blockchain sandbox: UTXO chain, p2p mining, attacker node

chain/utxo.go

@@ -0,0 +1,45 @@
+package chain
+
+import (
+	"crypto/ed25519"
+	"encoding/hex"
+	"maps"
+	"strconv"
+)
+
+type CoinID struct {
+	TxHash string
+	Index  int
+}
+
+func (id CoinID) Key() string { return id.TxHash + ":" + strconv.Itoa(id.Index) }
+
+type Coin struct {
+	Amount int
+	Owner  ed25519.PublicKey
+}
+
+func (c Coin) OwnerHex() string { return hex.EncodeToString(c.Owner) }
+
+type UnspentCoin struct {
+	Coin
+	CoinID CoinID
+}
+
+type CoinStore map[string]*UnspentCoin
+
+func (s CoinStore) Add(txHash string, idx int, coin Coin) {
+	id := CoinID{TxHash: txHash, Index: idx}
+	s[id.Key()] = &UnspentCoin{Coin: coin, CoinID: id}
+}
+
+func (s CoinStore) Spend(id CoinID) { delete(s, id.Key()) }
+
+func (s CoinStore) Get(id CoinID) *UnspentCoin { return s[id.Key()] }
+
+func (s CoinStore) Clone() CoinStore {
+	c := make(CoinStore, len(s))
+	maps.Copy(c, s)
+
+	return c
+}