backoff.js 5.8 KB

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  1. "use strict";
  2. var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
  3. function adopt(value) { return value instanceof P ? value : new P(function (resolve) { resolve(value); }); }
  4. return new (P || (P = Promise))(function (resolve, reject) {
  5. function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
  6. function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
  7. function step(result) { result.done ? resolve(result.value) : adopt(result.value).then(fulfilled, rejected); }
  8. step((generator = generator.apply(thisArg, _arguments || [])).next());
  9. });
  10. };
  11. var __generator = (this && this.__generator) || function (thisArg, body) {
  12. var _ = { label: 0, sent: function() { if (t[0] & 1) throw t[1]; return t[1]; }, trys: [], ops: [] }, f, y, t, g;
  13. return g = { next: verb(0), "throw": verb(1), "return": verb(2) }, typeof Symbol === "function" && (g[Symbol.iterator] = function() { return this; }), g;
  14. function verb(n) { return function (v) { return step([n, v]); }; }
  15. function step(op) {
  16. if (f) throw new TypeError("Generator is already executing.");
  17. while (_) try {
  18. if (f = 1, y && (t = op[0] & 2 ? y["return"] : op[0] ? y["throw"] || ((t = y["return"]) && t.call(y), 0) : y.next) && !(t = t.call(y, op[1])).done) return t;
  19. if (y = 0, t) op = [op[0] & 2, t.value];
  20. switch (op[0]) {
  21. case 0: case 1: t = op; break;
  22. case 4: _.label++; return { value: op[1], done: false };
  23. case 5: _.label++; y = op[1]; op = [0]; continue;
  24. case 7: op = _.ops.pop(); _.trys.pop(); continue;
  25. default:
  26. if (!(t = _.trys, t = t.length > 0 && t[t.length - 1]) && (op[0] === 6 || op[0] === 2)) { _ = 0; continue; }
  27. if (op[0] === 3 && (!t || (op[1] > t[0] && op[1] < t[3]))) { _.label = op[1]; break; }
  28. if (op[0] === 6 && _.label < t[1]) { _.label = t[1]; t = op; break; }
  29. if (t && _.label < t[2]) { _.label = t[2]; _.ops.push(op); break; }
  30. if (t[2]) _.ops.pop();
  31. _.trys.pop(); continue;
  32. }
  33. op = body.call(thisArg, _);
  34. } catch (e) { op = [6, e]; y = 0; } finally { f = t = 0; }
  35. if (op[0] & 5) throw op[1]; return { value: op[0] ? op[1] : void 0, done: true };
  36. }
  37. };
  38. Object.defineProperty(exports, "__esModule", { value: true });
  39. var options_1 = require("./options");
  40. var delay_factory_1 = require("./delay/delay.factory");
  41. /**
  42. * Executes a function with exponential backoff.
  43. * @param request the function to be executed
  44. * @param options options to customize the backoff behavior
  45. * @returns Promise that resolves to the result of the `request` function
  46. */
  47. function backOff(request, options) {
  48. if (options === void 0) { options = {}; }
  49. return __awaiter(this, void 0, void 0, function () {
  50. var sanitizedOptions, backOff;
  51. return __generator(this, function (_a) {
  52. switch (_a.label) {
  53. case 0:
  54. sanitizedOptions = options_1.getSanitizedOptions(options);
  55. backOff = new BackOff(request, sanitizedOptions);
  56. return [4 /*yield*/, backOff.execute()];
  57. case 1: return [2 /*return*/, _a.sent()];
  58. }
  59. });
  60. });
  61. }
  62. exports.backOff = backOff;
  63. var BackOff = /** @class */ (function () {
  64. function BackOff(request, options) {
  65. this.request = request;
  66. this.options = options;
  67. this.attemptNumber = 0;
  68. }
  69. BackOff.prototype.execute = function () {
  70. return __awaiter(this, void 0, void 0, function () {
  71. var e_1, shouldRetry;
  72. return __generator(this, function (_a) {
  73. switch (_a.label) {
  74. case 0:
  75. if (!!this.attemptLimitReached) return [3 /*break*/, 7];
  76. _a.label = 1;
  77. case 1:
  78. _a.trys.push([1, 4, , 6]);
  79. return [4 /*yield*/, this.applyDelay()];
  80. case 2:
  81. _a.sent();
  82. return [4 /*yield*/, this.request()];
  83. case 3: return [2 /*return*/, _a.sent()];
  84. case 4:
  85. e_1 = _a.sent();
  86. this.attemptNumber++;
  87. return [4 /*yield*/, this.options.retry(e_1, this.attemptNumber)];
  88. case 5:
  89. shouldRetry = _a.sent();
  90. if (!shouldRetry || this.attemptLimitReached) {
  91. throw e_1;
  92. }
  93. return [3 /*break*/, 6];
  94. case 6: return [3 /*break*/, 0];
  95. case 7: throw new Error("Something went wrong.");
  96. }
  97. });
  98. });
  99. };
  100. Object.defineProperty(BackOff.prototype, "attemptLimitReached", {
  101. get: function () {
  102. return this.attemptNumber >= this.options.numOfAttempts;
  103. },
  104. enumerable: true,
  105. configurable: true
  106. });
  107. BackOff.prototype.applyDelay = function () {
  108. return __awaiter(this, void 0, void 0, function () {
  109. var delay;
  110. return __generator(this, function (_a) {
  111. switch (_a.label) {
  112. case 0:
  113. delay = delay_factory_1.DelayFactory(this.options, this.attemptNumber);
  114. return [4 /*yield*/, delay.apply()];
  115. case 1:
  116. _a.sent();
  117. return [2 /*return*/];
  118. }
  119. });
  120. });
  121. };
  122. return BackOff;
  123. }());
  124. //# sourceMappingURL=backoff.js.map