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mirror of https://github.com/charlienet/go-mixed.git synced 2025-07-18 00:22:41 +08:00

布隆过滤器

This commit is contained in:
2022-09-23 10:22:23 +08:00
parent 5b4f8097d6
commit f043d2e5a7
2 changed files with 103 additions and 10 deletions

View File

@ -1,6 +1,9 @@
package bloom
import "github.com/bits-and-blooms/bitset"
import (
"github.com/bits-and-blooms/bitset"
"github.com/charlienet/go-mixed/locker"
)
const DEFAULT_SIZE = 2 << 24
@ -12,24 +15,53 @@ type simplehash struct {
}
type BloomFilter struct {
set *bitset.BitSet
funcs [6]simplehash
size int // 布隆过滤器大小
set *bitset.BitSet // 位图
funcs [6]simplehash // 哈希函数
lock locker.RWLocker
}
func NewBloomFilter() *BloomFilter {
bf := new(BloomFilter)
for i := 0; i < len(bf.funcs); i++ {
bf.funcs[i] = simplehash{DEFAULT_SIZE, seeds[i]}
type bloomOptions struct {
Size int
}
type option func(*bloomOptions)
// 布隆过滤器中所有位长度,请根据存储数量进行评估
func WithSize(size int) option {
return func(bo *bloomOptions) {
bo.Size = size
}
bf.set = bitset.New(DEFAULT_SIZE)
}
func NewBloomFilter(opts ...option) *BloomFilter {
opt := &bloomOptions{
Size: DEFAULT_SIZE,
}
for _, f := range opts {
f(opt)
}
bf := &BloomFilter{
size: opt.Size,
lock: locker.NewRWLocker(),
}
for i := 0; i < len(bf.funcs); i++ {
bf.funcs[i] = simplehash{uint(opt.Size), seeds[i]}
}
bf.set = bitset.New(uint(opt.Size))
return bf
}
func (bf *BloomFilter) Add(value string) {
funcs := bf.funcs[:]
for _, f := range funcs {
bf.set.Set(f.hash(value))
}
}
func (bf *BloomFilter) Contains(value string) bool {
@ -42,9 +74,15 @@ func (bf *BloomFilter) Contains(value string) bool {
for _, f := range funcs {
ret = ret && bf.set.Test(f.hash(value))
}
return ret
}
// 清空布隆过滤器
func (bf *BloomFilter) Clear() {
bf.set.ClearAll()
}
func (s simplehash) hash(value string) uint {
var result uint = 0
for i := 0; i < len(value); i++ {

View File

@ -6,6 +6,9 @@ import (
"testing"
"github.com/charlienet/go-mixed/bloom"
"github.com/charlienet/go-mixed/rand"
"github.com/charlienet/go-mixed/sys"
"github.com/stretchr/testify/assert"
)
func TestBloom(t *testing.T) {
@ -15,6 +18,58 @@ func TestBloom(t *testing.T) {
b.Add(strconv.Itoa(i))
}
fmt.Println(b.Contains(strconv.Itoa(9999)))
fmt.Println(b.Contains("ss"))
v := "6943553521463296-1635402930"
t.Log(b.Contains(v))
b.Add(v)
t.Log(b.Contains(v))
fmt.Println("过滤器中包含值:", b.Contains(strconv.Itoa(9999)))
fmt.Println("过滤器中未包含:", b.Contains("ss"))
t.Log(sys.ShowMemUsage())
}
func TestSize(t *testing.T) {
bloom.NewBloomFilter(bloom.WithSize(1 << 2))
}
func TestClear(t *testing.T) {
bf := bloom.NewBloomFilter()
v := "abc"
bf.Add(v)
assert.True(t, bf.Contains(v))
bf.Clear()
assert.False(t, bf.Contains(v))
}
func TestParallel(t *testing.T) {
f := bloom.NewBloomFilter()
for i := 0; i < 10000; i++ {
v := rand.Hex.Generate(10)
f.Add(v)
assert.True(t, f.Contains(v))
}
}
func BenchmarkFilter(b *testing.B) {
f := bloom.NewBloomFilter()
b.RunParallel(func(p *testing.PB) {
for p.Next() {
v := rand.Hex.Generate(10)
f.Add(v)
f.Contains(v)
// assert.True(b, f.Contains(v))
// assert.True(b, f.Contains(v))
}
})
}