lightstep-tracer/lib/imp/propagator_dd.js

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"use strict";

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

var _each2 = _interopRequireDefault(require("../_each"));

var _span_context_imp = _interopRequireDefault(require("./span_context_imp"));

var _propagator_ls = _interopRequireDefault(require("./propagator_ls"));

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

function _typeof(obj) { "@babel/helpers - typeof"; return _typeof = "function" == typeof Symbol && "symbol" == typeof Symbol.iterator ? function (obj) { return typeof obj; } : function (obj) { return obj && "function" == typeof Symbol && obj.constructor === Symbol && obj !== Symbol.prototype ? "symbol" : typeof obj; }, _typeof(obj); }

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 CARRIER_DD_TRACER_STATE_PREFIX = 'x-datadog-';

var DDPropagator = /*#__PURE__*/function () {
  function DDPropagator(tracer) {
    _classCallCheck(this, DDPropagator);

    this._tracer = tracer;
    this._baggagePrefix = _propagator_ls["default"];
    this._carrierPrefix = CARRIER_DD_TRACER_STATE_PREFIX;
  }

  _createClass(DDPropagator, [{
    key: "inject",
    value: function inject(spanContext, carrier) {
      var _this = this;

      if (!carrier) {
        this._tracer._error('Unexpected null carrier in call to inject');

        return;
      }

      if (_typeof(carrier) !== 'object') {
        this._tracer._error("Unexpected '".concat(_typeof(carrier), "' FORMAT_TEXT_MAP carrier in call to inject"));

        return;
      } // eslint-disable-next-line max-len
      // Per https://github.com/lightstep/lightstep-tracer-javascript/blob/master/src/imp/platform/node/platform_node.js#L91
      // all generated GUIDs are base 16 strings.
      // DD headers expect integers, not base 16 values.


      carrier["".concat(this._carrierPrefix, "parent-id")] = parseInt(spanContext._guid, 16).toString();
      carrier["".concat(this._carrierPrefix, "trace-id")] = parseInt(spanContext.traceGUID(), 16).toString();

      if (spanContext._sampled) {
        carrier["".concat(this._carrierPrefix, "sampling-priority")] = '1';
      } else {
        carrier["".concat(this._carrierPrefix, "sampling-priority")] = '0';
      }

      spanContext.forEachBaggageItem(function (key, value) {
        carrier["".concat(_this._baggagePrefix).concat(key)] = value;
      });
      return carrier;
    }
  }, {
    key: "extract",
    value: function extract(carrier) {
      var _this2 = this;

      // Iterate over the contents of the carrier and set the properties
      // accordingly.
      var foundFields = 0;
      var spanGUID = null;
      var traceGUID = null;
      var sampled = true;
      (0, _each2["default"])(carrier, function (value, key) {
        key = key.toLowerCase();

        if (key.substr(0, _this2._carrierPrefix.length) !== _this2._carrierPrefix) {
          return;
        }

        var suffix = key.substr(_this2._carrierPrefix.length);

        switch (suffix) {
          case 'trace-id':
            foundFields++;
            traceGUID = parseInt(value, 10).toString(16);
            break;

          case 'parent-id':
            foundFields++;
            spanGUID = parseInt(value, 10).toString(16);
            break;

          case 'sampling-priority':
            // TODO: support sampling priority somehow. This is a float64 that does not
            // necessarily represent the sampling decision
            if (value === 0) {
              sampled = false;
            }

            break;

          default:
            _this2._tracer._error("Unrecognized carrier key '".concat(key, "' with recognized prefix. Ignoring."));

            break;
        }
      });

      if (foundFields === 0) {
        // This is not an error per se, there was simply no SpanContext
        // in the carrier.
        return null;
      }

      if (foundFields < 2) {
        // A partial SpanContext suggests some sort of data corruption.
        this._tracer._error("Only found a partial SpanContext: ".concat(carrier));

        return null;
      }

      var spanContext = new _span_context_imp["default"](spanGUID, traceGUID, sampled);
      (0, _each2["default"])(carrier, function (value, key) {
        key = key.toLowerCase();

        if (key.substr(0, _this2._baggagePrefix.length) !== _this2._baggagePrefix) {
          return;
        }

        var suffix = key.substr(_this2._baggagePrefix.length);
        spanContext.setBaggageItem(suffix, value);
      });
      return spanContext;
    }
  }]);

  return DDPropagator;
}();

exports["default"] = DDPropagator;
module.exports = exports.default;

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