gno.land/r/moul/demo/vault/v0⧉

1// Package vault demonstrates a minimal time-locked token vault built on top of2// the grc20 token package. Deposited tokens are held at the realm's own3// address; withdrawing them is a two-step process: Unvault marks an amount for4// withdrawal and starts a lock timer, then (once the lock elapses) Redeem moves5// the tokens back to the depositor.6package vault78import (9	"chain/runtime"10	"chain/runtime/unsafe"1112	tokens "gno.land/p/nt/grc20/v0"13)1415// test1 receives the initial mint at construction.16var test1 = address("g1jg8mtutu9khhfwc4nxmuhcpftf0pajdhfvsqf5")1718// lockDuration is the number of blocks that must pass between Unvault and19// Redeem.20const lockDuration = int64(100)2122// Token and FooVault-equivalent state are exported for reading; privateLedger23// stays unexported (unrestricted mint/burn/transfer).24var (25	Token         *tokens.Token26	privateLedger *tokens.PrivateLedger27	vaultAddr     address // address holding all deposited tokens2829	vaulted   = map[address]uint{}    // still-locked deposits per owner30	pending   = map[address]uint{}    // amount marked for withdrawal31	unlockAt  = map[address]int64{}    // block height at which pending unlocks32	recoverOf = map[address]address{}  // recovery address per depositor33)3435func init(cur realm) {36	// generate the token and mint some tokens to test1.37	Token, privateLedger = tokens.NewToken("Foo Token", "FOO", 4, 0, cur)38	privateLedger.Mint(test1, 100000000)3940	// the vault holds deposited tokens at the realm's own address.41	vaultAddr = cur.Address()42}4344func MyBalance() int64 {45	return Token.BalanceOf(unsafe.OriginCaller())46}4748// Deposit moves amount tokens from the caller into the vault, recording a49// recovery address for later use.50func Deposit(cur realm, amount uint, recoverAddress address) {51	caller := unsafe.OriginCaller()52	if err := privateLedger.Transfer(caller, vaultAddr, int64(amount)); err != nil {53		panic(err)54	}55	vaulted[caller] += amount56	recoverOf[caller] = recoverAddress57}5859// Recover sends target's still-locked deposit to its recorded recovery address.60func Recover(cur realm, target address) {61	amount := vaulted[target]62	if amount == 0 {63		return64	}65	dest := recoverOf[target]66	if err := privateLedger.Transfer(vaultAddr, dest, int64(amount)); err != nil {67		panic(err)68	}69	vaulted[target] = 070}7172// Unvault marks amount of the caller's deposit for withdrawal and starts the73// lock timer.74func Unvault(cur realm, amount uint) {75	caller := unsafe.OriginCaller()76	if vaulted[caller] < amount {77		panic("insufficient vaulted balance")78	}79	vaulted[caller] -= amount80	pending[caller] += amount81	unlockAt[caller] = runtime.ChainHeight() + lockDuration82}8384// Redeem transfers amount of the caller's matured pending withdrawal back to85// the caller.86func Redeem(cur realm, amount uint) {87	caller := unsafe.OriginCaller()88	if pending[caller] < amount {89		panic("insufficient pending balance")90	}91	if runtime.ChainHeight() < unlockAt[caller] {92		panic("still locked")93	}94	if err := privateLedger.Transfer(vaultAddr, caller, int64(amount)); err != nil {95		panic(err)96	}97	pending[caller] -= amount98}99