最近STO成为了新的热点，赶紧跟上节奏看看。
今天分享的是首个STO项目 - tZERO的源码，该合约地址为0xc4BF277257C140A799b785C6C5096c6Da7ef6A62，ERC20合约。
pragma solidity >=0.4.24 <0.5.0;
/**
*
* @title AddressMap
* @dev Map of unique indexed addresseses.
*
* **NOTE**
* The internal collections are one-based.
* This is simply because null values are expressed as zero,
* which makes it hard to check for the existence of items within the array,
* or grabbing the first item of an array for non-existent items.
*
* This is only exposed internally, so callers still use zero-based indices.
*
*/
library AddressMap {
address constant ZERO_ADDRESS = address(0);
struct Data {
int256 count;
mapping(address => int256) indices;
mapping(int256 => address) items;
}
/**
* Appends the address to the end of the map, if the addres is not
* zero and the address doesn't currently exist.
* @param addr The address to append.
* @return true if the address was added.
*/
function append(Data storage self, address addr)
internal
returns (bool) {
if (addr == ZERO_ADDRESS) {
return false;
}
int256 index = self.indices[addr] - 1;
if (index >= 0 && index < self.count) {
return false;
}
self.count++;
self.indices[addr] = self.count;
self.items[self.count] = addr;
return true;
}
/**
* Removes the given address from the map.
* @param addr The address to remove from the map.
* @return true if the address was removed.
*/
function remove(Data storage self, address addr)
internal
returns (bool) {
int256 oneBasedIndex = self.indices[addr];
if (oneBasedIndex < 1 || oneBasedIndex > self.count) {
return false; // address doesn't exist, or zero.
}
// When the item being removed is not the last item in the collection,
// replace that item with the last one, otherwise zero it out.
//
// If {2} is the item to be removed
// [0, 1, 2, 3, 4]
// The result would be:
// [0, 1, 4, 3]
//
if (oneBasedIndex < self.count) {
// Replace with last item
address last = self.items[self.count]; // Get the last item
self.indices[last] = oneBasedIndex; // Update last items index to current index
self.items[oneBasedIndex] = last; // Update current index to last item
delete self.items[self.count]; // Delete the last item, since it's moved
} else {
// Delete the address
delete self.items[oneBasedIndex];
}
delete self.indices[addr];
self.count--;
return true;
}
/**
* Retrieves the address at the given index.
* THROWS when the index is invalid.
* @param index The index of the item to retrieve.
* @return The address of the item at the given index.
*/
function at(Data storage self, int256 index)
internal
view
returns (address) {
require(index >= 0 && index < self.count, "Index outside of bounds.");
return self.items[index + 1];
}
/**
* Gets the index of the given address.
* @param addr The address of the item to get the index for.
* @return The index of the given address.
*/
function indexOf(Data storage self, address addr)
internal
view
returns (int256) {
if (addr == ZERO_ADDRESS) {
return -1;
}
int256 index = self.indices[addr] - 1;
if (index < 0 || index >= self.count) {
return -1;
}
return index;
}
/**
* Returns whether or not the given address exists within the map.
* @param addr The address to check for existence.
* @return If the given address exists or not.
*/
function exists(Data storage self, address addr)
internal
view
returns (bool) {
int256 index = self.indices[addr] - 1;
return index >= 0 && index < self.count;
}
/**
* Clears all items within the map.
*/
function clear(Data storage self)
internal {
self.count = 0;
}
}
/**
*
* @title AccountMap
* @dev Map of unique indexed accounts.
*
* **NOTE**
* The internal collections are one-based.
* This is simply because null values are expressed as zero,
* which makes it hard to check for the existence of items within the array,
* or grabbing the first item of an array for non-existent items.
*
* This is only exposed internally, so callers still use zero-based indices.
*
*/
library AccountMap {
address constant ZERO_ADDRESS = address(0);
struct Account {
address addr;
uint8 kind;
bool frozen;
address parent;
}
struct Data {
int256 count;
mapping(address => int256) indices;
mapping(int256 => Account) items;
}
/**
* Appends the address to the end of the map, if the addres is not
* zero and the address doesn't currently exist.
