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authorFlorian Dold <florian@dold.me>2021-03-17 18:21:43 +0100
committerFlorian Dold <florian@dold.me>2021-03-17 18:21:43 +0100
commit51f2ad9b6dc23bd4a73ef1953fedc654b37e26f0 (patch)
tree441faa4f83fec0a58befb15754cd18e6bab6e299 /packages/taler-util
parent07cdfb2e4ec761021477271776b81f33af0e731d (diff)
use static helpers for amounts
Diffstat (limited to 'packages/taler-util')
-rw-r--r--packages/taler-util/src/amounts.test.ts4
-rw-r--r--packages/taler-util/src/amounts.ts564
-rw-r--r--packages/taler-util/src/helpers.ts2
-rw-r--r--packages/taler-util/src/talerTypes.ts20
-rw-r--r--packages/taler-util/src/talerconfig.ts2
5 files changed, 296 insertions, 296 deletions
diff --git a/packages/taler-util/src/amounts.test.ts b/packages/taler-util/src/amounts.test.ts
index d9734ce82..064023e2d 100644
--- a/packages/taler-util/src/amounts.test.ts
+++ b/packages/taler-util/src/amounts.test.ts
@@ -16,7 +16,7 @@
import test from "ava";
-import { Amounts, AmountJson } from "./amounts.js";
+import { Amounts, AmountJson, amountMaxValue } from "./amounts.js";
const jAmt = (
value: number,
@@ -36,7 +36,7 @@ test("amount addition (simple)", (t) => {
test("amount addition (saturation)", (t) => {
const a1 = jAmt(1, 0, "EUR");
- const res = Amounts.add(jAmt(Amounts.maxAmountValue, 0, "EUR"), a1);
+ const res = Amounts.add(jAmt(amountMaxValue, 0, "EUR"), a1);
t.true(res.saturated);
t.pass();
});
diff --git a/packages/taler-util/src/amounts.ts b/packages/taler-util/src/amounts.ts
index 8984db11b..e27bb79a8 100644
--- a/packages/taler-util/src/amounts.ts
+++ b/packages/taler-util/src/amounts.ts
@@ -32,19 +32,19 @@ import { AmountString } from "./talerTypes";
/**
* Number of fractional units that one value unit represents.
*/
-export const fractionalBase = 1e8;
+export const amountFractionalBase = 1e8;
/**
* How many digits behind the comma are required to represent the
* fractional value in human readable decimal format? Must match
* lg(fractionalBase)
*/
-export const fractionalLength = 8;
+export const amountFractionalLength = 8;
/**
* Maximum allowed value field of an amount.
*/
-export const maxAmountValue = 2 ** 52;
+export const amountMaxValue = 2 ** 52;
/**
* Non-negative financial amount. Fractional values are expressed as multiples
@@ -91,333 +91,333 @@ export interface Result {
}
/**
- * Get an amount that represents zero units of a currency.
+ * Type for things that are treated like amounts.
*/
-export function getZero(currency: string): AmountJson {
- return {
- currency,
- fraction: 0,
- value: 0,
- };
-}
-
export type AmountLike = AmountString | AmountJson;
-export function jsonifyAmount(amt: AmountLike): AmountJson {
- if (typeof amt === "string") {
- return parseOrThrow(amt);
- }
- return amt;
-}
-
-export function sum(amounts: AmountLike[]): Result {
- if (amounts.length <= 0) {
- throw Error("can't sum zero amounts");
- }
- const jsonAmounts = amounts.map((x) => jsonifyAmount(x));
- return add(jsonAmounts[0], ...jsonAmounts.slice(1));
-}
-
/**
- * Add two amounts. Return the result and whether
- * the addition overflowed. The overflow is always handled
- * by saturating and never by wrapping.
- *
- * Throws when currencies don't match.
+ * Helper class for dealing with amounts.
*/
-export function add(first: AmountJson, ...rest: AmountJson[]): Result {
- const currency = first.currency;
- let value = first.value + Math.floor(first.fraction / fractionalBase);
- if (value > maxAmountValue) {
+export class Amounts {
+ private constructor() {
+ throw Error("not instantiable");
+ }
+
+ /**
+ * Get an amount that represents zero units of a currency.
