Add Sampler & Diversified Sampler aggs to AggConfigs

src/plugins/data/common/search/aggs/agg_types.ts

@@ -62,6 +62,8 @@ export const getAggTypes = () => ({
     { name: BUCKET_TYPES.SIGNIFICANT_TERMS, fn: buckets.getSignificantTermsBucketAgg },
     { name: BUCKET_TYPES.GEOHASH_GRID, fn: buckets.getGeoHashBucketAgg },
     { name: BUCKET_TYPES.GEOTILE_GRID, fn: buckets.getGeoTitleBucketAgg },
+    { name: BUCKET_TYPES.SAMPLER, fn: buckets.getSamplerBucketAgg },
+    { name: BUCKET_TYPES.DIVERSIFIED_SAMPLER, fn: buckets.getDiversifiedSamplerBucketAgg },
   ],
 });
 
@@ -79,6 +81,8 @@ export const getAggTypesFunctions = () => [
   buckets.aggDateHistogram,
   buckets.aggTerms,
   buckets.aggMultiTerms,
+  buckets.aggSampler,
+  buckets.aggDiversifiedSampler,
   metrics.aggAvg,
   metrics.aggBucketAvg,
   metrics.aggBucketMax,

src/plugins/data/common/search/aggs/aggs_service.test.ts

@@ -73,6 +73,8 @@ describe('Aggs service', () => {
           "significant_terms",
           "geohash_grid",
           "geotile_grid",
+          "sampler",
+          "diversified_sampler",
           "foo",
         ]
       `);
@@ -122,6 +124,8 @@ describe('Aggs service', () => {
           "significant_terms",
           "geohash_grid",
           "geotile_grid",
+          "sampler",
+          "diversified_sampler",
         ]
       `);
       expect(bStart.types.getAll().metrics.map((t) => t(aggTypesDependencies).name))

src/plugins/data/common/search/aggs/buckets/bucket_agg_types.ts

@@ -19,4 +19,6 @@ export enum BUCKET_TYPES {
   GEOHASH_GRID = 'geohash_grid',
   GEOTILE_GRID = 'geotile_grid',
   DATE_HISTOGRAM = 'date_histogram',
+  SAMPLER = 'sampler',
+  DIVERSIFIED_SAMPLER = 'diversified_sampler',
 }

src/plugins/data/common/search/aggs/buckets/diversified_sampler.ts

@@ -0,0 +1,62 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0 and the Server Side Public License, v 1; you may not use this file except
+ * in compliance with, at your election, the Elastic License 2.0 or the Server
+ * Side Public License, v 1.
+ */
+
+import { i18n } from '@kbn/i18n';
+import { BucketAggType } from './bucket_agg_type';
+import { BaseAggParams } from '../types';
+import { aggDiversifiedSamplerFnName } from './diversified_sampler_fn';
+
+export const DIVERSIFIED_SAMPLER_AGG_NAME = 'diversified_sampler';
+
+const title = i18n.translate('data.search.aggs.buckets.diversifiedSamplerTitle', {
+  defaultMessage: 'Diversified sampler',
+  description: 'Diversified sampler aggregation title',
+});
+
+export interface AggParamsDiversifiedSampler extends BaseAggParams {
+  /**
+   * Is used to provide values used for de-duplication
+   */
+  field: string;
+
+  /**
+   * Limits how many top-scoring documents are collected in the sample processed on each shard.
+   */
+  shard_size?: number;
+
+  /**
+   * Limits how many documents are permitted per choice of de-duplicating value
+   */
+  max_docs_per_value?: number;
+}
+
+/**
+ * Like the sampler aggregation this is a filtering aggregation used to limit any sub aggregations' processing to a sample of the top-scoring documents.
+ * The diversified_sampler aggregation adds the ability to limit the number of matches that share a common value.
+ */
+export const getDiversifiedSamplerBucketAgg = () =>
+  new BucketAggType({
+    name: DIVERSIFIED_SAMPLER_AGG_NAME,
+    title,
+    customLabels: false,
+    expressionName: aggDiversifiedSamplerFnName,
+    params: [
+      {
+        name: 'shard_size',
+        type: 'number',
+      },
+      {
+        name: 'max_docs_per_value',
+        type: 'number',
+      },
+      {
+        name: 'field',
+        type: 'field',
+      },
+    ],
+  });

