perf: improve perf by refactoring code to be cleaner and more efficie…

…nt (#559)

Co-authored-by: Dan Shappir <dan.s@nextinsurance.com>

CHANGELOG.md

@@ -7,6 +7,10 @@ project adheres to [Semantic Versioning](http://semver.org/).
 
 ## [Unreleased]
 
+### Changed
+
+- Cleanup code and refactor to be more efficient
+
 ### Breaking
 
 - drop support for Node.js versions 10, 12 and 17

lib/histogram.js

@@ -56,8 +56,8 @@ class Histogram extends Metric {
 			this.hashMap = {
 				[hashObject({})]: createBaseValues(
 					{},
-					Object.assign({}, this.bucketValues),
-					Object.assign({}, this.bucketExemplars),
+					this.bucketValues,
+					this.bucketExemplars,
 				),
 			};
 		}
@@ -84,16 +84,17 @@ class Histogram extends Metric {
 
 	updateExemplar(labels, value, exemplarLabels) {
 		const hash = hashObject(labels);
-		const b = findBound(this.upperBounds, value);
-		if (!isObject(this.hashMap[hash].bucketExemplars[b])) {
-			this.hashMap[hash].bucketExemplars[b] = new Exemplar();
+		const bound = findBound(this.upperBounds, value);
+		const { bucketExemplars } = this.hashMap[hash];
+		let exemplar = bucketExemplars[bound];
+		if (!isObject(exemplar)) {
+			exemplar = new Exemplar();
+			bucketExemplars[bound] = exemplar;
 		}
-		this.hashMap[hash].bucketExemplars[b].validateExemplarLabelSet(
-			exemplarLabels,
-		);
-		this.hashMap[hash].bucketExemplars[b].labelSet = exemplarLabels;
-		this.hashMap[hash].bucketExemplars[b].value = value;
-		this.hashMap[hash].bucketExemplars[b].timestamp = nowTimestamp();
+		exemplar.validateExemplarLabelSet(exemplarLabels);
+		exemplar.labelSet = exemplarLabels;
+		exemplar.value = value;
+		exemplar.timestamp = nowTimestamp();
 	}
 
 	async get() {
@@ -134,8 +135,8 @@ class Histogram extends Metric {
 		const hash = hashObject(labels);
 		this.hashMap[hash] = createBaseValues(
 			labels,
-			Object.assign({}, this.bucketValues),
-			Object.assign({}, this.bucketExemplars),
+			this.bucketValues,
+			this.bucketExemplars,
 		);
 	}
 
@@ -218,8 +219,8 @@ function observe(labels) {
 		if (!valueFromMap) {
 			valueFromMap = createBaseValues(
 				labelValuePair.labels,
-				Object.assign({}, this.bucketValues),
-				Object.assign({}, this.bucketExemplars),
+				this.bucketValues,
+				this.bucketExemplars,
 			);
 		}
 
@@ -239,43 +240,39 @@ function observe(labels) {
 function createBaseValues(labels, bucketValues, bucketExemplars) {
 	return {
 		labels,
-		bucketValues,
-		bucketExemplars,
+		bucketValues: { ...bucketValues },
+		bucketExemplars: { ...bucketExemplars },
 		sum: 0,
 		count: 0,
 	};
 }
 
 function convertLabelsAndValues(labels, value) {
-	if (!isObject(labels)) {
-		return {
-			value: labels,
-			labels: {},
-		};
-	}
-	return {
-		labels,
-		value,
-	};
+	return isObject(labels)
+		? {
+				labels,
+				value,
+		  }
+		: {
+				value: labels,
+				labels: {},
+		  };
 }
 
 function extractBucketValuesForExport(histogram) {
+	const name = `${histogram.name}_bucket`;
 	return bucketData => {
-		const buckets = [];
 		let acc = 0;
-		for (const upperBound of histogram.upperBounds) {
+		const buckets = histogram.upperBounds.map(upperBound => {
 			acc += bucketData.bucketValues[upperBound];
-			const lbls = { le: upperBound };
-			buckets.push(
-				setValuePair(
-					lbls,
-					acc,
-					`${histogram.name}_bucket`,
-					bucketData.bucketExemplars[upperBound],
-					bucketData.labels,
-				),
+			return setValuePair(
+				{ le: upperBound },
+				acc,
+				name,
+				bucketData.bucketExemplars[upperBound],
+				bucketData.labels,
 			);
-		}
+		});
 		return { buckets, data: bucketData };
 	};
 }

lib/registry.js

@@ -42,13 +42,13 @@ class Registry {
 		const defaultLabels =
 			Object.keys(this._defaultLabels).length > 0 ? this._defaultLabels : null;
 