+ */
+ static getZero(currency: string): AmountJson {
return {
- amount: { currency, value: maxAmountValue, fraction: fractionalBase - 1 },
- saturated: true,
+ currency,
+ fraction: 0,
+ value: 0,
};
}
- let fraction = first.fraction % fractionalBase;
- for (const x of rest) {
- if (x.currency !== currency) {
- throw Error(`Mismatched currency: ${x.currency} and ${currency}`);
+
+ static jsonifyAmount(amt: AmountLike): AmountJson {
+ if (typeof amt === "string") {
+ return Amounts.parseOrThrow(amt);
+ }
+ return amt;
+ }
+
+ static sum(amounts: AmountLike[]): Result {
+ if (amounts.length <= 0) {
+ throw Error("can't sum zero amounts");
}
+ const jsonAmounts = amounts.map((x) => Amounts.jsonifyAmount(x));
+ return Amounts.add(jsonAmounts[0], ...jsonAmounts.slice(1));
+ }
- value =
- value + x.value + Math.floor((fraction + x.fraction) / fractionalBase);
- fraction = Math.floor((fraction + x.fraction) % fractionalBase);
- if (value > maxAmountValue) {
+ /**
+ * Add two amounts. Return the result and whether
+ * the addition overflowed. The overflow is always handled
+ * by saturating and never by wrapping.
+ *
+ * Throws when currencies don't match.
+ */
+ static add(first: AmountJson, ...rest: AmountJson[]): Result {
+ const currency = first.currency;
+ let value = first.value + Math.floor(first.fraction / amountFractionalBase);
+ if (value > amountMaxValue) {
return {
amount: {
currency,
- value: maxAmountValue,
- fraction: fractionalBase - 1,
+ value: amountMaxValue,
+ fraction: amountFractionalBase - 1,
},
saturated: true,
};
}
- }
- return { amount: { currency, value, fraction }, saturated: false };
-}
+ let fraction = first.fraction % amountFractionalBase;
+ for (const x of rest) {
+ if (x.currency !== currency) {
+ throw Error(`Mismatched currency: ${x.currency} and ${currency}`);
+ }
-/**
- * Subtract two amounts. Return the result and whether
- * the subtraction overflowed. The overflow is always handled
- * by saturating and never by wrapping.
- *
- * Throws when currencies don't match.
- */
-export function sub(a: AmountJson, ...rest: AmountJson[]): Result {
- const currency = a.currency;
- let value = a.value;
- let fraction = a.fraction;
-
- for (const b of rest) {
- if (b.currency !== currency) {
- throw Error(`Mismatched currency: ${b.currency} and ${currency}`);
- }
- if (fraction < b.fraction) {
- if (value < 1) {
- return { amount: { currency, value: 0, fraction: 0 }, saturated: true };
+ value =
+ value +
+ x.value +
+ Math.floor((fraction + x.fraction) / amountFractionalBase);
+ fraction = Math.floor((fraction + x.fraction) % amountFractionalBase);
+ if (value > amountMaxValue) {
+ return {
+ amount: {
+ currency,
+ value: amountMaxValue,
+ fraction: amountFractionalBase - 1,
+ },
+ saturated: true,
+ };
}
- value--;
- fraction += fractionalBase;
- }
- console.assert(fraction >= b.fraction);
- fraction -= b.fraction;
- if (value < b.value) {
- return { amount: { currency, value: 0, fraction: 0 }, saturated: true };
}
- value -= b.value;
+ return { amount: { currency, value, fraction }, saturated: false };
}
- return { amount: { currency, value, fraction }, saturated: false };
-}
+ /**
+ * Subtract two amounts. Return the result and whether
+ * the subtraction overflowed. The overflow is always handled
+ * by saturating and never by wrapping.
+ *
+ * Throws when currencies don't match.
