refactor(sdk-metrics-base): meter shared states (#2821)

legendecas · web-flow · commit 14bd6f93ed2d · 2022-04-12T01:32:41.000+08:00
diff --git a/experimental/CHANGELOG.md b/experimental/CHANGELOG.md
@@ -53,6 +53,7 @@ All notable changes to experimental packages in this project will be documented
 ### :house: (Internal)
 
 * chore: move trace exporters back to experimental #2835 @dyladan
+* refactor(sdk-metrics-base): meter shared states #2821 @legendecas
 
 ## v0.27.0
 
diff --git a/experimental/packages/opentelemetry-sdk-metrics-base/src/Meter.ts b/experimental/packages/opentelemetry-sdk-metrics-base/src/Meter.ts
@@ -16,35 +16,27 @@
 
 import * as metrics from '@opentelemetry/api-metrics';
 import { InstrumentationLibrary } from '@opentelemetry/core';
-import { createInstrumentDescriptor, InstrumentDescriptor, InstrumentType } from './InstrumentDescriptor';
+import { createInstrumentDescriptor, InstrumentType } from './InstrumentDescriptor';
 import { CounterInstrument, HistogramInstrument, UpDownCounterInstrument } from './Instruments';
 import { MeterProviderSharedState } from './state/MeterProviderSharedState';
-import { MultiMetricStorage } from './state/MultiWritableMetricStorage';
-import { SyncMetricStorage } from './state/SyncMetricStorage';
-import { InstrumentationLibraryMetrics } from './export/MetricData';
-import { isNotNullish } from './utils';
-import { MetricCollectorHandle } from './state/MetricCollector';
-import { HrTime } from '@opentelemetry/api';
-import { AsyncMetricStorage } from './state/AsyncMetricStorage';
-import { WritableMetricStorage } from './state/WritableMetricStorage';
-import { MetricStorageRegistry } from './state/MetricStorageRegistry';
+import { MeterSharedState } from './state/MeterSharedState';
 
 /**
  * This class implements the {@link metrics.Meter} interface.
  */
 export class Meter implements metrics.Meter {
-  private _metricStorageRegistry = new MetricStorageRegistry();
+  private _meterSharedState: MeterSharedState;
 
-  constructor(private _meterProviderSharedState: MeterProviderSharedState, private _instrumentationLibrary: InstrumentationLibrary) {
-    this._meterProviderSharedState.meters.push(this);
+  constructor(meterProviderSharedState: MeterProviderSharedState, instrumentationLibrary: InstrumentationLibrary) {
+    this._meterSharedState = meterProviderSharedState.getMeterSharedState(instrumentationLibrary);
   }
 
   /**
    * Create a {@link metrics.Histogram} instrument.
    */
   createHistogram(name: string, options?: metrics.HistogramOptions): metrics.Histogram {
     const descriptor = createInstrumentDescriptor(name, InstrumentType.HISTOGRAM, options);
-    const storage = this._registerMetricStorage(descriptor);
+    const storage = this._meterSharedState.registerMetricStorage(descriptor);
     return new HistogramInstrument(storage, descriptor);
   }
 
@@ -53,7 +45,7 @@ export class Meter implements metrics.Meter {
    */
   createCounter(name: string, options?: metrics.CounterOptions): metrics.Counter {
     const descriptor = createInstrumentDescriptor(name, InstrumentType.COUNTER, options);
-    const storage = this._registerMetricStorage(descriptor);
+    const storage = this._meterSharedState.registerMetricStorage(descriptor);
     return new CounterInstrument(storage, descriptor);
   }
 
@@ -62,7 +54,7 @@ export class Meter implements metrics.Meter {
    */
   createUpDownCounter(name: string, options?: metrics.UpDownCounterOptions): metrics.UpDownCounter {
     const descriptor = createInstrumentDescriptor(name, InstrumentType.UP_DOWN_COUNTER, options);
-    const storage = this._registerMetricStorage(descriptor);
+    const storage = this._meterSharedState.registerMetricStorage(descriptor);
     return new UpDownCounterInstrument(storage, descriptor);
   }
 
@@ -75,7 +67,7 @@ export class Meter implements metrics.Meter {
     options?: metrics.ObservableGaugeOptions,
   ): void {
     const descriptor = createInstrumentDescriptor(name, InstrumentType.OBSERVABLE_GAUGE, options);
-    this._registerAsyncMetricStorage(descriptor, callback);
+    this._meterSharedState.registerAsyncMetricStorage(descriptor, callback);
   }
 
   /**
@@ -87,7 +79,7 @@ export class Meter implements metrics.Meter {
     options?: metrics.ObservableCounterOptions,
   ): void {
     const descriptor = createInstrumentDescriptor(name, InstrumentType.OBSERVABLE_COUNTER, options);
-    this._registerAsyncMetricStorage(descriptor, callback);
+    this._meterSharedState.registerAsyncMetricStorage(descriptor, callback);
   }
 
