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可以看到 exercise 函数允许传入多个 vaultsToExerciseFrom，然后通过 for 循环调用 _exercise 函数对各个 vaultsToExerciseFrom 进行处理，现在我们切入 _exercise 函数进行具体的分析 function _exercise( uint256 oTokensToExercise, address payable vaultToExerciseFrom) internal { // 1. before exercise window: revert require( isExerciseWindow(), "Can't exercise outside of the exercise window" ); require(hasVault(vaultToExerciseFrom), "Vault does not exist"); Vault storage vault = vaults[vaultToExerciseFrom]; require(oTokensToExercise > 0, "Can't exercise 0 oTokens"); // Check correct amount of oTokens passed in) require( oTokensToExercise <= vault.oTokensIssued, "Can't exercise more oTokens than the owner has" ); // Ensure person calling has enough oTokens require( balanceOf(msg.sender) >= oTokensToExercise, "Not enough oTokens" ); // 1. Check sufficient underlying // 1.1 update underlying balances uint256 amtUnderlyingToPay = underlyingRequiredToExercise( oTokensToExercise ); vault.underlying = vault.underlying.add(amtUnderlyingToPay); // 2. Calculate Collateral to pay // 2.1 Payout enough collateral to get (strikePrice * oTokens) amount of collateral uint256 amtCollateralToPay = calculateCollateralToPay( oTokensToExercise, Number(1, 0) ); // 2.2 Take a small fee on every exercise uint256 amtFee = calculateCollateralToPay( oTokensToExercise, transactionFee ); totalFee = totalFee.add(amtFee); uint256 totalCollateralToPay = amtCollateralToPay.add(amtFee); require( totalCollateralToPay <= vault.collateral, "Vault underwater, can't exercise" ); // 3. Update collateral + oToken balances vault.collateral = vault.collateral.sub(totalCollateralToPay); vault.oTokensIssued = vault.oTokensIssued.sub(oTokensToExercise); // 4. Transfer in underlying, burn oTokens + pay out collateral // 4.1 Transfer in underlying if (isETH(underlying)) { require(msg.value == amtUnderlyingToPay, "Incorrect msg.value"); } else { require( underlying.transferFrom( msg.sender, address(this), amtUnderlyingToPay ), "Could not transfer in tokens" ); } // 4.2 burn oTokens _burn(msg.sender, oTokensToExercise); // 4.3 Pay out collateral transferCollateral(msg.sender, amtCollateralToPay); emit Exercise( amtUnderlyingToPay, amtCollateralToPay, msg.sender, vaultToExerciseFrom ); } (责任编辑：admin) |