@hyperlane-xyz/core

# ICanonicalTransactionChain > ICanonicalTransactionChain ## Methods ### appendSequencerBatch ```solidity function appendSequencerBatch() external nonpayable ``` Allows the sequencer to append a batch of transactions. *This function uses a custom encoding scheme for efficiency reasons. .param _shouldStartAtElement Specific batch we expect to start appending to. .param _totalElementsToAppend Total number of batch elements we expect to append. .param _contexts Array of batch contexts. .param _transactionDataFields Array of raw transaction data.* ### batches ```solidity function batches() external view returns (contract IChainStorageContainer) ``` Accesses the batch storage container. #### Returns | Name | Type | Description | |---|---|---| | _0 | contract IChainStorageContainer | Reference to the batch storage container. ### enqueue ```solidity function enqueue(address _target, uint256 _gasLimit, bytes _data) external nonpayable ``` Adds a transaction to the queue. #### Parameters | Name | Type | Description | |---|---|---| | _target | address | Target contract to send the transaction to. | _gasLimit | uint256 | Gas limit for the given transaction. | _data | bytes | Transaction data. ### getLastBlockNumber ```solidity function getLastBlockNumber() external view returns (uint40) ``` Returns the blocknumber of the last transaction. #### Returns | Name | Type | Description | |---|---|---| | _0 | uint40 | Blocknumber for the last transaction. ### getLastTimestamp ```solidity function getLastTimestamp() external view returns (uint40) ``` Returns the timestamp of the last transaction. #### Returns | Name | Type | Description | |---|---|---| | _0 | uint40 | Timestamp for the last transaction. ### getNextQueueIndex ```solidity function getNextQueueIndex() external view returns (uint40) ``` Returns the index of the next element to be enqueued. #### Returns | Name | Type | Description | |---|---|---| | _0 | uint40 | Index for the next queue element. ### getNumPendingQueueElements ```solidity function getNumPendingQueueElements() external view returns (uint40) ``` Get the number of queue elements which have not yet been included. #### Returns | Name | Type | Description | |---|---|---| | _0 | uint40 | Number of pending queue elements. ### getQueueElement ```solidity function getQueueElement(uint256 _index) external view returns (struct Lib_OVMCodec.QueueElement _element) ``` Gets the queue element at a particular index. #### Parameters | Name | Type | Description | |---|---|---| | _index | uint256 | Index of the queue element to access. #### Returns | Name | Type | Description | |---|---|---| | _element | Lib_OVMCodec.QueueElement | Queue element at the given index. ### getQueueLength ```solidity function getQueueLength() external view returns (uint40) ``` Retrieves the length of the queue, including both pending and canonical transactions. #### Returns | Name | Type | Description | |---|---|---| | _0 | uint40 | Length of the queue. ### getTotalBatches ```solidity function getTotalBatches() external view returns (uint256 _totalBatches) ``` Retrieves the total number of batches submitted. #### Returns | Name | Type | Description | |---|---|---| | _totalBatches | uint256 | Total submitted batches. ### getTotalElements ```solidity function getTotalElements() external view returns (uint256 _totalElements) ``` Retrieves the total number of elements submitted. #### Returns | Name | Type | Description | |---|---|---| | _totalElements | uint256 | Total submitted elements. ### setGasParams ```solidity function setGasParams(uint256 _l2GasDiscountDivisor, uint256 _enqueueGasCost) external nonpayable ``` Allows the Burn Admin to update the parameters which determine the amount of gas to burn. The value of enqueueL2GasPrepaid is immediately updated as well. #### Parameters | Name | Type | Description | |---|---|---| | _l2GasDiscountDivisor | uint256 | undefined | _enqueueGasCost | uint256 | undefined ## Events ### L2GasParamsUpdated ```solidity event L2GasParamsUpdated(uint256 l2GasDiscountDivisor, uint256 enqueueGasCost, uint256 enqueueL2GasPrepaid) ``` #### Parameters | Name | Type | Description | |---|---|---| | l2GasDiscountDivisor | uint256 | undefined | | enqueueGasCost | uint256 | undefined | | enqueueL2GasPrepaid | uint256 | undefined | ### QueueBatchAppended ```solidity event QueueBatchAppended(uint256 _startingQueueIndex, uint256 _numQueueElements, uint256 _totalElements) ``` #### Parameters | Name | Type | Description | |---|---|---| | _startingQueueIndex | uint256 | undefined | | _numQueueElements | uint256 | undefined | | _totalElements | uint256 | undefined | ### SequencerBatchAppended ```solidity event SequencerBatchAppended(uint256 _startingQueueIndex, uint256 _numQueueElements, uint256 _totalElements) ``` #### Parameters | Name | Type | Description | |---|---|---| | _startingQueueIndex | uint256 | undefined | | _numQueueElements | uint256 | undefined | | _totalElements | uint256 | undefined | ### TransactionBatchAppended ```solidity event TransactionBatchAppended(uint256 indexed _batchIndex, bytes32 _batchRoot, uint256 _batchSize, uint256 _prevTotalElements, bytes _extraData) ``` #### Parameters | Name | Type | Description | |---|---|---| | _batchIndex `indexed` | uint256 | undefined | | _batchRoot | bytes32 | undefined | | _batchSize | uint256 | undefined | | _prevTotalElements | uint256 | undefined | | _extraData | bytes | undefined | ### TransactionEnqueued ```solidity event TransactionEnqueued(address indexed _l1TxOrigin, address indexed _target, uint256 _gasLimit, bytes _data, uint256 indexed _queueIndex, uint256 _timestamp) ``` #### Parameters | Name | Type | Description | |---|---|---| | _l1TxOrigin `indexed` | address | undefined | | _target `indexed` | address | undefined | | _gasLimit | uint256 | undefined | | _data | bytes | undefined | | _queueIndex `indexed` | uint256 | undefined | | _timestamp | uint256 | undefined |