   /**
@@ -99,47 +91,6 @@ export class Meter implements metrics.Meter {
     options?: metrics.ObservableUpDownCounterOptions,
   ): void {
     const descriptor = createInstrumentDescriptor(name, InstrumentType.OBSERVABLE_UP_DOWN_COUNTER, options);
-    this._registerAsyncMetricStorage(descriptor, callback);
-  }
-
-  private _registerMetricStorage(descriptor: InstrumentDescriptor): WritableMetricStorage {
-    const views = this._meterProviderSharedState.viewRegistry.findViews(descriptor, this._instrumentationLibrary);
-    const storages = views.map(view => this._metricStorageRegistry.register(SyncMetricStorage.create(view, descriptor)))
-      .filter(isNotNullish);
-
-    if (storages.length === 1) {
-      return storages[0];
-    }
-
-    // This will be a no-op WritableMetricStorage when length is null.
-    return new MultiMetricStorage(storages);
-  }
-
-  private _registerAsyncMetricStorage(descriptor: InstrumentDescriptor, callback: metrics.ObservableCallback) {
-    const views = this._meterProviderSharedState.viewRegistry.findViews(descriptor, this._instrumentationLibrary);
-    views.forEach(view => {
-      this._metricStorageRegistry.register(AsyncMetricStorage.create(view, descriptor, callback));
-    });
-  }
-
-  /**
-   * @internal
-   * @param collector opaque handle of {@link MetricCollector} which initiated the collection.
-   * @param collectionTime the HrTime at which the collection was initiated.
-   * @returns the list of {@link MetricData} collected.
-   */
-  async collect(collector: MetricCollectorHandle, collectionTime: HrTime): Promise<InstrumentationLibraryMetrics> {
-    const metricData = await Promise.all(this._metricStorageRegistry.getStorages().map(metricStorage => {
-      return metricStorage.collect(
-        collector,
-        this._meterProviderSharedState.metricCollectors,
-        this._meterProviderSharedState.sdkStartTime,
-        collectionTime);
-    }));
-
-    return {
-      instrumentationLibrary: this._instrumentationLibrary,
-      metrics: metricData.filter(isNotNullish),
-    };
+    this._meterSharedState.registerAsyncMetricStorage(descriptor, callback);
   }
 }
diff --git a/experimental/packages/opentelemetry-sdk-metrics-base/src/state/MeterProviderSharedState.ts b/experimental/packages/opentelemetry-sdk-metrics-base/src/state/MeterProviderSharedState.ts
@@ -15,10 +15,10 @@
  */
 
 import { HrTime } from '@opentelemetry/api';
-import { hrTime } from '@opentelemetry/core';
+import { hrTime, InstrumentationLibrary } from '@opentelemetry/core';
 import { Resource } from '@opentelemetry/resources';
-import { Meter } from '../Meter';
 import { ViewRegistry } from '../view/ViewRegistry';
+import { MeterSharedState } from './MeterSharedState';
 import { MetricCollector } from './MetricCollector';
 
 /**
@@ -30,7 +30,15 @@ export class MeterProviderSharedState {
 
   metricCollectors: MetricCollector[] = [];
 
-  meters: Meter[] = [];
+  meterSharedStates: MeterSharedState[] = [];
 