+ */
+ static sub(a: AmountJson, ...rest: AmountJson[]): Result {
+ const currency = a.currency;
+ let value = a.value;
+ let fraction = a.fraction;
+
+ for (const b of rest) {
+ if (b.currency !== currency) {
+ throw Error(`Mismatched currency: ${b.currency} and ${currency}`);
+ }
+ if (fraction < b.fraction) {
+ if (value < 1) {
+ return {
+ amount: { currency, value: 0, fraction: 0 },
+ saturated: true,
+ };
+ }
+ value--;
+ fraction += amountFractionalBase;
+ }
+ console.assert(fraction >= b.fraction);
+ fraction -= b.fraction;
+ if (value < b.value) {
+ return { amount: { currency, value: 0, fraction: 0 }, saturated: true };
+ }
+ value -= b.value;
+ }
-/**
- * Compare two amounts. Returns 0 when equal, -1 when a < b
- * and +1 when a > b. Throws when currencies don't match.
- */
-export function cmp(a: AmountLike, b: AmountLike): -1 | 0 | 1 {
- a = jsonifyAmount(a);
- b = jsonifyAmount(b);
- if (a.currency !== b.currency) {
- throw Error(`Mismatched currency: ${a.currency} and ${b.currency}`);
+ return { amount: { currency, value, fraction }, saturated: false };
}
- const av = a.value + Math.floor(a.fraction / fractionalBase);
- const af = a.fraction % fractionalBase;
- const bv = b.value + Math.floor(b.fraction / fractionalBase);
- const bf = b.fraction % fractionalBase;
- switch (true) {
- case av < bv:
- return -1;
- case av > bv:
- return 1;
- case af < bf:
- return -1;
- case af > bf:
- return 1;
- case af === bf:
- return 0;
- default:
- throw Error("assertion failed");
- }
-}
-
-/**
- * Create a copy of an amount.
- */
-export function copy(a: AmountJson): AmountJson {
- return {
- currency: a.currency,
- fraction: a.fraction,
- value: a.value,
- };
-}
-/**
- * Divide an amount. Throws on division by zero.
- */
-export function divide(a: AmountJson, n: number): AmountJson {
- if (n === 0) {
- throw Error(`Division by 0`);
- }
- if (n === 1) {
- return { value: a.value, fraction: a.fraction, currency: a.currency };
+ /**
+ * Compare two amounts. Returns 0 when equal, -1 when a < b
+ * and +1 when a > b. Throws when currencies don't match.
+ */
+ static cmp(a: AmountLike, b: AmountLike): -1 | 0 | 1 {
+ a = Amounts.jsonifyAmount(a);
+ b = Amounts.jsonifyAmount(b);
+ if (a.currency !== b.currency) {
+ throw Error(`Mismatched currency: ${a.currency} and ${b.currency}`);
+ }
+ const av = a.value + Math.floor(a.fraction / amountFractionalBase);
+ const af = a.fraction % amountFractionalBase;
+ const bv = b.value + Math.floor(b.fraction / amountFractionalBase);
+ const bf = b.fraction % amountFractionalBase;
+ switch (true) {
+ case av < bv:
+ return -1;
+ case av > bv:
+ return 1;
+ case af < bf:
+ return -1;
+ case af > bf:
+ return 1;
+ case af === bf:
+ return 0;
+ default:
+ throw Error("assertion failed");
+ }
}
- const r = a.value % n;
- return {
- currency: a.currency,
- fraction: Math.floor((r * fractionalBase + a.fraction) / n),
- value: Math.floor(a.value / n),
- };
-}
-
-/**
- * Check if an amount is non-zero.
- */
-export function isNonZero(a: AmountJson): boolean {
- return a.value > 0 || a.fraction > 0;
-}
-
-export function isZero(a: AmountLike): boolean {
- a = jsonifyAmount(a);
- return a.value === 0 && a.fraction === 0;
-}
-/**
- * Parse an amount like 'EUR:20.5' for 20 Euros and 50 ct.
- */
-export function parse(s: string): AmountJson | undefined {
- const res = s.match(/^([a-zA-Z0-9_*-]+):([0-9]+)([.][0-9]+)?$/);
- if (!res) {
- return undefined;
- }
- const tail = res[3] || ".0";
- if (tail.length > fractionalLength + 1) {
- return undefined;
+ /**
+ * Create a copy of an amount.
