neoneo-go/pkg/core/state/nep17.go

155 lines
4 KiB
Go
Raw Normal View History

2020-03-05 07:45:50 +00:00
package state
import (
"bytes"
"math/big"
"github.com/nspcc-dev/neo-go/pkg/encoding/bigint"
2020-03-05 07:45:50 +00:00
"github.com/nspcc-dev/neo-go/pkg/io"
2020-03-05 14:11:58 +00:00
"github.com/nspcc-dev/neo-go/pkg/util"
2020-03-05 07:45:50 +00:00
)
// NEP17TransferBatchSize is the maximum number of entries for NEP17TransferLog.
const NEP17TransferBatchSize = 128
// NEP17TransferLog is a log of NEP17 token transfers for the specific command.
type NEP17TransferLog struct {
2020-03-05 14:11:58 +00:00
Raw []byte
}
// NEP17Transfer represents a single NEP17 Transfer event.
type NEP17Transfer struct {
// Asset is a NEP17 contract ID.
Asset int32
2020-03-05 14:11:58 +00:00
// Address is the address of the sender.
From util.Uint160
// To is the address of the receiver.
To util.Uint160
// Amount is the amount of tokens transferred.
// It is negative when tokens are sent and positive if they are received.
Amount big.Int
// Block is a number of block when the event occurred.
2020-03-05 14:11:58 +00:00
Block uint32
// Timestamp is the timestamp of the block where transfer occurred.
Timestamp uint64
2020-03-05 14:11:58 +00:00
// Tx is a hash the transaction.
Tx util.Uint256
}
// NEP17TransferInfo stores map of the NEP17 contract IDs to the balance's last updated
// block trackers along with information about NEP17 transfer batch.
type NEP17TransferInfo struct {
LastUpdated map[int32]uint32
// NextTransferBatch stores an index of the next transfer batch.
NextTransferBatch uint32
// NewBatch is true if batch with the `NextTransferBatch` index should be created.
NewBatch bool
}
// NewNEP17TransferInfo returns new NEP17TransferInfo.
func NewNEP17TransferInfo() *NEP17TransferInfo {
return &NEP17TransferInfo{
LastUpdated: make(map[int32]uint32),
}
}
// DecodeBinary implements io.Serializable interface.
func (bs *NEP17TransferInfo) DecodeBinary(r *io.BinReader) {
bs.NextTransferBatch = r.ReadU32LE()
bs.NewBatch = r.ReadBool()
lenBalances := r.ReadVarUint()
m := make(map[int32]uint32, lenBalances)
for i := 0; i < int(lenBalances); i++ {
key := int32(r.ReadU32LE())
m[key] = r.ReadU32LE()
}
bs.LastUpdated = m
}
// EncodeBinary implements io.Serializable interface.
func (bs *NEP17TransferInfo) EncodeBinary(w *io.BinWriter) {
w.WriteU32LE(bs.NextTransferBatch)
w.WriteBool(bs.NewBatch)
w.WriteVarUint(uint64(len(bs.LastUpdated)))
for k, v := range bs.LastUpdated {
w.WriteU32LE(uint32(k))
w.WriteU32LE(v)
}
}
2020-03-05 14:11:58 +00:00
// Append appends single transfer to a log.
func (lg *NEP17TransferLog) Append(tr *NEP17Transfer) error {
// The first entry, set up counter.
if len(lg.Raw) == 0 {
lg.Raw = append(lg.Raw, 0)
}
b := bytes.NewBuffer(lg.Raw)
w := io.NewBinWriterFromIO(b)
tr.EncodeBinary(w)
2020-03-05 14:11:58 +00:00
if w.Err != nil {
return w.Err
}
lg.Raw = b.Bytes()
lg.Raw[0]++
2020-03-05 14:11:58 +00:00
return nil
2020-03-05 12:16:03 +00:00
}
// ForEach iterates over transfer log returning on first error.
func (lg *NEP17TransferLog) ForEach(f func(*NEP17Transfer) (bool, error)) (bool, error) {
if lg == nil || len(lg.Raw) == 0 {
return true, nil
2020-03-05 12:16:03 +00:00
}
transfers := make([]NEP17Transfer, lg.Size())
r := io.NewBinReaderFromBuf(lg.Raw[1:])
for i := 0; i < lg.Size(); i++ {
transfers[i].DecodeBinary(r)
}
if r.Err != nil {
return false, r.Err
}
for i := len(transfers) - 1; i >= 0; i-- {
cont, err := f(&transfers[i])
if err != nil {
return false, err
}
if !cont {
return false, nil
2020-03-05 12:16:03 +00:00
}
}
return true, nil
2020-03-05 14:11:58 +00:00
}
// Size returns an amount of transfer written in log.
func (lg *NEP17TransferLog) Size() int {
if len(lg.Raw) == 0 {
return 0
}
return int(lg.Raw[0])
}
2020-03-05 14:11:58 +00:00
// EncodeBinary implements io.Serializable interface.
func (t *NEP17Transfer) EncodeBinary(w *io.BinWriter) {
w.WriteU32LE(uint32(t.Asset))
2020-03-05 14:11:58 +00:00
w.WriteBytes(t.Tx[:])
w.WriteBytes(t.From[:])
w.WriteBytes(t.To[:])
w.WriteU32LE(t.Block)
w.WriteU64LE(t.Timestamp)
amount := bigint.ToBytes(&t.Amount)
w.WriteVarBytes(amount)
2020-03-05 14:11:58 +00:00
}
// DecodeBinary implements io.Serializable interface.
func (t *NEP17Transfer) DecodeBinary(r *io.BinReader) {
t.Asset = int32(r.ReadU32LE())
2020-03-05 14:11:58 +00:00
r.ReadBytes(t.Tx[:])
r.ReadBytes(t.From[:])
r.ReadBytes(t.To[:])
t.Block = r.ReadU32LE()
t.Timestamp = r.ReadU64LE()
amount := r.ReadVarBytes(bigint.MaxBytesLen)
t.Amount = *bigint.FromBytes(amount)
2020-03-05 14:11:58 +00:00
}