feat: add metadata event emitter contract #1138
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Signed-off-by: amateima <amatei@umaproject.org>
Signed-off-by: amateima <amatei@umaproject.org>
amateima
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contracts/AcrossEventEmitter.sol
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| /** | ||
| * @notice Prevents native token from being sent to this contract | ||
| */ | ||
| receive() external payable { | ||
| revert("Contract does not accept native token"); | ||
| } | ||
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| /** | ||
| * @notice Prevents native token from being sent to this contract via fallback | ||
| */ | ||
| fallback() external payable { | ||
| revert("Contract doesn't accept native token"); | ||
| } |
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nit: why implement these functions at all?
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I considered would be good practice to not allow funds being sent by mistake, but I can remove this
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If you don't implement them, they'll revert when users try to call them, so it would be the same outcome.
contracts/AcrossEventEmitter.sol
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| require(data.length > 0, "Data cannot be empty"); | ||
| require(data.length <= 2048, "Data too large"); |
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Why limit the size of the data?
Would this protect us from anything?
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I removed the upper limit here, but I'd keep the > 0 validation, so that the indexer would not index events with no metadata at all
Signed-off-by: amateima <amatei@umaproject.org>
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contracts/AcrossEventEmitter.sol
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| * @notice Emits metadata as an event | ||
| * @param data The bytes data to emit | ||
| */ | ||
| function emitData(bytes calldata data) external nonReentrant { |
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Re-entrancy guards are generally best practice, but you don't need them if your contract isn't making any external calls (which is the case in this contract).
I would suggest removing to save a little gas.
This PR introduces a new
AcrossEventEmittercontract that provides a dedicated mechanism for emitting on-chain metadata events.Changes
AcrossEventEmitteris a simple contract for emitting arbitrary bytes-encoded metadata as on-chain events. The usecase behind this contract is to emit metadata without modifying Across core contracts. This will allow the indexer to enrich Across protocol data with additional info that cannot be grabbed easily from onchain events (e.g swaps performed as destination actions)