* @param addr The address to append.
* @return true if the address was added.
*/
function append(Data storage self, address addr, uint8 kind, bool isFrozen, address parent)
internal
returns (bool) {
if (addr == ZERO_ADDRESS) {
return false;
}
int256 index = self.indices[addr] - 1;
if (index >= 0 && index < self.count) {
return false;
}
self.count++;
self.indices[addr] = self.count;
self.items[self.count] = Account(addr, kind, isFrozen, parent);
return true;
}
/**
* Removes the given address from the map.
* @param addr The address to remove from the map.
* @return true if the address was removed.
*/
function remove(Data storage self, address addr)
internal
returns (bool) {
int256 oneBasedIndex = self.indices[addr];
if (oneBasedIndex < 1 || oneBasedIndex > self.count) {
return false; // address doesn't exist, or zero.
}
// When the item being removed is not the last item in the collection,
// replace that item with the last one, otherwise zero it out.
//
// If {2} is the item to be removed
// [0, 1, 2, 3, 4]
// The result would be:
// [0, 1, 4, 3]
//
if (oneBasedIndex < self.count) {
// Replace with last item
Account storage last = self.items[self.count]; // Get the last item
self.indices[last.addr] = oneBasedIndex; // Update last items index to current index
self.items[oneBasedIndex] = last; // Update current index to last item
delete self.items[self.count]; // Delete the last item, since it's moved
} else {
// Delete the account
delete self.items[oneBasedIndex];
}
delete self.indices[addr];
self.count--;
return true;
}
/**
* Retrieves the address at the given index.
* THROWS when the index is invalid.
* @param index The index of the item to retrieve.
* @return The address of the item at the given index.
*/
function at(Data storage self, int256 index)
internal
view
returns (Account) {
require(index >= 0 && index < self.count, "Index outside of bounds.");
return self.items[index + 1];
}
/**
* Gets the index of the given address.
* @param addr The address of the item to get the index for.
* @return The index of the given address.
*/
function indexOf(Data storage self, address addr)
internal
view
returns (int256) {
if (addr == ZERO_ADDRESS) {
return -1;
}
int256 index = self.indices[addr] - 1;
if (index < 0 || index >= self.count) {
return -1;
}
return index;
}
/**
* Gets the Account for the given address.
* THROWS when an account doesn't exist for the given address.
* @param addr The address of the item to get.
* @return The account of the given address.
*/
function get(Data storage self, address addr)
internal
view
returns (Account) {
return at(self, indexOf(self, addr));
}
/**
* Returns whether or not the given address exists within the map.
* @param addr The address to check for existence.
* @return If the given address exists or not.
*/
function exists(Data storage self, address addr)
internal
view
returns (bool) {
int256 index = self.indices[addr] - 1;
return index >= 0 && index < self.count;
}
/**
* Clears all items within the map.
*/
function clear(Data storage self)
internal {
self.count = 0;
}
}
/**
* @title Ownable
* @dev Provides a modifier that requires the caller to be the owner of the contract.
*/
contract Ownable {
address public owner;
event OwnerTransferred(
address indexed oldOwner,
address indexed newOwner
);
constructor() public {
owner = msg.sender;
}
modifier onlyOwner() {
require(msg.sender == owner, "Owner account is required");
_;
}
/**
* @dev Allows the current owner to transfer control of the contract to newOwner.
* @param newOwner The address to transfer ownership to.
*/
function transferOwner(address newOwner)
public
onlyOwner {
require(newOwner != owner, "New Owner cannot be the current owner");
require(newOwner != address(0), "New Owner cannot be zero address");
address prevOwner = owner;
owner = newOwner;
emit OwnerTransferred(prevOwner, newOwner);
}
}
/**
* @title Lockable
* @dev The Lockable contract adds the ability for the contract owner to set the lock status
* of the account. A modifier is provided that checks the throws when the contract is
* in the locked state.
