RabbitHole Quest Protocol contest - SAAJ's results

Gas Optimizations Report

This report focuses on RabbitHole contest, in context of various improvements that can be made in terms of gas cost.

Some of the opportunities identified for improving gas efficiency throughout the codebase of RabbitHole Quest Protocol are categorised into 03 main areas; with further instances in each of the category.

Summary

[G-01] Multiple mappings can be combined into a single one (04 Instances)

[G-02] 0perator assignment is more gas efficient than compound assignment (01 Instance)

[G-03] Functions with public visibility, if not called within the contract needed to be changed external (27 Instances)

 

[G-01] Multiple mappings can be combine into a single one (04 Instances)

When multiple mappings are used in same function, it’s better to combined them into a single mapping of an address struct.

Combined mapping reduces storage slot per mapping and also are cheaper in terms of associated Stack operations calculation carried out.

Link to the Code:

1. https://github.com/rabbitholegg/quest-protocol/blob/8c4c1f71221570b14a0479c216583342bd652d8d/contracts/QuestFactory.sol#L28
2. https://github.com/rabbitholegg/quest-protocol/blob/8c4c1f71221570b14a0479c216583342bd652d8d/contracts/QuestFactory.sol#L30
3. https://github.com/rabbitholegg/quest-protocol/blob/8c4c1f71221570b14a0479c216583342bd652d8d/contracts/RabbitHoleReceipt.sol#L30
4. https://github.com/rabbitholegg/quest-protocol/blob/8c4c1f71221570b14a0479c216583342bd652d8d/contracts/RabbitHoleReceipt.sol#L34

[G-02] 0perator assignment is more gas efficient than compound assignment (01 Instance)

Compound assignment operators (+= / -=) are more expensive in terms of gas consumption and needs to be avoided.

Operator assignment (a = a + b / a - b) is preferable in terms of increasing gas optimization.

Link to the Code:

1. https://github.com/rabbitholegg/quest-protocol/blob/8c4c1f71221570b14a0479c216583342bd652d8d/contracts/Quest.sol#L115

[G-03] Public visibility consumes more gas as compared to external functions (27 Instances)

Functions with public visibility, if not called within the contract needed to be changed external.

Link to the Code:

1. https://github.com/rabbitholegg/quest-protocol/blob/8c4c1f71221570b14a0479c216583342bd652d8d/contracts/QuestFactory.sol#L37
2. https://github.com/rabbitholegg/quest-protocol/blob/8c4c1f71221570b14a0479c216583342bd652d8d/contracts/QuestFactory.sol#L61
3. https://github.com/rabbitholegg/quest-protocol/blob/8c4c1f71221570b14a0479c216583342bd652d8d/contracts/QuestFactory.sol#L142
4. https://github.com/rabbitholegg/quest-protocol/blob/8c4c1f71221570b14a0479c216583342bd652d8d/contracts/QuestFactory.sol#L159
5. https://github.com/rabbitholegg/quest-protocol/blob/8c4c1f71221570b14a0479c216583342bd652d8d/contracts/QuestFactory.sol#L172
6. https://github.com/rabbitholegg/quest-protocol/blob/8c4c1f71221570b14a0479c216583342bd652d8d/contracts/QuestFactory.sol#L193
7. https://github.com/rabbitholegg/quest-protocol/blob/8c4c1f71221570b14a0479c216583342bd652d8d/contracts/QuestFactory.sol#L199
8. https://github.com/rabbitholegg/quest-protocol/blob/8c4c1f71221570b14a0479c216583342bd652d8d/contracts/QuestFactory.sol#L219
9. https://github.com/rabbitholegg/quest-protocol/blob/8c4c1f71221570b14a0479c216583342bd652d8d/contracts/RabbitHoleReceipt.sol#L43
10. https://github.com/rabbitholegg/quest-protocol/blob/8c4c1f71221570b14a0479c216583342bd652d8d/contracts/RabbitHoleReceipt.sol#L65
11. https://github.com/rabbitholegg/quest-protocol/blob/8c4c1f71221570b14a0479c216583342bd652d8d/contracts/RabbitHoleReceipt.sol#L71
12. https://github.com/rabbitholegg/quest-protocol/blob/8c4c1f71221570b14a0479c216583342bd652d8d/contracts/RabbitHoleReceipt.sol#L77
13. https://github.com/rabbitholegg/quest-protocol/blob/8c4c1f71221570b14a0479c216583342bd652d8d/contracts/RabbitHoleReceipt.sol#L83
14. https://github.com/rabbitholegg/quest-protocol/blob/8c4c1f71221570b14a0479c216583342bd652d8d/contracts/RabbitHoleReceipt.sol#L90
15. https://github.com/rabbitholegg/quest-protocol/blob/8c4c1f71221570b14a0479c216583342bd652d8d/contracts/RabbitHoleReceipt.sol#L109
16. https://github.com/rabbitholegg/quest-protocol/blob/8c4c1f71221570b14a0479c216583342bd652d8d/contracts/Quest.sol#L50
17. https://github.com/rabbitholegg/quest-protocol/blob/8c4c1f71221570b14a0479c216583342bd652d8d/contracts/Quest.sol#L96
18. https://github.com/rabbitholegg/quest-protocol/blob/8c4c1f71221570b14a0479c216583342bd652d8d/contracts/Quest.sol#L140
19. https://github.com/rabbitholegg/quest-protocol/blob/8c4c1f71221570b14a0479c216583342bd652d8d/contracts/Quest.sol#L145
20. https://github.com/rabbitholegg/quest-protocol/blob/8c4c1f71221570b14a0479c216583342bd652d8d/contracts/RabbitHoleTickets.sol#L32
21. https://github.com/rabbitholegg/quest-protocol/blob/8c4c1f71221570b14a0479c216583342bd652d8d/contracts/RabbitHoleTickets.sol#L54
22. https://github.com/rabbitholegg/quest-protocol/blob/8c4c1f71221570b14a0479c216583342bd652d8d/contracts/RabbitHoleTickets.sol#L60
23. https://github.com/rabbitholegg/quest-protocol/blob/8c4c1f71221570b14a0479c216583342bd652d8d/contracts/RabbitHoleTickets.sol#L66
24. https://github.com/rabbitholegg/quest-protocol/blob/8c4c1f71221570b14a0479c216583342bd652d8d/contracts/RabbitHoleTickets.sol#L73
25. https://github.com/rabbitholegg/quest-protocol/blob/8c4c1f71221570b14a0479c216583342bd652d8d/contracts/Erc20Quest.sol#L102
26. https://github.com/rabbitholegg/quest-protocol/blob/8c4c1f71221570b14a0479c216583342bd652d8d/contracts/ReceiptRenderer.sol#L21
27. https://github.com/rabbitholegg/quest-protocol/blob/8c4c1f71221570b14a0479c216583342bd652d8d/contracts/TicketRenderer.sol#L16