Pair Addresses

getPair

The most obvious way to get the address for a pair is to call getPair on the factory. If the pair exists, this function will return its address, else address(0) (0x0000000000000000000000000000000000000000).

• The "canonical" way to determine whether or not a pair exists.
• Requires an on-chain lookup.

CREATE2

Ring Swap pair addresses can also be computed without any on-chain lookups because the factory uses CREATE2. The following values are required for this technique:

address	The factory address
salt	keccak256(abi.encodePacked(token0, token1))
keccak256(init_code)	The Ring Swap Pair Init Code for the target chain from the deployment table.

• token0 must be strictly less than token1 by sort order.

• Can be computed offline.
• Requires the ability to perform keccak256.

Examples

Solidity

address factory = 0xeb2A625B704d73e82946D8d026E1F588Eed06416; // Ring Swap Factory on Ethereum mainnet
address token0 = 0xCAFE000000000000000000000000000000000000; // change me!
address token1 = 0xF00D000000000000000000000000000000000000; // change me!
bytes32 initCodeHash = 0xa7ae6a5ec37f0c21bbdac560794258c4089b8ae3ffa6e3909b53c6091764a676;

address pair = address(uint160(bytes20(keccak256(abi.encodePacked(
  hex'ff',
  factory,
  keccak256(abi.encodePacked(token0, token1)),
  initCodeHash
))));