fix: push notification registration latency on PinScreen

[alexruzenhack]

Acceptance Criteria

• fix: PinScreen dismiss response
• fix: exits script after dispatch failure effect
• fix: replace BLOCKED to DENIED enum value
• fix: push notification authorization logic

PinScreen response latency now in miliseconds:

pinscreen-response-latency.mp4

Closes: #415

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Performance Profiling

We have 2 major offenders:

• generateAccessDataFromSeed consuming ~4s
• generateCreateWalletAuthData consuming ~14s

Under generateCreateWalletAuthData we have other 3 offenders:

• getXPrivKeyFromSeed using ~4s
• getXPubKeyFromSeed using ~4s
• getAuthXPubKeyFromSeed using ~4s

Both getXPubKeyFromSeed and getAuthXPubKeyFromSeed calls getXPrivKeyFromSeed under the hood, which took almost all execution time. Therefore the real offender for this group is getXPrivKeyFromSeed.

Wallet start

Both methods generateAccessDataFromSeed and generateCreateWalletAuthData are called from wallet start. We start an instance of HathorWalletServiceWallet when a user is operating a fullnode's wallet facade.

There are 4 options to try to solve or reduce the effect of this latency, either:

1. We implement a common wallet API to mount an authentication payload that can be used to call wallet-service API without the need to instantiate HathorWalletServiceWallet.
2. We store the HathorWalletServiceWallet instance once it is started for the first time, which can decrease the latency for subsequent interactions with push notification operations.
3. We remove support of push notification for users operating a fullnode's wallet facade and make it a feature strict to wallet-service users; which would allow us to remove this logic to instantiate a HathorWalletServiceWallet.
4. We implement a lightweight wallet just for the purpose to call wallet-service APIs.

We can discuss other possibilities, these ones were the ones I identified quickly without thinking too much.

Note

PM me to get the profiler.

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Security Checklist

• Make sure you do not include new dependencies in the project unless strictly necessary and do not include dev-dependencies as production ones. More dependencies increase the possibility of one of them being hijacked and affecting us.

[pedroferreira1]

Does it work if you use delay(0)?

[alexruzenhack]

Good point. I will test.