+ */
+ static copy(a: AmountJson): AmountJson {
+ return {
+ currency: a.currency,
+ fraction: a.fraction,
+ value: a.value,
+ };
}
- const value = Number.parseInt(res[2]);
- if (value > maxAmountValue) {
- return undefined;
+
+ /**
+ * Divide an amount. Throws on division by zero.
+ */
+ static divide(a: AmountJson, n: number): AmountJson {
+ if (n === 0) {
+ throw Error(`Division by 0`);
+ }
+ if (n === 1) {
+ return { value: a.value, fraction: a.fraction, currency: a.currency };
+ }
+ const r = a.value % n;
+ return {
+ currency: a.currency,
+ fraction: Math.floor((r * amountFractionalBase + a.fraction) / n),
+ value: Math.floor(a.value / n),
+ };
}
- return {
- currency: res[1],
- fraction: Math.round(fractionalBase * Number.parseFloat(tail)),
- value,
- };
-}
-/**
- * Parse amount in standard string form (like 'EUR:20.5'),
- * throw if the input is not a valid amount.
- */
-export function parseOrThrow(s: string): AmountJson {
- const res = parse(s);
- if (!res) {
- throw Error(`Can't parse amount: "${s}"`);
+ /**
+ * Check if an amount is non-zero.
+ */
+ static isNonZero(a: AmountJson): boolean {
+ return a.value > 0 || a.fraction > 0;
}
- return res;
-}
-/**
- * Convert a float to a Taler amount.
- * Loss of precision possible.
- */
-export function fromFloat(floatVal: number, currency: string): AmountJson {
- return {
- currency,
- fraction: Math.floor((floatVal - Math.floor(floatVal)) * fractionalBase),
- value: Math.floor(floatVal),
- };
-}
+ static isZero(a: AmountLike): boolean {
+ a = Amounts.jsonifyAmount(a);
+ return a.value === 0 && a.fraction === 0;
+ }
-/**
- * Convert to standard human-readable string representation that's
- * also used in JSON formats.
- */
-export function stringify(a: AmountLike): string {
- a = jsonifyAmount(a);
- const av = a.value + Math.floor(a.fraction / fractionalBase);
- const af = a.fraction % fractionalBase;
- let s = av.toString();
-
- if (af) {
- s = s + ".";
- let n = af;
- for (let i = 0; i < fractionalLength; i++) {
- if (!n) {
- break;
- }
- s = s + Math.floor((n / fractionalBase) * 10).toString();
- n = (n * 10) % fractionalBase;
+ /**
+ * Parse an amount like 'EUR:20.5' for 20 Euros and 50 ct.
+ */
+ static parse(s: string): AmountJson | undefined {
+ const res = s.match(/^([a-zA-Z0-9_*-]+):([0-9]+)([.][0-9]+)?$/);
+ if (!res) {
+ return undefined;
+ }
+ const tail = res[3] || ".0";
+ if (tail.length > amountFractionalLength + 1) {
+ return undefined;
}
+ const value = Number.parseInt(res[2]);
+ if (value > amountMaxValue) {
+ return undefined;
+ }
+ return {
+ currency: res[1],
+ fraction: Math.round(amountFractionalBase * Number.parseFloat(tail)),
+ value,
+ };
}
- return `${a.currency}:${s}`;
-}
-
-/**
- * Check if the argument is a valid amount in string form.
- */
-function check(a: any): boolean {
- if (typeof a !== "string") {
- return false;
- }
- try {
- const parsedAmount = parse(a);
- return !!parsedAmount;
- } catch {
- return false;
+ /**
+ * Parse amount in standard string form (like 'EUR:20.5'),
+ * throw if the input is not a valid amount.
+ */
+ static parseOrThrow(s: string): AmountJson {
+ const res = Amounts.parse(s);
+ if (!res) {
+ throw Error(`Can't parse amount: "${s}"`);
+ }
+ return res;
}
-}
-function mult(a: AmountJson, n: number): Result {
- if (!Number.isInteger(n)) {
- throw Error("amount can only be multipied by an integer");
- }
- if (n < 0) {
- throw Error("amount can only be multiplied by a positive integer");
+ /**
+ * Convert a float to a Taler amount.
