package mainimport ("fmt""math""strconv"
)type BloomFilter struct {*bitMapk      uint64  // hash function countm      uint64  // bits array lengthn      uint64  // insert n numberp      float64 // 失误率p_true float64 // 真是失误率
}func (b *BloomFilter) Insert(id uint64) {for i := 0; uint64(i) < b.k; i++ {b.bitMap.insert(getHash(strconv.Itoa(int(id)), uint64(i)) % b.bitMap.Size)}
}func (b *BloomFilter) IsExist(id uint64) bool {for i := 0; uint64(i) < b.k; i++ {if !b.bitMap.isExist(getHash(strconv.Itoa(int(id)), uint64(i)) % b.bitMap.Size) {return false}}return true
}func NewBloomFilter(p float64, n uint64) *BloomFilter {m := uint64(-(float64(n)*math.Log2(p))/(math.Ln2*math.Ln2) + 0.5)k := uint64(math.Ln2*(float64(m)/float64(n)) + 0.5)p_true := math.Pow(1-math.Pow(math.E, -(float64(n)*float64(k))/float64(m)), float64(k))bl := &BloomFilter{bitMap: newBitMap(m/64 + 1)}bl.m = m           // bits array lengthbl.n = n           // insert n numberbl.k = k           // hash function countbl.p = p           // 失误率bl.p_true = p_true // 真实失误率return bl
}func main() {bl := NewBloomFilter(0.00000001, 100)bl.Insert(10000)fmt.Println(bl.IsExist(10000))fmt.Println(bl.IsExist(10001))
}func main1() {p := 0.00000000001n := 100m := uint(-(float64(n)*math.Log2(p))/(math.Ln2*math.Ln2) + 0.5)fmt.Println(m/64 + 1)k := uint64(math.Ln2*(float64(m)/float64(n)) + 0.5)fmt.Println(m)fmt.Println(k)p_true := float64(0)p_true = math.Pow(1-math.Pow(math.E, -(float64(n)*float64(k))/float64(m)), float64(k))fmt.Println(p_true < p)}type bitMap struct {Map  []uint64Cap  uint64Size uint64
}func newBitMap(cap uint64) *bitMap {return &bitMap{make([]uint64, cap), cap, cap * 64}
}func (b *bitMap) insert(id uint64) {b.Map[id/64] |= 1 << (id % 64)
}func (b *bitMap) isExist(id uint64) bool {return (b.Map[id/64])&(1<<(id%64)) > 0
}func (b *bitMap) delete(id uint64) {b.Map[id/64] &^= 1 << (id % 64)
}func (b *bitMap) range_() (res []uint64) {for i := 0; uint64(i) < b.Cap; i++ {if b.Map[i] > 0 {for j, bits := 0, b.Map[i]; bits > 0; j, bits = j+1, bits>>1 {if bits&1 == 1 {res = append(res, uint64(i)*64+uint64(j))}}}}return res
}func getHash(str string, i uint64) uint64 {return hash(str) + i*hash1(str)
}func hash(str string) (res uint64) {factor := ")k+,p-m~90$#2(*&6q}ev73541]n{fl['?|c"str = str + factor[:16-(len(str)%16)]for start, end := 0, len(str)/16; end > 0; start, end = start+16, end-1 {h0 := uint64(0)for i := 15; i >= 0; i-- {h0 += uint64(str[start+i]-byte(i))*uint64(pow(36, i)) ^ uint64(factor[(i+start)%36])}h0 *= 0x12345res += (res >> 30) ^ h0<<34res += (res >> 32) | (h0 << 32) ^ uint64(start*start*start) ^ uint64(factor[start%36])res += (res>>16)&(h0<<48) ^ uint64(factor[35-start%36]) ^ uint64(start-end*end)res += (res >> 17) | (h0 << 47) ^ uint64(start*start)}res += 235791113<<32 | 1719232931>>32return res
}func hash1(str string) (res uint64) {factor := ")k+,p-m~90$#2(*&6q}ev73541]n{fl['?|c"str = str + factor[:16-(len(str)%16)]for start, end := 0, len(str)/16; end > 0; start, end = start+16, end-1 {h0 := uint64(0)for i := 15; i >= 0; i-- {h0 += uint64(str[start+i]-byte(i))*uint64(pow(36, i)) ^ uint64(factor[(i+start)%36])}h0 *= 0x54321res += (res >> 32) | (h0 << 32) ^ uint64(start*start*start) ^ uint64(factor[start%36])res += (res>>16)&(h0<<48) ^ uint64(factor[35-start%36]) ^ uint64(start-end*end)res += (res >> 17) | (h0 << 47) ^ uint64(start*start)res += (res >> 30) ^ h0<<34}res += 1719232931<<32 | 235791113>>32return res
}func pow(x, n int) int {if n == 0 {return 1} else {for (n & 1) == 0 {n, x = n>>1, x*x}}result := xn >>= 1for n != 0 {x *= xif n&1 == 1 {result *= x}n >>= 1}return result
}