1package common
 2
 3import (
 4	"encoding/binary"
 5	"fmt"
 6	"math/big"
 7
 8	ethCommon "github.com/ethereum/go-ethereum/common"
 9)
10
11const batchNumBytesLen = 8
12
13// Batch is a struct that represents Hermez network batch
14type Batch struct {
15	BatchNum      BatchNum             `meddler:"batch_num"`
16	EthBlockNum   int64                `meddler:"eth_block_num"` // Ethereum block in which the batch is forged
17	ForgerAddr    ethCommon.Address    `meddler:"forger_addr"`   // TODO: Should this be retrieved via slot reference?
18	CollectedFees map[TokenID]*big.Int `meddler:"fees_collected,json"`
19	StateRoot     *big.Int             `meddler:"state_root,bigint"`
20	NumAccounts   int                  `meddler:"num_accounts"`
21	ExitRoot      *big.Int             `meddler:"exit_root,bigint"`
22	ForgeL1TxsNum *int64               `meddler:"forge_l1_txs_num"` // optional, Only when the batch forges L1 txs. Identifier that corresponds to the group of L1 txs forged in the current batch.
23	SlotNum       int64                `meddler:"slot_num"`         // Slot in which the batch is forged
24	TotalFeesUSD  *float64             `meddler:"total_fees_usd"`
25}
26
27// BatchNum identifies a batch
28type BatchNum int64
29
30// Bytes returns a byte array of length 4 representing the BatchNum
31func (bn BatchNum) Bytes() []byte {
32	var batchNumBytes [batchNumBytesLen]byte
33	binary.BigEndian.PutUint64(batchNumBytes[:], uint64(bn))
34	return batchNumBytes[:]
35}
36
37// BatchNumFromBytes returns BatchNum from a []byte
38func BatchNumFromBytes(b []byte) (BatchNum, error) {
39	if len(b) != batchNumBytesLen {
40		return 0, fmt.Errorf("can not parse BatchNumFromBytes, bytes len %d, expected %d", len(b), batchNumBytesLen)
41	}
42	batchNum := binary.BigEndian.Uint64(b[:batchNumBytesLen])
43	return BatchNum(batchNum), nil
44}