feat(sdk-metrics)!: replace attributeKeys with an option to add custo…

…m processors (#4532)

CHANGELOG_NEXT.md

@@ -6,6 +6,8 @@
 * chore(otel-core): replace deprecated SpanAttributes [#4408](https://github.com/open-telemetry/opentelemetry-js/pull/4408) @JamieDanielson
 * feat(sdk-metrics)!: remove MeterProvider.addMetricReader() in favor of constructor option [#4419](https://github.com/open-telemetry/opentelemetry-js/pull/4419) @pichlermarc
 * chore(otel-resources): replace deprecated SpanAttributes [#4428](https://github.com/open-telemetry/opentelemetry-js/pull/4428) @JamieDanielson
+* feat(sdk-metrics)!: remove MeterProvider.addMetricReader() in favor of constructor option [#4419](https://github.com/open-telemetry/opentelemetry-js/pull/4419) @pichlermarc
+* feat(sdk-metrics)!: replace attributeKeys with custom processors option [#4532](https://github.com/open-telemetry/opentelemetry-js/pull/4532) @pichlermarc
 
 ### :rocket: (Enhancement)
 

packages/sdk-metrics/src/index.ts

@@ -80,4 +80,10 @@ export {
 
 export { View, ViewOptions } from './view/View';
 
+export {
+  IAttributesProcessor,
+  createAllowListAttributesProcessor,
+  createDenyListAttributesProcessor,
+} from './view/AttributesProcessor';
+
 export { TimeoutError } from './utils';

packages/sdk-metrics/src/state/AsyncMetricStorage.ts

@@ -17,7 +17,6 @@
 import { HrTime } from '@opentelemetry/api';
 import { Accumulation, Aggregator } from '../aggregator/types';
 import { InstrumentDescriptor } from '../InstrumentDescriptor';
-import { AttributesProcessor } from '../view/AttributesProcessor';
 import { MetricStorage } from './MetricStorage';
 import { MetricData } from '../export/MetricData';
 import { DeltaMetricProcessor } from './DeltaMetricProcessor';
@@ -26,6 +25,7 @@ import { Maybe } from '../utils';
 import { MetricCollectorHandle } from './MetricCollector';
 import { AttributeHashMap } from './HashMap';
 import { AsyncWritableMetricStorage } from './WritableMetricStorage';
+import { IAttributesProcessor } from '../view/AttributesProcessor';
 
 /**
  * Internal interface.
@@ -42,7 +42,7 @@ export class AsyncMetricStorage<T extends Maybe<Accumulation>>
   constructor(
     _instrumentDescriptor: InstrumentDescriptor,
     aggregator: Aggregator<T>,
-    private _attributesProcessor: AttributesProcessor,
+    private _attributesProcessor: IAttributesProcessor,
     collectorHandles: MetricCollectorHandle[]
   ) {
     super(_instrumentDescriptor);

packages/sdk-metrics/src/state/MeterSharedState.ts

@@ -32,7 +32,10 @@ import { MultiMetricStorage } from './MultiWritableMetricStorage';
 import { ObservableRegistry } from './ObservableRegistry';
 import { SyncMetricStorage } from './SyncMetricStorage';
 import { Accumulation, Aggregator } from '../aggregator/types';
-import { AttributesProcessor } from '../view/AttributesProcessor';
+import {
+  createNoopAttributesProcessor,
+  IAttributesProcessor,
+} from '../view/AttributesProcessor';
 import { MetricStorage } from './MetricStorage';
 
 /**
@@ -166,7 +169,7 @@ export class MeterSharedState {
           const storage = new MetricStorageType(
             descriptor,
             aggregator,
-            AttributesProcessor.Noop(),
+            createNoopAttributesProcessor(),
             [collector]
           ) as R;
           this.metricStorageRegistry.registerForCollector(collector, storage);
@@ -189,7 +192,7 @@ interface MetricStorageConstructor {
   new (
     instrumentDescriptor: InstrumentDescriptor,
     aggregator: Aggregator<Maybe<Accumulation>>,
-    attributesProcessor: AttributesProcessor,
+    attributesProcessor: IAttributesProcessor,
     collectors: MetricCollectorHandle[]
   ): MetricStorage;
 }

