a16aecfa96
Why: big.Float is not an ideal type for dealing with monetary amounts, because no matter how high the precision, some non-integer decimal values can not be represented exactly in base-2 floating point. Also, storing gob-encoded big.Float values in the database makes it very hard to use those values in meaningful queries, making it difficult to do any sort of analysis on billing. For better accuracy, then, we can just represent monetary values as integers (in whatever base units are appropriate for the currency). For example, STORJ tokens or Bitcoins can not be split into pieces smaller than 10^-8, so we can store amounts of STORJ or BTC with precision simply by moving the decimal point 8 digits to the right. For USD values (assuming we don't want to deal with fractional cents), we can move the decimal point 2 digits to the right. To make it easier and less error-prone to deal with the math involved, I introduce here a new type, monetary.Amount, instances of which have an associated value _and_ a currency. Change-Id: I03395d52f0e2473cf301361f6033722b54640265
29 lines
892 B
Go
29 lines
892 B
Go
// Copyright (C) 2019 Storj Labs, Inc.
|
|
// See LICENSE for copying information.
|
|
|
|
package coinpayments
|
|
|
|
import (
|
|
"storj.io/storj/satellite/payments/monetary"
|
|
)
|
|
|
|
// CurrencySymbol is a symbol for a currency as recognized by coinpayments.net.
|
|
type CurrencySymbol string
|
|
|
|
var (
|
|
// CurrencyLTCT defines LTCT, coins used for testing purpose.
|
|
CurrencyLTCT = monetary.NewCurrency("LTCT test coins", "LTCT", 8)
|
|
|
|
// currencySymbols maps known currency objects to the currency symbols
|
|
// as recognized on coinpayments.net. In many cases, the currency's own
|
|
// idea of its symbol (currency.Symbol()) will be the same as this
|
|
// CurrencySymbol, but we should probably not count on that always being
|
|
// the case.
|
|
currencySymbols = map[*monetary.Currency]CurrencySymbol{
|
|
monetary.USDollars: "USD",
|
|
monetary.StorjToken: "STORJ",
|
|
monetary.Bitcoin: "BTC",
|
|
CurrencyLTCT: "LTCT",
|
|
}
|
|
)
|