1：官网：https://sushiswap.org/

2：部分合约源码浏览

pragma solidity 0.6.12;

?

?

import "@openzeppelin/contracts/token/ERC20/ERC20.sol";

import "@openzeppelin/contracts/access/Ownable.sol";

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?

// SushiToken with Governance.

contract SushiToken is ERC20("SushiToken", "SUSHI"), Ownable {

? ? /// @notice Creates `_amount` token to `_to`. Must only be called by the owner (MasterChef).

? ? function mint(address _to, uint256 _amount) public onlyOwner {

? ? ? ? _mint(_to, _amount);

? ? ? ? _moveDelegates(address(0), _delegates[_to], _amount);

? ? }

?

? ? // Copied and modified from YAM code:

? ? // https://github.com/yam-finance/yam-protocol/blob/master/contracts/token/YAMGovernanceStorage.sol

? ? // https://github.com/yam-finance/yam-protocol/blob/master/contracts/token/YAMGovernance.sol

? ? // Which is copied and modified from COMPOUND:

? ? // https://github.com/compound-finance/compound-protocol/blob/master/contracts/Governance/Comp.sol

?

? ? /// @notice A record of each accounts delegate

? ? mapping (address => address) internal _delegates;

?

? ? /// @notice A checkpoint for marking number of votes from a given block

? ? struct Checkpoint {

? ? ? ? uint32 fromBlock;

? ? ? ? uint256 votes;

? ? }

?

? ? /// @notice A record of votes checkpoints for each account, by index

? ? mapping (address => mapping (uint32 => Checkpoint)) public checkpoints;

?

? ? /// @notice The number of checkpoints for each account

? ? mapping (address => uint32) public numCheckpoints;

?

? ? /// @notice The EIP-712 typehash for the contract's domain

? ? bytes32 public constant DOMAIN_TYPEHASH = keccak256("EIP712Domain(string name,uint256 chainId,address verifyingContract)");

?

? ? /// @notice The EIP-712 typehash for the delegation struct used by the contract

? ? bytes32 public constant DELEGATION_TYPEHASH = keccak256("Delegation(address delegatee,uint256 nonce,uint256 expiry)");

?

? ? /// @notice A record of states for signing / validating signatures

? ? mapping (address => uint) public nonces;

?

? ? ? /// @notice An event thats emitted when an account changes its delegate

? ? event DelegateChanged(address indexed delegator, address indexed fromDelegate, address indexed toDelegate);

?

? ? /// @notice An event thats emitted when a delegate account's vote balance changes

? ? event DelegateVotesChanged(address indexed delegate, uint previousBalance, uint newBalance);

?

? ? /**

? ? ?* @notice Delegate votes from `msg.sender` to `delegatee`

? ? ?* @param delegator The address to get delegatee for

? ? ?*/

? ? function delegates(address delegator)

? ? ? ? external

? ? ? ? view

? ? ? ? returns (address)

? ? {

? ? ? ? return _delegates[delegator];

? ? }

?

? ?/**

? ? * @notice Delegate votes from `msg.sender` to `delegatee`

? ? * @param delegatee The address to delegate votes to

? ? */

? ? function delegate(address delegatee) external {

? ? ? ? return _delegate(msg.sender, delegatee);

? ? }

?

? ? /**

? ? ?* @notice Delegates votes from signatory to `delegatee`

? ? ?* @param delegatee The address to delegate votes to

? ? ?* @param nonce The contract state required to match the signature

? ? ?* @param expiry The time at which to expire the signature

? ? ?* @param v The recovery byte of the signature

? ? ?* @param r Half of the ECDSA signature pair

? ? ?* @param s Half of the ECDSA signature pair

? ? ?*/

? ? function delegateBySig(

? ? ? ? address delegatee,

? ? ? ? uint nonce,

? ? ? ? uint expiry,

? ? ? ? uint8 v,

? ? ? ? bytes32 r,

? ? ? ? bytes32 s

? ? )

? ? ? ? external

? ? {

? ? ? ? bytes32 domainSeparator = keccak256(

? ? ? ? ? ? abi.encode(

? ? ? ? ? ? ? ? DOMAIN_TYPEHASH,

? ? ? ? ? ? ? ? keccak256(bytes(name())),

? ? ? ? ? ? ? ? getChainId(),

? ? ? ? ? ? ? ? address(this)

? ? ? ? ? ? )

? ? ? ? );

?