+		const isOpenMetrics =
+			this.contentType === Registry.OPENMETRICS_CONTENT_TYPE;
+
 		for (const val of metric.values || []) {
 			let { metricName = name, labels = {} } = val;
 			const { sharedLabels = {} } = val;
-			if (
-				this.contentType === Registry.OPENMETRICS_CONTENT_TYPE &&
-				metric.type === 'counter'
-			) {
+			if (isOpenMetrics && metric.type === 'counter') {
 				metricName = `${metricName}_total`;
 			}
 
@@ -58,13 +58,7 @@ class Registry {
 
 			// We have to flatten these separately to avoid duplicate labels appearing
 			// between the base labels and the shared labels
-			const formattedLabels = [];
-			for (const [n, v] of Object.entries(labels)) {
-				if (Object.prototype.hasOwnProperty.call(sharedLabels, n)) {
-					continue;
-				}
-				formattedLabels.push(`${n}="${escapeLabelValue(v)}"`);
-			}
+			const formattedLabels = formatLabels(labels, sharedLabels);
 
 			const flattenedShared = flattenSharedLabels(sharedLabels);
 			const labelParts = [...formattedLabels, flattenedShared].filter(Boolean);
@@ -74,7 +68,7 @@ class Registry {
 			)}`;
 
 			const { exemplar } = val;
-			if (exemplar && this.contentType === Registry.OPENMETRICS_CONTENT_TYPE) {
+			if (exemplar && isOpenMetrics) {
 				const formattedExemplars = formatLabels(exemplar.labelSet);
 				fullMetricLine += ` # {${formattedExemplars.join(
 					',',
@@ -87,25 +81,21 @@ class Registry {
 	}
 
 	async metrics() {
-		const promises = [];
+		const isOpenMetrics =
+			this.contentType === Registry.OPENMETRICS_CONTENT_TYPE;
 
-		for (const metric of this.getMetricsAsArray()) {
-			if (
-				this.contentType === Registry.OPENMETRICS_CONTENT_TYPE &&
-				metric.type === 'counter'
-			) {
+		const promises = this.getMetricsAsArray().map(metric => {
+			if (isOpenMetrics && metric.type === 'counter') {
 				metric.name = standardizeCounterName(metric.name);
 			}
-			promises.push(this.getMetricsAsString(metric));
-		}
+			return this.getMetricsAsString(metric);
+		});
 
 		const resolves = await Promise.all(promises);
 
-		if (this.contentType === Registry.OPENMETRICS_CONTENT_TYPE) {
-			return `${resolves.join('\n')}\n# EOF\n`;
-		} else {
-			return `${resolves.join('\n\n')}\n`;
-		}
+		return isOpenMetrics
+			? `${resolves.join('\n')}\n# EOF\n`
+			: `${resolves.join('\n\n')}\n`;
 	}
 
 	registerMetric(metric) {
@@ -212,10 +202,15 @@ class Registry {
 	}
 }
 
-function formatLabels(labels) {
-	return Object.entries(labels).map(
-		([n, v]) => `${n}="${escapeLabelValue(v)}"`,
-	);
+function formatLabels(labels, exclude) {
+	const { hasOwnProperty } = Object.prototype;
+	const formatted = [];
+	for (const [name, value] of Object.entries(labels)) {
+		if (!exclude || !hasOwnProperty.call(exclude, name)) {
+			formatted.push(`${name}="${escapeLabelValue(value)}"`);
+		}
+	}
+	return formatted;
 }
 
 const sharedLabelCache = new WeakMap();