*/
contract Lockable is Ownable {
bool public isLocked;
constructor() public {
isLocked = false;
}
modifier isUnlocked() {
require(!isLocked, "Contract is currently locked for modification");
_;
}
/**
* Set the contract to a read-only state.
* @param locked The locked state to set the contract to.
*/
function setLocked(bool locked)
onlyOwner
external {
require(isLocked != locked, "Contract already in requested lock state");
isLocked = locked;
}
}
/**
* @title Destroyable
* @dev The Destroyable contract alows the owner address to `selfdestruct` the contract.
*/
contract Destroyable is Ownable {
/**
* Allow the owner to destroy this contract.
*/
function kill()
onlyOwner
external {
selfdestruct(owner);
}
}
/**
* Contract to facilitate locking and self destructing.
*/
contract LockableDestroyable is Lockable, Destroyable { }
/**
* @title Registry Storage
*/
contract Storage is Ownable, LockableDestroyable {
struct Mapping {
address key;
address value;
}
using AccountMap for AccountMap.Data;
using AddressMap for AddressMap.Data;
// ------------------------------- Variables -------------------------------
// Nmber of data slots available for accounts
uint8 MAX_DATA = 30;
// Accounts
AccountMap.Data public accounts;
// Account Data
// - mapping of:
// (address => (index => data))
mapping(address => mapping(uint8 => bytes32)) public data;
// Address write permissions
// (kind => address)
mapping(uint8 => AddressMap.Data) public permissions;
// ------------------------------- Modifiers -------------------------------
/**
* Ensures the `msg.sender` has permission for the given kind/type of account.
*
* - The `owner` account is always allowed
* - Addresses/Contracts must have a corresponding entry, for the given kind
*/
modifier isAllowed(uint8 kind) {
require(kind > 0, "Invalid, or missing permission");
if (msg.sender != owner) {
require(permissions[kind].exists(msg.sender), "Missing permission");
}
_;
}
// ---------------------------- Address Getters ----------------------------
/**
* Gets the account at the given index
* THROWS when the index is out-of-bounds
* @param index The index of the item to retrieve
* @return The address, kind, frozen status, and parent of the account at the given index
*/
function accountAt(int256 index)
external
view
returns(address, uint8, bool, address) {
AccountMap.Account memory acct = accounts.at(index);
return (acct.addr, acct.kind, acct.frozen, acct.parent);
}
/**
* Gets the account for the given address
* THROWS when the account doesn't exist
* @param addr The address of the item to retrieve
* @return The address, kind, frozen status, and parent of the account at the given index
*/
function accountGet(address addr)
external
view
returns(uint8, bool, address) {
AccountMap.Account memory acct = accounts.get(addr);
return (acct.kind, acct.frozen, acct.parent);
}
/**
* Gets the parent address for the given account address
* THROWS when the account doesn't exist
* @param addr The address of the account
* @return The parent address
*/
function accountParent(address addr)
external
view
returns(address) {
return accounts.get(addr).parent;
}
/**
* Gets the account kind, for the given account address
* THROWS when the account doesn't exist
* @param addr The address of the account
* @return The kind of account
*/
function accountKind(address addr)
external
view
returns(uint8) {
return accounts.get(addr).kind;
}
/**
* Gets the frozen status of the account
* THROWS when the account doesn't exist
* @param addr The address of the account
* @return The frozen status of the account
*/
function accountFrozen(address addr)
external
view
returns(bool) {
return accounts.get(addr).frozen;
}
/**
* Gets the index of the account
* Returns -1 for missing accounts
* @param addr The address of the account to get the index for
* @return The index of the given account address
*/
function accountIndexOf(address addr)
external
view
returns(int256) {
return accounts.indexOf(addr);
}
/**
* Returns wether or not the given address exists
* @param addr The account address
* @return If the given address exists
*/
function accountExists(address addr)
external
view
returns(bool) {
return accounts.exists(addr);
}
/**
* Returns wether or not the given address exists for the given kind
* @param addr The account address
* @param kind The kind of address
* @return If the given address exists with the given kind
*/
function accountExists(address addr, uint8 kind)
