mirror of
https://github.com/nspcc-dev/neo-go.git
synced 2024-11-22 09:29:38 +00:00
427 lines
12 KiB
Go
427 lines
12 KiB
Go
/*
|
|
Package nft contains divisible non-fungible NEP-11-compatible token
|
|
implementation. This token can be minted with GAS transfer to contract address,
|
|
it will retrieve NeoFS container ID and object ID from the transfer data and
|
|
produce NFT which represents NeoFS object.
|
|
*/
|
|
package nft
|
|
|
|
import (
|
|
"github.com/nspcc-dev/neo-go/pkg/interop"
|
|
"github.com/nspcc-dev/neo-go/pkg/interop/contract"
|
|
"github.com/nspcc-dev/neo-go/pkg/interop/iterator"
|
|
"github.com/nspcc-dev/neo-go/pkg/interop/lib/address"
|
|
"github.com/nspcc-dev/neo-go/pkg/interop/native/crypto"
|
|
"github.com/nspcc-dev/neo-go/pkg/interop/native/gas"
|
|
"github.com/nspcc-dev/neo-go/pkg/interop/native/management"
|
|
"github.com/nspcc-dev/neo-go/pkg/interop/native/std"
|
|
"github.com/nspcc-dev/neo-go/pkg/interop/runtime"
|
|
"github.com/nspcc-dev/neo-go/pkg/interop/storage"
|
|
"github.com/nspcc-dev/neo-go/pkg/interop/util"
|
|
)
|
|
|
|
const (
|
|
decimals = 2
|
|
multiplier = 100
|
|
)
|
|
|
|
// Prefixes used for contract data storage.
|
|
const (
|
|
totalSupplyPrefix = "s"
|
|
// balancePrefix contains map from [address + token id] to address's balance of the specified token.
|
|
balancePrefix = "b"
|
|
// tokenOwnerPrefix contains map from [token id + owner] to token's owner.
|
|
tokenOwnerPrefix = "t"
|
|
// tokenPrefix contains map from token id to its properties (serialised containerID + objectID).
|
|
tokenPrefix = "i"
|
|
)
|
|
|
|
var (
|
|
// contractOwner is a special address that can perform some management
|
|
// functions on this contract like updating/destroying it and can also
|
|
// be used for contract address verification.
|
|
contractOwner = address.ToHash160("NbrUYaZgyhSkNoRo9ugRyEMdUZxrhkNaWB")
|
|
)
|
|
|
|
// ObjectIdentifier represents NFT structure and contains the container ID and
|
|
// object ID of the NeoFS object.
|
|
type ObjectIdentifier struct {
|
|
ContainerID []byte
|
|
ObjectID []byte
|
|
}
|
|
|
|
// Common methods
|
|
|
|
// Symbol returns token symbol, it's NFSO.
|
|
func Symbol() string {
|
|
return "NFSO"
|
|
}
|
|
|
|
// Decimals returns token decimals, this NFT is divisible.
|
|
func Decimals() int {
|
|
return decimals
|
|
}
|
|
|
|
// TotalSupply is a contract method that returns the number of tokens minted.
|
|
func TotalSupply() int {
|
|
return totalSupply(storage.GetReadOnlyContext())
|
|
}
|
|
|
|
// totalSupply is an internal implementation of TotalSupply operating with
|
|
// given context. The number itself is stored raw in the DB with totalSupplyPrefix
|
|
// key.
|
|
func totalSupply(ctx storage.Context) int {
|
|
var res int
|
|
|
|
val := storage.Get(ctx, []byte(totalSupplyPrefix))
|
|
if val != nil {
|
|
res = val.(int)
|
|
}
|
|
return res
|
|
}
|
|
|
|
// mkBalancePrefix creates DB key-prefix for account balances specified
|
|
// by concatenating balancePrefix and account address.
|
|
func mkBalancePrefix(holder interop.Hash160) []byte {
|
|
res := []byte(balancePrefix)
|
|
return append(res, holder...)
|
|
}
|
|
|
|
// mkBalanceKey creates DB key for account specified by concatenating balancePrefix,
|
|
// account address and token ID.
|
|
func mkBalanceKey(holder interop.Hash160, tokenID []byte) []byte {
|
|
res := mkBalancePrefix(holder)
|
|
return append(res, tokenID...)
|
|
}
|
|
|
|
// mkTokenOwnerPrefix creates DB key prefix for token specified by its ID.
