Implement a Conditional update:

Conditional update is a common optimistic approach to keep data consistent in the face of concurrent accessing, that is, consistency in the face of concurrency. For more about such a case, please refer to the Q&A here : Users can concurrently withdraw above their wallet balance by initiating multiple concurrent withdrawals

Note: The refactored code below may differ in syntax as I follow mongoose for Object modelling. However the logic for a conditional update remains the same, please apply the necessary syntactical corrections with respect to prisma in the given statement.

Please refactor the below code :

if (apiResponse.success) {
  // Deduct the balance after successful payout
  await this.user.findOneAndUpdate({
    { id: userId },
     { totalPayout: availableBalance - payoutAmount },
  });
}

as this :

// performing a conditional update to safeguard
// the possible write-write conflict
if (apiResponse.success) {
  // Deduct the balance after successful payout
  const newDoc = await this.user.findOneAndUpdate({
    { id: userId, totalPayout: { $gte : availableBalance  } },
    { totalPayout: availableBalance - payoutAmount },
  });

 // informing user for the needful action
  if (newdoc) {
    console.log(`Updation passed`);
  } else {
    console.log(
      `Updation failed - write-write conflict detected`
    );
    // please provide the code to revert the payout transaction here.
  }
}

The refactored code equipped with the conditional update checks for the sufficient balance at time of the update. If there is sufficient balance, then it is safe to proceed, otherwise, it means, there is a race condition has ben occurred, some other user session has already utilised the balance. Under the event of aborting the update, the user must be informed accordingly, and the payout transaction which has already been taken place must be reverted as well.

Please also note that, if there had been concurrent session which utilised some balance, still there is enough left for the current transaction, then it is safe to proceed. Therefore this approach does not work in a pessimistic way so that even a possible concurrent transaction will be blocked.