external
view
returns(bool) {
int256 index = accounts.indexOf(addr);
if (index < 0) {
return false;
}
return accounts.at(index).kind == kind;
}
// -------------------------- Permission Getters ---------------------------
/**
* Retrieves the permission address at the index for the given type
* THROWS when the index is out-of-bounds
* @param kind The kind of permission
* @param index The index of the item to retrieve
* @return The permission address of the item at the given index
*/
function permissionAt(uint8 kind, int256 index)
external
view
returns(address) {
return permissions[kind].at(index);
}
/**
* Gets the index of the permission address for the given type
* Returns -1 for missing permission
* @param kind The kind of perission
* @param addr The address of the permission to get the index for
* @return The index of the given permission address
*/
function permissionIndexOf(uint8 kind, address addr)
external
view
returns(int256) {
return permissions[kind].indexOf(addr);
}
/**
* Returns wether or not the given permission address exists for the given type
* @param kind The kind of permission
* @param addr The address to check for permission
* @return If the given address has permission or not
*/
function permissionExists(uint8 kind, address addr)
external
view
returns(bool) {
return permissions[kind].exists(addr);
}
// -------------------------------------------------------------------------
/**
* Adds an account to storage
* THROWS when `msg.sender` doesn't have permission
* THROWS when the account already exists
* @param addr The address of the account
* @param kind The kind of account
* @param isFrozen The frozen status of the account
* @param parent The account parent/owner
*/
function addAccount(address addr, uint8 kind, bool isFrozen, address parent)
isUnlocked
isAllowed(kind)
external {
require(accounts.append(addr, kind, isFrozen, parent), "Account already exists");
}
/**
* Sets an account's frozen status
* THROWS when the account doesn't exist
* @param addr The address of the account
* @param frozen The frozen status of the account
*/
function setAccountFrozen(address addr, bool frozen)
isUnlocked
isAllowed(accounts.get(addr).kind)
external {
// NOTE: Not bounds checking `index` here, as `isAllowed` ensures the address exists.
// Indices are one-based internally, so we need to add one to compensate.
int256 index = accounts.indexOf(addr) + 1;
accounts.items[index].frozen = frozen;
}
/**
* Removes an account from storage
* THROWS when the account doesn't exist
* @param addr The address of the account
*/
function removeAccount(address addr)
isUnlocked
isAllowed(accounts.get(addr).kind)
external {
bytes32 ZERO_BYTES = bytes32(0);
mapping(uint8 => bytes32) accountData = data[addr];
// Remove data
for (uint8 i = 0; i < MAX_DATA; i++) {
if (accountData[i] != ZERO_BYTES) {
delete accountData[i];
}
}
// Remove account
accounts.remove(addr);
}
/**
* Sets data for an address/caller
* THROWS when the account doesn't exist
* @param addr The address
* @param index The index of the data
* @param customData The data store set
*/
function setAccountData(address addr, uint8 index, bytes32 customData)
isUnlocked
isAllowed(accounts.get(addr).kind)
external {
require(index < MAX_DATA, "index outside of bounds");
data[addr][index] = customData;
}
/**
* Grants the address permission for the given kind
* @param kind The kind of address
* @param addr The address
*/
function grantPermission(uint8 kind, address addr)
isUnlocked
isAllowed(kind)
external {
permissions[kind].append(addr);
}
/**
* Revokes the address permission for the given kind
* @param kind The kind of address
* @param addr The address
*/
function revokePermission(uint8 kind, address addr)
isUnlocked
isAllowed(kind)
external {
permissions[kind].remove(addr);
}
}
interface ERC20 {
event Approval(address indexed owner, address indexed spender, uint256 value);
event Transfer(address indexed from, address indexed to, uint256 value);
function allowance(address owner, address spender) external view returns (uint256);
function approve(address spender, uint256 value) external returns (bool);
function balanceOf(address who) external view returns (uint256);
function totalSupply() external view returns (uint256);
function transfer(address to, uint256 value) external returns (bool);
function transferFrom(address from, address to, uint256 value) external returns (bool);
}
library AdditiveMath {
/**
