Golang Currency.Big方法代碼示例

// currencyUnits converts a types.Currency to a string with human-readable
// units. The unit used will be the largest unit that results in a value
// greater than 1. The value is rounded to 4 significant digits.
func currencyUnits(c types.Currency) string {
	pico := types.SiacoinPrecision.Div64(1e12)
	if c.Cmp(pico) < 0 {
		return c.String() + " H"
	}

	// iterate until we find a unit greater than c
	mag := pico
	unit := ""
	for _, unit = range []string{"pS", "nS", "uS", "mS", "SC", "KS", "MS", "GS", "TS"} {
		if c.Cmp(mag.Mul64(1e3)) < 0 {
			break
		} else if unit != "TS" {
			// don't want to perform this multiply on the last iter; that
			// would give us 1.235 TS instead of 1235 TS
			mag = mag.Mul64(1e3)
		}
	}

	num := new(big.Rat).SetInt(c.Big())
	denom := new(big.Rat).SetInt(mag.Big())
	res, _ := new(big.Rat).Mul(num, denom.Inv(denom)).Float64()

	return fmt.Sprintf("%.4g %s", res, unit)
}

// wallettransactionscmd lists all of the transactions related to the wallet,
// providing a net flow of siacoins and siafunds for each.
func wallettransactionscmd() {
	wtg := new(api.WalletTransactionsGET)
	err := getAPI("/wallet/transactions?startheight=0&endheight=10000000", wtg)
	if err != nil {
		fmt.Println("Could not fetch transaction history:", err)
		return
	}

	fmt.Println("    [height]                                                   [transaction id]    [net siacoins]   [net siafunds]")
	txns := append(wtg.ConfirmedTransactions, wtg.UnconfirmedTransactions...)
	for _, txn := range txns {
		// Determine the number of outgoing siacoins and siafunds.
		var outgoingSiacoins types.Currency
		var outgoingSiafunds types.Currency
		for _, input := range txn.Inputs {
			if input.FundType == types.SpecifierSiacoinInput && input.WalletAddress {
				outgoingSiacoins = outgoingSiacoins.Add(input.Value)
			}
			if input.FundType == types.SpecifierSiafundInput && input.WalletAddress {
				outgoingSiafunds = outgoingSiafunds.Add(input.Value)
			}
		}

		// Determine the number of incoming siacoins and siafunds.
		var incomingSiacoins types.Currency
		var incomingSiafunds types.Currency
		for _, output := range txn.Outputs {
			if output.FundType == types.SpecifierMinerPayout {
				incomingSiacoins = incomingSiacoins.Add(output.Value)
			}
			if output.FundType == types.SpecifierSiacoinOutput && output.WalletAddress {
				incomingSiacoins = incomingSiacoins.Add(output.Value)
			}
			if output.FundType == types.SpecifierSiafundOutput && output.WalletAddress {
				incomingSiafunds = incomingSiafunds.Add(output.Value)
			}
		}

		// Convert the siacoins to a float.
		incomingSiacoinsFloat, _ := new(big.Rat).SetFrac(incomingSiacoins.Big(), types.SiacoinPrecision.Big()).Float64()
		outgoingSiacoinsFloat, _ := new(big.Rat).SetFrac(outgoingSiacoins.Big(), types.SiacoinPrecision.Big()).Float64()

		// Print the results.
		if txn.ConfirmationHeight < 1e9 {
			fmt.Printf("%12v", txn.ConfirmationHeight)
		} else {
			fmt.Printf(" unconfirmed")
		}
		fmt.Printf("%67v%15.2f SC", txn.TransactionID, incomingSiacoinsFloat-outgoingSiacoinsFloat)
		// For siafunds, need to avoid having a negative types.Currency.
		if incomingSiafunds.Cmp(outgoingSiafunds) >= 0 {
			fmt.Printf("%14v SF\n", incomingSiafunds.Sub(outgoingSiafunds))
		} else {
			fmt.Printf("-%14v SF\n", outgoingSiafunds.Sub(incomingSiafunds))
		}
	}
}