ChainIdTools Library

The ChainidTools library provides helpers to convert the uint256 chain ID provided by block.chainid to a uint32 chain ID used across this Data Index implementation.

Errors

1. UnsupportedChain

error UnsupportedChain(uint256 chainId);

Thrown when the chain ID is not supported (i.e., when it's larger than uint32.max).

2. UnexpectedChain

error UnexpectedChain(uint32 expected, uint32 requested);

Thrown when the current chain ID doesn't match the requested chain ID.

Functions

1. chainid()

function chainid() internal view returns (uint32);

Description	Parameters	Returns	Modifiers
Converts block.chainid to uint32 chain ID	None	uint32 chain ID	internal view

This function returns the current chain ID as a uint32. If the current chain ID is larger than uint32.max, it reverts with an UnsupportedChain error.

2. requireCurrentChain()

function requireCurrentChain(uint32 chainId) internal view;

Description	Parameters	Returns	Modifiers
Requires current chain to be the same as requested	chainId: Requested chain ID	None	internal view

This function checks if the current chain ID matches the requested chain ID. If they don't match, it reverts with an UnexpectedChain error.

Implementation Details

• The library uses block.chainid to get the current chain ID.
• It assumes that most chain IDs can fit within a uint32, which is true for all major blockchain networks as of now.
• The chainid() function provides a safe way to convert the uint256 chain ID to uint32, reverting if the conversion would result in data loss.
• The requireCurrentChain() function is useful for ensuring that a function is being called on the expected blockchain network.