Merge remote-tracking branch 'upstream/master'

examples/prometheus/README.md

@@ -48,7 +48,8 @@ prometheus --config.file=prometheus.yml
 
 If you are using the default configurations, the prometheus client will be available at <http://localhost:9090>
 
-<p align="center"><img src="images/prom-ui.png?raw=true"/></p>
+<p align="center"><img src="images/prom-counter.png?raw=true"/></p>
+<p align="center"><img src="images/prom-updowncounter.png?raw=true"/></p>
 
 ## Useful links
 

examples/prometheus/index.js

@@ -19,21 +19,17 @@ const meter = new MeterProvider({
   interval: 1000,
 }).getMeter('example-prometheus');
 
-// Monotonic counters can only be increased.
-const monotonicCounter = meter.createCounter('monotonic_counter', {
-  monotonic: true,
-  description: 'Example of a monotonic counter',
+const requestCounter = meter.createCounter('requests', {
+  description: 'Example of a Counter',
 });
 
-// Non-monotonic counters can be increased or decreased.
-const nonMonotonicCounter = meter.createCounter('non_monotonic_counter', {
-  monotonic: false,
-  description: 'Example of a non-monotonic counter',
+const upDownCounter = meter.createUpDownCounter('test_up_down_counter', {
+  description: 'Example of a UpDownCounter',
 });
 
-const labels = { pid: process.pid };
+const labels = { pid: process.pid, environment: 'staging' };
 
 setInterval(() => {
-  monotonicCounter.bind(labels).add(1);
-  nonMonotonicCounter.bind(labels).add(Math.random() > 0.5 ? 1 : -1);
+  requestCounter.bind(labels).add(1);
+  upDownCounter.bind(labels).add(Math.random() > 0.5 ? 1 : -1);
 }, 1000);

getting-started/README.md

@@ -253,7 +253,6 @@ const { MeterProvider } = require('@opentelemetry/metrics');
 const meter = new MeterProvider().getMeter('your-meter-name');
 
 const requestCount = meter.createCounter("requests", {
-  monotonic: true,
   description: "Count all incoming requests"
 });
 
@@ -323,7 +322,6 @@ const meter = new MeterProvider({
 }).getMeter('your-meter-name');
 
 const requestCount = meter.createCounter("requests", {
-  monotonic: true,
   description: "Count all incoming requests"
 });
 

getting-started/monitored-example/monitoring.js

@@ -20,7 +20,6 @@ const meter = new MeterProvider({
 }).getMeter('example-monitored');
 
 const requestCount = meter.createCounter("requests", {
-  monotonic: true,
   description: "Count all incoming requests"
 });
 

getting-started/ts-example/README.md

@@ -252,7 +252,6 @@ import { Metric, BoundCounter } from '@opentelemetry/api';
 const meter = new MeterProvider().getMeter('your-meter-name');
 
 const requestCount: Metric<BoundCounter> = meter.createCounter("requests", {
-  monotonic: true,
   description: "Count all incoming requests"
 });
 
@@ -321,7 +320,6 @@ const meter = new MeterProvider({
 }).getMeter('your-meter-name');
 
 const requestCount: Metric<BoundCounter> = meter.createCounter("requests", {
-  monotonic: true,
   description: "Count all incoming requests"
 });
 

getting-started/ts-example/monitoring.ts

@@ -19,7 +19,6 @@ const meter = new MeterProvider({
 }).getMeter('example-ts');
 
 const requestCount: Metric<BoundCounter> = meter.createCounter("requests", {
-  monotonic: true,
   description: "Count all incoming requests"
 });
 

packages/opentelemetry-api/package.json

@@ -56,7 +56,7 @@
   },
   "devDependencies": {
     "@types/mocha": "7.0.2",
-    "@types/node": "14.0.13",
+    "@types/node": "14.0.14",
     "@types/webpack-env": "1.15.2",
     "codecov": "3.7.0",
     "gts": "2.0.2",

packages/opentelemetry-context-async-hooks/package.json

@@ -43,7 +43,7 @@
   },
   "devDependencies": {
     "@types/mocha": "7.0.2",
-    "@types/node": "14.0.13",
+    "@types/node": "14.0.14",
     "@types/shimmer": "1.0.1",
     "codecov": "3.7.0",
     "gts": "2.0.2",

packages/opentelemetry-context-async-hooks/src/AbstractAsyncHooksContextManager.ts

