genesis block binary creation (#462)

core/genesis_block_test.json

@@ -0,0 +1,8 @@
+{
+    "b7a2c103728b7305b5ae6e961c94ee99c9fe8e2b": {
+        "wei": "50000000000000000000000"
+    },
+    "b498bb0f520005b6216a4425b75aa9adc52d622b": {
+        "wei": "4000000000000000000000"
+    }
+}

core/genesis_util.go

@@ -0,0 +1,71 @@
+package core
+
+import (
+	"encoding/json"
+	"fmt"
+	"io/ioutil"
+	"math/big"
+	"sort"
+
+	"github.com/ethereum/go-ethereum/rlp"
+)
+
+// GenesisItem represents one genesis block transaction
+type GenesisItem struct {
+	Addr    *big.Int
+	Balance *big.Int
+}
+
+// genesisConfig is a format compatible with genesis_block.json file
+type genesisConfig map[string]map[string]string
+
+func encodeGenesisConfig(ga []GenesisItem) string {
+	by, err := rlp.EncodeToBytes(ga)
+	if err != nil {
+		panic("ops")
+	}
+
+	return string(by)
+}
+
+func parseGenesisConfigFile(fileName string) genesisConfig {
+	input, err := ioutil.ReadFile(fileName)
+	if err != nil {
+		panic(fmt.Sprintf("cannot open genesisblock config file %v, err %v\n", fileName, err))
+	}
+	var gc genesisConfig
+	err = json.Unmarshal(input, &gc)
+	if err != nil {
+		panic(fmt.Sprintf("cannot parse json file %v, err %v\n", fileName, err))
+	}
+	return gc
+}
+
+// StringToBigInt converts a string to BigInt
+func StringToBigInt(s string, base int) *big.Int {
+	z := new(big.Int)
+	z, ok := z.SetString(s, base)
+	if !ok {
+		panic(fmt.Sprintf("%v cannot convert to bigint with base %v", s, base))
+	}
+	return z
+}
+
+func convertToGenesisItems(gc genesisConfig) []GenesisItem {
+	gi := []GenesisItem{}
+	for k, v := range gc {
+		gi = append(gi, GenesisItem{StringToBigInt(k, 16), StringToBigInt(v["wei"], 10)})
+	}
+	sort.Slice(gi, func(i, j int) bool {
+		return gi[i].Addr.Cmp(gi[j].Addr) == -1
+	})
+	return gi
+}
+
+// EncodeGenesisConfig converts json file into binary format for genesis block
+func EncodeGenesisConfig(fileName string) string {
+	gc := parseGenesisConfigFile(fileName)
+	gi := convertToGenesisItems(gc)
+	by := encodeGenesisConfig(gi)
+	return string(by)
+}

core/genesis_util_test.go

@@ -0,0 +1,19 @@
+package core
+
+import (
+	"strings"
+	"testing"
+)
+
+func TestEncodeGenesisConfig(t *testing.T) {
+	fileName := "genesis_block_test.json"
+	s := EncodeGenesisConfig(fileName)
+	genesisAcc := decodePrealloc(s)
+
+	for k := range genesisAcc {
+		key := strings.ToLower(k.Hex())
+		if key != "0xb7a2c103728b7305b5ae6e961c94ee99c9fe8e2b" && key != "0xb498bb0f520005b6216a4425b75aa9adc52d622b" {
+			t.Errorf("EncodeGenesisConfig incorrect")
+		}
+	}
+}