tempus-api-graphql/dist/utils/cached_by_key_resource.js

A GraphQL wrapper for the tempus api (tempus2.xyz)

"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports["default"] = void 0;

var _lruCache = _interopRequireDefault(require("lru-cache"));

function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { "default": obj }; }

function asyncGeneratorStep(gen, resolve, reject, _next, _throw, key, arg) { try { var info = gen[key](arg); var value = info.value; } catch (error) { reject(error); return; } if (info.done) { resolve(value); } else { Promise.resolve(value).then(_next, _throw); } }

function _asyncToGenerator(fn) { return function () { var self = this, args = arguments; return new Promise(function (resolve, reject) { var gen = fn.apply(self, args); function _next(value) { asyncGeneratorStep(gen, resolve, reject, _next, _throw, "next", value); } function _throw(err) { asyncGeneratorStep(gen, resolve, reject, _next, _throw, "throw", err); } _next(undefined); }); }; }

function _classCallCheck(instance, Constructor) { if (!(instance instanceof Constructor)) { throw new TypeError("Cannot call a class as a function"); } }

function _defineProperties(target, props) { for (var i = 0; i < props.length; i++) { var descriptor = props[i]; descriptor.enumerable = descriptor.enumerable || false; descriptor.configurable = true; if ("value" in descriptor) descriptor.writable = true; Object.defineProperty(target, descriptor.key, descriptor); } }

function _createClass(Constructor, protoProps, staticProps) { if (protoProps) _defineProperties(Constructor.prototype, protoProps); if (staticProps) _defineProperties(Constructor, staticProps); Object.defineProperty(Constructor, "prototype", { writable: false }); return Constructor; }

var CachedByKeyResource = /*#__PURE__*/function () {
  function CachedByKeyResource(loader) {
    var options = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : {};

    _classCallCheck(this, CachedByKeyResource);

    var timeout = options.timeout || 60;
    var max = options.max || 100;
    this.loader = loader;

    this.keyFunc = options.keyFunc || function (x) {
      return JSON.stringify(x);
    }; // insired by https://spin.atomicobject.com/2018/09/10/javascript-concurrency/
    // My knowledge of JS's runtime is not good enough to fully vet this, but seems reasonable ish
    // Also I don't really need concurrency guarantees for this project anyway


    this.inFlight = {};
    this.cache = new _lruCache["default"]({
      max: max,
      maxAge: timeout * 1000
    });
  }

  _createClass(CachedByKeyResource, [{
    key: "set",
    value: function set(item, value) {
      this.cache.set(this.keyFunc(item), value);
    }
  }, {
    key: "load",
    value: function () {
      var _load = _asyncToGenerator( /*#__PURE__*/regeneratorRuntime.mark(function _callee3(item) {
        var _this = this;

        var key, inFlight;
        return regeneratorRuntime.wrap(function _callee3$(_context3) {
          while (1) {
            switch (_context3.prev = _context3.next) {
              case 0:
                if (!(item === null)) {
                  _context3.next = 2;
                  break;
                }

                return _context3.abrupt("return", null);

              case 2:
                key = this.keyFunc(item);
                inFlight = this.inFlight;

                if (!inFlight[key]) {
                  inFlight[key] = _asyncToGenerator( /*#__PURE__*/regeneratorRuntime.mark(function _callee2() {
                    var cached, r;
                    return regeneratorRuntime.wrap(function _callee2$(_context2) {
                      while (1) {
                        switch (_context2.prev = _context2.next) {
                          case 0:
                            _context2.prev = 0;
                            cached = _this.cache.get(key);

                            if (!cached) {
                              _context2.next = 6;
                              break;
                            }

                            _context2.next = 5;
                            return _asyncToGenerator( /*#__PURE__*/regeneratorRuntime.mark(function _callee() {
                              return regeneratorRuntime.wrap(function _callee$(_context) {
                                while (1) {
                                  switch (_context.prev = _context.next) {
                                    case 0:
                                      return _context.abrupt("return", cached);

                                    case 1:
                                    case "end":
                                      return _context.stop();
                                  }
                                }
                              }, _callee);
                            }))();

                          case 5:
                            return _context2.abrupt("return", _context2.sent);

                          case 6:
                            _context2.next = 8;
                            return _this.loader(item);

                          case 8:
                            r = _context2.sent;

                            _this.cache.set(key, r);

                            return _context2.abrupt("return", r);

                          case 11:
                            _context2.prev = 11;
                            delete inFlight[key];
                            return _context2.finish(11);

                          case 14:
                          case "end":
                            return _context2.stop();
                        }
                      }
                    }, _callee2, null, [[0,, 11, 14]]);
                  }))();
                }

                return _context3.abrupt("return", inFlight[key]);

              case 6:
              case "end":
                return _context3.stop();
            }
          }
        }, _callee3, this);
      }));

      function load(_x) {
        return _load.apply(this, arguments);
      }

      return load;
    }()
  }, {
    key: "clearCache",
    value: function clearCache() {
      this.cache.reset();
    }
  }]);

  return CachedByKeyResource;
}();

var _default = CachedByKeyResource;
exports["default"] = _default;