github.com/weaviate/weaviate@v1.24.6/adapters/repos/db/vector/hnsw/distancer/hamming.go (about)

     1  //                           _       _
     2  // __      _____  __ ___   ___  __ _| |_ ___
     3  // \ \ /\ / / _ \/ _` \ \ / / |/ _` | __/ _ \
     4  //  \ V  V /  __/ (_| |\ V /| | (_| | ||  __/
     5  //   \_/\_/ \___|\__,_| \_/ |_|\__,_|\__\___|
     6  //
     7  //  Copyright © 2016 - 2024 Weaviate B.V. All rights reserved.
     8  //
     9  //  CONTACT: hello@weaviate.io
    10  //
    11  
    12  package distancer
    13  
    14  import (
    15  	"github.com/pkg/errors"
    16  )
    17  
    18  var hammingImpl func(a, b []float32) float32 = func(a, b []float32) float32 {
    19  	var sum float32 // default value of float in golang is 0
    20  
    21  	for i := range a {
    22  		if a[i] != b[i] {
    23  			sum += float32(1)
    24  		}
    25  	}
    26  
    27  	return sum
    28  }
    29  
    30  type Hamming struct {
    31  	a []float32
    32  }
    33  
    34  func (l Hamming) Distance(b []float32) (float32, bool, error) {
    35  	if len(l.a) != len(b) {
    36  		return 0, false, errors.Errorf("vector lengths don't match: %d vs %d",
    37  			len(l.a), len(b))
    38  	}
    39  
    40  	return hammingImpl(l.a, b), true, nil
    41  }
    42  
    43  type HammingProvider struct{}
    44  
    45  func NewHammingProvider() HammingProvider {
    46  	return HammingProvider{}
    47  }
    48  
    49  func (l HammingProvider) SingleDist(a, b []float32) (float32, bool, error) {
    50  	if len(a) != len(b) {
    51  		return 0, false, errors.Errorf("vector lengths don't match: %d vs %d",
    52  			len(a), len(b))
    53  	}
    54  
    55  	return hammingImpl(a, b), true, nil
    56  }
    57  
    58  func (l HammingProvider) Type() string {
    59  	return "hamming"
    60  }
    61  
    62  func (l HammingProvider) New(a []float32) Distancer {
    63  	return &Hamming{a: a}
    64  }
    65  
    66  func (l HammingProvider) Step(x, y []float32) float32 {
    67  	var sum float32 // default value of float in golang is 0
    68  
    69  	for i := range x {
    70  		if x[i] != y[i] {
    71  			sum += float32(1)
    72  		}
    73  	}
    74  
    75  	return sum
    76  }
    77  
    78  func (l HammingProvider) Wrap(x float32) float32 {
    79  	return x
    80  }