src/plugins/data/common/search/aggs/buckets/diversified_sampler_fn.test.ts

@@ -0,0 +1,58 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0 and the Server Side Public License, v 1; you may not use this file except
+ * in compliance with, at your election, the Elastic License 2.0 or the Server
+ * Side Public License, v 1.
+ */
+
+import { functionWrapper } from '../test_helpers';
+import { aggDiversifiedSampler } from './diversified_sampler_fn';
+
+describe('aggDiversifiedSampler', () => {
+  const fn = functionWrapper(aggDiversifiedSampler());
+
+  test('fills in defaults when only required args are provided', () => {
+    const actual = fn({ id: 'sampler', schema: 'bucket', field: 'author' });
+    expect(actual).toMatchInlineSnapshot(`
+      Object {
+        "type": "agg_type",
+        "value": Object {
+          "enabled": true,
+          "id": "sampler",
+          "params": Object {
+            "field": "author",
+            "max_docs_per_value": undefined,
+            "shard_size": undefined,
+          },
+          "schema": "bucket",
+          "type": "diversified_sampler",
+        },
+      }
+    `);
+  });
+
+  test('includes optional params when they are provided', () => {
+    const actual = fn({
+      id: 'sampler',
+      schema: 'bucket',
+      shard_size: 300,
+      field: 'author',
+      max_docs_per_value: 3,
+    });
+
+    expect(actual.value).toMatchInlineSnapshot(`
+      Object {
+        "enabled": true,
+        "id": "sampler",
+        "params": Object {
+          "field": "author",
+          "max_docs_per_value": 3,
+          "shard_size": 300,
+        },
+        "schema": "bucket",
+        "type": "diversified_sampler",
+      }
+    `);
+  });
+});

src/plugins/data/common/search/aggs/buckets/diversified_sampler_fn.ts

@@ -0,0 +1,90 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0 and the Server Side Public License, v 1; you may not use this file except
+ * in compliance with, at your election, the Elastic License 2.0 or the Server
+ * Side Public License, v 1.
+ */
+
+import { i18n } from '@kbn/i18n';
+import { ExpressionFunctionDefinition } from 'src/plugins/expressions/common';
+import { AggExpressionFunctionArgs, AggExpressionType, BUCKET_TYPES } from '../';
+import { DIVERSIFIED_SAMPLER_AGG_NAME } from './diversified_sampler';
+
+export const aggDiversifiedSamplerFnName = 'aggDiversifiedSampler';
+
+type Input = any;
+type Arguments = AggExpressionFunctionArgs<typeof BUCKET_TYPES.DIVERSIFIED_SAMPLER>;
+
+type Output = AggExpressionType;
+type FunctionDefinition = ExpressionFunctionDefinition<
+  typeof aggDiversifiedSamplerFnName,
+  Input,
+  Arguments,
+  Output
+>;
+
+export const aggDiversifiedSampler = (): FunctionDefinition => ({
+  name: aggDiversifiedSamplerFnName,
+  help: i18n.translate('data.search.aggs.function.buckets.diversifiedSampler.help', {
+    defaultMessage: 'Generates a serialized agg config for a Diversified sampler agg',
+  }),
+  type: 'agg_type',
+  args: {
+    id: {
+      types: ['string'],
+      help: i18n.translate('data.search.aggs.buckets.diversifiedSampler.id.help', {
+        defaultMessage: 'ID for this aggregation',
+      }),
+    },
+    enabled: {
+      types: ['boolean'],
+      default: true,
+      help: i18n.translate('data.search.aggs.buckets.diversifiedSampler.enabled.help', {
+        defaultMessage: 'Specifies whether this aggregation should be enabled',
+      }),
+    },
+    schema: {
+      types: ['string'],
+      help: i18n.translate('data.search.aggs.buckets.diversifiedSampler.schema.help', {
+        defaultMessage: 'Schema to use for this aggregation',
+      }),
+    },
+    shard_size: {
+      types: ['number'],
+      help: i18n.translate('data.search.aggs.buckets.diversifiedSampler.shardSize.help', {
+        defaultMessage:
+          'The shard_size parameter limits how many top-scoring documents are collected in the sample processed on each shard.',
+      }),
+    },
+    max_docs_per_value: {
+      types: ['number'],
+      help: i18n.translate('data.search.aggs.buckets.diversifiedSampler.maxDocsPerValue.help', {
+        defaultMessage:
+          'Limits how many documents are permitted per choice of de-duplicating value.',
+      }),
+    },
+    field: {
+      types: ['string'],
+      help: i18n.translate('data.search.aggs.buckets.diversifiedSampler.field.help', {
+        defaultMessage: 'Used to provide values used for de-duplication.',
+      }),
+    },
+  },
+  fn: (input, args) => {
+    const { id, enabled, schema, ...rest } = args;
+
+    return {
+      type: 'agg_type',
+      value: {
+        id,
+        enabled,
+        schema,
+        type: DIVERSIFIED_SAMPLER_AGG_NAME,
+        params: {
+          ...rest,
+        },
+      },
+    };
+  },
+});

