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authorFlorian Dold <florian@dold.me>2021-03-27 19:35:44 +0100
committerFlorian Dold <florian@dold.me>2021-03-27 19:35:44 +0100
commit93128f935817c86172406c9de41677db125d0273 (patch)
tree12edbc6d39cb365bf75797f552fa8b690556dc19 /packages/taler-wallet-core/src
parentd44740b787c974c5388811a2989557d93923c49a (diff)
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fix coin selection
Diffstat (limited to 'packages/taler-wallet-core/src')
-rw-r--r--packages/taler-wallet-core/src/operations/pay.ts70
-rw-r--r--packages/taler-wallet-core/src/util/coinSelection.ts215
2 files changed, 206 insertions, 79 deletions
diff --git a/packages/taler-wallet-core/src/operations/pay.ts b/packages/taler-wallet-core/src/operations/pay.ts
index 168a0f965..da3980565 100644
--- a/packages/taler-wallet-core/src/operations/pay.ts
+++ b/packages/taler-wallet-core/src/operations/pay.ts
@@ -24,12 +24,72 @@
/**
* Imports.
*/
-import { AmountJson, Amounts, timestampIsBetween, getTimestampNow, isTimestampExpired, Timestamp, RefreshReason, CoinDepositPermission, NotificationType, TalerErrorDetails, Duration, durationMax, durationMin, durationMul, ContractTerms, codecForProposal, TalerErrorCode, codecForContractTerms, timestampAddDuration, ConfirmPayResult, ConfirmPayResultType, codecForMerchantPayResponse, PreparePayResult, PreparePayResultType, parsePayUri } from "@gnu-taler/taler-util";
+import {
+ AmountJson,
+ Amounts,
+ timestampIsBetween,
+ getTimestampNow,
+ isTimestampExpired,
+ Timestamp,
+ RefreshReason,
+ CoinDepositPermission,
+ NotificationType,
+ TalerErrorDetails,
+ Duration,
+ durationMax,
+ durationMin,
+ durationMul,
+ ContractTerms,
+ codecForProposal,
+ TalerErrorCode,
+ codecForContractTerms,
+ timestampAddDuration,
+ ConfirmPayResult,
+ ConfirmPayResultType,
+ codecForMerchantPayResponse,
+ PreparePayResult,
+ PreparePayResultType,
+ parsePayUri,
+} from "@gnu-taler/taler-util";
import { encodeCrock, getRandomBytes } from "../crypto/talerCrypto";
-import { AbortStatus, AllowedAuditorInfo, AllowedExchangeInfo, CoinRecord, CoinStatus, DenominationRecord, getHttpResponseErrorDetails, guardOperationException, HttpResponseStatus, Logger, makeErrorDetails, OperationFailedAndReportedError, OperationFailedError, ProposalRecord, ProposalStatus, PurchaseRecord, readSuccessResponseJsonOrErrorCode, readSuccessResponseJsonOrThrow, readTalerErrorResponse, Stores, throwUnexpectedRequestError, TransactionHandle, URL, WalletContractData } from "../index.js";
-import { PayCoinSelection, CoinCandidateSelection, AvailableCoinInfo, selectPayCoins } from "../util/coinSelection.js";
+import {
+ AbortStatus,
+ AllowedAuditorInfo,
+ AllowedExchangeInfo,
+ CoinRecord,
+ CoinStatus,
+ DenominationRecord,
+ getHttpResponseErrorDetails,
+ guardOperationException,
+ HttpResponseStatus,
+ Logger,
+ makeErrorDetails,
+ OperationFailedAndReportedError,
+ OperationFailedError,
+ ProposalRecord,
+ ProposalStatus,
+ PurchaseRecord,
+ readSuccessResponseJsonOrErrorCode,
+ readSuccessResponseJsonOrThrow,
+ readTalerErrorResponse,
+ Stores,
+ throwUnexpectedRequestError,
+ TransactionHandle,
+ URL,
+ WalletContractData,
+} from "../index.js";
+import {
+ PayCoinSelection,
+ CoinCandidateSelection,
+ AvailableCoinInfo,
+ selectPayCoins,
+} from "../util/coinSelection.js";
import { canonicalJson } from "../util/helpers.js";
-import { initRetryInfo, updateRetryInfoTimeout, getRetryDuration } from "../util/retries.js";
+import {
+ initRetryInfo,
+ updateRetryInfoTimeout,
+ getRetryDuration,
+} from "../util/retries.js";
import { getTotalRefreshCost, createRefreshGroup } from "./refresh.js";
import { InternalWalletState, EXCHANGE_COINS_LOCK } from "./state.js";
@@ -38,7 +98,6 @@ import { InternalWalletState, EXCHANGE_COINS_LOCK } from "./state.js";
*/
const logger = new Logger("pay.ts");
-
/**
* Compute the total cost of a payment to the customer.
