package alphabetcontract import ( "github.com/nspcc-dev/neo-go/pkg/interop/binary" "github.com/nspcc-dev/neo-go/pkg/interop/blockchain" "github.com/nspcc-dev/neo-go/pkg/interop/contract" "github.com/nspcc-dev/neo-go/pkg/interop/crypto" "github.com/nspcc-dev/neo-go/pkg/interop/engine" "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" ) type ( irNode struct { key []byte } ballot struct { id []byte // id of the voting decision n [][]byte // already voted inner ring nodes block int // block with the last vote } ) const ( // native gas token script hash gasHash = "\xbc\xaf\x41\xd6\x84\xc7\xd4\xad\x6e\xe0\xd9\x9d\xa9\x70\x7b\x9d\x1f\x0c\x8e\x66" // native neo token script hash neoHash = "\x25\x05\x9e\xcb\x48\x78\xd3\xa8\x75\xf9\x1c\x51\xce\xde\xd3\x30\xd4\x57\x5f\xde" name = "Dobro" index = 4 netmapContractKey = "netmapScriptHash" blockDiff = 20 // amount of blocks when ballot get discarded threshold = totalAlphabetContracts*2/3 + 1 voteKey = "ballots" totalAlphabetContracts = 7 ) var ( ctx storage.Context ) func init() { if runtime.GetTrigger() != runtime.Application { panic("contract has not been called in application node") } ctx = storage.GetContext() } func Init(addrNetmap []byte) { if storage.Get(ctx, netmapContractKey) != nil { panic("contract already deployed") } if len(addrNetmap) != 20 { panic("incorrect length of contract script hash") } storage.Put(ctx, netmapContractKey, addrNetmap) setSerialized(ctx, voteKey, []ballot{}) runtime.Log(name + " contract initialized") } func Gas() int { contractHash := runtime.GetExecutingScriptHash() return balance(gasHash, contractHash) } func Neo() int { contractHash := runtime.GetExecutingScriptHash() return balance(neoHash, contractHash) } func balance(hash string, addr []byte) int { balance := engine.AppCall([]byte(hash), "balanceOf", addr) return balance.(int) } func irList() []irNode { netmapContractAddr := storage.Get(ctx, netmapContractKey).([]byte) return engine.AppCall(netmapContractAddr, "innerRingList").([]irNode) } func checkPermission(ir []irNode) bool { if len(ir) <= index { return false } node := ir[index] return runtime.CheckWitness(node.key) } func innerRingInvoker(ir []irNode) []byte { for i := 0; i < len(ir); i++ { if i >= totalAlphabetContracts { return nil } node := ir[i] if runtime.CheckWitness(node.key) { return node.key } } return nil } func Emit() bool { innerRingKeys := irList() if !checkPermission(innerRingKeys) { panic("invalid invoker") } contractHash := runtime.GetExecutingScriptHash() neo := balance(neoHash, contractHash) _ = engine.AppCall([]byte(neoHash), "transfer", contractHash, contractHash, neo) gas := balance(gasHash, contractHash) gasPerNode := gas * 7 / 8 / len(innerRingKeys) if gasPerNode == 0 { runtime.Log("no gas to emit") return false } for i := range innerRingKeys { node := innerRingKeys[i] address := contract.CreateStandardAccount(node.key) _ = engine.AppCall([]byte(gasHash), "transfer", contractHash, address, gasPerNode) } runtime.Log("utility token has been emitted to inner ring nodes") return true } func Vote(epoch int, candidates [][]byte) { innerRingKeys := irList() key := innerRingInvoker(innerRingKeys) if len(key) == 0 { panic("invalid invoker") } id := voteID(epoch, candidates) n := vote(ctx, id, key) if n >= threshold { candidate := candidates[index%len(candidates)] address := runtime.GetExecutingScriptHash() ok := engine.AppCall([]byte(neoHash), "vote", address, candidate).(bool) if ok { runtime.Log(name + ": successfully voted for validator") removeVotes(ctx, id) } else { runtime.Log(name + ": vote has been failed") } } else { runtime.Log(name + ": saved vote for validator") } return } func Name() string { return name } func vote(ctx storage.Context, id, from []byte) int { var ( newCandidates []ballot candidates = getBallots(ctx) found = -1 blockHeight = blockchain.GetHeight() ) for i := 0; i < len(candidates); i++ { cnd := candidates[i] if bytesEqual(cnd.id, id) { voters := cnd.n for j := range voters { if bytesEqual(voters[j], from) { return len(voters) } } voters = append(voters, from) cnd = ballot{id: id, n: voters, block: blockHeight} found = len(voters) } // do not add old ballots, they are invalid if blockHeight-cnd.block <= blockDiff { newCandidates = append(newCandidates, cnd) } } if found < 0 { voters := [][]byte{from} newCandidates = append(newCandidates, ballot{ id: id, n: voters, block: blockHeight}) found = 1 } setSerialized(ctx, voteKey, newCandidates) return found } func removeVotes(ctx storage.Context, id []byte) { var ( newCandidates []ballot candidates = getBallots(ctx) ) for i := 0; i < len(candidates); i++ { cnd := candidates[i] if !bytesEqual(cnd.id, id) { newCandidates = append(newCandidates, cnd) } } setSerialized(ctx, voteKey, newCandidates) } func getBallots(ctx storage.Context) []ballot { data := storage.Get(ctx, voteKey) if data != nil { return binary.Deserialize(data.([]byte)).([]ballot) } return []ballot{} } func setSerialized(ctx storage.Context, key interface{}, value interface{}) { data := binary.Serialize(value) storage.Put(ctx, key, data) } // neo-go#1176 func bytesEqual(a []byte, b []byte) bool { return util.Equals(string(a), string(b)) } func voteID(epoch interface{}, args [][]byte) []byte { var ( result []byte epochBytes = epoch.([]byte) ) result = append(result, epochBytes...) for i := range args { result = append(result, args[i]...) } return crypto.SHA256(result) }