Expose proximity boosting (#39385)

docs/reference/query-dsl/distance-feature-query.asciidoc

@@ -0,0 +1,177 @@
+[[query-dsl-distance-feature-query]]
+=== Distance Feature Query
+
+The `distance_feature` query is a specialized query that only works
+on <<date, `date`>>, <<date_nanos, `date_nanos`>> or <<geo-point,`geo_point`>>
+fields. Its goal is to boost documents' scores based on proximity
+to some given origin. For example, use this query if you want to
+give more weight to documents with dates closer to a certain date,
+or to documents with locations closer to a certain location.
+
+This query is called `distance_feature` query, because it dynamically
+calculates distances between the given origin and documents' field values,
+and use these distances as features to boost the documents' scores.
+
+`distance_feature` query is typically used on its own to find the nearest
+neighbors to a given point, or put in a `should` clause of a
+<<query-dsl-bool-query,`bool`>> query so that its score is added to the score
+of the query.
+
+Compared to using <<query-dsl-function-score-query,`function_score`>> or other
+ways to modify the score, this query has the benefit of being able to
+efficiently skip non-competitive hits when
+<<search-uri-request,`track_total_hits`>> is not set to `true`.
+
+==== Syntax of distance_feature query
+
+`distance_feature` query has the following syntax:
+[source,js]
+--------------------------------------------------
+"distance_feature": {
+  "field": <field>,
+  "origin": <origin>,
+  "pivot": <pivot>,
+  "boost" : <boost>
+}
+--------------------------------------------------
+// NOTCONSOLE
+
+[horizontal]
+`field`::
+    Required parameter. Defines the name of the field on which to calculate
+    distances. Must be a field of the type `date`, `date_nanos` or `geo_point`,
+    and must be indexed (`"index": true`, which is the default) and has
+    <<doc-values, doc values>> (`"doc_values": true`, which is the default).
+
+`origin`::
+    Required parameter. Defines a point of origin used for calculating
+    distances. Must be a date for date and date_nanos fields,
+    and a geo-point for geo_point fields. Date math (for example `now-1h`) is
+    supported for a date origin.
+
+`pivot`::
+    Required parameter. Defines the distance from origin at which the computed
+    score will equal to a half of the `boost` parameter. Must be
+    a `number+date unit` ("1h", "10d",...) for date and date_nanos fields,
+    and a `number + geo unit` ("1km", "12m",...) for geo fields.
+
+`boost`::
+    Optional parameter with a default value of `1`. Defines the factor by which
+    to multiply the score. Must be a non-negative float number.
+
+
+The `distance_feature` query computes a document's score as following:
+
+`score = boost * pivot / (pivot + distance)`
+
+where `distance` is the absolute difference between the origin and
+a document's field value.
+
+==== Example using distance_feature query
+
+Let's look at an example. We index several documents containing
+information about sales items, such as name, production date,
+and location.
+
+[source,js]
+--------------------------------------------------
+PUT items
+{
+  "mappings": {
+    "properties": {
+      "name": {
+        "type": "keyword"
+      },
+      "production_date": {
+        "type": "date"
+      },
+      "location": {
+        "type": "geo_point"
+      }
+    }
+  }
+}
+
+PUT items/_doc/1
+{
+  "name" : "chocolate",
+  "production_date": "2018-02-01",
+  "location": [-71.34, 41.12]
+}
+
+PUT items/_doc/2
+{
+  "name" : "chocolate",
+  "production_date": "2018-01-01",
+  "location": [-71.3, 41.15]
+}
+
+
+PUT items/_doc/3
+{
+  "name" : "chocolate",
+  "production_date": "2017-12-01",
+  "location": [-71.3, 41.12]
+}
+
+POST items/_refresh
+--------------------------------------------------
+// CONSOLE
+
+We look for all chocolate items, but we also want chocolates
+that are produced recently (closer to the date `now`)
+to be ranked higher.
+
+[source,js]
+--------------------------------------------------
+GET items/_search
+{
+  "query": {
+    "bool": {
+      "must": {
+        "match": {
+          "name": "chocolate"
+        }
+      },
+      "should": {
+        "distance_feature": {
+          "field": "production_date",
+          "pivot": "7d",
+          "origin": "now"
+        }
+      }
+    }
+  }
+}
+--------------------------------------------------
+// CONSOLE
+// TEST[continued]
+
+We can look for all chocolate items, but we also want chocolates
+that are produced locally (closer to our geo origin)
+come first in the result list.
+
+[source,js]
+--------------------------------------------------
+GET items/_search
+{
+  "query": {
+    "bool": {
+      "must": {
+        "match": {
+          "name": "chocolate"
+        }
+      },
+      "should": {
+        "distance_feature": {
+          "field": "location",
+          "pivot": "1000m",
+          "origin": [-71.3, 41.15]
+        }
+      }
+    }
+  }
+}
+--------------------------------------------------
+// CONSOLE
+// TEST[continued]

docs/reference/query-dsl/special-queries.asciidoc

@@ -28,6 +28,12 @@ the specified document.
 A query that computes scores based on the values of numeric features and is
 able to efficiently skip non-competitive hits.
 
