package common import ( "github.com/nspcc-dev/neo-go/pkg/interop" "github.com/nspcc-dev/neo-go/pkg/interop/binary" "github.com/nspcc-dev/neo-go/pkg/interop/crypto" "github.com/nspcc-dev/neo-go/pkg/interop/native/ledger" "github.com/nspcc-dev/neo-go/pkg/interop/storage" "github.com/nspcc-dev/neo-go/pkg/interop/util" ) type Ballot struct { // ID of the voting decision. ID []byte // Public keys of already voted inner ring nodes. Voters []interop.PublicKey // Height of block with the last vote. Height int } const voteKey = "ballots" const blockDiff = 20 // change base on performance evaluation func InitVote(ctx storage.Context) { SetSerialized(ctx, voteKey, []Ballot{}) } // Vote adds ballot for the decision with specific 'id' and returns amount // on unique voters for that decision. func Vote(ctx storage.Context, id, from []byte) int { var ( newCandidates []Ballot candidates = getBallots(ctx) found = -1 blockHeight = ledger.CurrentIndex() ) for i := 0; i < len(candidates); i++ { cnd := candidates[i] if blockHeight-cnd.Height > blockDiff { continue } if BytesEqual(cnd.ID, id) { voters := cnd.Voters for j := range voters { if BytesEqual(voters[j], from) { return len(voters) } } voters = append(voters, from) cnd = Ballot{ID: id, Voters: voters, Height: blockHeight} found = len(voters) } newCandidates = append(newCandidates, cnd) } if found < 0 { voters := []interop.PublicKey{from} newCandidates = append(newCandidates, Ballot{ ID: id, Voters: voters, Height: blockHeight}) found = 1 } SetSerialized(ctx, voteKey, newCandidates) return found } // RemoveVotes clears ballots of the decision that has been accepted by // inner ring nodes. 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) } // getBallots returns deserialized slice of vote ballots. func getBallots(ctx storage.Context) []Ballot { data := storage.Get(ctx, voteKey) if data != nil { return binary.Deserialize(data.([]byte)).([]Ballot) } return []Ballot{} } // BytesEqual compares two slice of bytes by wrapping them into strings, // which is necessary with new util.Equal interop behaviour, see neo-go#1176. func BytesEqual(a []byte, b []byte) bool { return util.Equals(string(a), string(b)) } func InvokeID(args []interface{}, prefix []byte) []byte { for i := range args { arg := args[i].([]byte) prefix = append(prefix, arg...) } return crypto.SHA256(prefix) }