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LYPTUS vs EGG code

Created 3 years agoDiff never expires

23 removals

254 lines

10 additions

242 lines

pragma solidity 0.6.12;

// .----------------. .----------------. .----------------. .----------------. .----------------.

import "./libs/BEP20.sol";

// | .--------------. || .--------------. || .--------------. || .--------------. || .--------------. |

// | | ___ ____ | || | ____ | || | __ | || | _____ | || | __ | |

// | | |_ ||_ _| | || | .' `. | || | / \ | || | |_ _| | || | / \ | |

// | | | |_/ / | || | / .--. \ | || | / /\ \ | || | | | | || | / /\ \ | |

// | | | __'. | || | | | | | | || | / ____ \ | || | | | _ | || | / ____ \ | |

// | | _| | \ \_ | || | \ `--' / | || | _/ / \ \_ | || | _| |__/ | | || | _/ / \ \_ | |

// | | |____||____| | || | `.____.' | || ||____| |____|| || | |________| | || ||____| |____|| |

// | | | || | | || | | || | | || | | |

// | '--------------' || '--------------' || '--------------' || '--------------' || '--------------' |

// '----------------' '----------------' '----------------' '----------------' '----------------'

import "./BEP20.sol";

// EggToken with Governance.

contract EggToken is BEP20('Goose Golden Egg', 'EGG') {

// LyptusToken with Governance.

contract LyptusToken is BEP20('Lyptus Token', 'LYPTUS') {

/// @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), "LYPTUS::delegateBySig: invalid signature");

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

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

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

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

require(now <= expiry, "EGG::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, "LYPTUS::getPriorVotes: not yet determined");

require(blockNumber < block.number, "EGG::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 LYPTUSs (not scaled);

uint256 delegatorBalance = balanceOf(delegator); // balance of underlying EGGs (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, "LYPTUS::_writeCheckpoint: block number exceeds 32 bits");

uint32 blockNumber = safe32(block.number, "EGG::_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;

}

Saved diffs

Original text

Open file

pragma solidity 0.6.12;

//  .----------------.  .----------------.  .----------------.  .----------------.  .----------------. 
// | .--------------. || .--------------. || .--------------. || .--------------. || .--------------. |
// | |  ___  ____   | || |     ____     | || |      __      | || |   _____      | || |      __      | |
// | | |_  ||_  _|  | || |   .'    `.   | || |     /  \     | || |  |_   _|     | || |     /  \     | |
// | |   | |_/ /    | || |  /  .--.  \  | || |    / /\ \    | || |    | |       | || |    / /\ \    | |
// | |   |  __'.    | || |  | |    | |  | || |   / ____ \   | || |    | |   _   | || |   / ____ \   | |
// | |  _| |  \ \_  | || |  \  `--'  /  | || | _/ /    \ \_ | || |   _| |__/ |  | || | _/ /    \ \_ | |
// | | |____||____| | || |   `.____.'   | || ||____|  |____|| || |  |________|  | || ||____|  |____|| |
// | |              | || |              | || |              | || |              | || |              | |
// | '--------------' || '--------------' || '--------------' || '--------------' || '--------------' |
// '----------------'  '----------------'  '----------------'  '----------------'  '----------------' 

import "./BEP20.sol";

// LyptusToken with Governance.
contract LyptusToken is BEP20('Lyptus Token', 'LYPTUS') {
    /// @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), "LYPTUS::delegateBySig: invalid signature");
        require(nonce == nonces[signatory]++, "LYPTUS::delegateBySig: invalid nonce");
        require(now <= expiry, "LYPTUS::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, "LYPTUS::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 LYPTUSs (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, "LYPTUS::_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;
    }
}

Changed text

Open file

pragma solidity 0.6.12;

import "./libs/BEP20.sol";

// EggToken with Governance.
contract EggToken is BEP20('Goose Golden Egg', 'EGG') {
    /// @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), "EGG::delegateBySig: invalid signature");
        require(nonce == nonces[signatory]++, "EGG::delegateBySig: invalid nonce");
        require(now <= expiry, "EGG::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, "EGG::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 EGGs (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, "EGG::_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;
    }
}