@instana/core/src/tracing/opentracing/Span.js

Core library for Instana's Node.js packages

/*
 * (c) Copyright IBM Corp. 2021
 * (c) Copyright Instana Inc. and contributors 2016
 */

'use strict';

const opentracing = require('opentracing');
const spanBuffer = require('../spanBuffer');
const tracingUtil = require('../tracingUtil');

/** @typedef {import('../../../../collector/src/pidStore')} CollectorPIDStore */

/**
 * @typedef {Object} OpenTracingSpanDataSdkCustom
 * @property {*} tags
 * @property {*} logs
 */

/**
 * @typedef {Object} OpenTracingSpanDataSdk
 * @property {'local' | 'entry' | 'exit'} type
 * @property {string} name
 * @property {OpenTracingSpanDataSdkCustom} custom
 */

/**
 * @typedef {Object} OpenTracingSpanData
 * @property {string} service
 * @property {OpenTracingSpanDataSdk} sdk
 */

/**
 * @typedef {Object} OpenTracingSpan
 * @property {string} s
 * @property {string} t
 * @property {string} p
 * @property {number} ec
 * @property {number} ts
 * @property {number} d
 * @property {string} n
 * @property {*} stack
 * @property {OpenTracingSpanData} data
 * @property {*} [f]
 */

/**
 * @typedef {Object} SpanFieldReference
 * @property {() => string} type
 * @property {() => *} referencedContext
 */

/**
 * @typedef {Object} SpanFields
 * @property {Array.<SpanFieldReference>} references
 * @property {number} startTime
 * @property {string} operationName
 * @property {*} tags
 */

// can be set via config
/** @type {string} */
let serviceName;

/** @type {CollectorPIDStore} */
let processIdentityProvider = null;

/**
 *
 * @param {import('./Tracer')} tracer
 * @param {string} name
 * @param {SpanFields} fields
 */
function Span(tracer, name, fields) {
  opentracing.Span.call(this);
  this.tracerImpl = tracer;

  let parentContext;
  if (fields && fields.references) {
    for (let i = 0, length = fields.references.length; i < length; i++) {
      const reference = fields.references[i];

      if (
        reference.type() === opentracing.REFERENCE_CHILD_OF ||
        reference.type() === opentracing.REFERENCE_FOLLOWS_FROM
      ) {
        parentContext = reference.referencedContext();
      }
    }
  }

  const spanId = tracingUtil.generateRandomSpanId();
  /** @type {string} */
  const traceId = (parentContext ? parentContext.t : null) || spanId;
  const parentId = (parentContext ? parentContext.s : null) || undefined;
  this._contextImpl = new opentracing.SpanContext();
  // @ts-ignore
  this._contextImpl.s = spanId;
  // @ts-ignore
  this._contextImpl.t = traceId;
  // @ts-ignore
  this._contextImpl.baggage = copyBaggage(parentContext && parentContext.baggage);
  // @ts-ignore
  this._contextImpl.samplingPriority = parentContext ? parentContext.samplingPriority : 1;

  /** @type {OpenTracingSpan} */
  this.span = {
    s: spanId,
    t: traceId,
    p: parentId,
    ec: 0,
    ts: (fields ? fields.startTime : null) || Date.now(),
    d: 0,
    n: 'sdk',
    stack: tracingUtil.getStackTrace(Span),
    data: {
      service: serviceName,
      sdk: {
        type: parentContext ? 'local' : 'entry',
        name,
        custom: {
          tags: {},
          logs: {}
        }
      }
    }
  };

  if (processIdentityProvider && typeof processIdentityProvider.getFrom === 'function') {
    this.span.f = processIdentityProvider.getFrom();
  }

  if (fields && fields.tags) {
    this._addTags(fields.tags);
  }

  if (fields && fields.operationName) {
    this.span.data.sdk.name = fields.operationName;
  }
}

module.exports = Span;

