package common import ( "encoding/binary" "fmt" "math/big" "time" ethCommon "github.com/ethereum/go-ethereum/common" ) // tokenIDBytesLen defines the length of the TokenID byte array representation const tokenIDBytesLen = 4 // Token is a struct that represents an Ethereum token that is supported in Hermez network type Token struct { TokenID TokenID `json:"id" meddler:"token_id"` EthBlockNum int64 `json:"ethereumBlockNum" meddler:"eth_block_num"` // Ethereum block number in which this token was registered EthAddr ethCommon.Address `json:"ethereumAddress" meddler:"eth_addr"` Name string `json:"name" meddler:"name"` Symbol string `json:"symbol" meddler:"symbol"` Decimals uint64 `json:"decimals" meddler:"decimals"` } // TokenInfo provides the price of the token in USD type TokenInfo struct { TokenID uint32 Value float64 LastUpdated time.Time } // TokenID is the unique identifier of the token, as set in the smart contract type TokenID uint32 // current implementation supports up to 2^32 tokens // Bytes returns a byte array of length 4 representing the TokenID func (t TokenID) Bytes() []byte { var tokenIDBytes [4]byte binary.BigEndian.PutUint32(tokenIDBytes[:], uint32(t)) return tokenIDBytes[:] } // BigInt returns the *big.Int representation of the TokenID func (t TokenID) BigInt() *big.Int { return big.NewInt(int64(t)) } // TokenIDFromBytes returns TokenID from a byte array func TokenIDFromBytes(b []byte) (TokenID, error) { if len(b) != tokenIDBytesLen { return 0, fmt.Errorf("can not parse TokenID, bytes len %d, expected 4", len(b)) } tid := binary.BigEndian.Uint32(b[:4]) return TokenID(tid), nil } // TokenIDFromBigInt returns a TokenID with the value of the given *big.Int func TokenIDFromBigInt(b *big.Int) TokenID { return TokenID(b.Int64()) }