From the perspective of conceptual model,the metauniverse is the superposition of technology system,content system,economic system,cooperation system and governance system.The core of the technical system is integration,and its technical system should be characterized by open source,programmability,interconnection,scalability,pluggable and other technical features;The core of the content system is communication,which should have the ability of multiple content generation modes,content presentation modes and content operation management
//calculates the CREATE2 address for a pair without making any external calls
//在不进行任何外部调用的情况下计算一对的CREATE2地址
function pairFor(address factory,address tokenA,address tokenB)internal pure returns(address pair){
(address token0,address token1)=sortTokens(tokenA,tokenB);
pair=address(uint(keccak256(abi.encodePacked(
hex'ff',
factory,
keccak256(abi.encodePacked(token0,token1)),
hex'96e8ac4277198ff8b6f785478aa9a39f403cb768dd02cbee326c3e7da348845f'//init code hash
))));
}
//fetches and sorts the reserves for a pair
//获取并排序一对的储备
function getReserves(address factory,address tokenA,address tokenB)internal view returns(uint reserveA,uint reserveB){
(address token0,)=sortTokens(tokenA,tokenB);
(uint reserve0,uint reserve1,)=IUniswapV2Pair(pairFor(factory,tokenA,tokenB)).getReserves();
(reserveA,reserveB)=tokenA==token0?(reserve0,reserve1):(reserve1,reserve0);
}
//given some amount of an asset and pair reserves,returns an equivalent amount of the other asset
//给定一定数量的资产和配对准备金，返回等量的其他资产
//BB/AA=B/A-->BB=AA*(B/A)
function quote(uint amountA,uint reserveA,uint reserveB)internal pure returns(uint amountB){
require(amountA>0,'UniswapV2Library:INSUFFICIENT_AMOUNT');
require(reserveA>0&&reserveB>0,'UniswapV2Library:INSUFFICIENT_LIQUIDITY');
amountB=amountA.mul(reserveB)/reserveA;
}