   constructor(public resource: Resource) {}
+
+  getMeterSharedState(instrumentationLibrary: InstrumentationLibrary) {
+    // TODO: meter identity
+    // https://github.com/open-telemetry/opentelemetry-js/issues/2593
+    const meterSharedState = new MeterSharedState(this, instrumentationLibrary);
+    this.meterSharedStates.push(meterSharedState);
+    return meterSharedState;
+  }
 }
diff --git a/experimental/packages/opentelemetry-sdk-metrics-base/src/state/MeterSharedState.ts b/experimental/packages/opentelemetry-sdk-metrics-base/src/state/MeterSharedState.ts
@@ -0,0 +1,89 @@
+/*
+ * 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 { HrTime } from '@opentelemetry/api';
+import * as metrics from '@opentelemetry/api-metrics';
+import { InstrumentationLibrary } from '@opentelemetry/core';
+import { InstrumentationLibraryMetrics } from '../export/MetricData';
+import { createInstrumentDescriptorWithView, InstrumentDescriptor } from '../InstrumentDescriptor';
+import { isNotNullish } from '../utils';
+import { AsyncMetricStorage } from './AsyncMetricStorage';
+import { MeterProviderSharedState } from './MeterProviderSharedState';
+import { MetricCollectorHandle } from './MetricCollector';
+import { MetricStorageRegistry } from './MetricStorageRegistry';
+import { MultiMetricStorage } from './MultiWritableMetricStorage';
+import { SyncMetricStorage } from './SyncMetricStorage';
+
+/**
+ * An internal record for shared meter provider states.
+ */
+export class MeterSharedState {
+  private _metricStorageRegistry = new MetricStorageRegistry();
+
+  constructor(private _meterProviderSharedState: MeterProviderSharedState, private _instrumentationLibrary: InstrumentationLibrary) {}
+
+  registerMetricStorage(descriptor: InstrumentDescriptor) {
+    const views = this._meterProviderSharedState.viewRegistry.findViews(descriptor, this._instrumentationLibrary);
+    const storages = views
+      .map(view => {
+        const viewDescriptor = createInstrumentDescriptorWithView(view, descriptor);
+        const aggregator = view.aggregation.createAggregator(viewDescriptor);
+        const storage = new SyncMetricStorage(viewDescriptor, aggregator, view.attributesProcessor);
+        return this._metricStorageRegistry.register(storage);
+      })
+      .filter(isNotNullish);
+    if (storages.length === 1)  {
+      return storages[0];
+    }
+    return new MultiMetricStorage(storages);
+  }
+
+  registerAsyncMetricStorage(descriptor: InstrumentDescriptor, callback: metrics.ObservableCallback) {
+    const views = this._meterProviderSharedState.viewRegistry.findViews(descriptor, this._instrumentationLibrary);
+    views.forEach(view => {
+      const viewDescriptor = createInstrumentDescriptorWithView(view, descriptor);
+      const aggregator = view.aggregation.createAggregator(viewDescriptor);
+      const viewStorage = new AsyncMetricStorage(viewDescriptor, aggregator, view.attributesProcessor, callback);
+      this._metricStorageRegistry.register(viewStorage);
+    });
+  }
+
+  /**
+   * @param collector opaque handle of {@link MetricCollector} which initiated the collection.
+   * @param collectionTime the HrTime at which the collection was initiated.
+   * @returns the list of {@link MetricData} collected.
+   */
+  async collect(collector: MetricCollectorHandle, collectionTime: HrTime): Promise<InstrumentationLibraryMetrics> {
+    /**
+     * 1. Call all observable callbacks first.
+     * 2. Collect metric result for the collector.
+     */
+    const metricDataList = await Promise.all(Array.from(this._metricStorageRegistry.getStorages())
+      .map(metricStorage => {
+        return metricStorage.collect(
+          collector,
+          this._meterProviderSharedState.metricCollectors,
+          this._meterProviderSharedState.sdkStartTime,
+          collectionTime);
+      })
+      .filter(isNotNullish));
+
+    return {
+      instrumentationLibrary: this._instrumentationLibrary,
+      metrics: metricDataList.filter(isNotNullish),
+    };
+  }
+}
diff --git a/experimental/packages/opentelemetry-sdk-metrics-base/src/state/MetricCollector.ts b/experimental/packages/opentelemetry-sdk-metrics-base/src/state/MetricCollector.ts
@@ -34,8 +34,8 @@ export class MetricCollector implements MetricProducer {
 
   async collect(): Promise<ResourceMetrics> {
     const collectionTime = hrTime();
-    const instrumentationLibraryMetrics = (await Promise.all(this._sharedState.meters
-      .map(meter => meter.collect(this, collectionTime))));
+    const instrumentationLibraryMetrics = (await Promise.all(this._sharedState.meterSharedStates
+      .map(meterSharedState => meterSharedState.collect(this, collectionTime))));
 
     return {
       resource: this._sharedState.resource,
diff --git a/experimental/packages/opentelemetry-sdk-metrics-base/test/export/TestMetricExporter.ts b/experimental/packages/opentelemetry-sdk-metrics-base/test/export/TestMetricExporter.ts
@@ -0,0 +1,39 @@
+/*
+ * 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 { ExportResult, ExportResultCode } from '@opentelemetry/core';
+import { AggregationTemporality, PushMetricExporter, ResourceMetrics } from '../../src';
+
+export class TestMetricExporter implements PushMetricExporter {
+  resourceMetricsList: ResourceMetrics[] = [];
+  export(resourceMetrics: ResourceMetrics, resultCallback: (result: ExportResult) => void): void {
+    this.resourceMetricsList.push(resourceMetrics);
+    process.nextTick(() => resultCallback({ code: ExportResultCode.SUCCESS }));
+  }
+
+  async forceFlush(): Promise<void> {}
+  async shutdown(): Promise<void> {}
+
+  getPreferredAggregationTemporality(): AggregationTemporality {
+    return AggregationTemporality.CUMULATIVE;
+  }
+}
+
+export class TestDeltaMetricExporter extends TestMetricExporter {
+  override getPreferredAggregationTemporality(): AggregationTemporality {
+    return AggregationTemporality.DELTA;
+  }
+}
diff --git a/experimental/packages/opentelemetry-sdk-metrics-base/test/state/MeterSharedState.test.ts b/experimental/packages/opentelemetry-sdk-metrics-base/test/state/MeterSharedState.test.ts
diff --git a/experimental/packages/opentelemetry-sdk-metrics-base/test/state/MetricCollector.test.ts b/experimental/packages/opentelemetry-sdk-metrics-base/test/state/MetricCollector.test.ts
diff --git a/experimental/packages/opentelemetry-sdk-metrics-base/test/util.ts b/experimental/packages/opentelemetry-sdk-metrics-base/test/util.ts