*
@@ -123,7 +182,6 @@ export async function getEffectiveDepositAmount(
return Amounts.sub(Amounts.sum(amt).amount, Amounts.sum(fees).amount).amount;
}
-
export function isSpendableCoin(
coin: CoinRecord,
denom: DenominationRecord,
diff --git a/packages/taler-wallet-core/src/util/coinSelection.ts b/packages/taler-wallet-core/src/util/coinSelection.ts
index e9cec6144..a840993c4 100644
--- a/packages/taler-wallet-core/src/util/coinSelection.ts
+++ b/packages/taler-wallet-core/src/util/coinSelection.ts
@@ -23,8 +23,11 @@
/**
* Imports.
*/
-import { AmountJson, Amounts } from "@gnu-taler/taler-util";
-import { strcmp } from "./helpers";
+import { AmountJson, AmountLike, Amounts } from "@gnu-taler/taler-util";
+import { strcmp } from "./helpers.js";
+import { Logger } from "./logging.js";
+
+const logger = new Logger("coinSelection.ts");
/**
* Result of selecting coins, contains the exchange, and selected
@@ -107,6 +110,103 @@ export interface SelectPayCoinRequest {
prevPayCoins?: PreviousPayCoins;
}
+interface CoinSelectionTally {
+ /**
+ * Amount that still needs to be paid.
+ * May increase during the computation when fees need to be covered.
+ */
+ amountPayRemaining: AmountJson;
+
+ /**
+ * Allowance given by the merchant towards wire fees
+ */
+ amountWireFeeLimitRemaining: AmountJson;
+
+ /**
+ * Allowance given by the merchant towards deposit fees
+ * (and wire fees after wire fee limit is exhausted)
+ */
+ amountDepositFeeLimitRemaining: AmountJson;
+
+ customerDepositFees: AmountJson;
+
+ customerWireFees: AmountJson;
+
+ wireFeeCoveredForExchange: Set<string>;
+}
+
+/**
+ * Account for the fees of spending a coin.
+ */
+function tallyFees(
+ tally: CoinSelectionTally,
+ wireFeesPerExchange: Record<string, AmountJson>,
+ wireFeeAmortization: number,
+ exchangeBaseUrl: string,
+ feeDeposit: AmountJson,
+): CoinSelectionTally {
+ const currency = tally.amountPayRemaining.currency;
+ let amountWireFeeLimitRemaining = tally.amountWireFeeLimitRemaining;
+ let amountDepositFeeLimitRemaining = tally.amountDepositFeeLimitRemaining;
+ let customerDepositFees = tally.customerDepositFees;
+ let customerWireFees = tally.customerWireFees;
+ let amountPayRemaining = tally.amountPayRemaining;
+ const wireFeeCoveredForExchange = new Set(tally.wireFeeCoveredForExchange);
+
+ if (!tally.wireFeeCoveredForExchange.has(exchangeBaseUrl)) {
+ const wf =
+ wireFeesPerExchange[exchangeBaseUrl] ?? Amounts.getZero(currency);
+ const wfForgiven = Amounts.min(amountWireFeeLimitRemaining, wf);
+ amountWireFeeLimitRemaining = Amounts.sub(
+ amountWireFeeLimitRemaining,
+ wfForgiven,
+ ).amount;
+ // The remaining, amortized amount needs to be paid by the
+ // wallet or covered by the deposit fee allowance.
