github.com/m3db/m3@v1.5.0/src/m3ninx/search/query/disjunction.go (about)

     1  // Copyright (c) 2018 Uber Technologies, Inc.
     2  //
     3  // Permission is hereby granted, free of charge, to any person obtaining a copy
     4  // of this software and associated documentation files (the "Software"), to deal
     5  // in the Software without restriction, including without limitation the rights
     6  // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
     7  // copies of the Software, and to permit persons to whom the Software is
     8  // furnished to do so, subject to the following conditions:
     9  //
    10  // The above copyright notice and this permission notice shall be included in
    11  // all copies or substantial portions of the Software.
    12  //
    13  // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
    14  // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
    15  // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
    16  // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
    17  // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
    18  // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
    19  // THE SOFTWARE.
    20  
    21  package query
    22  
    23  import (
    24  	"sort"
    25  	"strings"
    26  
    27  	"github.com/m3db/m3/src/m3ninx/generated/proto/querypb"
    28  	"github.com/m3db/m3/src/m3ninx/search"
    29  	"github.com/m3db/m3/src/m3ninx/search/searcher"
    30  )
    31  
    32  // DisjuctionQuery finds documents which match at least one of the given queries.
    33  type DisjuctionQuery struct {
    34  	str     string
    35  	queries []search.Query
    36  }
    37  
    38  // NewDisjunctionQuery constructs a new query which matches documents that match any
    39  // of the given queries.
    40  func NewDisjunctionQuery(queries []search.Query) search.Query {
    41  	qs := make([]search.Query, 0, len(queries))
    42  	for _, query := range queries {
    43  		// Merge disjunction queries into slice of top-level queries.
    44  		q, ok := query.(*DisjuctionQuery)
    45  		if ok {
    46  			qs = append(qs, q.queries...)
    47  			continue
    48  		}
    49  
    50  		qs = append(qs, query)
    51  	}
    52  	// Cause a sort of the queries/negations for deterministic cache key.
    53  	sort.Slice(qs, func(i, j int) bool {
    54  		return qs[i].String() < qs[j].String()
    55  	})
    56  	q := &DisjuctionQuery{
    57  		queries: qs,
    58  	}
    59  	// NB(r): Calculate string value up front so
    60  	// not allocated every time String() is called to determine
    61  	// the cache key.
    62  	q.str = q.string()
    63  	return q
    64  }
    65  
    66  // Searcher returns a searcher over the provided readers.
    67  func (q *DisjuctionQuery) Searcher() (search.Searcher, error) {
    68  	switch len(q.queries) {
    69  	case 0:
    70  		return searcher.NewEmptySearcher(), nil
    71  
    72  	case 1:
    73  		return q.queries[0].Searcher()
    74  	}
    75  
    76  	srs := make(search.Searchers, 0, len(q.queries))
    77  	for _, q := range q.queries {
    78  		sr, err := q.Searcher()
    79  		if err != nil {
    80  			return nil, err
    81  		}
    82  		srs = append(srs, sr)
    83  	}
    84  
    85  	return searcher.NewDisjunctionSearcher(srs)
    86  }
    87  
    88  // Equal reports whether q is equivalent to o.
    89  func (q *DisjuctionQuery) Equal(o search.Query) bool {
    90  	if len(q.queries) == 1 {
    91  		return q.queries[0].Equal(o)
    92  	}
    93  
    94  	inner, ok := o.(*DisjuctionQuery)
    95  	if !ok {
    96  		return false
    97  	}
    98  
    99  	if len(q.queries) != len(inner.queries) {
   100  		return false
   101  	}
   102  
   103  	// TODO: Should order matter?
   104  	for i := range q.queries {
   105  		if !q.queries[i].Equal(inner.queries[i]) {
   106  			return false
   107  		}
   108  	}
   109  	return true
   110  }
   111  
   112  // ToProto returns the Protobuf query struct corresponding to the disjunction query.
   113  func (q *DisjuctionQuery) ToProto() *querypb.Query {
   114  	qs := make([]*querypb.Query, 0, len(q.queries))
   115  	for _, qry := range q.queries {
   116  		qs = append(qs, qry.ToProto())
   117  	}
   118  	disj := querypb.DisjunctionQuery{Queries: qs}
   119  
   120  	return &querypb.Query{
   121  		Query: &querypb.Query_Disjunction{Disjunction: &disj},
   122  	}
   123  }
   124  
   125  func (q *DisjuctionQuery) String() string {
   126  	return q.str
   127  }
   128  
   129  func (q *DisjuctionQuery) string() string {
   130  	var str strings.Builder
   131  	str.WriteString("disjunction(")
   132  	join(&str, q.queries)
   133  	str.WriteRune(')')
   134  	return str.String()
   135  }