packages/sdk-metrics/src/state/SyncMetricStorage.ts

@@ -18,7 +18,7 @@ import { Context, HrTime, MetricAttributes } from '@opentelemetry/api';
 import { WritableMetricStorage } from './WritableMetricStorage';
 import { Accumulation, Aggregator } from '../aggregator/types';
 import { InstrumentDescriptor } from '../InstrumentDescriptor';
-import { AttributesProcessor } from '../view/AttributesProcessor';
+import { IAttributesProcessor } from '../view/AttributesProcessor';
 import { MetricStorage } from './MetricStorage';
 import { MetricData } from '../export/MetricData';
 import { DeltaMetricProcessor } from './DeltaMetricProcessor';
@@ -41,7 +41,7 @@ export class SyncMetricStorage<T extends Maybe<Accumulation>>
   constructor(
     instrumentDescriptor: InstrumentDescriptor,
     aggregator: Aggregator<T>,
-    private _attributesProcessor: AttributesProcessor,
+    private _attributesProcessor: IAttributesProcessor,
     collectorHandles: MetricCollectorHandle[]
   ) {
     super(instrumentDescriptor);

packages/sdk-metrics/src/view/AttributesProcessor.ts

@@ -14,48 +14,46 @@
  * limitations under the License.
  */
 
-import { Context, MetricAttributes } from '@opentelemetry/api';
+import { Context, Attributes } from '@opentelemetry/api';
 
 /**
  * The {@link AttributesProcessor} is responsible for customizing which
  * attribute(s) are to be reported as metrics dimension(s) and adding
  * additional dimension(s) from the {@link Context}.
  */
-export abstract class AttributesProcessor {
+export interface IAttributesProcessor {
   /**
    * Process the metric instrument attributes.
    *
    * @param incoming The metric instrument attributes.
    * @param context The active context when the instrument is synchronous.
    * `undefined` otherwise.
    */
-  abstract process(
-    incoming: MetricAttributes,
-    context?: Context
-  ): MetricAttributes;
-
-  static Noop() {
-    return NOOP;
-  }
+  process: (incoming: Attributes, context?: Context) => Attributes;
 }
 
-export class NoopAttributesProcessor extends AttributesProcessor {
-  process(incoming: MetricAttributes, _context?: Context) {
+class NoopAttributesProcessor implements IAttributesProcessor {
+  process(incoming: Attributes, _context?: Context) {
     return incoming;
   }
 }
 
-/**
- * {@link AttributesProcessor} that filters by allowed attribute names and drops any names that are not in the
- * allow list.
- */
-export class FilteringAttributesProcessor extends AttributesProcessor {
-  constructor(private _allowedAttributeNames: string[]) {
-    super();
+class MultiAttributesProcessor implements IAttributesProcessor {
+  constructor(private readonly _processors: IAttributesProcessor[]) {}
+  process(incoming: Attributes, context?: Context): Attributes {
+    let filteredAttributes = incoming;
+    for (const processor of this._processors) {
+      filteredAttributes = processor.process(filteredAttributes, context);
+    }
+    return filteredAttributes;
   }
+}
+
+class AllowListProcessor implements IAttributesProcessor {
+  constructor(private _allowedAttributeNames: string[]) {}
 
-  process(incoming: MetricAttributes, _context: Context): MetricAttributes {
-    const filteredAttributes: MetricAttributes = {};
+  process(incoming: Attributes, _context?: Context): Attributes {
+    const filteredAttributes: Attributes = {};
     Object.keys(incoming)
       .filter(attributeName =>
         this._allowedAttributeNames.includes(attributeName)
@@ -68,4 +66,62 @@ export class FilteringAttributesProcessor extends AttributesProcessor {
   }
 }
 
