github.com/m3db/m3@v1.5.0/src/dbnode/storage/index/results_new_map.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 index
    22  
    23  import (
    24  	"bytes"
    25  
    26  	"github.com/cespare/xxhash/v2"
    27  )
    28  
    29  const (
    30  	defaultInitialResultsMapSize = 64
    31  )
    32  
    33  func newResultsMap() *ResultsMap {
    34  	return _ResultsMapAlloc(_ResultsMapOptions{
    35  		hash: func(k []byte) ResultsMapHash {
    36  			return ResultsMapHash(xxhash.Sum64(k))
    37  		},
    38  		equals: bytes.Equal,
    39  		copy: func(k []byte) []byte {
    40  			return append(make([]byte, 0, len(k)), k...)
    41  		},
    42  		finalize: func(k []byte) {
    43  			// NB(nate): no-op for bytes IDs
    44  		},
    45  		initialSize: defaultInitialResultsMapSize,
    46  	})
    47  }