Function applyTransaction

database/balance.go:1518–1540

applyTransaction applies a single transaction to update balance totals

(txn struct {
	PreciseAmount string
	Source        string
	Destination   string
	CreatedAt     time.Time
	EffectiveDate time.Time
}, balanceID string, creditBalance, debitBalance *big.Int,
)

// applyTransaction applies a single transaction to update balance totals
func applyTransaction(txn struct {
	PreciseAmount string
	Source        string
	Destination   string
	CreatedAt     time.Time
	EffectiveDate time.Time
}, balanceID string, creditBalance, debitBalance *big.Int,
) (*big.Int, *big.Int, error) {
	txAmount, ok := new(big.Int).SetString(txn.PreciseAmount, 10)
	if !ok {
		return nil, nil, apierror.NewAPIError(apierror.ErrInternalServer, "Invalid transaction amount", nil)
	}

	// Use the transaction amount to update the appropriate balance
	if txn.Source == balanceID {
		debitBalance = new(big.Int).Add(debitBalance, txAmount)
	}
	if txn.Destination == balanceID {
		creditBalance = new(big.Int).Add(creditBalance, txAmount)
	}

	return creditBalance, debitBalance, nil
}

// calculateBalanceFromTransactions applies transactions to calculate the balance at a specific time
func (d Datasource) calculateBalanceFromTransactions(ctx context.Context, tx *sql.Tx, balanceID string, startTime time.Time, targetTime time.Time, initialCredit, initialDebit *big.Int) (creditBalance, debitBalance *big.Int, err error) {