smom-dbis-138/docs/bridge/trustless/BATCH_PROCESSING.md

Batch Processing Documentation

Overview

This document describes batch processing capabilities for the trustless bridge system, allowing multiple operations to be executed in a single transaction.

Current State

Individual Operations

Currently, all operations are individual:

• One claim submission per transaction
• One challenge per transaction
• One finalization per transaction

Gas Costs

• Multiple transactions = multiple base costs (21k gas each)
• Batch operations = single base cost + operation costs

Proposed Batch Functions

1. Batch Claim Submission

Function: InboxETH.submitClaimsBatch()

Implementation:

function submitClaimsBatch(
    uint256[] calldata depositIds,
    address[] calldata assets,
    uint256[] calldata amounts,
    address[] calldata recipients,
    bytes[] calldata proofs
) external payable {
    require(depositIds.length == assets.length, "Length mismatch");
    require(depositIds.length == amounts.length, "Length mismatch");
    require(depositIds.length == recipients.length, "Length mismatch");
    
    uint256 totalBond = 0;
    for (uint256 i = 0; i < depositIds.length; i++) {
        totalBond += bondManager.getRequiredBond(amounts[i]);
    }
    require(msg.value >= totalBond, "Insufficient bond");
    
    for (uint256 i = 0; i < depositIds.length; i++) {
        submitClaim(depositIds[i], assets[i], amounts[i], recipients[i], proofs[i]);
    }
}

Gas Savings: ~20k gas per additional claim (saves base cost)

2. Batch Finalization

Function: ChallengeManager.finalizeClaimsBatch()

Implementation:

function finalizeClaimsBatch(uint256[] calldata depositIds) external {
    for (uint256 i = 0; i < depositIds.length; i++) {
        finalizeClaim(depositIds[i]);
    }
}

Gas Savings: ~20k gas per additional finalization

3. Batch Bond Release

Function: BondManager.releaseBondsBatch()

Implementation:

function releaseBondsBatch(uint256[] calldata depositIds) external {
    for (uint256 i = 0; i < depositIds.length; i++) {
        releaseBond(depositIds[i]);
    }
}

Gas Savings: ~20k gas per additional release

Benefits

1. Gas Efficiency

• Single base cost (21k gas) vs multiple
• Significant savings for multiple operations
• Example: 10 claims = 210k gas saved

2. User Experience

• Faster processing
• Single transaction
• Lower total gas costs

3. Network Efficiency

• Fewer transactions
• Reduced network congestion
• Lower overall gas usage

Considerations

1. Transaction Size

• Batch operations increase transaction size
• May hit block gas limit
• Recommend max batch size (e.g., 50 operations)

2. Error Handling

• If one operation fails, entire batch fails
• Consider partial success mechanisms
• Or revert all on any failure

3. Reentrancy

• Batch operations increase reentrancy risk
• Ensure proper guards
• Use nonReentrant modifier

Implementation

Priority

1. High: Batch finalization (most common)
2. Medium: Batch claim submission
3. Low: Batch bond release

Testing

Create comprehensive tests:

• test/bridge/trustless/BatchOperations.t.sol
• Test batch sizes
• Test error handling
• Test gas costs

References

• Contracts: contracts/bridge/trustless/
• Test Suite: test/bridge/trustless/BatchOperations.t.sol