|
|
func mkTokenOwnerPrefix(tokenID []byte) []byte {
|
|
res := []byte(tokenOwnerPrefix)
|
|
return append(res, tokenID...)
|
|
}
|
|
|
|
// mkTokenOwnerKey creates DB key for token specified by concatenating tokenOwnerPrefix,
|
|
// token ID and holder.
|
|
func mkTokenOwnerKey(tokenID []byte, holder interop.Hash160) []byte {
|
|
res := mkTokenOwnerPrefix(tokenID)
|
|
return append(res, holder...)
|
|
}
|
|
|
|
// mkTokenKey creates DB key for token specified by its ID.
|
|
func mkTokenKey(tokenID []byte) []byte {
|
|
res := []byte(tokenPrefix)
|
|
return append(res, tokenID...)
|
|
}
|
|
|
|
// BalanceOf returns the overall number of tokens owned by specified address.
|
|
func BalanceOf(holder interop.Hash160) int {
|
|
if len(holder) != interop.Hash160Len {
|
|
panic("bad owner address")
|
|
}
|
|
ctx := storage.GetReadOnlyContext()
|
|
balance := 0
|
|
iter := tokensOf(ctx, holder)
|
|
for iterator.Next(iter) {
|
|
tokenID := iterator.Value(iter).([]byte)
|
|
key := mkBalanceKey(holder, tokenID)
|
|
balance += getBalanceOf(ctx, key)
|
|
}
|
|
return balance
|
|
}
|
|
|
|
// getBalanceOf returns balance of the account of the specified tokenID using
|
|
// database key.
|
|
func getBalanceOf(ctx storage.Context, balanceKey []byte) int {
|
|
val := storage.Get(ctx, balanceKey)
|
|
if val != nil {
|
|
return val.(int)
|
|
}
|
|
return 0
|
|
}
|
|
|
|
// addToBalance adds amount to the account balance. Amount can be negative. It returns
|
|
// updated balance value.
|
|
func addToBalance(ctx storage.Context, holder interop.Hash160, tokenID []byte, amount int) int {
|
|
key := mkBalanceKey(holder, tokenID)
|
|
old := getBalanceOf(ctx, key)
|
|
old += amount
|
|
if old > 0 {
|
|
storage.Put(ctx, key, old)
|
|
} else {
|
|
storage.Delete(ctx, key)
|
|
}
|
|
return old
|
|
}
|
|
|
|
// TokensOf returns an iterator with all tokens held by specified address.
|
|
func TokensOf(holder interop.Hash160) iterator.Iterator {
|
|
if len(holder) != interop.Hash160Len {
|
|
panic("bad owner address")
|
|
}
|
|
ctx := storage.GetReadOnlyContext()
|
|
|
|
return tokensOf(ctx, holder)
|
|
}
|
|
|
|
func tokensOf(ctx storage.Context, holder interop.Hash160) iterator.Iterator {
|
|
key := mkBalancePrefix(holder)
|
|
// We don't store zero balances, thus only relevant token IDs of the holder will
|
|
// be returned.
|
|
iter := storage.Find(ctx, key, storage.KeysOnly|storage.RemovePrefix)
|
|
return iter
|
|
}
|
|
|
|
// Transfer token from its owner to another user, if there's one owner of the token.
|
|
// It will return false if token is shared between multiple owners.
|
|
func Transfer(to interop.Hash160, token []byte, data any) bool {
|
|
if len(to) != interop.Hash160Len {
|
|
panic("invalid 'to' address")
|
|
}
|
|
ctx := storage.GetContext()
|
|
var (
|
|
owner interop.Hash160
|
|
ok bool
|
|
)
|
|
iter := ownersOf(ctx, token)
|
|
for iterator.Next(iter) {
|
|
if ok {
|
|
// Token is shared between multiple owners.
|
|
return false
|
|
}
|
|
owner = iterator.Value(iter).(interop.Hash160)
|
|
ok = true
|
|
}
|
|
if !ok {
|
|
panic("unknown token")
|
|
}
|
|
|
|
// Note that although calling script hash is not checked explicitly in
|
|
// this contract it is in fact checked for in `CheckWitness` itself.
