LINK_TOKEN_POINTER 是做什么的

Question

我正在尝试让 chainlink 在 harmony one 区块链上工作，我正在尝试部署一个扩展 chainlinkclient.sol 的测试合约来测试设置，但由于某种原因它不会部署。我想知道这是否是因为 LINK_TOKEN_POINTER 硬编码为 0xC89bD4E1632D3A43CB03AAAd5262cbe4038Bc571。有谁知道那个地址是什么？所有 ETH 测试网（rinkeby、kovan 等）和其他链是否都一样？

我正在尝试将 TestConsumer.sol 合约部署到 Harmony One 链上，但出现错误。我能够让它在 Kovan 上工作。

我怀疑这可能是由于 LINK_TOKEN_POINTER。有谁知道我如何让它工作？

pragma solidity 0.4.24;

import "https://github.com/smartcontractkit/chainlink/evm-contracts/src/v0.4/ChainlinkClient.sol";
import "https://github.com/smartcontractkit/chainlink/evm-contracts/src/v0.4/vendor/Ownable.sol";

contract ATestnetConsumer is ChainlinkClient, Ownable {
  uint256 constant private ORACLE_PAYMENT = 1 * LINK;

  uint256 public currentPrice;
  int256 public changeDay;
  bytes32 public lastMarket;

  event RequestEthereumPriceFulfilled(
    bytes32 indexed requestId,
    uint256 indexed price
  );

  event RequestEthereumChangeFulfilled(
    bytes32 indexed requestId,
    int256 indexed change
  );

  event RequestEthereumLastMarket(
    bytes32 indexed requestId,
    bytes32 indexed market
  );

  constructor() public Ownable() {
    setPublicChainlinkToken();
  }

  function requestEthereumPrice(address _oracle, string _jobId)
    public
    onlyOwner
  {
    Chainlink.Request memory req = buildChainlinkRequest(stringToBytes32(_jobId), this, this.fulfillEthereumPrice.selector);
    req.add("get", "https://min-api.cryptocompare.com/data/price?fsym=ETH&tsyms=USD");
    req.add("path", "USD");
    req.addInt("times", 100);
    sendChainlinkRequestTo(_oracle, req, ORACLE_PAYMENT);
  }

  function requestEthereumChange(address _oracle, string _jobId)
    public
    onlyOwner
  {
    Chainlink.Request memory req = buildChainlinkRequest(stringToBytes32(_jobId), this, this.fulfillEthereumChange.selector);
    req.add("get", "https://min-api.cryptocompare.com/data/pricemultifull?fsyms=ETH&tsyms=USD");
    req.add("path", "RAW.ETH.USD.CHANGEPCTDAY");
    req.addInt("times", 1000000000);
    sendChainlinkRequestTo(_oracle, req, ORACLE_PAYMENT);
  }

  function requestEthereumLastMarket(address _oracle, string _jobId)
    public
    onlyOwner
  {
    Chainlink.Request memory req = buildChainlinkRequest(stringToBytes32(_jobId), this, this.fulfillEthereumLastMarket.selector);
    req.add("get", "https://min-api.cryptocompare.com/data/pricemultifull?fsyms=ETH&tsyms=USD");
    string[] memory path = new string[](4);
    path[0] = "RAW";
    path[1] = "ETH";
    path[2] = "USD";
    path[3] = "LASTMARKET";
    req.addStringArray("path", path);
    sendChainlinkRequestTo(_oracle, req, ORACLE_PAYMENT);
  }

  function fulfillEthereumPrice(bytes32 _requestId, uint256 _price)
    public
    recordChainlinkFulfillment(_requestId)
  {
    emit RequestEthereumPriceFulfilled(_requestId, _price);
    currentPrice = _price;
  }

  function fulfillEthereumChange(bytes32 _requestId, int256 _change)
    public
    recordChainlinkFulfillment(_requestId)
  {
    emit RequestEthereumChangeFulfilled(_requestId, _change);
    changeDay = _change;
  }

  function fulfillEthereumLastMarket(bytes32 _requestId, bytes32 _market)
    public
    recordChainlinkFulfillment(_requestId)
  {
    emit RequestEthereumLastMarket(_requestId, _market);
    lastMarket = _market;
  }

  function getChainlinkToken() public view returns (address) {
    return chainlinkTokenAddress();
  }

  function withdrawLink() public onlyOwner {
    LinkTokenInterface link = LinkTokenInterface(chainlinkTokenAddress());
    require(link.transfer(msg.sender, link.balanceOf(address(this))), "Unable to transfer");
  }

  function cancelRequest(
    bytes32 _requestId,
    uint256 _payment,
    bytes4 _callbackFunctionId,
    uint256 _expiration
  )
    public
    onlyOwner
  {
    cancelChainlinkRequest(_requestId, _payment, _callbackFunctionId, _expiration);
  }

  function stringToBytes32(string memory source) private pure returns (bytes32 result) {
    bytes memory tempEmptyStringTest = bytes(source);
    if (tempEmptyStringTest.length == 0) {
      return 0x0;
    }

    assembly { // solhint-disable-line no-inline-assembly
      result := mload(add(source, 32))
    }
  }

}

Answer 1

LINK_TOKEN_POINTER 是一个硬编码的合约，带有指向各种链上 LINK 代币的指针。这是为了让合约知道要使用哪个 LINK 代币。

对于和谐这样的链，可能还没有为该链添加 LINK 令牌指针。

要解决此问题，您需要手动设置 LINK 令牌，如下所示：

constructor(address _link) public {
        if (_link == address(0)) {
            setPublicChainlinkToken();
        } else {
            setChainlinkToken(_link);
        }

Harmony 链上似乎还没有 LINK 代币，因此您可以部署一个虚拟 LINK 代币并将地址指向它。

LINK_TOKEN_POINTER 是做什么的

What does LINK_TOKEN_POINTER do

solidity

chainlink