+ * Loss of precision possible.
+ */
+ static fromFloat(floatVal: number, currency: string): AmountJson {
+ return {
+ currency,
+ fraction: Math.floor(
+ (floatVal - Math.floor(floatVal)) * amountFractionalBase,
+ ),
+ value: Math.floor(floatVal),
+ };
}
- if (n == 0) {
- return { amount: getZero(a.currency), saturated: false };
+
+ static min(a: AmountLike, b: AmountLike): AmountJson {
+ const cr = Amounts.cmp(a, b);
+ if (cr >= 0) {
+ return Amounts.jsonifyAmount(b);
+ } else {
+ return Amounts.jsonifyAmount(a);
+ }
}
- let x = a;
- let acc = getZero(a.currency);
- while (n > 1) {
- if (n % 2 == 0) {
- n = n / 2;
+
+ static max(a: AmountLike, b: AmountLike): AmountJson {
+ const cr = Amounts.cmp(a, b);
+ if (cr >= 0) {
+ return Amounts.jsonifyAmount(a);
} else {
- n = (n - 1) / 2;
- const r2 = add(acc, x);
+ return Amounts.jsonifyAmount(b);
+ }
+ }
+
+ static mult(a: AmountJson, n: number): Result {
+ if (!Number.isInteger(n)) {
+ throw Error("amount can only be multipied by an integer");
+ }
+ if (n < 0) {
+ throw Error("amount can only be multiplied by a positive integer");
+ }
+ if (n == 0) {
+ return { amount: Amounts.getZero(a.currency), saturated: false };
+ }
+ let x = a;
+ let acc = Amounts.getZero(a.currency);
+ while (n > 1) {
+ if (n % 2 == 0) {
+ n = n / 2;
+ } else {
+ n = (n - 1) / 2;
+ const r2 = Amounts.add(acc, x);
+ if (r2.saturated) {
+ return r2;
+ }
+ acc = r2.amount;
+ }
+ const r2 = Amounts.add(x, x);
if (r2.saturated) {
return r2;
}
- acc = r2.amount;
+ x = r2.amount;
}
- const r2 = add(x, x);
- if (r2.saturated) {
- return r2;
- }
- x = r2.amount;
+ return Amounts.add(acc, x);
}
- return add(acc, x);
-}
-function max(a: AmountLike, b: AmountLike): AmountJson {
- const cr = Amounts.cmp(a, b);
- if (cr >= 0) {
- return jsonifyAmount(a);
- } else {
- return jsonifyAmount(b);
+ /**
+ * Check if the argument is a valid amount in string form.
+ */
+ static check(a: any): boolean {
+ if (typeof a !== "string") {
+ return false;
+ }
+ try {
+ const parsedAmount = Amounts.parse(a);
+ return !!parsedAmount;
+ } catch {
+ return false;
+ }
}
-}
-function min(a: AmountLike, b: AmountLike): AmountJson {
- const cr = Amounts.cmp(a, b);
- if (cr >= 0) {
- return jsonifyAmount(b);
- } else {
- return jsonifyAmount(a);
+ /**
+ * Convert to standard human-readable string representation that's
+ * also used in JSON formats.
+ */
+ static stringify(a: AmountLike): string {
+ a = Amounts.jsonifyAmount(a);
+ const av = a.value + Math.floor(a.fraction / amountFractionalBase);
+ const af = a.fraction % amountFractionalBase;
+ let s = av.toString();
+
+ if (af) {
+ s = s + ".";
+ let n = af;
+ for (let i = 0; i < amountFractionalLength; i++) {
+ if (!n) {
+ break;
+ }
+ s = s + Math.floor((n / amountFractionalBase) * 10).toString();
+ n = (n * 10) % amountFractionalBase;
+ }
+ }
+
+ return `${a.currency}:${s}`;
}
}
-
-
-// Export all amount-related functions here for better IDE experience.
