fix: apply changes picked up in rebase

Author: mwear

packages/sdk-metrics/src/aggregator/ExponentialHistogram.ts

@@ -29,9 +29,8 @@ import { InstrumentDescriptor, InstrumentType } from '../InstrumentDescriptor';
 import { Maybe } from '../utils';
 import { AggregationTemporality } from '../export/AggregationTemporality';
 import { Buckets } from './exponential-histogram/Buckets';
+import { getMapping } from './exponential-histogram/mapping/getMapping';
 import { Mapping } from './exponential-histogram/mapping/types';
-import { ExponentMapping } from './exponential-histogram/mapping/ExponentMapping';
-import { LogarithmMapping } from './exponential-histogram/mapping/LogarithmMapping';
 import * as util from './exponential-histogram//util';
 
 /**
@@ -66,13 +65,14 @@ class HighLow {
   constructor(public low: number, public high: number) {}
 }
 
-export class ExponentialHistogramAccumulation implements Accumulation {
-  static DEFAULT_MAX_SIZE = 160;
-  static MIN_MAX_SIZE = 2;
+const MAX_SCALE = 20;
+const DEFAULT_MAX_SIZE = 160;
+const MIN_MAX_SIZE = 2;
 
+export class ExponentialHistogramAccumulation implements Accumulation {
   constructor(
     public startTime: HrTime = startTime,
-    private _maxSize = ExponentialHistogramAccumulation.DEFAULT_MAX_SIZE,
+    private _maxSize = DEFAULT_MAX_SIZE,
     private _recordMinMax = true,
     private _sum = 0,
     private _count = 0,
@@ -81,13 +81,12 @@ export class ExponentialHistogramAccumulation implements Accumulation {
     private _max = Number.NEGATIVE_INFINITY,
     private _positive = new Buckets(),
     private _negative = new Buckets(),
-    private _mapping: Mapping = LogarithmMapping.get(LogarithmMapping.MAX_SCALE)
+    private _mapping: Mapping = getMapping(MAX_SCALE)
   ) {
-    if (this._maxSize < ExponentialHistogramAccumulation.MIN_MAX_SIZE) {
+    if (this._maxSize < MIN_MAX_SIZE) {
       diag.warn(`Exponential Histogram Max Size set to ${this._maxSize}, \
-                changing to the minimum size of: \
-                ${ExponentialHistogramAccumulation.MIN_MAX_SIZE}`);
-      this._maxSize = ExponentialHistogramAccumulation.MIN_MAX_SIZE;
+                changing to the minimum size of: ${MIN_MAX_SIZE}`);
+      this._maxSize = MIN_MAX_SIZE;
     }
   }
 
@@ -419,11 +418,7 @@ export class ExponentialHistogramAccumulation implements Accumulation {
     this._positive.downscale(change);
     this._negative.downscale(change);
 
-    if (newScale <= 0) {
-      this._mapping = ExponentMapping.get(newScale);
-    } else {
-      this._mapping = LogarithmMapping.get(newScale);
-    }
+    this._mapping = getMapping(newScale);
   }
 
   /**

packages/sdk-metrics/test/aggregator/ExponentialHistogram.test.ts

@@ -26,9 +26,8 @@ import {
   ExponentialHistogramAggregator,
 } from '../../src/aggregator/ExponentialHistogram';
 import { Buckets } from '../../src/aggregator/exponential-histogram/Buckets';
+import { getMapping } from '../../src/aggregator/exponential-histogram/mapping/getMapping';
 import { Mapping } from '../../src/aggregator/exponential-histogram//mapping/types';
-import { ExponentMapping } from '../../src/aggregator/exponential-histogram//mapping/ExponentMapping';
-import { LogarithmMapping } from '../../src/aggregator/exponential-histogram/mapping/LogarithmMapping';
 import * as assert from 'assert';
 import {
   assertInEpsilon,
@@ -534,10 +533,7 @@ describe('ExponentialHistogramAccumulation', () => {
   describe('min max size', () => {
     it('auto-corrects to min max', () => {
       const acc: any = new ExponentialHistogramAccumulation([0, 0], 0);
-      assert.strictEqual(
-        acc['_maxSize'],
-        ExponentialHistogramAccumulation.MIN_MAX_SIZE
-      );
+      assert.strictEqual(acc['_maxSize'], 2);
     });
   });
 });
@@ -783,14 +779,6 @@ function centerValue(mapper: Mapping, x: number): number {
   return (lower + upper) / 2;
 }
 
-function getMapping(scale: number): Mapping {
-  if (scale <= 0) {
-    return ExponentMapping.get(scale);
-  } else {
-    return LogarithmMapping.get(scale);
-  }
-}
-
 function assertHistogramsEqual(
   actual: ExponentialHistogramAccumulation,
   expected: ExponentialHistogramAccumulation

packages/sdk-metrics/test/aggregator/exponential-histogram/helpers.ts

@@ -21,7 +21,7 @@ export function assertInEpsilon(
   epsilon: number
 ) {
   assert.ok(!Number.isNaN(actual), 'unexpected NaN for actual argument');
-  assert.ok(!Number.isNaN(expected), 'unexpected NaN for expected argument');
+  assert.ok(!Number.isNaN(expected), 'unexpected NaN for exepected argument');
   assert.ok(actual !== 0, 'unexpected 0 for actual argument');
 
   const relErr = Math.abs(actual - expected) / Math.abs(actual);
@@ -31,3 +31,11 @@ export function assertInEpsilon(
     `expected relative error: ${relErr} to be < ${epsilon}`
   );
 }
+
+export function assertInDelta(actual: number, expected: number, delta: number) {
+  const actualDelta = Math.abs(expected - actual);
+  assert.ok(
+    actualDelta < delta,
+    `expected delta: ${delta} to be < ${actualDelta}`
+  );
+}