? ? ? ? bytes32 structHash = keccak256(

? ? ? ? ? ? abi.encode(

? ? ? ? ? ? ? ? DELEGATION_TYPEHASH,

? ? ? ? ? ? ? ? delegatee,

? ? ? ? ? ? ? ? nonce,

? ? ? ? ? ? ? ? expiry

? ? ? ? ? ? )

? ? ? ? );

?

? ? ? ? bytes32 digest = keccak256(

? ? ? ? ? ? abi.encodePacked(

? ? ? ? ? ? ? ? "\x19\x01",

? ? ? ? ? ? ? ? domainSeparator,

? ? ? ? ? ? ? ? structHash

? ? ? ? ? ? )

? ? ? ? );

?

? ? ? ? address signatory = ecrecover(digest, v, r, s);

? ? ? ? require(signatory != address(0), "SUSHI::delegateBySig: invalid signature");

? ? ? ? require(nonce == nonces[signatory]++, "SUSHI::delegateBySig: invalid nonce");

? ? ? ? require(now <= expiry, "SUSHI::delegateBySig: signature expired");

? ? ? ? return _delegate(signatory, delegatee);

? ? }

?

? ? /**

? ? ?* @notice Gets the current votes balance for `account`

? ? ?* @param account The address to get votes balance

? ? ?* @return The number of current votes for `account`

? ? ?*/

? ? function getCurrentVotes(address account)

? ? ? ? external

? ? ? ? view

? ? ? ? returns (uint256)

? ? {

? ? ? ? uint32 nCheckpoints = numCheckpoints[account];

? ? ? ? return nCheckpoints > 0 ? checkpoints[account][nCheckpoints - 1].votes : 0;

? ? }

?

? ? /**

? ? ?* @notice Determine the prior number of votes for an account as of a block number

? ? ?* @dev Block number must be a finalized block or else this function will revert to prevent misinformation.

? ? ?* @param account The address of the account to check

? ? ?* @param blockNumber The block number to get the vote balance at

? ? ?* @return The number of votes the account had as of the given block

? ? ?*/

? ? function getPriorVotes(address account, uint blockNumber)

? ? ? ? external

? ? ? ? view

? ? ? ? returns (uint256)

? ? {

? ? ? ? require(blockNumber < block.number, "SUSHI::getPriorVotes: not yet determined");

?

? ? ? ? uint32 nCheckpoints = numCheckpoints[account];

? ? ? ? if (nCheckpoints == 0) {

? ? ? ? ? ? return 0;

? ? ? ? }

?

? ? ? ? // First check most recent balance

? ? ? ? if (checkpoints[account][nCheckpoints - 1].fromBlock <= blockNumber) {

? ? ? ? ? ? return checkpoints[account][nCheckpoints - 1].votes;

? ? ? ? }

?

? ? ? ? // Next check implicit zero balance

? ? ? ? if (checkpoints[account][0].fromBlock > blockNumber) {

? ? ? ? ? ? return 0;

? ? ? ? }

?

? ? ? ? uint32 lower = 0;

? ? ? ? uint32 upper = nCheckpoints - 1;

? ? ? ? while (upper > lower) {

? ? ? ? ? ? uint32 center = upper - (upper - lower) / 2; // ceil, avoiding overflow

? ? ? ? ? ? Checkpoint memory cp = checkpoints[account][center];

? ? ? ? ? ? if (cp.fromBlock == blockNumber) {

? ? ? ? ? ? ? ? return cp.votes;

? ? ? ? ? ? } else if (cp.fromBlock < blockNumber) {

? ? ? ? ? ? ? ? lower = center;

? ? ? ? ? ? } else {

? ? ? ? ? ? ? ? upper = center - 1;

? ? ? ? ? ? }

? ? ? ? }

? ? ? ? return checkpoints[account][lower].votes;

? ? }

?

