add transaction, utils, utils_test.

transaction.go

@@ -0,0 +1,48 @@
+package main
+
+import (
+	"bytes"
+	"crypto/sha256"
+	"encoding/gob"
+	"log"
+	"strconv"
+	"strings"
+)
+
+// Transaction represents a Bitcoin transaction
+type Transaction struct {
+	ID            []byte
+	inputAddresss []string
+	outputAddress []string
+	value         []int
+}
+
+func (tx *Transaction) Parse(data string) {
+	items := strings.Split(data, ",")
+	for _, value := range items {
+		pair := strings.Split(value, " ")
+		if len(pair) == 3 {
+			intValue, err := strconv.Atoi(pair[2])
+			if err != nil {
+				tx.inputAddress = append(tx.inputAddresss, strings.Trim(pair[0]))
+				tx.outputAddress = append(tx.outputAddress, strings.Trim(pair[1]))
+				tx.value = append(tx.value, intValue)
+			}
+		}
+	}
+	return res
+}
+
+// SetID sets ID of a transaction
+func (tx *Transaction) SetID() {
+	var encoded bytes.Buffer
+	var hash [32]byte
+
+	enc := gob.NewEncoder(&encoded)
+	err := enc.Encode(tx)
+	if err != nil {
+		log.Panic(err)
+	}
+	hash = sha256.Sum256(encoded.Bytes())
+	tx.ID = hash[:]
+}

utils.go

@@ -5,6 +5,8 @@ import (
 	"encoding/binary"
 	"encoding/gob"
 	"log"
+	"strconv"
+	"strings"
 )
 
 // IntToHex converts an int64 to a byte array
@@ -37,3 +39,32 @@ func DeserializeBlock(d []byte) *Block {
 
 	return &block
 }
+
+// Helper library to convert '1,2,3,4' into []int{1,2,3,4}.
+func ConvertIntoInts(data string) []int {
+	var res = []int{}
+	items := strings.Split(data, " ")
+	for _, value := range items {
+		intValue, err := strconv.Atoi(value)
+		checkError(err)
+		res = append(res, intValue)
+	}
+	return res
+}
+
+// Helper library to convert '1,2,3,4' into []int{1,2,3,4}.
+func ConvertIntoMap(data string) map[string]int {
+	var res = map[string]int
+	items := strings.Split(data, ",")
+	for _, value := range items {
+		pair := strings.Split(value, " ")
+		if len(pair) == 3 {
+			intValue, err := strconv.Atoi(pair[2])
+			if err != nil {
+				pair[0] = strings.Trim(pair[0])
+				res[pair[0]] = intValue
+			}
+		}
+	}
+	return res
+}

utils_test.go

@@ -0,0 +1,25 @@
+package main
+
+import "testing"
+
+func TestConvertIntoMap(t *testing.T) {
+	data := "minh:3,mike:2"
+	res := ConvertIntoMap(data)
+	if len(res) != 2 {
+		t.Errorf("Result should have 2 pairs (key, value)")
+	}
+	if val, ok := res["minh"]; !ok {
+		t.Errorf("Result should contain key minh")
+	} else {
+		if res["minh"] != 3 {
+			t.Errorf("Value of minh should be 3")
+		}
+	}
+	if val, ok := res["mike"]; !ok {
+		t.Errorf("Result should contain key mike")
+	} else {
+		if res["minh"] != 3 {
+			t.Errorf("Value of minh should be 2")
+		}
+	}
+}