1package common
 2
 3import (
 4	"encoding/binary"
 5	"fmt"
 6	"math/big"
 7)
 8
 9const (
10	idxBytesLen = 4
11	// maxIdxValue is the maximum value that Idx can have (32 bits: maxIdxValue=2**32-1)
12	maxIdxValue = 0xffffffff
13)
14
15// Idx represents the account Index in the MerkleTree
16type Idx uint32
17
18// Bytes returns a byte array representing the Idx
19func (idx Idx) Bytes() []byte {
20	var b [4]byte
21	binary.LittleEndian.PutUint32(b[:], uint32(idx))
22	return b[:]
23}
24
25// BigInt returns a *big.Int representing the Idx
26func (idx Idx) BigInt() *big.Int {
27	return big.NewInt(int64(idx))
28}
29
30// IdxFromBytes returns Idx from a byte array
31func IdxFromBytes(b []byte) (Idx, error) {
32	if len(b) != idxBytesLen {
33		return 0, fmt.Errorf("can not parse Idx, bytes len %d, expected 4", len(b))
34	}
35	idx := binary.LittleEndian.Uint32(b[:4])
36	return Idx(idx), nil
37}
38
39// IdxFromBigInt converts a *big.Int to Idx type
40func IdxFromBigInt(b *big.Int) (Idx, error) {
41	if b.Int64() > maxIdxValue {
42		return 0, ErrNumOverflow
43	}
44	return Idx(uint32(b.Int64())), nil
45}
46
47// TxID is the identifier of a Hermez network transaction
48type TxID Hash // Hash is a guess
49
50// TxType is a string that represents the type of a Hermez network transaction
51type TxType string
52
53const (
54	// TxTypeExit represents L2->L1 token transfer.  A leaf for this account appears in the exit tree of the block
55	TxTypeExit TxType = "Exit"
56	// TxTypeWithdrawn represents the balance that was moved from L2->L1 has been widthrawn from the smart contract
57	TxTypeWithdrawn TxType = "Withdrawn"
58	// TxTypeTransfer represents L2->L2 token transfer
59	TxTypeTransfer TxType = "Transfer"
60	// TxTypeDeposit represents L1->L2 transfer
61	TxTypeDeposit TxType = "Deposit"
62	// TxTypeCreateAccountDeposit represents creation of a new leaf in the state tree (newAcconut) + L1->L2 transfer
63	TxTypeCreateAccountDeposit TxType = "CreateAccountDeposit"
64	// TxTypeCreateAccountDepositTransfer represents L1->L2 transfer + L2->L2 transfer
65	TxTypeCreateAccountDepositTransfer TxType = "CreateAccountDepositTransfer"
66	// TxTypeDepositTransfer TBD
67	TxTypeDepositTransfer TxType = "TxTypeDepositTransfer"
68	// TxTypeForceTransfer TBD
69	TxTypeForceTransfer TxType = "TxTypeForceTransfer"
70	// TxTypeForceExit TBD
71	TxTypeForceExit TxType = "TxTypeForceExit"
72	// TxTypeTransferToEthAddr TBD
73	TxTypeTransferToEthAddr TxType = "TxTypeTransferToEthAddr"
74	// TxTypeTransferToBJJ TBD
75	TxTypeTransferToBJJ TxType = "TxTypeTransferToBJJ"
76)
77
78// Tx is a struct used by the TxSelector & BatchBuilder as a generic type generated from L1Tx & PoolL2Tx
79type Tx struct {
80	TxID     TxID
81	FromIdx  Idx // FromIdx is used by L1Tx/Deposit to indicate the Idx receiver of the L1Tx.LoadAmount (deposit)
82	ToIdx    Idx // ToIdx is ignored in L1Tx/Deposit, but used in the L1Tx/DepositTransfer
83	Amount   *big.Int
84	Nonce    Nonce // effective 40 bits used
85	Fee      FeeSelector
86	Type     TxType   // optional, descrives which kind of tx it's
87	BatchNum BatchNum // batchNum in which this tx was forged. Presence indicates "forged" state.
88}