* Adds two numbers and returns the result
* THROWS when the result overflows
* @return The sum of the arguments
*/
function add(uint256 x, uint256 y)
internal
pure
returns (uint256) {
uint256 sum = x + y;
require(sum >= x, "Results in overflow");
return sum;
}
/**
* Subtracts two numbers and returns the result
* THROWS when the result underflows
* @return The difference of the arguments
*/
function subtract(uint256 x, uint256 y)
internal
pure
returns (uint256) {
require(y <= x, "Results in underflow");
return x - y;
}
}
interface ComplianceRule {
/**
* @param from The address of the sender
* @param to The address of the receiver
* @param toKind The kind of the to address
* @param store The Storage contract
* @return true if transfer is allowed
*/
function canTransfer(address from, address to, uint8 toKind, Storage store)
external
view
returns(bool);
}
interface Compliance {
/**
* This event is emitted when an address's frozen status has changed.
* @param addr The address whose frozen status has been updated.
* @param isFrozen Whether the custodian is being frozen.
* @param owner The address that updated the frozen status.
*/
event AddressFrozen(
address indexed addr,
bool indexed isFrozen,
address indexed owner
);
/**
* Sets an address frozen status for this token
* @param addr The address to update frozen status.
* @param freeze Frozen status of the address.
*/
function setAddressFrozen(address addr, bool freeze)
external;
/**
* Returns all of the current compliance rules for this token
* @param kind The bucket of rules to get.
* @return List of all compliance rules.
*/
function getRules(uint8 kind)
view
external
returns(ComplianceRule[]);
/**
* Replaces all of the existing rules with the given ones
* @param kind The bucket of rules to set.
* @param rules New compliance rules.
*/
function setRules(uint8 kind, ComplianceRule[] rules)
external;
/**
* Checks if a transfer can occur between the from/to addresses.
* Both addressses must be valid, unfrozen, and pass all compliance rule checks.
* @param from The address of the sender.
* @param to The address of the receiver.
* @return If a transfer can occure between the from/to addresses.
*/
function canTransfer(address from, address to)
view
external
returns(bool);
}
contract T0ken is ERC20, Ownable, LockableDestroyable {
// ------------------------------- Variables -------------------------------
using AdditiveMath for uint256;
using AddressMap for AddressMap.Data;
AddressMap.Data public shareholders;
mapping(address => address) public cancellations;
mapping(address => uint256) internal balances;
mapping (address => mapping (address => uint256)) private allowed;
address public issuer;
bool public issuingFinished = false;
uint256 internal totalSupplyTokens;
address constant internal ZERO_ADDRESS = address(0);
Compliance public compliance;
Storage public store;
// Possible 3rd party integration variables
string public constant name = "TZERO PREFERRED";
string public constant symbol = "TZROP";
uint8 public constant decimals = 0;
// ------------------------------- Modifiers -------------------------------
modifier transferCheck(uint256 value, address fromAddr) {
require(value <= balances[fromAddr], "Balance is more than from address has");
_;
}
modifier isNotCancelled(address addr) {
require(cancellations[addr] == ZERO_ADDRESS, "Address has been cancelled");
_;
}
modifier onlyIssuer() {
require(msg.sender == issuer, "Only issuer allowed");
_;
}
modifier canIssue() {
require(!issuingFinished, "Issuing is already finished");
_;
}
modifier canTransfer(address fromAddress, address toAddress) {
if(fromAddress == issuer) {
require(store.accountExists(toAddress), "The to address does not exist");
}
else {
require(compliance.canTransfer(fromAddress, toAddress), "Address cannot transfer");
}
_;
}
modifier canTransferFrom(address fromAddress, address toAddress) {
if(msg.sender == owner) {
require(store.accountExists(toAddress), "The to address does not exist");
}
else {
require(compliance.canTransfer(fromAddress, toAddress), "Address cannot transfer");
}
_;
}
// -------------------------- Events -------------------------------
/**
* This event is emitted when an address is cancelled and replaced with
* a new address. This happens in the case where a shareholder has
* lost access to their original address and needs to have their share
* reissued to a new address. This is the equivalent of issuing replacement
* share certificates.