+class DenyListProcessor implements IAttributesProcessor {
+  constructor(private _deniedAttributeNames: string[]) {}
+
+  process(incoming: Attributes, _context?: Context): Attributes {
+    const filteredAttributes: Attributes = {};
+    Object.keys(incoming)
+      .filter(
+        attributeName => !this._deniedAttributeNames.includes(attributeName)
+      )
+      .forEach(
+        attributeName =>
+          (filteredAttributes[attributeName] = incoming[attributeName])
+      );
+    return filteredAttributes;
+  }
+}
+
+/**
+ * @internal
+ *
+ * Create an {@link IAttributesProcessor} that acts as a simple pass-through for attributes.
+ */
+export function createNoopAttributesProcessor(): IAttributesProcessor {
+  return NOOP;
+}
+
+/**
+ * @internal
+ *
+ * Create an {@link IAttributesProcessor} that applies all processors from the provided list in order.
+ *
+ * @param processors Processors to apply in order.
+ */
+export function createMultiAttributesProcessor(
+  processors: IAttributesProcessor[]
+): IAttributesProcessor {
+  return new MultiAttributesProcessor(processors);
+}
+
+/**
+ * Create an {@link IAttributesProcessor} that filters by allowed attribute names and drops any names that are not in the
+ * allow list.
+ */
+export function createAllowListAttributesProcessor(
+  attributeAllowList: string[]
+): IAttributesProcessor {
+  return new AllowListProcessor(attributeAllowList);
+}
+
+/**
+ * Create an {@link IAttributesProcessor} that drops attributes based on the names provided in the deny list
+ */
+export function createDenyListAttributesProcessor(
+  attributeDenyList: string[]
+): IAttributesProcessor {
+  return new DenyListProcessor(attributeDenyList);
+}
+
 const NOOP = new NoopAttributesProcessor();

packages/sdk-metrics/src/view/View.ts

@@ -16,8 +16,9 @@
 
 import { PatternPredicate } from './Predicate';
 import {
-  AttributesProcessor,
-  FilteringAttributesProcessor,
+  createMultiAttributesProcessor,
+  createNoopAttributesProcessor,
+  IAttributesProcessor,
 } from './AttributesProcessor';
 import { InstrumentSelector } from './InstrumentSelector';
 import { MeterSelector } from './MeterSelector';
@@ -42,15 +43,18 @@ export type ViewOptions = {
   description?: string;
   /**
    * Alters the metric stream:
-   * If provided, the attributes that are not in the list will be ignored.
+   * If provided, the attributes will be modified as defined by the processors in the list. Processors are applied
+   * in the order they're provided.
    * If not provided, all attribute keys will be used by default.
    *
    * @example <caption>drops all attributes with top-level keys except for 'myAttr' and 'myOtherAttr'</caption>
-   * attributeKeys: ['myAttr', 'myOtherAttr']
+   * attributesProcessors: [createAllowListProcessor(['myAttr', 'myOtherAttr'])]
    * @example <caption>drops all attributes</caption>
-   * attributeKeys: []
+   * attributesProcessors: [createAllowListProcessor([])]
+   * @example <caption>allows all attributes except for 'myAttr'</caption>
+   * attributesProcessors: [createDenyListProcessor(['myAttr']]
    */
-  attributeKeys?: string[];
+  attributesProcessors?: IAttributesProcessor[];
   /**
    * Alters the metric stream:
    * Alters the {@link Aggregation} of the metric stream.
@@ -135,7 +139,7 @@ export class View {
   readonly name?: string;
   readonly description?: string;
   readonly aggregation: Aggregation;
-  readonly attributesProcessor: AttributesProcessor;
+  readonly attributesProcessor: IAttributesProcessor;
   readonly instrumentSelector: InstrumentSelector;
   readonly meterSelector: MeterSelector;
 
@@ -157,9 +161,9 @@ export class View {
    * Alters the metric stream:
    *  This will be used as the description of the metrics stream.
    *  If not provided, the original Instrument description will be used by default.
-   * @param viewOptions.attributeKeys
+   * @param viewOptions.attributesProcessors
    * Alters the metric stream:
-   *  If provided, the attributes that are not in the list will be ignored.
+   *  If provided, the attributes will be modified as defined by the added processors.
    *  If not provided, all attribute keys will be used by default.
    * @param viewOptions.aggregation
    * Alters the metric stream:
@@ -210,13 +214,13 @@ export class View {
       );
     }
 
