PackedUserOperation Contract
This contract defines a packed user operation structure. It is designed for use with the EntryPoint contract, which handles the execution of user operations.
Structure
The `PackedUserOperation` structure is a tightly packed representation of a user operation, designed to minimize gas costs when storing and transmitting it.
Fields
- nonce: uint256 - The user's nonce for this operation. This field is used to prevent replay attacks.
- sender: address - The address of the user initiating the operation.
- initCode: bytes - The initialization code for the entry point of the operation. This is used to deploy a new contract if needed.
- callData: bytes - The call data for the operation, which will be executed by the entry point.
- callGasLimit: uint256 - The maximum amount of gas that the entry point can consume for executing the operation.
- verificationGasLimit: uint256 - The maximum amount of gas that the entry point can consume for verifying the signature of the operation.
- preVerificationGas: uint256 - The amount of gas that is consumed before the signature is verified.
- maxFeePerGas: uint256 - The maximum fee per gas that the user is willing to pay for the operation.
- maxPriorityFeePerGas: uint256 - The maximum priority fee per gas that the user is willing to pay for the operation.
- paymasterAndData: bytes - Data that is passed to the paymaster, if one is used for this operation.
- signature: bytes - The signature of the user operation, which is used to verify the authenticity of the operation.
Usage
The `PackedUserOperation` structure is used by the EntryPoint contract to handle user operations. It is passed to the EntryPoint's `handleOps` function, which executes the operations and interacts with the paymaster (if one is used).
Best Practices
- Use the appropriate gas limits: Set the 'callGasLimit', 'verificationGasLimit', and 'preVerificationGas' fields to appropriate values to ensure that the operation can be executed successfully.
- Use a paymaster (if needed): A paymaster can be used to cover the costs of an operation for the user. Make sure to set the 'paymasterAndData' field accordingly.
- Verify the signature: Before executing an operation, the EntryPoint contract must verify the signature of the user operation.
- Use a nonce to prevent replay attacks: The nonce field should be incremented for each user operation to ensure that the operation cannot be replayed.