|
|
if !runtime.CheckWitness(owner) {
|
|
return false
|
|
}
|
|
|
|
key := mkBalanceKey(owner, token)
|
|
amount := getBalanceOf(ctx, key)
|
|
|
|
if !owner.Equals(to) {
|
|
addToBalance(ctx, owner, token, -amount)
|
|
removeOwner(ctx, token, owner)
|
|
|
|
addToBalance(ctx, to, token, amount)
|
|
addOwner(ctx, token, to)
|
|
}
|
|
postTransfer(owner, to, token, amount, data)
|
|
return true
|
|
}
|
|
|
|
// postTransfer emits Transfer event and calls onNEP11Payment if needed.
|
|
func postTransfer(from interop.Hash160, to interop.Hash160, token []byte, amount int, data any) {
|
|
runtime.Notify("Transfer", from, to, amount, token)
|
|
if management.GetContract(to) != nil {
|
|
contract.Call(to, "onNEP11Payment", contract.All, from, amount, token, data)
|
|
}
|
|
}
|
|
|
|
// end of common methods.
|
|
|
|
// Optional methods.
|
|
|
|
// Properties returns properties of the given NFT.
|
|
func Properties(id []byte) map[string]string {
|
|
ctx := storage.GetReadOnlyContext()
|
|
if !isTokenValid(ctx, id) {
|
|
panic("unknown token")
|
|
}
|
|
key := mkTokenKey(id)
|
|
props := storage.Get(ctx, key).([]byte)
|
|
t := std.Deserialize(props).(ObjectIdentifier)
|
|
result := map[string]string{
|
|
"name": "NeoFS Object " + std.Base64Encode(id), // Not a hex for contract simplicity.
|
|
"containerID": std.Base64Encode(t.ContainerID),
|
|
"objectID": std.Base64Encode(t.ObjectID),
|
|
}
|
|
return result
|
|
}
|
|
|
|
// Tokens returns all token IDs minted by the contract.
|
|
func Tokens() iterator.Iterator {
|
|
ctx := storage.GetReadOnlyContext()
|
|
prefix := []byte(tokenPrefix)
|
|
iter := storage.Find(ctx, prefix, storage.KeysOnly|storage.RemovePrefix)
|
|
return iter
|
|
}
|
|
|
|
func isTokenValid(ctx storage.Context, tokenID []byte) bool {
|
|
key := mkTokenKey(tokenID)
|
|
result := storage.Get(ctx, key)
|
|
return result != nil
|
|
}
|
|
|
|
// End of optional methods.
|
|
|
|
// Divisible methods.
|
|
|
|
// TransferDivisible token from its owner to another user, notice that it only has three
|
|
// parameters because token owner can be deduced from token ID itself.
|
|
func TransferDivisible(from, to interop.Hash160, amount int, token []byte, data any) bool {
|
|
if len(from) != interop.Hash160Len {
|
|
panic("invalid 'from' address")
|
|
}
|
|
if len(to) != interop.Hash160Len {
|
|
panic("invalid 'to' address")
|
|
}
|
|
if amount < 0 {
|
|
panic("negative 'amount'")
|
|
}
|
|
if amount > multiplier {
|
|
panic("invalid 'amount'")
|
|
}
|
|
ctx := storage.GetContext()
|
|
if !isTokenValid(ctx, token) {
|
|
panic("unknown token")
|
|
}
|
|
|
|
// Note that although calling script hash is not checked explicitly in
|
|
// this contract it is in fact checked for in `CheckWitness` itself.
|
|
if !runtime.CheckWitness(from) {
|
|
return false
|
|
}
|
|
|
|
key := mkBalanceKey(from, token)
|
|
balance := getBalanceOf(ctx, key)
|
|
if amount > balance {
|
|
return false
|
|
}
|
|
|
|
if !from.Equals(to) {
|
|
updBalance := addToBalance(ctx, from, token, -amount)
|
|
if updBalance == 0 {
|
|
removeOwner(ctx, token, from)
|
|
}
|
|
|
|
updBalance = addToBalance(ctx, to, token, amount)
|
|
if updBalance != 0 {
|
|
addOwner(ctx, token, to)
|
|
}
|
|
}
|
|
postTransfer(from, to, token, amount, data)
|
|
return true
|
|
}
|
|
|
|
// OwnerOf returns owner of specified token.
|
|
func OwnerOf(token []byte) iterator.Iterator {
|
|
ctx := storage.GetReadOnlyContext()
|
|
if !isTokenValid(ctx, token) {
|
|
panic("unknown token")
|
|
}
|
|
return ownersOf(ctx, token)
|
|
}
|
|
|
|
// BalanceOfDivisible returns the number of token with the specified tokenID owned by specified address.
