Submission Details
Severity:
Boolean Optimization in Mappings of `CharityRegistry.sol`
Description: Using boolean values in mappings is inefficient from a gas perspective. Each slot in storage is 32 bytes, but we only need 1 bit to store a boolean.
mapping(address => bool) public verifiedCharities;
mapping(address => bool) public registeredCharities;
Impact:
Unnecessary gas consumption during storage operations
Higher deployment costs
Increased transaction costs for users
Gas Savings:
Storage Write (Original): ~20,000 gas
Storage Write (Optimized): ~5,000 gas
Potential savings: ~15,000 gas per storage operation
Recommended Mitigation:
// Use uint256 for packing multiple booleans
mapping(address => uint256) public charityStatus;
// Constants for bit positions
uint256 constant REGISTERED_BIT = 1;
uint256 constant VERIFIED_BIT = 2;
function registerCharity(address charity) public onlyAdmin {
charityStatus[charity] |= REGISTERED_BIT;
emit CharityRegistered(charity);
}
function isRegistered(address charity) public view returns (bool) {
return charityStatus[charity] & REGISTERED_BIT != 0;
}
Rewards breakdown
nSLOC
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20 EXP
2 EXP
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