neo-go/pkg/core/state/nep5.go
2020-03-05 18:22:40 +03:00

106 lines
2.9 KiB
Go

package state
import (
"github.com/nspcc-dev/neo-go/pkg/io"
"github.com/nspcc-dev/neo-go/pkg/util"
)
// NEP5Tracker contains info about a single account in a NEP5 contract.
type NEP5Tracker struct {
// Balance is the current balance of the account.
Balance int64
// LastUpdatedBlock is a number of block when last `transfer` to or from the
// account occured.
LastUpdatedBlock uint32
}
// NEP5TransferLog is a log of NEP5 token transfers for the specific command.
type NEP5TransferLog struct {
Raw []byte
}
// NEP5TransferSize is a size of a marshaled NEP5Transfer struct in bytes.
const NEP5TransferSize = util.Uint160Size*3 + 8 + 4 + 4 + util.Uint256Size
// NEP5Transfer represents a single NEP5 Transfer event.
type NEP5Transfer struct {
// Asset is a NEP5 contract hash.
Asset util.Uint160
// 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 int64
// Block is a number of block when the event occured.
Block uint32
// Timestamp is the timestamp of the block where transfer occured.
Timestamp uint32
// Tx is a hash the transaction.
Tx util.Uint256
}
// Append appends single transfer to a log.
func (lg *NEP5TransferLog) Append(tr *NEP5Transfer) error {
w := io.NewBufBinWriter()
tr.EncodeBinary(w.BinWriter)
if w.Err != nil {
return w.Err
}
lg.Raw = append(lg.Raw, w.Bytes()...)
return nil
}
// ForEach iterates over transfer log returning on first error.
func (lg *NEP5TransferLog) ForEach(f func(*NEP5Transfer) error) error {
if lg == nil {
return nil
}
tr := new(NEP5Transfer)
for i := 0; i < len(lg.Raw); i += NEP5TransferSize {
r := io.NewBinReaderFromBuf(lg.Raw[i : i+NEP5TransferSize])
tr.DecodeBinary(r)
if r.Err != nil {
return r.Err
} else if err := f(tr); err != nil {
return nil
}
}
return nil
}
// EncodeBinary implements io.Serializable interface.
func (t *NEP5Tracker) EncodeBinary(w *io.BinWriter) {
w.WriteU64LE(uint64(t.Balance))
w.WriteU32LE(t.LastUpdatedBlock)
}
// DecodeBinary implements io.Serializable interface.
func (t *NEP5Tracker) DecodeBinary(r *io.BinReader) {
t.Balance = int64(r.ReadU64LE())
t.LastUpdatedBlock = r.ReadU32LE()
}
// EncodeBinary implements io.Serializable interface.
// Note: change NEP5TransferSize constant when changing this function.
func (t *NEP5Transfer) EncodeBinary(w *io.BinWriter) {
w.WriteBytes(t.Asset[:])
w.WriteBytes(t.Tx[:])
w.WriteBytes(t.From[:])
w.WriteBytes(t.To[:])
w.WriteU32LE(t.Block)
w.WriteU32LE(t.Timestamp)
w.WriteU64LE(uint64(t.Amount))
}
// DecodeBinary implements io.Serializable interface.
func (t *NEP5Transfer) DecodeBinary(r *io.BinReader) {
r.ReadBytes(t.Asset[:])
r.ReadBytes(t.Tx[:])
r.ReadBytes(t.From[:])
r.ReadBytes(t.To[:])
t.Block = r.ReadU32LE()
t.Timestamp = r.ReadU32LE()
t.Amount = int64(r.ReadU64LE())
}