eth-token-index/solidity/TokenUniqueSymbolIndex.sol
2023-03-25 16:23:16 +00:00

187 lines
4.1 KiB
Solidity

pragma solidity >=0.8.0;
// SPDX-License-Identifier: AGPL-3.0-or-later
contract TokenUniqueSymbolIndex {
mapping(address => bool) isWriter;
mapping ( bytes32 => uint256 ) registry;
mapping ( address => bytes32 ) tokenIndex;
address[] tokens;
// Implements EIP173
address public owner;
// Implements Registry
bytes32[] public identifiers;
// Implements EIP173
event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
// Implements AccountsIndex
event AddressKey(bytes32 indexed _symbol, address _token);
// Implements AccountsIndex
event AddressAdded(address _token);
// Implements AccountsIndexMutable
event AddressRemoved(address _token);
// Implements Writer
event WriterAdded(address _writer);
// Implements Writer
event WriterDeleted(address _writer);
constructor() {
owner = msg.sender;
tokens.push(address(0));
}
// Implements AccountsIndex
function entry(uint256 _idx) public view returns ( address ) {
return tokens[_idx + 1];
}
// Implements RegistryClient
function addressOf(bytes32 _key) public view returns ( address ) {
uint256 idx;
idx = registry[_key];
return tokens[idx];
}
// Attempt to register the token at the given address.
// Will revet if symbol cannot be retrieved, or if symbol already exists.
function register(address _token) public returns (bool) {
require(isWriter[msg.sender]);
bytes memory token_symbol;
bytes32 token_symbol_key;
uint256 idx;
(bool _ok, bytes memory _r) = _token.call(abi.encodeWithSignature('symbol()'));
require(_ok);
token_symbol = abi.decode(_r, (bytes));
require(token_symbol.length <= 32, 'ERR_TOKEN_SYMBOL_TOO_LONG');
token_symbol_key = bytes32(token_symbol);
idx = registry[token_symbol_key];
require(idx == 0);
registry[token_symbol_key] = tokens.length;
tokens.push(_token);
identifiers.push(token_symbol_key);
tokenIndex[_token] = token_symbol_key;
emit AddressKey(token_symbol_key, _token);
emit AddressAdded(_token);
return true;
}
// Implements AccountsIndex
function add(address _token) public returns (bool) {
return register(_token);
}
// Implements AccountsIndexMutable
function remove(address _token) external returns (bool) {
uint256 i;
uint256 l;
require(isWriter[msg.sender], 'ERR_AXX');
require(tokenIndex[_token] != bytes32(0), 'ERR_NOT_FOUND');
l = tokens.length - 1;
i = registry[tokenIndex[_token]];
if (i < l) {
tokens[i] = tokens[l];
identifiers[i] = identifiers[l];
}
tokens.pop();
registry[tokenIndex[_token]] = 0;
emit AddressRemoved(_token);
return true;
}
// Implements AccountsIndexMutable
function activate(address _token) public pure returns(bool) {
_token;
return false;
}
// Implements AccountsIndexMutable
function deactivate(address _token) public pure returns(bool) {
_token;
return false;
}
// Implements AccountsIndex
function entryCount() public view returns ( uint256 ) {
return tokens.length - 1;
}
// Implements EIP173
function transferOwnership(address _newOwner) public returns (bool) {
address oldOwner;
require(msg.sender == owner);
oldOwner = owner;
owner = _newOwner;
emit OwnershipTransferred(oldOwner, owner);
return true;
}
// Implements Writer
function addWriter(address _writer) public returns (bool) {
require(owner == msg.sender);
isWriter[_writer] = true;
emit WriterAdded(_writer);
return true;
}
// Implements Writer
function deleteWriter(address _writer) public returns (bool) {
require(owner == msg.sender);
delete isWriter[_writer];
emit WriterDeleted(_writer);
return true;
}
// Implements Registry
function identifierCount() public view returns(uint256) {
return identifiers.length;
}
// Implements EIP165
function supportsInterface(bytes4 _sum) public pure returns (bool) {
if (_sum == 0x12625fe5) { // Registry
return true;
}
if (_sum == 0xb7bca625) { // AccountsIndex
return true;
}
if (_sum == 0x9479f0ae) { // AccountsIndexMutable
return true;
}
if (_sum == 0x01ffc9a7) { // EIP165
return true;
}
if (_sum == 0x9493f8b2) { // EIP173
return true;
}
if (_sum == 0x80c84bd6) { // Writer
return true;
}
return false;
}
}