feat: support numeric labels in neighbor algorithms

base/hnsw/bruteforce.go

@@ -0,0 +1,71 @@
+// Copyright 2023 gorse Project Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package hnsw
+
+import (
+	"context"
+
+	"github.com/chewxy/math32"
+	"github.com/zhenghaoz/gorse/base/heap"
+)
+
+type Bruteforce struct {
+	vectors []Vector
+	distFn  Distance
+}
+
+func NewBruteforce(dist Distance) *Bruteforce {
+	return &Bruteforce{
+		distFn: dist,
+	}
+}
+
+func (b *Bruteforce) Add(ctx context.Context, vectors ...Vector) {
+	b.vectors = append(b.vectors, vectors...)
+}
+
+func (b *Bruteforce) Evaluate(n int) float64 {
+	return 1
+}
+
+// Search returns the nearest neighbors of q.
+func (b *Bruteforce) Search(q Vector, n int) []Result {
+	if q == nil {
+		return nil
+	}
+	pq := heap.NewPriorityQueue(true)
+	for i, vec := range b.vectors {
+		if vec != nil && vec != q {
+			d := b.distFn(q, vec)
+			if math32.IsInf(d, 1) {
+				continue
+			}
+			pq.Push(int32(i), d)
+			if pq.Len() > n {
+				pq.Pop()
+			}
+		}
+	}
+	pq = pq.Reverse()
+	var results []Result
+	for pq.Len() > 0 {
+		value, score := pq.Pop()
+		results = append(results, Result{
+			Index:    value,
+			Distance: score,
+		})
+	}
+	return results
+}

base/hnsw/bruteforce_test.go

@@ -0,0 +1,62 @@
+// Copyright 2023 gorse Project Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package hnsw
+
+import (
+	"context"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestBruteforce(t *testing.T) {
+	bf := NewBruteforce(Euclidean)
+	bf.Add(context.Background(), NewDenseVector([]float32{0, 0, 0, 0, 0, 1}))
+	bf.Add(context.Background(), NewDenseVector([]float32{0, 0, 0, 0, 1, 1}))
+	bf.Add(context.Background(), NewDenseVector([]float32{0, 0, 0, 1, 1, 1}))
+	bf.Add(context.Background(), NewDenseVector([]float32{0, 0, 1, 1, 1, 1}))
+	bf.Add(context.Background(), NewDenseVector([]float32{0, 1, 1, 1, 1, 1}))
+	bf.Add(context.Background(), NewDenseVector([]float32{1, 1, 1, 1, 1, 1}))
+	results := bf.Search(NewDenseVector([]float32{0, 0, 0, 0, 0, 0}), 3)
+	assert.Equal(t, []Result{
+		{Index: 0, Distance: 1},
+		{Index: 1, Distance: 2},
+		{Index: 2, Distance: 3},
+	}, results)
+
+	bf.distFn = Dot
+	results = bf.Search(NewDenseVector([]float32{1, 1, 1, 1, 1, 1}), 3)
+	assert.Equal(t, []Result{
+		{Index: 5, Distance: -6},
+		{Index: 4, Distance: -5},
+		{Index: 3, Distance: -4},
+	}, results)
+}
+
+func TestBruteforce_HasNil(t *testing.T) {
+	vectors := []Vector{nil, nil, NewDenseVector([]float32{0, 0, 0, 0, 0, 1}), nil}
+	bf := NewBruteforce(Euclidean)
+	bf.Add(context.Background(), vectors...)
+	results := bf.Search(NewDenseVector([]float32{0, 0, 0, 0, 0, 1}), 3)
+	assert.Equal(t, []Result{{Index: 2, Distance: 0}}, results)
+}
+
+func TestBruteforce_HasInf(t *testing.T) {
+	bf := NewBruteforce(Euclidean)
+	bf.Add(context.Background(), NewSparseVector([]int32{1, 3, 5}, []float32{1, 2, 3}))
+	bf.Add(context.Background(), NewSparseVector([]int32{2, 4, 6}, []float32{1, 2, 3}))
+	results := bf.Search(NewSparseVector([]int32{1, 3, 5}, []float32{1, 2, 3}), 3)
+	assert.Equal(t, []Result{{Index: 0, Distance: 0}}, results)
+}