; i++ {
+		val[i] = b[i]
+	}
+
+	return val, nil
+}
+
+func ReverseByteSlice(b []byte) []byte {
+	dest := make([]byte, len(b))
+
+	for i, j := 0, len(b)-1; i < j; i, j = i+1, j-1 {
+		dest[i], dest[j] = b[j], b[i]
+	}
+
+	return dest
+}
+
+// ToSlice returns a byte slice of u.
+func (u Uint256) ToSlice() []byte {
+	b := make([]byte, uint256Size)
+	for i := 0; i < uint256Size; i++ {
+		b[i] = byte(u[i])
+	}
+	return b
+}
+
+// ToSliceReverse returns a reversed byte slice of u.
+func (u Uint256) ToSliceReverse() []byte {
+	b := make([]byte, uint256Size)
+	for i, j := 0, uint256Size-1; i < j; i, j = i+1, j-1 {
+		b[i], b[j] = byte(u[j]), byte(u[i])
+	}
+	return b
+}
+
+// Equals returns true if both Uint256 values are the same.
+func (u Uint256) Equals(other Uint256) bool {
+	return u.String() == other.String()
+}
+
+// String implements the stringer interface.
+func (u Uint256) String() string {
+	return hex.EncodeToString(u.ToSliceReverse())
+}