feat: add stats core

Author: djonathascardoso

packages/opencensus-core/src/exporters/console-exporter.ts

@@ -15,6 +15,7 @@
  */
 
 import * as loggerTypes from '../common/types';
+import {Measure, Measurement, View} from '../stats/model/types';
 import * as modelTypes from '../trace/model/types';
 
 import {ExporterBuffer} from './exporter-buffer';
@@ -45,17 +46,14 @@ export class ConsoleExporter implements types.Exporter {
     this.buffer = new ExporterBuffer(this, config);
     this.logger = config.logger;
   }
-
   onStartSpan(root: modelTypes.RootSpan) {}
-
   /**
    * Event called when a span is ended.
    * @param root Ended span.
    */
   onEndSpan(root: modelTypes.RootSpan) {
     this.buffer.addToBuffer(root);
   }
-
   /**
    * Sends the spans information to the console.
    * @param rootSpans
@@ -77,3 +75,25 @@ export class ConsoleExporter implements types.Exporter {
     return Promise.resolve();
   }
 }
+
+/** Exporter that receives stats data and shows in the log console. */
+export class ConsoleStatsExporter implements types.StatsExporter {
+  /**
+   * Event called when a view is registered
+   * @param view registered view
+   * @param measure registered measure
+   */
+  onRegisterView(view: View, measure: Measure) {
+    console.log(
+        `View registered: ${view.name}, Measure registered: ${measure.name}`);
+  }
+  /**
+   * Event called when a measurement is recorded
+   * @param view recorded view from measurement
+   * @param measurement recorded measurement
+   */
+  onRecord(view: View, measurement: Measurement) {
+    console.log(`Measurement recorded: ${measurement.measure.name}, value: ${
+        measurement.value}`);
+  }
+}

packages/opencensus-core/src/exporters/types.ts

@@ -15,7 +15,7 @@
  */
 
 
-import * as loggerTypes from '../common/types';
+import {Measure, Measurement, View} from '../stats/model/types';
 import * as configTypes from '../trace/config/types';
 import * as modelTypes from '../trace/model/types';
 
@@ -29,4 +29,19 @@ export interface Exporter extends modelTypes.SpanEventListener {
   publish(rootSpans: modelTypes.RootSpan[]): Promise<number|string|void>;
 }
 
+export interface StatsExporter {
+  /**
+   * Event called when a view is registered
+   * @param view registered view
+   * @param measure registered measure
+   */
+  onRegisterView(view: View, measure: Measure): void;
+  /**
+   * Event called when a measurement is recorded
+   * @param view recorded view from measurement
+   * @param measurement recorded measurement
+   */
+  onRecord(view: View, measurement: Measurement): void;
+}
+
 export type ExporterConfig = configTypes.BufferConfig;

packages/opencensus-core/src/index.ts

@@ -40,6 +40,16 @@ export * from './trace/instrumentation/base-plugin';
 export * from './exporters/exporter-buffer';
 export * from './exporters/console-exporter';
 
+// STATS CLASSES
+
+// domain models impls
+export * from './stats/model/aggregation';
+export * from './stats/model/measure';
+export * from './stats/model/stats-manager';
+
+// interfaces
+export * from './stats/model/types';
+
 // logger
 import * as logger from './common/console-logger';
 export {logger};

packages/opencensus-core/src/stats/model/aggregation.ts

@@ -0,0 +1,122 @@
+/**
+ * Copyright 2018, OpenCensus 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
+ *
+ *      http://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 {Aggregation, HistogramBucket, Measurement} from './types';
+
+/** Counts the number of recorded measurements. */
+export class AggregationCount implements Aggregation {
+  measurements: Measurement[] = [];
+
+  getValue(): number {
+    return this.measurements.length;
+  }
+
+  getType(): string {
+    return 'COUNT';
+  }
+}
+
+/** Returns the recorded measurements values summed. */
+export class AggregationSum implements Aggregation {
+  measurements: Measurement[] = [];
+
+  getValue(): number {
+    let sum = 0;
+    for (const measurement of this.measurements) {
+      sum += measurement.value;
+    }
+    return sum;
+  }
+
+  getType(): string {
+    return 'SUM';
+  }
+}
+
+/** Returns the last recorded measurement value. */
+export class AggregationLastValue implements Aggregation {
+  measurements: Measurement[] = [];
+
+  getValue(): number {
+    return this.measurements[this.measurements.length - 1].value;
+  }
+
+  getType(): string {
+    return 'LAST VALUE';
+  }
+}
+
+/**
+ * Returns a histogram distribution. A distribution Aggregation may contain a
+ * histogram of the values in the population.
+ */
+export class AggregationDistribution implements Aggregation {
+  private bucketBoundaries: number[];
+  measurements: Measurement[] = [];
+
+  constructor(bucketBoundaries: number[]) {
+    this.bucketBoundaries = bucketBoundaries;
+  }
+
+  getValue(): HistogramBucket[] {
+    const histograms = this.createHistogramBase();
+
+    /** loop to calculate the bucket sizes */
+    for (const measurement of this.measurements) {
+      for (const histogram of histograms) {
+        if (measurement.value < histogram.range.max) {
+          histogram.bucketCount += 1;
+          break;
+        }
+      }
+    }
+
+    return histograms;
+  }
+
+  getType(): string {
+    return 'DISTRIBUTION';
+  }
+
+  /**
+   * Creates the initial histogram with the bucket boundaries
+   */
+  private createHistogramBase(): HistogramBucket[] {
+    const histogram: HistogramBucket[] = [];
+    const bucketBoundaries = this.bucketBoundaries;
+
+    // pushing the first value
+    histogram.push(
+        {range: {min: -Infinity, max: bucketBoundaries[0]}, bucketCount: 0});
+
+    // pushing the second value to the penultimate value
+    for (let i = 1; i < bucketBoundaries.length; i++) {
+      histogram.push({
+        range: {min: bucketBoundaries[i - 1], max: bucketBoundaries[i]},
+        bucketCount: 0
+      });
+    }
+
+    // pushing the last value
+    histogram.push({
+      range:
+          {min: bucketBoundaries[bucketBoundaries.length - 1], max: Infinity},
+      bucketCount: 0
+    });
+
+    return histogram;
+  }
+}

packages/opencensus-core/src/stats/model/measure.ts

@@ -0,0 +1,47 @@
+/**
+ * Copyright 2018, OpenCensus 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
+ *
+ *      http://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 {Measure} from './types';
+
+/** Measure class for double type */
+export class MeasureDouble implements Measure {
+  name: string;
+  description: string;
+  unit: string;
+  type: string;
+
+  constructor(name: string, description: string, unit: string) {
+    this.name = name;
+    this.description = description;
+    this.unit = unit;
+    this.type = 'DOUBLE';
+  }
+}
+
+/** Measure class for int64 type */
+export class MeasureInt64 implements Measure {
+  name: string;
+  description: string;
+  unit: string;
+  type: string;
+
+  constructor(name: string, description: string, unit: string) {
+    this.name = name;
+    this.description = description;
+    this.unit = unit;
+    this.type = 'INT64';
+  }
+}