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Release 01.10.2024: migration guide

This release of =nil; fixes several issues and bugs related to async request chaining, feeCredit estimations, and gas forwarding.

Summary of key changes​

  • The cluster now handles async call chains (two or more async calls following each other) more reliably
  • Several function names in Nil.sol have been changed to be more representative of what these functions do
  • Nil.currencyBalance() produces more accurate results
  • Nil.sendRequest() and Nil.awaitCall() require purchasing gas for processing the response, which guarantees that said response will always be executed

Migration of smart contracts​

  • Change usage of sendRequest() and awaitCall()

Both sendRequest() and awaitCall() have new signatures in the latest release:

 function sendRequest(
        address dst,
        uint256 value,
        uint responseProcessingGas,
        bytes memory context,
        bytes memory callData
    ) internal {}
 
 function awaitCall(
        address dst,
        uint responseProcessingGas,
        bytes memory callData
    ) internal returns(bytes memory, bool) {}

The responseProcessingGas argument is the amount of gas that has to be reserved for processing the response to sendRequest() and awaitCall(). The specified amount is immediately purchased when the function is called and is later spent to guarantee that the response is executed correctly.

tip

Use the Nil.ASYNC_REQUEST_MIN_GAS constant value to reserve the minimum possible amount of gas for processing an async response.

  • If needed, change asyncCall() and sendRequest() to asyncCallWithTokens() and sendRequestWithTokens()

To reduce enthropy in the function names and their overloads, the variants of asyncCall() and sendRequest() that sent custom currencies to other contracts have been renamed to asyncCallWithTokens() and sendRequest() with tokens, respectively. It is now impossible to send custom currencies when using asyncCall() and sendRequest().

Migration of the =nil; CLI​

No specific changes have to be made to the =nil; CLI commands.

Migration of Nil.js scripts​

No specific changes have to be made to existing Nil.js scripts.

Migration of Hardhat scripts​

No specific changes have to be made to existing Hardhat scripts.