src/plugins/data/common/search/aggs/buckets/index.ts

@@ -38,3 +38,7 @@ export * from './terms_fn';
 export * from './terms';
 export * from './multi_terms_fn';
 export * from './multi_terms';
+export * from './sampler_fn';
+export * from './sampler';
+export * from './diversified_sampler_fn';
+export * from './diversified_sampler';

src/plugins/data/common/search/aggs/buckets/sampler.ts

@@ -0,0 +1,43 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0 and the Server Side Public License, v 1; you may not use this file except
+ * in compliance with, at your election, the Elastic License 2.0 or the Server
+ * Side Public License, v 1.
+ */
+
+import { i18n } from '@kbn/i18n';
+import { BucketAggType } from './bucket_agg_type';
+import { BaseAggParams } from '../types';
+import { aggSamplerFnName } from './sampler_fn';
+
+export const SAMPLER_AGG_NAME = 'sampler';
+
+const title = i18n.translate('data.search.aggs.buckets.samplerTitle', {
+  defaultMessage: 'Sampler',
+  description: 'Sampler aggregation title',
+});
+
+export interface AggParamsSampler extends BaseAggParams {
+  /**
+   * Limits how many top-scoring documents are collected in the sample processed on each shard.
+   */
+  shard_size?: number;
+}
+
+/**
+ * A filtering aggregation used to limit any sub aggregations' processing to a sample of the top-scoring documents.
+ */
+export const getSamplerBucketAgg = () =>
+  new BucketAggType({
+    name: SAMPLER_AGG_NAME,
+    title,
+    customLabels: false,
+    expressionName: aggSamplerFnName,
+    params: [
+      {
+        name: 'shard_size',
+        type: 'number',
+      },
+    ],
+  });

src/plugins/data/common/search/aggs/buckets/sampler_fn.test.ts

@@ -0,0 +1,52 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0 and the Server Side Public License, v 1; you may not use this file except
+ * in compliance with, at your election, the Elastic License 2.0 or the Server
+ * Side Public License, v 1.
+ */
+
+import { functionWrapper } from '../test_helpers';
+import { aggSampler } from './sampler_fn';
+
+describe('aggSampler', () => {
+  const fn = functionWrapper(aggSampler());
+
+  test('fills in defaults when only required args are provided', () => {
+    const actual = fn({ id: 'sampler', schema: 'bucket' });
+    expect(actual).toMatchInlineSnapshot(`
+      Object {
+        "type": "agg_type",
+        "value": Object {
+          "enabled": true,
+          "id": "sampler",
+          "params": Object {
+            "shard_size": undefined,
+          },
+          "schema": "bucket",
+          "type": "sampler",
+        },
+      }
+    `);
+  });
+
+  test('includes optional params when they are provided', () => {
+    const actual = fn({
+      id: 'sampler',
+      schema: 'bucket',
+      shard_size: 300,
+    });
+
+    expect(actual.value).toMatchInlineSnapshot(`
+      Object {
+        "enabled": true,
+        "id": "sampler",
+        "params": Object {
+          "shard_size": 300,
+        },
+        "schema": "bucket",
+        "type": "sampler",
+      }
+    `);
+  });
+});