lbry-desktop/ui/js/lighthouse.js

import lbry from "./lbry.js";
import jsonrpc from "./jsonrpc.js";

const queryTimeout = 3000;
const maxQueryTries = 2;
const defaultServers = [
  "http://lighthouse7.lbry.io:50005",
  "http://lighthouse8.lbry.io:50005",
  "http://lighthouse9.lbry.io:50005",
];
const path = "/";

let server = null;
let connectTryNum = 0;

function getServers() {
  return defaultServers;
}

function call(method, params, callback, errorCallback) {
  if (connectTryNum >= maxQueryTries) {
    errorCallback(
      new Error(
        __(
          `Could not connect to Lighthouse server. Last server attempted: %s`,
          server
        )
      )
    );
    return;
  }

  /**
   * Set the Lighthouse server if it hasn't been set yet, if the current server is not in current
   * set of servers (most likely because of a settings change), or we're re-trying after a failed
   * query.
   */
  if (!server || !getServers().includes(server) || connectTryNum > 0) {
    // If there's a current server, filter it out so we get a new one
    const newServerChoices = server
      ? getServers().filter(s => s != server)
      : getServers();
    server =
      newServerChoices[
        Math.round(Math.random() * (newServerChoices.length - 1))
      ];
  }

  jsonrpc.call(
    server + path,
    method,
    params,
    response => {
      connectTryNum = 0;
      callback(response);
    },
    error => {
      connectTryNum = 0;
      errorCallback(error);
    },
    () => {
      connectTryNum++;
      call(method, params, callback, errorCallback);
    },
    queryTimeout
  );
}

const lighthouse = new Proxy(
  {},
  {
    get: function(target, name) {
      return function(...params) {
        return new Promise((resolve, reject) => {
          call(name, params, resolve, reject);
        });
      };
    },
  }
);

export default lighthouse;