105 lines
2.9 KiB
Go
105 lines
2.9 KiB
Go
// Copyright 2012-present Oliver Eilhard. All rights reserved.
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// Use of this source code is governed by a MIT-license.
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// See http://olivere.mit-license.org/license.txt for details.
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package elastic
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// DisMaxQuery is a query that generates the union of documents produced by
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// its subqueries, and that scores each document with the maximum score
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// for that document as produced by any subquery, plus a tie breaking
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// increment for any additional matching subqueries.
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//
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// For more details, see:
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// https://www.elastic.co/guide/en/elasticsearch/reference/6.2/query-dsl-dis-max-query.html
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type DisMaxQuery struct {
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queries []Query
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boost *float64
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tieBreaker *float64
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queryName string
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}
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// NewDisMaxQuery creates and initializes a new dis max query.
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func NewDisMaxQuery() *DisMaxQuery {
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return &DisMaxQuery{
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queries: make([]Query, 0),
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}
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}
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// Query adds one or more queries to the dis max query.
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func (q *DisMaxQuery) Query(queries ...Query) *DisMaxQuery {
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q.queries = append(q.queries, queries...)
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return q
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}
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// Boost sets the boost for this query. Documents matching this query will
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// (in addition to the normal weightings) have their score multiplied by
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// the boost provided.
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func (q *DisMaxQuery) Boost(boost float64) *DisMaxQuery {
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q.boost = &boost
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return q
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}
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// TieBreaker is the factor by which the score of each non-maximum disjunct
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// for a document is multiplied with and added into the final score.
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//
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// If non-zero, the value should be small, on the order of 0.1, which says
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// that 10 occurrences of word in a lower-scored field that is also in a
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// higher scored field is just as good as a unique word in the lower scored
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// field (i.e., one that is not in any higher scored field).
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func (q *DisMaxQuery) TieBreaker(tieBreaker float64) *DisMaxQuery {
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q.tieBreaker = &tieBreaker
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return q
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}
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// QueryName sets the query name for the filter that can be used
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// when searching for matched filters per hit.
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func (q *DisMaxQuery) QueryName(queryName string) *DisMaxQuery {
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q.queryName = queryName
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return q
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}
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// Source returns the JSON serializable content for this query.
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func (q *DisMaxQuery) Source() (interface{}, error) {
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// {
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// "dis_max" : {
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// "tie_breaker" : 0.7,
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// "boost" : 1.2,
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// "queries" : {
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// {
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// "term" : { "age" : 34 }
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// },
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// {
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// "term" : { "age" : 35 }
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// }
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// ]
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// }
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// }
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query := make(map[string]interface{})
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params := make(map[string]interface{})
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query["dis_max"] = params
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if q.tieBreaker != nil {
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params["tie_breaker"] = *q.tieBreaker
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}
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if q.boost != nil {
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params["boost"] = *q.boost
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}
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if q.queryName != "" {
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params["_name"] = q.queryName
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}
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// queries
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var clauses []interface{}
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for _, subQuery := range q.queries {
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src, err := subQuery.Source()
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if err != nil {
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return nil, err
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}
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clauses = append(clauses, src)
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}
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params["queries"] = clauses
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return query, nil
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}
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