-    // Create AttributesProcessor if attributeKeys are defined set.
-    if (viewOptions.attributeKeys != null) {
-      this.attributesProcessor = new FilteringAttributesProcessor(
-        viewOptions.attributeKeys
+    // Create multi-processor if attributesProcessors are defined.
+    if (viewOptions.attributesProcessors != null) {
+      this.attributesProcessor = createMultiAttributesProcessor(
+        viewOptions.attributesProcessors
       );
     } else {
-      this.attributesProcessor = AttributesProcessor.Noop();
+      this.attributesProcessor = createNoopAttributesProcessor();
     }
 
     this.name = viewOptions.name;

packages/sdk-metrics/test/MeterProvider.test.ts

@@ -32,6 +32,7 @@ import { TestMetricReader } from './export/TestMetricReader';
 import * as sinon from 'sinon';
 import { View } from '../src/view/View';
 import { Meter } from '../src/Meter';
+import { createAllowListAttributesProcessor } from '../src/view/AttributesProcessor';
 
 describe('MeterProvider', () => {
   afterEach(() => {
@@ -200,15 +201,17 @@ describe('MeterProvider', () => {
       );
     });
 
-    it('with attributeKeys should drop non-listed attributes', async () => {
+    it('with allowListProcessor should drop non-listed attributes', async () => {
       const reader = new TestMetricReader();
 
       // Add view to drop all attributes except 'attrib1'
       const meterProvider = new MeterProvider({
         resource: defaultResource,
         views: [
           new View({
-            attributeKeys: ['attrib1'],
+            attributesProcessors: [
+              createAllowListAttributesProcessor(['attrib1']),
+            ],
             instrumentName: 'non-renamed-instrument',
           }),
         ],

packages/sdk-metrics/test/state/AsyncMetricStorage.test.ts

@@ -21,7 +21,7 @@ import { AggregationTemporality } from '../../src/export/AggregationTemporality'
 import { DataPointType } from '../../src/export/MetricData';
 import { MetricCollectorHandle } from '../../src/state/MetricCollector';
 import { AsyncMetricStorage } from '../../src/state/AsyncMetricStorage';
-import { NoopAttributesProcessor } from '../../src/view/AttributesProcessor';
+import { createNoopAttributesProcessor } from '../../src/view/AttributesProcessor';
 import { ObservableRegistry } from '../../src/state/ObservableRegistry';
 import {
   assertMetricData,
@@ -49,7 +49,7 @@ describe('AsyncMetricStorage', () => {
         const metricStorage = new AsyncMetricStorage(
           defaultInstrumentDescriptor,
           new SumAggregator(true),
-          new NoopAttributesProcessor(),
+          createNoopAttributesProcessor(),
           [deltaCollector]
         );
 
@@ -149,7 +149,7 @@ describe('AsyncMetricStorage', () => {
         const metricStorage = new AsyncMetricStorage(
           defaultInstrumentDescriptor,
           new SumAggregator(true),
-          new NoopAttributesProcessor(),
+          createNoopAttributesProcessor(),
           [deltaCollector]
         );
 
@@ -233,7 +233,7 @@ describe('AsyncMetricStorage', () => {
         const metricStorage = new AsyncMetricStorage(
           defaultInstrumentDescriptor,
           new SumAggregator(false),
-          new NoopAttributesProcessor(),
+          createNoopAttributesProcessor(),
           [deltaCollector]
         );
 
@@ -319,7 +319,7 @@ describe('AsyncMetricStorage', () => {
         const metricStorage = new AsyncMetricStorage(
           defaultInstrumentDescriptor,
           new SumAggregator(true),
-          new NoopAttributesProcessor(),
+          createNoopAttributesProcessor(),
           [cumulativeCollector]
         );
 
@@ -451,7 +451,7 @@ describe('AsyncMetricStorage', () => {
         const metricStorage = new AsyncMetricStorage(
           defaultInstrumentDescriptor,
           new SumAggregator(true),
-          new NoopAttributesProcessor(),
+          createNoopAttributesProcessor(),
           [cumulativeCollector]
         );
 
@@ -545,7 +545,7 @@ describe('AsyncMetricStorage', () => {
         const metricStorage = new AsyncMetricStorage(
           defaultInstrumentDescriptor,
           new SumAggregator(false),
-          new NoopAttributesProcessor(),
+          createNoopAttributesProcessor(),
           [cumulativeCollector]
         );