NFT铸造系统开发（成熟及技术）丨功能源码

增加流动性
任何人都可以通过调用函数 addLiquidity 向池中添加流动性。有
首次增加流动性：可以存入任意数量的 BSV 和 Token 。
添加更多流动性： BSV 和 Token 存入的比率必须与池中的现有比率相匹配（第 22 行）。
// add bsv and token to liquidity pool
public function addLiquidity(PubKey sender, Sig senderSig, int tokenAmount, int senderBalance, int senderKeyIndex, int oldTokenBalance,

                        int lpSenderBalance, int lpSenderKeyIndex, int newBsvBalance, SigHashPreimage txPreimage) {
require(checkSig(senderSig, sender));

int oldBsvBalance = SigHash.value(txPreimage);

// mint new lp tokens for the liquidity provider
if (oldBsvBalance == 0) {
    // initialize pool
    
    // initially, just mint new lp tokens per the amount of new bsvs deposited
    int lpMint = newBsvBalance;
    require(this.lpToken.mint(sender, lpSenderBalance, lpMint, lpSenderKeyIndex));
} else {
    // add more liquidity

    int bsvAmount = newBsvBalance - oldBsvBalance;
    
    // deposit ratio must be the same with current pool ration
    // i.e., oldBsvBalance / oldTokenBalance == bsvAmount / tokenAmount
    require(oldBsvBalance * tokenAmount == bsvAmount * oldTokenBalance);

    // mint new lp tokens, proportinal to the amount of new bsvs deposited
    int lpMint = this.lpToken.totalSupply() * bsvAmount / oldBsvBalance;
    require(this.lpToken.mint(sender, lpSenderBalance, lpMint, lpSenderKeyIndex));
}

// transfer tokens to the pool
require(this.token.transferFrom(sender, this.poolPubkey, tokenAmount, senderBalance, senderKeyIndex, oldTokenBalance, senderKeyIndex));

require(this.propagateState(newBsvBalance, txPreimage));

}