* @param original The address being superseded.
* @param replacement The new address.
* @param sender The address that caused the address to be superseded.
*/
event VerifiedAddressSuperseded(address indexed original, address indexed replacement, address indexed sender);
event IssuerSet(address indexed previousIssuer, address indexed newIssuer);
event Issue(address indexed to, uint256 amount);
event IssueFinished();
// ---------------------------- Getters ----------------------------
/**
* @return total number of tokens in existence
*/
function totalSupply()
external
view
returns (uint256) {
return totalSupplyTokens;
}
/**
* @dev Gets the balance of the specified address.
* @param addr The address to query the the balance of.
* @return An uint256 representing the amount owned by the passed address.
*/
function balanceOf(address addr)
external
view
returns (uint256) {
return balances[addr];
}
/**
* @dev Function to check the amount of tokens that an owner allowed to a spender.
* @param addrOwner address The address which owns the funds.
* @param spender address The address which will spend the funds.
* @return A uint256 specifying the amount of tokens still available for the spender.
*/
function allowance(address addrOwner, address spender)
isUnlocked
external
view
returns (uint256) {
return allowed[addrOwner][spender];
}
/**
* By counting the number of token holders using `holderCount`
* you can retrieve the complete list of token holders, one at a time.
* It MUST throw if `index >= holderCount()`.
* @param index The zero-based index of the holder.
* @return the address of the token holder with the given index.
*/
function holderAt(int256 index)
external
view
returns (address){
return shareholders.at(index);
}
/**
* Checks to see if the supplied address is a share holder.
* @param addr The address to check.
* @return true if the supplied address owns a token.
*/
function isHolder(address addr)
external
view
returns (bool) {
return shareholders.exists(addr);
}
/**
* Checks to see if the supplied address was superseded.
* @param addr The address to check.
* @return true if the supplied address was superseded by another address.
*/
function isSuperseded(address addr)
onlyOwner
external
view
returns (bool) {
return cancellations[addr] != ZERO_ADDRESS;
}
/**
* Gets the most recent address, given a superseded one.
* Addresses may be superseded multiple times, so this function needs to
* follow the chain of addresses until it reaches the final, verified address.
* @param addr The superseded address.
* @return the verified address that ultimately holds the share.
*/
function getSuperseded(address addr)
onlyOwner
public
view
returns (address) {
require(addr != ZERO_ADDRESS, "Non-zero address required");
address candidate = cancellations[addr];
if (candidate == ZERO_ADDRESS) {
return ZERO_ADDRESS;
}
return candidate;
}
// -----------------------------------------------------------------
function setCompliance(address newComplianceAddress)
isUnlocked
onlyOwner
external {
compliance = Compliance(newComplianceAddress);
}
function setStorage(Storage s)
isUnlocked
onlyOwner
external {
store = s;
}
/**
* @dev transfer token for a specified address
* @param to The address to transfer to.
* @param value The amount to be transferred.
* The `transfer` function MUST NOT allow transfers to addresses that
* have not been verified and added to the contract.
* If the `to` address is not currently a shareholder then it MUST become one.
* If the transfer will reduce `msg.sender`'s balance to 0 then that address
* MUST be removed from the list of shareholders.