@@ -0,0 +1,187 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import { ContextManager, Context } from '@opentelemetry/context-base';
+import { EventEmitter } from 'events';
+
+type Func<T> = (...args: unknown[]) => T;
+
+type PatchedEventEmitter = {
+  /**
+   * Store a map for each event of all original listener and their "patched"
+   * version so when the listener is removed by the user, we remove the
+   * corresponding "patched" function.
+   */
+  __ot_listeners?: { [name: string]: WeakMap<Func<void>, Func<void>> };
+} & EventEmitter;
+
+const ADD_LISTENER_METHODS = [
+  'addListener' as 'addListener',
+  'on' as 'on',
+  'once' as 'once',
+  'prependListener' as 'prependListener',
+  'prependOnceListener' as 'prependOnceListener',
+];
+
+export abstract class AbstractAsyncHooksContextManager
+  implements ContextManager {
+  abstract active(): Context;
+
+  abstract with<T extends (...args: unknown[]) => ReturnType<T>>(
+    context: Context,
+    fn: T
+  ): ReturnType<T>;
+
+  abstract enable(): this;
+
+  abstract disable(): this;
+
+  bind<T>(target: T, context: Context = this.active()): T {
+    if (target instanceof EventEmitter) {
+      return this._bindEventEmitter(target, context);
+    }
+
+    if (typeof target === 'function') {
+      return this._bindFunction(target, context);
+    }
+    return target;
+  }
+
+  private _bindFunction<T extends Function>(target: T, context: Context): T {
+    const manager = this;
+    const contextWrapper = function (this: {}, ...args: unknown[]) {
+      return manager.with(context, () => target.apply(this, args));
+    };
+    Object.defineProperty(contextWrapper, 'length', {
+      enumerable: false,
+      configurable: true,
+      writable: false,
+      value: target.length,
+    });
+    /**
+     * It isn't possible to tell Typescript that contextWrapper is the same as T
+     * so we forced to cast as any here.
+     */
+    // eslint-disable-next-line @typescript-eslint/no-explicit-any
+    return contextWrapper as any;
+  }
+
+  /**
+   * By default, EventEmitter call their callback with their context, which we do
+   * not want, instead we will bind a specific context to all callbacks that
+   * go through it.
+   * @param target EventEmitter a instance of EventEmitter to patch
+   * @param context the context we want to bind
+   */
+  private _bindEventEmitter<T extends EventEmitter>(
+    target: T,
+    context: Context
+  ): T {
+    const ee = (target as unknown) as PatchedEventEmitter;
+    if (ee.__ot_listeners !== undefined) return target;
+    ee.__ot_listeners = {};
+
+    // patch methods that add a listener to propagate context
+    ADD_LISTENER_METHODS.forEach(methodName => {
+      if (ee[methodName] === undefined) return;
+      ee[methodName] = this._patchAddListener(ee, ee[methodName], context);
+    });
+    // patch methods that remove a listener
+    if (typeof ee.removeListener === 'function') {
+      ee.removeListener = this._patchRemoveListener(ee, ee.removeListener);
+    }
+    if (typeof ee.off === 'function') {
+      ee.off = this._patchRemoveListener(ee, ee.off);
+    }
+    // patch method that remove all listeners
+    if (typeof ee.removeAllListeners === 'function') {
+      ee.removeAllListeners = this._patchRemoveAllListeners(
+        ee,
+        ee.removeAllListeners
+      );
+    }
+    return target;
+  }
+
+  /**
+   * Patch methods that remove a given listener so that we match the "patched"
+   * version of that listener (the one that propagate context).
+   * @param ee EventEmitter instance
+   * @param original reference to the patched method
+   */
+  private _patchRemoveListener(ee: PatchedEventEmitter, original: Function) {
+    return function (this: {}, event: string, listener: Func<void>) {
+      if (
+        ee.__ot_listeners === undefined ||
+        ee.__ot_listeners[event] === undefined
+      ) {
+        return original.call(this, event, listener);
+      }
+      const events = ee.__ot_listeners[event];
+      const patchedListener = events.get(listener);
+      return original.call(this, event, patchedListener || listener);
+    };
+  }
+
+  /**
+   * Patch methods that remove all listeners so we remove our
+   * internal references for a given event.
+   * @param ee EventEmitter instance
+   * @param original reference to the patched method
+   */
+  private _patchRemoveAllListeners(
+    ee: PatchedEventEmitter,
+    original: Function
+  ) {
+    return function (this: {}, event: string) {
+      if (
+        ee.__ot_listeners === undefined ||
+        ee.__ot_listeners[event] === undefined
+      ) {
+        return original.call(this, event);
+      }
+      delete ee.__ot_listeners[event];
+      return original.call(this, event);
+    };
+  }
+
+  /**
+   * Patch methods on an event emitter instance that can add listeners so we
+   * can force them to propagate a given context.
+   * @param ee EventEmitter instance
+   * @param original reference to the patched method
+   * @param [context] context to propagate when calling listeners
+   */
+  private _patchAddListener(
+    ee: PatchedEventEmitter,
+    original: Function,
+    context: Context
+  ) {
+    const contextManager = this;
+    return function (this: {}, event: string, listener: Func<void>) {
+      if (ee.__ot_listeners === undefined) ee.__ot_listeners = {};
+      let listeners = ee.__ot_listeners[event];
+      if (listeners === undefined) {
+        listeners = new WeakMap();
+        ee.__ot_listeners[event] = listeners;
+      }
+      const patchedListener = contextManager.bind(listener, context);
+      // store a weak reference of the user listener to ours
+      listeners.set(listener, patchedListener);
+      return original.call(this, event, patchedListener);
+    };
+  }
+}