Add semver check to metrics API (#3357)

experimental/CHANGELOG.md

@@ -6,6 +6,9 @@ All notable changes to experimental packages in this project will be documented
 
 ### :boom: Breaking Change
 
+* Add semver check to metrics API [#3357](https://github.com/open-telemetry/opentelemetry-js/pull/3357) @dyladan
+  * Previously API versions were only considered compatible if the API was exactly the same
+
 ### :rocket: (Enhancement)
 
 * feat(metrics-sdk): Add tracing suppresing for Metrics Export [#3332](https://github.com/open-telemetry/opentelemetry-js/pull/3332) @hectorhdzg

experimental/packages/opentelemetry-api-metrics/src/api/metrics.ts

@@ -17,12 +17,7 @@
 import { Meter, MeterOptions } from '../types/Meter';
 import { MeterProvider } from '../types/MeterProvider';
 import { NOOP_METER_PROVIDER } from '../NoopMeterProvider';
-import {
-  API_BACKWARDS_COMPATIBILITY_VERSION,
-  GLOBAL_METRICS_API_KEY,
-  makeGetter,
-  _global,
-} from './global-utils';
+import { getGlobal, registerGlobal, unregisterGlobal } from '../internal/global-utils';
 
 /**
  * Singleton object which represents the entry point to the OpenTelemetry Metrics API
@@ -43,31 +38,18 @@ export class MetricsAPI {
   }
 
   /**
-   * Set the current global meter. Returns the initialized global meter provider.
+   * Set the current global meter provider.
+   * Returns true if the meter provider was successfully registered, else false.
    */
-  public setGlobalMeterProvider(provider: MeterProvider): MeterProvider {
-    if (_global[GLOBAL_METRICS_API_KEY]) {
-      // global meter provider has already been set
-      return this.getMeterProvider();
-    }
-
-    _global[GLOBAL_METRICS_API_KEY] = makeGetter(
-      API_BACKWARDS_COMPATIBILITY_VERSION,
-      provider,
-      NOOP_METER_PROVIDER
-    );
-
-    return provider;
+  public setGlobalMeterProvider(provider: MeterProvider): boolean {
+    return registerGlobal('metrics', provider);
   }
 
   /**
    * Returns the global meter provider.
    */
   public getMeterProvider(): MeterProvider {
-    return (
-      _global[GLOBAL_METRICS_API_KEY]?.(API_BACKWARDS_COMPATIBILITY_VERSION) ??
-      NOOP_METER_PROVIDER
-    );
+    return getGlobal('metrics') || NOOP_METER_PROVIDER;
   }
 
   /**
@@ -79,6 +61,6 @@ export class MetricsAPI {
 
   /** Remove the global meter provider */
   public disable(): void {
-    delete _global[GLOBAL_METRICS_API_KEY];
+    unregisterGlobal('metrics');
   }
 }

experimental/packages/opentelemetry-api-metrics/src/internal/global-utils.ts

@@ -0,0 +1,96 @@
+/*
+ * 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 { diag } from '@opentelemetry/api';
+import { _globalThis } from '../platform';
+import { MeterProvider } from '../types/MeterProvider';
+import { VERSION } from '../version';
+import { isCompatible } from './semver';
+
+const major = VERSION.split('.')[0];
+const GLOBAL_OPENTELEMETRY_METRICS_API_KEY = Symbol.for(
+  `opentelemetry.js.api.metrics.${major}`
+);
+
+const _global = _globalThis as OTelGlobal;
+
+export function registerGlobal<Type extends keyof OTelGlobalAPI>(
+  type: Type,
+  instance: OTelGlobalAPI[Type],
+  allowOverride = false
+): boolean {
+  const api = (_global[GLOBAL_OPENTELEMETRY_METRICS_API_KEY] = _global[
+    GLOBAL_OPENTELEMETRY_METRICS_API_KEY
+  ] ?? {
+    version: VERSION,
+  });
+
+  if (!allowOverride && api[type]) {
+    // already registered an API of this type
+    const err = new Error(
+      `@opentelemetry/api: Attempted duplicate registration of API: ${type}`
+    );
+    diag.error(err.stack || err.message);
+    return false;
+  }
+
+  if (api.version !== VERSION) {
+    // All registered APIs must be of the same version exactly
+    const err = new Error(
+      '@opentelemetry/api: All API registration versions must match'
+    );
+    diag.error(err.stack || err.message);
+    return false;
+  }
+
+  api[type] = instance;
+  diag.debug(
+    `@opentelemetry/api: Registered a global for ${type} v${VERSION}.`
+  );
+
+  return true;
+}
+
+export function getGlobal<Type extends keyof OTelGlobalAPI>(
+  type: Type
+): OTelGlobalAPI[Type] | undefined {
+  const globalVersion = _global[GLOBAL_OPENTELEMETRY_METRICS_API_KEY]?.version;
+  if (!globalVersion || !isCompatible(globalVersion)) {
+    return;
+  }
+  return _global[GLOBAL_OPENTELEMETRY_METRICS_API_KEY]?.[type];
+}
+
+export function unregisterGlobal(type: keyof OTelGlobalAPI) {
+  diag.debug(
+    `@opentelemetry/api-metrics: Unregistering a global for ${type} v${VERSION}.`
+  );
+  const api = _global[GLOBAL_OPENTELEMETRY_METRICS_API_KEY];
+
+  if (api) {
+    delete api[type];
+  }
+}
+
+type OTelGlobal = {
+  [GLOBAL_OPENTELEMETRY_METRICS_API_KEY]?: OTelGlobalAPI;
+};
+
+type OTelGlobalAPI = {
+  version: string;
+
+  metrics?: MeterProvider;
+};

