Cap the domain deposit amount for certain assets (#157)

* Cache asset sum

* Fix function name

* fix deposit amount

* common integer only allow positive sub result

* maximum value for some special assets

* asset total value should only be changed when snapshot

---------

Co-authored-by: Cedric Fung <[email protected]>

storage/badger_asset.go

@@ -0,0 +1,71 @@
+package storage
+
+import (
+	"github.com/MixinNetwork/mixin/common"
+	"github.com/MixinNetwork/mixin/crypto"
+	"github.com/MixinNetwork/mixin/domains/bitcoin"
+	"github.com/MixinNetwork/mixin/domains/ethereum"
+	"github.com/dgraph-io/badger/v4"
+)
+
+func assetCapAt(id crypto.Hash) common.Integer {
+	switch id {
+	case bitcoin.BitcoinChainId:
+		return common.NewIntegerFromString("10000")
+	case ethereum.EthereumChainId:
+		return common.NewIntegerFromString("100000")
+	case common.XINAssetId:
+		return common.NewIntegerFromString("1000000")
+	default: // TODO more assets and better default value
+		return common.NewIntegerFromString("115792089237316195423570985008687907853269984665640564039457.58400791")
+	}
+}
+
+func readTotalInAsset(txn *badger.Txn, hash crypto.Hash) (common.Integer, error) {
+	key := graphAssetTotalKey(hash)
+	item, err := txn.Get(key)
+	if err == badger.ErrKeyNotFound {
+		return common.Zero, nil
+	} else if err != nil {
+		return common.Zero, err
+	}
+	val, err := item.ValueCopy(nil)
+	if err != nil {
+		return common.Zero, err
+	}
+	return common.NewIntegerFromString(string(val)), nil
+}
+
+func writeTotalInAsset(txn *badger.Txn, ver *common.VersionedTransaction) error {
+	total, err := readTotalInAsset(txn, ver.Asset)
+	if err != nil {
+		return err
+	}
+
+	typ := ver.TransactionType()
+	switch { // TODO needs full test code for all kind of transactions
+	case typ == common.TransactionTypeWithdrawalSubmit:
+		total = total.Sub(ver.Outputs[0].Amount)
+	case typ == common.TransactionTypeDeposit:
+		total = total.Add(ver.DepositData().Amount)
+	case typ == common.TransactionTypeMint:
+		total = total.Add(ver.Inputs[0].Mint.Amount)
+	case len(ver.Inputs[0].Genesis) > 0:
+		for _, out := range ver.Outputs {
+			total = total.Add(out.Amount)
+		}
+	default:
+		return nil
+	}
+
+	max := assetCapAt(ver.Asset)
+	if total.Cmp(max) > 0 {
+		panic(total.String())
+	}
+	key := graphAssetTotalKey(ver.Asset)
+	return txn.Set(key, []byte(total.String()))
+}
+
+func graphAssetTotalKey(id crypto.Hash) []byte {
+	return append([]byte(graphPrefixAssetTotal), id[:]...)
+}

storage/badger_graph.go

@@ -31,6 +31,7 @@ const (
 	graphPrefixWorkSnapshot    = "WORKSNAPSHOT"
 	graphPrefixSpaceCheckpoint = "SPACECHECKPOINT"
 	graphPrefixSpaceQueue      = "SPACEQUEUE"
+	graphPrefixAssetTotal      = "ASSETTOTAL"
 	graphPrefixCustodianUpdate = "CUSTODIANUPDATE"
 )
 

storage/badger_transaction.go

@@ -171,7 +171,8 @@ func finalizeTransaction(txn *badger.Txn, ver *common.VersionedTransaction, snap
 			return err
 		}
 	}
-	return nil
+
+	return writeTotalInAsset(txn, ver)
 }
 
 func writeUTXO(txn *badger.Txn, utxo *common.UTXOWithLock, extra []byte, timestamp uint64, genesis bool) error {