Question about parallelism

[paulocoutinhox]

Question

Hi, thanks for this lib.

I would just like to understand the mechanics behind the lib. Although I use it, I would just like to confirm with you that the transactions that Apple sends us are in a kind of queue in its lib and within the transaction loop this queue is being consumed.

In practice, what I want to validate is actually just a guarantee that this queue will never be processed in parallel or multiple times, but always in the sequence of received transactions.

Example for complete purchases (it run in parallel or only in sequence?):

DispatchQueue.global(qos: .background).async {
    SwiftyStoreKit.completeTransactions(atomically: false) { purchases in
        ItunesSubscriptionSystemService.completePurchases(purchases: purchases, onSuccess: {
            DispatchQueue.global(qos: .background).async {
                var canFinishTransaction = false
                
                for purchase in purchases {
                    // process transaction
                    canFinishTransaction = false
                    
                    if purchase.transaction.transactionState == .purchased {
                        let receiptData = SwiftyStoreKit.localReceiptData
                        let receiptString = (receiptData != nil ? receiptData!.base64EncodedString(options: []) : "")
                        
                        //[...]
                        //canFinishTransaction = true
                    } else if purchase.transaction.transactionState == .restored {
                        let receiptData = SwiftyStoreKit.localReceiptData
                        let receiptString = (receiptData != nil ? receiptData!.base64EncodedString(options: []) : "")
                        
                        //[...]
                        //canFinishTransaction = true
                    } else if purchase.transaction.transactionState == .failed {
                        //canFinishTransaction = false
                    }
                    
                    sleep(1)
                    
                    if canFinishTransaction, purchase.needsFinishTransaction {
                        SwiftyStoreKit.finishTransaction(purchase.transaction)
                    }
                }
            }
        }, onError: { _ in
            //
        })
    }
}

Example about restore:

DispatchQueue.main.async {
    UIUtil.showAlertLoading()
}

DispatchQueue.global(qos: .background).async {
    SwiftyStoreKit.restorePurchases(atomically: false, applicationUsername: "", completion: { results in
        DispatchQueue.global(qos: .background).async {
            if results.restoreFailedPurchases.count > 0 {
                // [...]
                // exit
            } else if results.restoredPurchases.count > 0 {
                var canFinishTransaction = false
                
                for (index, purchase) in results.restoredPurchases.enumerated() {
                    // canFinishTransaction = true
                    // [...]
                    // UIUtil.hideAlertLoading()
                }
            } else {
                // UIUtil.hideAlertLoading()
            }
        }
    })
}