experimental/packages/opentelemetry-api-metrics/src/internal/semver.ts

@@ -0,0 +1,140 @@
+/*
+ * 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 { VERSION } from '../version';
+
+const re = /^(\d+)\.(\d+)\.(\d+)(-(.+))?$/;
+
+/**
+ * Create a function to test an API version to see if it is compatible with the provided ownVersion.
+ *
+ * The returned function has the following semantics:
+ * - Exact match is always compatible
+ * - Major versions must match exactly
+ *    - 1.x package cannot use global 2.x package
+ *    - 2.x package cannot use global 1.x package
+ * - The minor version of the API module requesting access to the global API must be less than or equal to the minor version of this API
+ *    - 1.3 package may use 1.4 global because the later global contains all functions 1.3 expects
+ *    - 1.4 package may NOT use 1.3 global because it may try to call functions which don't exist on 1.3
+ * - If the major version is 0, the minor version is treated as the major and the patch is treated as the minor
+ * - Patch and build tag differences are not considered at this time
+ *
+ * @param ownVersion version which should be checked against
+ */
+export function _makeCompatibilityCheck(
+  ownVersion: string
+): (globalVersion: string) => boolean {
+  const acceptedVersions = new Set<string>([ownVersion]);
+  const rejectedVersions = new Set<string>();
+
+  const myVersionMatch = ownVersion.match(re);
+  if (!myVersionMatch) {
+    // we cannot guarantee compatibility so we always return noop
+    return () => false;
+  }
+
+  const ownVersionParsed = {
+    major: +myVersionMatch[1],
+    minor: +myVersionMatch[2],
+    patch: +myVersionMatch[3],
+    prerelease: myVersionMatch[4],
+  };
+
+  // if ownVersion has a prerelease tag, versions must match exactly
+  if (ownVersionParsed.prerelease != null) {
+    return function isExactmatch(globalVersion: string): boolean {
+      return globalVersion === ownVersion;
+    };
+  }
+
+  function _reject(v: string) {
+    rejectedVersions.add(v);
+    return false;
+  }
+
+  function _accept(v: string) {
+    acceptedVersions.add(v);
+    return true;
+  }
+
+  return function isCompatible(globalVersion: string): boolean {
+    if (acceptedVersions.has(globalVersion)) {
+      return true;
+    }
+
+    if (rejectedVersions.has(globalVersion)) {
+      return false;
+    }
+
+    const globalVersionMatch = globalVersion.match(re);
+    if (!globalVersionMatch) {
+      // cannot parse other version
+      // we cannot guarantee compatibility so we always noop
+      return _reject(globalVersion);
+    }
+
+    const globalVersionParsed = {
+      major: +globalVersionMatch[1],
+      minor: +globalVersionMatch[2],
+      patch: +globalVersionMatch[3],
+      prerelease: globalVersionMatch[4],
+    };
+
+    // if globalVersion has a prerelease tag, versions must match exactly
+    if (globalVersionParsed.prerelease != null) {
+      return _reject(globalVersion);
+    }
+
+    // major versions must match
+    if (ownVersionParsed.major !== globalVersionParsed.major) {
+      return _reject(globalVersion);
+    }
+
+    if (ownVersionParsed.major === 0) {
+      if (
+        ownVersionParsed.minor === globalVersionParsed.minor &&
+        ownVersionParsed.patch <= globalVersionParsed.patch
+      ) {
+        return _accept(globalVersion);
+      }
+
+      return _reject(globalVersion);
+    }
+
+    if (ownVersionParsed.minor <= globalVersionParsed.minor) {
+      return _accept(globalVersion);
+    }
+
+    return _reject(globalVersion);
+  };
+}
+
+/**
+ * Test an API version to see if it is compatible with this API.
+ *
+ * - Exact match is always compatible
+ * - Major versions must match exactly
+ *    - 1.x package cannot use global 2.x package
+ *    - 2.x package cannot use global 1.x package
+ * - The minor version of the API module requesting access to the global API must be less than or equal to the minor version of this API
+ *    - 1.3 package may use 1.4 global because the later global contains all functions 1.3 expects
+ *    - 1.4 package may NOT use 1.3 global because it may try to call functions which don't exist on 1.3
+ * - If the major version is 0, the minor version is treated as the major and the patch is treated as the minor
+ * - Patch and build tag differences are not considered at this time
+ *
+ * @param version version of the API requesting an instance of the global API
+ */
+export const isCompatible = _makeCompatibilityCheck(VERSION);