? ? function _delegate(address delegator, address delegatee)

? ? ? ? internal

? ? {

? ? ? ? address currentDelegate = _delegates[delegator];

? ? ? ? uint256 delegatorBalance = balanceOf(delegator); // balance of underlying SUSHIs (not scaled);

? ? ? ? _delegates[delegator] = delegatee;

?

? ? ? ? emit DelegateChanged(delegator, currentDelegate, delegatee);

?

? ? ? ? _moveDelegates(currentDelegate, delegatee, delegatorBalance);

? ? }

?

? ? function _moveDelegates(address srcRep, address dstRep, uint256 amount) internal {

? ? ? ? if (srcRep != dstRep && amount > 0) {

? ? ? ? ? ? if (srcRep != address(0)) {

? ? ? ? ? ? ? ? // decrease old representative

? ? ? ? ? ? ? ? uint32 srcRepNum = numCheckpoints[srcRep];

? ? ? ? ? ? ? ? uint256 srcRepOld = srcRepNum > 0 ? checkpoints[srcRep][srcRepNum - 1].votes : 0;

? ? ? ? ? ? ? ? uint256 srcRepNew = srcRepOld.sub(amount);

? ? ? ? ? ? ? ? _writeCheckpoint(srcRep, srcRepNum, srcRepOld, srcRepNew);

? ? ? ? ? ? }

?

? ? ? ? ? ? if (dstRep != address(0)) {

? ? ? ? ? ? ? ? // increase new representative

? ? ? ? ? ? ? ? uint32 dstRepNum = numCheckpoints[dstRep];

? ? ? ? ? ? ? ? uint256 dstRepOld = dstRepNum > 0 ? checkpoints[dstRep][dstRepNum - 1].votes : 0;

? ? ? ? ? ? ? ? uint256 dstRepNew = dstRepOld.add(amount);

? ? ? ? ? ? ? ? _writeCheckpoint(dstRep, dstRepNum, dstRepOld, dstRepNew);

? ? ? ? ? ? }

? ? ? ? }

? ? }

?

? ? function _writeCheckpoint(

? ? ? ? address delegatee,

? ? ? ? uint32 nCheckpoints,

? ? ? ? uint256 oldVotes,

? ? ? ? uint256 newVotes

? ? )

? ? ? ? internal

? ? {

? ? ? ? uint32 blockNumber = safe32(block.number, "SUSHI::_writeCheckpoint: block number exceeds 32 bits");

?

? ? ? ? if (nCheckpoints > 0 && checkpoints[delegatee][nCheckpoints - 1].fromBlock == blockNumber) {

? ? ? ? ? ? checkpoints[delegatee][nCheckpoints - 1].votes = newVotes;

? ? ? ? } else {

? ? ? ? ? ? checkpoints[delegatee][nCheckpoints] = Checkpoint(blockNumber, newVotes);

? ? ? ? ? ? numCheckpoints[delegatee] = nCheckpoints + 1;

? ? ? ? }

?

? ? ? ? emit DelegateVotesChanged(delegatee, oldVotes, newVotes);

? ? }

?

? ? function safe32(uint n, string memory errorMessage) internal pure returns (uint32) {

? ? ? ? require(n < 2**32, errorMessage);

? ? ? ? return uint32(n);

? ? }

?

? ? function getChainId() internal pure returns (uint) {

? ? ? ? uint256 chainId;

? ? ? ? assembly { chainId := chainid() }

? ? ? ? return chainId;

? ? }

}

完整sushi源码下载地址：https://github.com/sushiswap/sushiswap/tree/master/contracts