Spark fee calculation fix

[levonpetrosyan93]

Summary by CodeRabbit

• Refactor
  • Improved the accuracy of transaction size calculations in the wallet, affecting fees and transaction times.

[coderabbitai]

Walkthrough

The recent update brings a refined approach to the calculation of transaction sizes in the wallet software. It specifically adjusts the way nBytes—a key metric representing the size of transactions—is computed. This adjustment takes into account various factors such as different types of proofs, data sizes, and the components of transactions, ensuring more accurate estimations and optimizations for users.

Changes

Files	Change Summary
.../coincontroldialog.cpp, .../sparkwallet.cpp	Adjusted nBytes calculation to include various proofs, data sizes, grootle proofs, private outputs, and transaction parts.

🐰✨
Changes abound, in the code, they're found,
Bytes dance, numbers prance, in a more precise round.
With each proof and byte, our transactions take flight,
A hop, skip, and a jump, towards efficiency's light.
🌟🚀🐇

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Actionable comments posted: 0

Review Status

Configuration used: CodeRabbit UI

Commits

Files that changed from the base of the PR and between 17aab98 and dfb75e3.

Files selected for processing (2)

• src/qt/coincontroldialog.cpp (1 hunks)
• src/spark/sparkwallet.cpp (1 hunks)

Additional comments not posted (5)

src/qt/coincontroldialog.cpp (1)

530-532: The adjustments to the nBytes calculation for Spark transactions introduce specific constants and multipliers for different transaction components. Ensure these values accurately reflect the transaction structure and sizes for Spark and other proofs. It's crucial to validate these constants against the actual transaction sizes to prevent underestimating or overestimating transaction fees.

Consider adding comments detailing the source or rationale behind these constants and multipliers for future maintainability and clarity. This will help others understand the basis of these calculations and make it easier to update them if transaction structures change.

src/spark/sparkwallet.cpp (4)

1698-1700: The calculation for the transaction size seems to be hardcoded with specific values for grootle proofs, private outputs, and transaction parts. This approach might not be flexible or accurate for future changes or different transaction types.

Consider implementing a more dynamic way to calculate transaction sizes based on the actual components of the transaction. This could involve calculating sizes based on the serialized sizes of each component or using predefined constants that can be easily updated.

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1698-1700: The loop for fee estimation in SelectSparkCoins recalculates the required amount and selects coins until the estimated fee stabilizes. However, this approach might lead to unnecessary iterations if the fee estimation does not change significantly between iterations.

Consider adding a condition to break out of the loop if the difference between the new fee and the previous fee is below a certain threshold. This could improve efficiency by avoiding unnecessary iterations.

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1698-1700: The method GetAvailableSparkCoins correctly filters out coins based on coin control selection and locked coins. However, the readability of the lambda function used for filtering could be improved.

Consider extracting the lambda function into a separate, named function or adding comments to explain the filtering criteria more clearly. This could improve the readability and maintainability of the code.

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1698-1700: The method CreateSparkSpendTransaction contains complex logic for creating a Spark spend transaction. The error handling in this method could be improved to provide more detailed information about the failure reasons.

Consider adding more specific error messages or exceptions for different failure scenarios, such as insufficient funds, transaction size limits, or invalid inputs. This could help in diagnosing issues more effectively.