-export const Amounts = {
- stringify: stringify,
- parse: parse,
- parseOrThrow: parseOrThrow,
- cmp: cmp,
- add: add,
- sum: sum,
- sub: sub,
- mult: mult,
- max: max,
- min: min,
- check: check,
- getZero: getZero,
- isZero: isZero,
- maxAmountValue: maxAmountValue,
- fromFloat: fromFloat,
- copy: copy,
- fractionalBase: fractionalBase,
- divide: divide,
-};
diff --git a/packages/taler-util/src/helpers.ts b/packages/taler-util/src/helpers.ts
index f5c204310..d3093d1b1 100644
--- a/packages/taler-util/src/helpers.ts
+++ b/packages/taler-util/src/helpers.ts
@@ -31,7 +31,7 @@ import { URL } from "./url";
* settings such as significant digits or currency symbols.
*/
export function amountToPretty(amount: AmountJson): string {
- const x = amount.value + amount.fraction / Amounts.fractionalBase;
+ const x = amount.value + amount.fraction / Amounts.amountFractionalBase;
return `${x} ${amount.currency}`;
}
diff --git a/packages/taler-util/src/talerTypes.ts b/packages/taler-util/src/talerTypes.ts
index bef7ab223..1019ce478 100644
--- a/packages/taler-util/src/talerTypes.ts
+++ b/packages/taler-util/src/talerTypes.ts
@@ -187,7 +187,7 @@ export interface RecoupRequest {
/**
* Response that we get from the exchange for a payback request.
*/
-export class RecoupConfirmation {
+export interface RecoupConfirmation {
/**
* Public key of the reserve that will receive the payback.
*/
@@ -235,7 +235,7 @@ export interface CoinDepositPermission {
* Information about an exchange as stored inside a
* merchant's contract terms.
*/
-export class ExchangeHandle {
+export interface ExchangeHandle {
/**
* Master public signing key of the exchange.
*/
@@ -247,7 +247,7 @@ export class ExchangeHandle {
url: string;
}
-export class AuditorHandle {
+export interface AuditorHandle {
/**
* Official name of the auditor.
*/
@@ -349,7 +349,7 @@ export interface InternationalizedString {
/**
* Contract terms from a merchant.
*/
-export class ContractTerms {
+export interface ContractTerms {
/**
* Hash of the merchant's wire details.
*/
@@ -489,7 +489,7 @@ export class ContractTerms {
/**
* Refund permission in the format that the merchant gives it to us.
*/
-export class MerchantAbortPayRefundDetails {
+export interface MerchantAbortPayRefundDetails {
/**
* Amount to be refunded.
*/
@@ -540,7 +540,7 @@ export class MerchantAbortPayRefundDetails {
/**
* Response for a refund pickup or a /pay in abort mode.
*/
-export class MerchantRefundResponse {
+export interface MerchantRefundResponse {
/**
* Public key of the merchant
*/
@@ -592,7 +592,7 @@ export interface TipPickupRequest {
* Reserve signature, defined as separate class to facilitate
* schema validation with "@Checkable".
*/
-export class BlindSigWrapper {
+export interface BlindSigWrapper {
/**
* Reserve signature.
*/
@@ -603,7 +603,7 @@ export class BlindSigWrapper {
* Response of the merchant
* to the TipPickupRequest.
*/
-export class TipResponse {
+export interface TipResponse {
/**
* The order of the signatures matches the planchets list.
*/
@@ -705,12 +705,12 @@ export class WireFeesJson {
end_date: Timestamp;
}
-export class AccountInfo {
+export interface AccountInfo {
payto_uri: string;
master_sig: string;
}
-export class ExchangeWireJson {
+export interface ExchangeWireJson {
accounts: AccountInfo[];
fees: { [methodName: string]: WireFeesJson[] };
}
diff --git a/packages/taler-util/src/talerconfig.ts b/packages/taler-util/src/talerconfig.ts
index fa8c2d40f..2a388f8d3 100644
--- a/packages/taler-util/src/talerconfig.ts
+++ b/packages/taler-util/src/talerconfig.ts
@@ -24,7 +24,7 @@
* Imports
*/
import { AmountJson } from "./amounts";
-import * as Amounts from "./amounts";
+import { Amounts } from "./amounts";
import fs from "fs";
export class ConfigError extends Error {