|
|
func BalanceOfDivisible(holder interop.Hash160, token []byte) int {
|
|
if len(holder) != interop.Hash160Len {
|
|
panic("bad holder address")
|
|
}
|
|
ctx := storage.GetReadOnlyContext()
|
|
key := mkBalanceKey(holder, token)
|
|
return getBalanceOf(ctx, key)
|
|
}
|
|
|
|
// end of divisible methods.
|
|
|
|
// ownersOf returns iterator over owners of the specified token. Owner is
|
|
// stored as value of the token key (prefix + token ID + owner).
|
|
func ownersOf(ctx storage.Context, token []byte) iterator.Iterator {
|
|
key := mkTokenOwnerPrefix(token)
|
|
iter := storage.Find(ctx, key, storage.ValuesOnly)
|
|
return iter
|
|
}
|
|
|
|
func addOwner(ctx storage.Context, token []byte, holder interop.Hash160) {
|
|
key := mkTokenOwnerKey(token, holder)
|
|
storage.Put(ctx, key, holder)
|
|
}
|
|
|
|
func removeOwner(ctx storage.Context, token []byte, holder interop.Hash160) {
|
|
key := mkTokenOwnerKey(token, holder)
|
|
storage.Delete(ctx, key)
|
|
}
|
|
|
|
// OnNEP17Payment mints tokens if at least 10 GAS is provided. You don't call
|
|
// this method directly, instead it's called by GAS contract when you transfer
|
|
// GAS from your address to the address of this NFT contract.
|
|
func OnNEP17Payment(from interop.Hash160, amount int, data any) {
|
|
defer func() {
|
|
if r := recover(); r != nil {
|
|
runtime.Log(r.(string))
|
|
util.Abort()
|
|
}
|
|
}()
|
|
callingHash := runtime.GetCallingScriptHash()
|
|
if !callingHash.Equals(gas.Hash) {
|
|
panic("only GAS is accepted")
|
|
}
|
|
if amount < 10_00000000 {
|
|
panic("minting NFSO costs at least 10 GAS")
|
|
}
|
|
tokenInfo := data.([]any)
|
|
if len(tokenInfo) != 2 {
|
|
panic("invalid 'data'")
|
|
}
|
|
containerID := tokenInfo[0].([]byte)
|
|
if len(containerID) != interop.Hash256Len {
|
|
panic("invalid container ID")
|
|
}
|
|
objectID := tokenInfo[1].([]byte)
|
|
if len(objectID) != interop.Hash256Len {
|
|
panic("invalid object ID")
|
|
}
|
|
|
|
t := ObjectIdentifier{
|
|
ContainerID: containerID,
|
|
ObjectID: objectID,
|
|
}
|
|
props := std.Serialize(t)
|
|
id := crypto.Ripemd160(props)
|
|
|
|
var ctx = storage.GetContext()
|
|
if isTokenValid(ctx, id) {
|
|
panic("NFSO for the specified object is already minted")
|
|
}
|
|
key := mkTokenKey(id)
|
|
storage.Put(ctx, key, props)
|
|
|
|
total := totalSupply(ctx)
|
|
|
|
addOwner(ctx, id, from)
|
|
addToBalance(ctx, from, id, multiplier)
|
|
|
|
total++
|
|
storage.Put(ctx, []byte(totalSupplyPrefix), total)
|
|
|
|
postTransfer(nil, from, id, multiplier, nil) // no `data` during minting
|
|
}
|
|
|
|
// Verify allows owner to manage contract's address, including earned GAS
|
|
// transfer from contract's address to somewhere else. It just checks for transaction
|
|
// to also be signed by contract owner, so contract's witness should be empty.
|
|
func Verify() bool {
|
|
return runtime.CheckWitness(contractOwner)
|
|
}
|
|
|
|
// Destroy destroys the contract, only owner can do that.
|
|
func Destroy() {
|
|
if !Verify() {
|
|
panic("only owner can destroy")
|
|
}
|
|
management.Destroy()
|
|
}
|
|
|
|
// Update updates the contract, only owner can do that.
|
|
func Update(nef, manifest []byte) {
|
|
if !Verify() {
|
|
panic("only owner can update")
|
|
}
|
|
management.Update(nef, manifest)
|
|
}
|