+ let wfRemaining = Amounts.divide(
+ Amounts.sub(wf, wfForgiven).amount,
+ wireFeeAmortization,
+ );
+
+ // This is the amount forgiven via the deposit fee allowance.
+ const wfDepositForgiven = Amounts.min(
+ amountDepositFeeLimitRemaining,
+ wfRemaining,
+ );
+ amountDepositFeeLimitRemaining = Amounts.sub(
+ amountDepositFeeLimitRemaining,
+ wfDepositForgiven,
+ ).amount;
+
+ wfRemaining = Amounts.sub(wfRemaining, wfDepositForgiven).amount;
+ customerWireFees = Amounts.add(customerWireFees, wfRemaining).amount;
+ amountPayRemaining = Amounts.add(amountPayRemaining, wfRemaining).amount;
+
+ wireFeeCoveredForExchange.add(exchangeBaseUrl);
+ }
+
+ const dfForgiven = Amounts.min(feeDeposit, amountDepositFeeLimitRemaining);
+
+ amountDepositFeeLimitRemaining = Amounts.sub(
+ amountDepositFeeLimitRemaining,
+ dfForgiven,
+ ).amount;
+
+ // How much does the user spend on deposit fees for this coin?
+ const dfRemaining = Amounts.sub(feeDeposit, dfForgiven).amount;
+ customerDepositFees = Amounts.add(customerDepositFees, dfRemaining).amount;
+ amountPayRemaining = Amounts.add(amountPayRemaining, dfRemaining).amount;
+
+ return {
+ amountDepositFeeLimitRemaining,
+ amountPayRemaining,
+ amountWireFeeLimitRemaining,
+ customerDepositFees,
+ customerWireFees,
+ wireFeeCoveredForExchange,
+ };
+}
+
/**
* Given a list of candidate coins, select coins to spend under the merchant's
* constraints.
@@ -134,75 +234,31 @@ export function selectPayCoins(
const coinPubs: string[] = [];
const coinContributions: AmountJson[] = [];
const currency = contractTermsAmount.currency;
- // Amount that still needs to be paid.
- // May increase during the computation when fees need to be covered.
- let amountPayRemaining = contractTermsAmount;
- // Allowance given by the merchant towards wire fees
- let amountWireFeeLimitRemaining = wireFeeLimit;
- // Allowance given by the merchant towards deposit fees
- // (and wire fees after wire fee limit is exhausted)
- let amountDepositFeeLimitRemaining = depositFeeLimit;
- let customerDepositFees = Amounts.getZero(currency);
- let customerWireFees = Amounts.getZero(currency);
-
- const wireFeeCoveredForExchange: Set<string> = new Set();
- /**
- * Account for the fees of spending a coin.
- */
- function tallyFees(exchangeBaseUrl: string, feeDeposit: AmountJson): void {
- if (!wireFeeCoveredForExchange.has(exchangeBaseUrl)) {
- const wf =
- candidates.wireFeesPerExchange[exchangeBaseUrl] ??
- Amounts.getZero(currency);
- const wfForgiven = Amounts.min(amountWireFeeLimitRemaining, wf);
- amountWireFeeLimitRemaining = Amounts.sub(
- amountWireFeeLimitRemaining,
- wfForgiven,
- ).amount;
- // The remaining, amortized amount needs to be paid by the
- // wallet or covered by the deposit fee allowance.
- let wfRemaining = Amounts.divide(
- Amounts.sub(wf, wfForgiven).amount,
- wireFeeAmortization,
- );
-
- // This is the amount forgiven via the deposit fee allowance.
