区块链积分商城系统丨区块链积分商城系统开发技术详细丨区块链积分商城开发源码及案例
新零售是什么?新零售是通过投资建设门店、电子商务等营销手段，开放线上线下，以满足消费者的多元化需求。
传统零售以生产、零售为主，而新零售则是以消费者体验为中心的数据驱动的泛零售形式，从本质上重构了人、货、场。
新零售的核心特点在于：对传统零售的升级，无论是流通端、销售端甚至消费者都在经历一次升级。这种升级是以云计算、大数据、人工智能等技术发展作为背景支撑的升级。
event Mint(address indexed sender,uint amount0,uint amount1);
event Burn(address indexed sender,uint amount0,uint amount1,address indexed to);
event Swap(address indexed sender,uint amount0In,uint amount1In,uint amount0Out,uint amount1Out,address indexed to);
event Sync(uint112 reserve0,uint112 reserve1);
//部署此合约时将msg.sender设置为factory，后续初始化时会用到这个值
constructor()public{开发部署I59模式2OO7开发3O69
factory=msg.sender;
}
//called once by the factory at time of deployment
//在UniswapV2Factory.sol的createPair中调用过
function initialize(address _token0,address _token1)external{
require(msg.sender==factory,'UniswapV2:FORBIDDEN');//sufficient check
token0=_token0;
token1=_token1;
}
//update reserves and,on the first call per block,price accumulators
//更新储备，并在每个区块的第一次调用时更新价格累加器
/**
更新变量：案例详细源码：yy625019
blockTimestampLast
reserve0
reserve1
price0CumulativeLast
price1CumulativeLast
*/
//这个函数是用来更新价格oracle的，计算累计价格
function _update(uint balance0,uint balance1,uint112 _reserve0,uint112 _reserve1)private{
//溢出校验
require(balance0<=uint112(-1)&&balance1<=uint112(-1),'UniswapV2:OVERFLOW');
uint32 blockTimestamp=uint32(block.timestamp%2**32);
uint32 timeElapsed=blockTimestamp-blockTimestampLast;//overflow is desired
//计算时间加权的累计价格，256位中，前112位用来存整数，后112位用来存小数，多的32位用来存溢出的值
if(timeElapsed>0&&_reserve0!=0&&_reserve1!=0){
//*never overflows,and+overflow is desired
price0CumulativeLast+=uint(UQ112x112.encode(_reserve1).uqdiv(_reserve0))*timeElapsed;
price1CumulativeLast+=uint(UQ112x112.encode(_reserve0).uqdiv(_reserve1))*timeElapsed;
}
//更新reserve值
reserve0=uint112(balance0);
reserve1=uint112(balance1);
blockTimestampLast=blockTimestamp;
emit Sync(reserve0,reserve1);
}
//if fee is on,mint liquidity equivalent to 1/6th of the growth in sqrt(k)
//如果收费，增发流动性相当于sqrt(k)增长的1/6
function _mintFee(uint112 _reserve0,uint112 _reserve1)private returns(bool feeOn){
//获取接收手续费的地址
address feeTo=IUniswapV2Factory(factory).feeTo();
//手续费接收者不为0地址
feeOn=feeTo!=address(0);
uint _kLast=kLast;//gas savings
//手续费接收者不为0地址
if(feeOn){
if(_kLast!=0){
uint rootK=Math.sqrt(uint(_reserve0).mul(_reserve1));
uint rootKLast=Math.sqrt(_kLast);
if(rootK>rootKLast){
uint numerator=totalSupply.mul(rootK.sub(rootKLast));
uint denominator=rootK.mul(5).add(rootKLast);
uint liquidity=numerator/denominator;
if(liquidity>0)_mint(feeTo,liquidity);
}
}
}
//手续费接收者为0，并且kLast不为0
else if(_kLast!=0){
kLast=0;
}
}
