f8fdfebb6c
- TermSearcher has alternate constructor if term is []byte, this can avoid copying in some cases. TermScorer updated to accept []byte term. Also removed a few struct fields which were not being used. - New MultiTermSearcher searches for documents containing any of a list of terms. Current implementation simply uses DisjunctionSearcher. - Several other searcher constructors now simply build a list of terms and then delegate to the MultiTermSearcher - NewPrefixSearcher - NewRegexpSearcher - NewFuzzySearcher - NewNumericRangeSearcher - NewGeoBoundingBoxSearcher and NewGeoPointDistanceSearcher make use of the MultiTermSearcher internally, and follow the pattern of returning an existing search.Searcher, as opposed to their own wrapping struct. - Callback filter functions used in NewGeoBoundingBoxSearcher and NewGeoPointDistanceSearcher have been extracted into separate functions which makes the code much easier to read.
116 lines
3.7 KiB
Go
116 lines
3.7 KiB
Go
// Copyright (c) 2017 Couchbase, Inc.
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package searcher
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import (
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"github.com/blevesearch/bleve/geo"
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"github.com/blevesearch/bleve/index"
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"github.com/blevesearch/bleve/numeric"
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"github.com/blevesearch/bleve/search"
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)
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func NewGeoPointDistanceSearcher(indexReader index.IndexReader, centerLon,
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centerLat, dist float64, field string, boost float64,
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options search.SearcherOptions) (search.Searcher, error) {
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// compute bounding box containing the circle
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topLeftLon, topLeftLat, bottomRightLon, bottomRightLat :=
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geo.ComputeBoundingBox(centerLon, centerLat, dist)
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// build a searcher for the box
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boxSearcher, err := boxSearcher(indexReader,
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topLeftLon, topLeftLat, bottomRightLon, bottomRightLat,
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field, boost, options)
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if err != nil {
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return nil, err
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}
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// wrap it in a filtering searcher which checks the actual distance
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return NewFilteringSearcher(boxSearcher,
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buildDistFilter(indexReader, field, centerLon, centerLat, dist)), nil
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}
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// boxSearcher builds a searcher for the described bounding box
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// if the desired box crosses the dateline, it is automatically split into
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// two boxes joined through a disjunction searcher
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func boxSearcher(indexReader index.IndexReader,
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topLeftLon, topLeftLat, bottomRightLon, bottomRightLat float64,
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field string, boost float64, options search.SearcherOptions) (
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search.Searcher, error) {
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if bottomRightLon < topLeftLon {
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// cross date line, rewrite as two parts
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leftSearcher, err := NewGeoBoundingBoxSearcher(indexReader,
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-180, bottomRightLat, bottomRightLon, topLeftLat,
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field, boost, options, false)
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if err != nil {
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return nil, err
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}
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rightSearcher, err := NewGeoBoundingBoxSearcher(indexReader,
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topLeftLon, bottomRightLat, 180, topLeftLat, field, boost, options, false)
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if err != nil {
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_ = leftSearcher.Close()
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return nil, err
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}
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boxSearcher, err := NewDisjunctionSearcher(indexReader,
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[]search.Searcher{leftSearcher, rightSearcher}, 0, options)
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if err != nil {
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_ = leftSearcher.Close()
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_ = rightSearcher.Close()
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return nil, err
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}
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return boxSearcher, nil
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}
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// build geoboundinggox searcher for that bounding box
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boxSearcher, err := NewGeoBoundingBoxSearcher(indexReader,
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topLeftLon, bottomRightLat, bottomRightLon, topLeftLat, field, boost,
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options, false)
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if err != nil {
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return nil, err
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}
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return boxSearcher, nil
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}
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func buildDistFilter(indexReader index.IndexReader, field string,
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centerLon, centerLat, maxDist float64) FilterFunc {
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return func(d *search.DocumentMatch) bool {
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var lon, lat float64
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var found bool
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err := indexReader.DocumentVisitFieldTerms(d.IndexInternalID,
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[]string{field}, func(field string, term []byte) {
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// only consider the values which are shifted 0
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prefixCoded := numeric.PrefixCoded(term)
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shift, err := prefixCoded.Shift()
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if err == nil && shift == 0 {
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i64, err := prefixCoded.Int64()
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if err == nil {
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lon = geo.MortonUnhashLon(uint64(i64))
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lat = geo.MortonUnhashLat(uint64(i64))
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found = true
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}
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}
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})
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if err == nil && found {
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dist := geo.Haversin(lon, lat, centerLon, centerLat)
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if dist <= maxDist/1000 {
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return true
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}
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}
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return false
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}
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}
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