- const wfDepositForgiven = Amounts.min(
- amountDepositFeeLimitRemaining,
- wfRemaining,
- );
- amountDepositFeeLimitRemaining = Amounts.sub(
- amountDepositFeeLimitRemaining,
- wfDepositForgiven,
- ).amount;
-
- wfRemaining = Amounts.sub(wfRemaining, wfDepositForgiven).amount;
- customerWireFees = Amounts.add(customerWireFees, wfRemaining).amount;
- amountPayRemaining = Amounts.add(amountPayRemaining, wfRemaining).amount;
- wireFeeCoveredForExchange.add(exchangeBaseUrl);
- }
-
- const dfForgiven = Amounts.min(feeDeposit, amountDepositFeeLimitRemaining);
-
- amountDepositFeeLimitRemaining = Amounts.sub(
- amountDepositFeeLimitRemaining,
- dfForgiven,
- ).amount;
-
- // How much does the user spend on deposit fees for this coin?
- const dfRemaining = Amounts.sub(feeDeposit, dfForgiven).amount;
- customerDepositFees = Amounts.add(customerDepositFees, dfRemaining).amount;
- amountPayRemaining = Amounts.add(amountPayRemaining, dfRemaining).amount;
- }
+ let tally: CoinSelectionTally = {
+ amountPayRemaining: contractTermsAmount,
+ amountWireFeeLimitRemaining: wireFeeLimit,
+ amountDepositFeeLimitRemaining: depositFeeLimit,
+ customerDepositFees: Amounts.getZero(currency),
+ customerWireFees: Amounts.getZero(currency),
+ wireFeeCoveredForExchange: new Set(),
+ };
const prevPayCoins = req.prevPayCoins ?? [];
// Look at existing pay coin selection and tally up
for (const prev of prevPayCoins) {
- tallyFees(prev.exchangeBaseUrl, prev.feeDeposit);
- amountPayRemaining = Amounts.sub(amountPayRemaining, prev.contribution)
- .amount;
+ tally = tallyFees(
+ tally,
+ candidates.wireFeesPerExchange,
+ wireFeeAmortization,
+ prev.exchangeBaseUrl,
+ prev.feeDeposit,
+ );
+ tally.amountPayRemaining = Amounts.sub(
+ tally.amountPayRemaining,
+ prev.contribution,
+ ).amount;
coinPubs.push(prev.coinPub);
coinContributions.push(prev.contribution);
@@ -231,7 +287,7 @@ export function selectPayCoins(
if (Amounts.cmp(aci.feeDeposit, aci.availableAmount) >= 0) {
continue;
}
- if (Amounts.isZero(amountPayRemaining)) {
+ if (Amounts.isZero(tally.amountPayRemaining)) {
// We have spent enough!
break;
}
@@ -242,21 +298,34 @@ export function selectPayCoins(
continue;
}
- tallyFees(aci.exchangeBaseUrl, aci.feeDeposit);
-
- const coinSpend = Amounts.min(amountPayRemaining, aci.availableAmount);
- amountPayRemaining = Amounts.sub(amountPayRemaining, coinSpend).amount;
+ tally = tallyFees(
+ tally,
+ candidates.wireFeesPerExchange,
+ wireFeeAmortization,
+ aci.exchangeBaseUrl,
+ aci.feeDeposit,
+ );
+
+ let coinSpend = Amounts.max(
+ Amounts.min(tally.amountPayRemaining, aci.availableAmount),
+ aci.feeDeposit,
+ );
+
+ tally.amountPayRemaining = Amounts.sub(
+ tally.amountPayRemaining,
+ coinSpend,
+ ).amount;
coinPubs.push(aci.coinPub);
coinContributions.push(coinSpend);
}
- if (Amounts.isZero(amountPayRemaining)) {
+ if (Amounts.isZero(tally.amountPayRemaining)) {
return {
paymentAmount: contractTermsAmount,
coinContributions,
coinPubs,
- customerDepositFees,
- customerWireFees,
+ customerDepositFees: tally.customerDepositFees,
+ customerWireFees: tally.customerWireFees,
};
}
return undefined;