*/
function transfer(address to, uint256 value)
isUnlocked
isNotCancelled(to)
transferCheck(value, msg.sender)
canTransfer(msg.sender, to)
public
returns (bool) {
balances[msg.sender] = balances[msg.sender].subtract(value);
balances[to] = balances[to].add(value);
// Adds the shareholder, if they don't already exist.
shareholders.append(to);
// Remove the shareholder if they no longer hold tokens.
if (balances[msg.sender] == 0) {
shareholders.remove(msg.sender);
}
emit Transfer(msg.sender, to, value);
return true;
}
/**
* @dev Transfer tokens from one address to another
* @param from address The address which you want to send tokens from
* @param to address The address which you want to transfer to
* @param value uint256 the amount of tokens to be transferred
* The `transferFrom` function MUST NOT allow transfers to addresses that
* have not been verified and added to the contract.
* If the `to` address is not currently a shareholder then it MUST become one.
* If the transfer will reduce `from`'s balance to 0 then that address
* MUST be removed from the list of shareholders.
*/
function transferFrom(address from, address to, uint256 value)
public
transferCheck(value, from)
isNotCancelled(to)
canTransferFrom(from, to)
isUnlocked
returns (bool) {
if(msg.sender != owner) {
require(value <= allowed[from][msg.sender], "Value exceeds what is allowed to transfer");
allowed[from][msg.sender] = allowed[from][msg.sender].subtract(value);
}
balances[from] = balances[from].subtract(value);
balances[to] = balances[to].add(value);
// Adds the shareholder, if they don't already exist.
shareholders.append(to);
// Remove the shareholder if they no longer hold tokens.
if (balances[msg.sender] == 0) {
shareholders.remove(from);
}
emit Transfer(from, to, value);
return true;
}
/**
* @dev Approve the passed address to spend the specified amount of tokens on behalf of msg.sender.
*
* Beware that changing an allowance with this method brings the risk that someone may use both the old
* and the new allowance by unfortunate transaction ordering. One possible solution to mitigate this
* race condition is to first reduce the spender's allowance to 0 and set the desired value afterwards:
* https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
* @param spender The address which will spend the funds.
* @param value The amount of tokens to be spent.
*/
function approve(address spender, uint256 value)
isUnlocked
external
returns (bool) {
allowed[msg.sender][spender] = value;
emit Approval(msg.sender, spender, value);
return true;
}
function setIssuer(address newIssuer)
isUnlocked
onlyOwner
external {
issuer = newIssuer;
emit IssuerSet(issuer, newIssuer);
}
/**
* Tokens will be issued only to the issuer's address
* @param quantity The amount of tokens to mint.
* @return A boolean that indicates if the operation was successful.
*/
function issueTokens(uint256 quantity)
isUnlocked
onlyIssuer
canIssue
public
returns (bool) {
address issuer = msg.sender;
totalSupplyTokens = totalSupplyTokens.add(quantity);
balances[issuer] = balances[issuer].add(quantity);
shareholders.append(issuer);
emit Issue(issuer, quantity);
return true;
}
function finishIssuing()
isUnlocked
onlyIssuer
canIssue
public
returns (bool) {
issuingFinished = true;
emit IssueFinished();
return issuingFinished;
}
/**
* Cancel the original address and reissue the Tokens to the replacement address.
*
* ***It's on the issuer to make sure the replacement address belongs to a verified investor.***
*
* Access to this function MUST be strictly controlled.
* The `original` address MUST be removed from the set of verified addresses.
* Throw if the `original` address supplied is not a shareholder.
* Throw if the replacement address is not a verified address.
* This function MUST emit the `VerifiedAddressSuperseded` event.
* @param original The address to be superseded. This address MUST NOT be reused.
* @param replacement The address that supersedes the original. This address MUST be verified.
*/
function cancelAndReissue(address original, address replacement)
isUnlocked
onlyOwner
isNotCancelled(replacement)
external {
// replace the original address in the shareholders mapping
// and update all the associated mappings
require(shareholders.exists(original) && !shareholders.exists(replacement), "Original doesn't exist or replacement does");
shareholders.remove(original);
shareholders.append(replacement);
cancellations[original] = replacement;
balances[replacement] = balances[original];
balances[original] = 0;
emit VerifiedAddressSuperseded(original, replacement, msg.sender);
}
}
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