Span.prototype = Object.create(opentracing.Span.prototype);

Span.prototype._context = function _context() {
  return this._contextImpl;
};

Span.prototype._tracer = function _tracer() {
  return this.tracerImpl;
};

/**
 * @param {string} name
 */
Span.prototype._setOperationName = function _setOperationName(name) {
  this.span.data.sdk.name = name;
};

/**
 * @param {string} key
 * @param {*} value
 */
Span.prototype._setBaggageItem = function _setBaggageItem(key, value) {
  // @ts-ignore
  this._contextImpl.baggage[key] = value;
};

/**
 * @param {string} key
 */
Span.prototype._getBaggageItem = function _getBaggageItem(key) {
  // @ts-ignore
  return this._contextImpl.baggage[key];
};

/**
 * @param {Object.<string, *>} keyValuePairs
 */
Span.prototype._addTags = function _addTags(keyValuePairs) {
  const keys = Object.keys(keyValuePairs);
  for (let i = 0, length = keys.length; i < length; i++) {
    const key = keys[i];
    this._addTag(key, keyValuePairs[key]);
  }
};

/**
 * @param {string} key
 * @param {*} value
 */
Span.prototype._addTag = function _addTag(key, value) {
  if (key === opentracing.Tags.ERROR) {
    if (value) {
      this.span.ec = 1;
    }
  } else if (key === opentracing.Tags.SPAN_KIND) {
    if (value === opentracing.Tags.SPAN_KIND_RPC_SERVER || value === 'consumer') {
      this.span.data.sdk.type = 'entry';
    } else if (value === opentracing.Tags.SPAN_KIND_RPC_CLIENT || value === 'producer') {
      this.span.data.sdk.type = 'exit';
    }
  } else if (key === opentracing.Tags.SAMPLING_PRIORITY) {
    // @ts-ignore
    this._contextImpl.samplingPriority = value;
  } else {
    this.span.data.sdk.custom.tags[key] = value;
  }
};

/**
 * @param {Object.<string, *>} keyValuePairs
 * @param {number} timestamp
 */
Span.prototype._log = function _log(keyValuePairs, timestamp) {
  if (timestamp == null) {
    timestamp = Date.now();
  }

  let timestampData = this.span.data.sdk.custom.logs[timestamp];
  if (!timestampData) {
    timestampData = this.span.data.sdk.custom.logs[timestamp] = {};
  }

  const keys = Object.keys(keyValuePairs);
  for (let i = 0, length = keys.length; i < length; i++) {
    const key = keys[i];
    timestampData[key] = keyValuePairs[key];
  }
};

/**
 * @param {number} finishTime
 */
Span.prototype._finish = function _finish(finishTime) {
  // @ts-ignore
  if (this._contextImpl.samplingPriority <= 0) {
    return;
  }

  if (finishTime == null) {
    finishTime = Date.now();
  }
  this.span.d = Math.max(0, finishTime - this.span.ts);
  spanBuffer.addSpan(this.span);
};

/**
 * @param {Object.<string, *>} baggage
 */
function copyBaggage(baggage) {
  if (!baggage) {
    return {};
  }

  /** @type {Object.<string, *>} */
  const copy = {};

  const keys = Object.keys(baggage);
  for (let i = 0, length = keys.length; i < length; i++) {
    const key = keys[i];
    copy[key] = baggage[key];
  }

  return copy;
}

/**
 * @param {import('../../config').InstanaConfig} config
 * @param {CollectorPIDStore} _processIdentityProvider
 */
Span.init = function init(config, _processIdentityProvider) {
  if (config.serviceName) {
    serviceName = config.serviceName;
  }
  processIdentityProvider = _processIdentityProvider;
};

/**
 * @param {CollectorPIDStore} fn
 */
Span.setProcessIdentityProvider = function setProcessIdentityProvider(fn) {
  processIdentityProvider = fn;
};