+<<query-dsl-distance-feature-query,`distance_feature` query>>::
+
+A query that computes scores based on the dynamically computed distances
+between the origin and documents' date, date_nanos and geo_point fields.
+It is able to efficiently skip non-competitive hits.
+
 <<query-dsl-wrapper-query,`wrapper` query>>::
 
 A query that accepts other queries as json or yaml string.
@@ -42,4 +48,6 @@ include::percolate-query.asciidoc[]
 
 include::rank-feature-query.asciidoc[]
 
+include::distance-feature-query.asciidoc[]
+
 include::wrapper-query.asciidoc[]

libs/x-content/src/main/java/org/elasticsearch/common/xcontent/ObjectParser.java

@@ -440,6 +440,7 @@ public enum ValueType {
         OBJECT_OR_LONG(START_OBJECT, VALUE_NUMBER),
         OBJECT_ARRAY_BOOLEAN_OR_STRING(START_OBJECT, START_ARRAY, VALUE_BOOLEAN, VALUE_STRING),
         OBJECT_ARRAY_OR_STRING(START_OBJECT, START_ARRAY, VALUE_STRING),
+        OBJECT_ARRAY_STRING_OR_NUMBER(START_OBJECT, START_ARRAY, VALUE_STRING, VALUE_NUMBER),
         VALUE(VALUE_BOOLEAN, VALUE_NULL, VALUE_EMBEDDED_OBJECT, VALUE_NUMBER, VALUE_STRING),
         VALUE_OBJECT_ARRAY(VALUE_BOOLEAN, VALUE_NULL, VALUE_EMBEDDED_OBJECT, VALUE_NUMBER, VALUE_STRING, START_OBJECT, START_ARRAY),
         VALUE_ARRAY(VALUE_BOOLEAN, VALUE_NULL, VALUE_NUMBER, VALUE_STRING, START_ARRAY);

rest-api-spec/src/main/resources/rest-api-spec/test/search/250_distance_feature.yml

@@ -0,0 +1,87 @@
+setup:
+  - skip:
+      version: " - 7.0.99" 
+      reason:  "Implemented in 7.1"
+
+  - do:
+      indices.create:
+        index: index1
+        body:
+          settings:
+            number_of_replicas: 0
+          mappings:
+            properties:
+              my_date:
+                type: date
+              my_date_nanos:
+                type: date_nanos
+              my_geo:
+                type: geo_point
+
+  - do:
+      bulk:
+        refresh: true
+        body:
+        - '{ "index" : { "_index" : "index1", "_id" : "1" } }'
+        - '{ "my_date": "2018-02-01T10:00:00Z", "my_date_nanos": "2018-02-01T00:00:00.223456789Z", "my_geo": [-71.34, 41.13] }'
+        - '{ "index" : { "_index" : "index1", "_id" : "2" } }'
+        - '{ "my_date": "2018-02-01T11:00:00Z", "my_date_nanos": "2018-02-01T00:00:00.123456789Z", "my_geo": [-71.34, 41.14] }'
+        - '{ "index" : { "_index" : "index1", "_id" : "3" } }'
+        - '{ "my_date": "2018-02-01T09:00:00Z", "my_date_nanos": "2018-02-01T00:00:00.323456789Z", "my_geo": [-71.34, 41.12] }'
+
+---
+"test distance_feature query on date type":
+
+- do:
+    search:
+      rest_total_hits_as_int: true
+      index: index1
+      body:
+        query:
+          distance_feature:
+            field: my_date
+            pivot: 1h
+            origin: 2018-02-01T08:00:30Z
+
+- length: { hits.hits: 3 }
+- match: { hits.hits.0._id: "3" }
+- match: { hits.hits.1._id: "1" }
+- match: { hits.hits.2._id: "2" }
+
+---
+"test distance_feature query on date_nanos type":
+
+- do:
+    search:
+      rest_total_hits_as_int: true
+      index: index1
+      body:
+        query:
+          distance_feature:
+            field: my_date_nanos
+            pivot: 100000000nanos
+            origin: 2018-02-01T00:00:00.323456789Z
+
+- length: { hits.hits: 3 }
+- match: { hits.hits.0._id: "3" }
+- match: { hits.hits.1._id: "1" }
+- match: { hits.hits.2._id: "2" }
+
+---
+"test distance_feature query on geo_point type":
+
+- do:
+    search:
+      rest_total_hits_as_int: true
+      index: index1
+      body:
+        query:
+          distance_feature:
+            field: my_geo
+            pivot: 1km
+            origin: [-71.35, 41.12]
+
+- length: { hits.hits: 3 }
+- match: { hits.hits.0._id: "3" }
+- match: { hits.hits.1._id: "1" }
+- match: { hits.hits.2._id: "2" }

server/src/main/java/org/elasticsearch/common/geo/GeoUtils.java

@@ -545,6 +545,27 @@ private static GeoPoint parseGeoHash(GeoPoint point, String geohash, EffectivePo
         }
     }
 
+    /**
+     * Parse a {@link GeoPoint} from a string. The string must have one of the following forms:
+     *
+     * <ul>
+     *     <li>Latitude, Longitude form: <pre>&quot;<i>&lt;latitude&gt;</i>,<i>&lt;longitude&gt;</i>&quot;</pre></li>
+     *     <li>Geohash form:: <pre>&quot;<i>&lt;geohash&gt;</i>&quot;</pre></li>
+     * </ul>
+     *
+     * @param val a String to parse the value from
+     * @return new parsed {@link GeoPoint}
+     */
+    public static GeoPoint parseFromString(String val) {
+        GeoPoint point = new GeoPoint();
+        boolean ignoreZValue = false;
+        if (val.contains(",")) {
+            return point.resetFromString(val, ignoreZValue);
+        } else {
+            return parseGeoHash(point, val, EffectivePoint.BOTTOM_LEFT);
+        }
+    }
+
     /**
      * Parse a precision that can be expressed as an integer or a distance measure like "1km", "10m".
      *

server/src/main/java/org/elasticsearch/index/mapper/DateFieldMapper.java

@@ -308,6 +308,10 @@ public DateFormatter dateTimeFormatter() {
             return dateTimeFormatter;
         }
 
+        public Resolution resolution() {
+            return resolution;
+        }
+
         void setDateTimeFormatter(DateFormatter formatter) {
             checkIfFrozen();
             this.dateTimeFormatter = formatter;