Files
cloudpods/pkg/util/bitmap/bitmap.go
rainzm f204b5e605 feat(util): support uint64 in bitmap
The bitmap feature of low-digit uint type can be implemented by this of uint64
2021-02-18 11:14:58 +08:00

97 lines
2.0 KiB
Go

// Copyright 2019 Yunion
//
// 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 bitmap
// Uint2IntArray transfer bitmap displayed as n to int array
func Uint2IntArray(n uint32) []int {
return Uint64ToIntArray(uint64(n))
}
// IntArray2Uint transfer int array nums to bitmap number
func IntArray2Uint(nums []int) uint32 {
return uint32(IntArrayToUint64(nums))
}
func Uint64ToIntArray(n uint64) []int {
ret := make([]int, 0, 2)
var i uint = 0
for n != 0 {
if n&(1<<i) != 0 {
n &= uint64(^(1 << i))
ret = append(ret, int(i))
}
i++
}
return ret
}
func IntArrayToUint64(nums []int) uint64 {
var ret uint64 = 0
for _, i := range nums {
ret |= (1 << uint(i))
}
return ret
}
// Determine if int slice a euqals b
func IntSliceEqual(a, b []int) bool {
if len(a) != len(b) {
return false
}
for i := 0; i < len(a); i++ {
if a[i] != b[i] {
return false
}
}
return true
}
type BitMap struct {
bits []byte
size int64
}
func (bm *BitMap) Set(idx int64) {
if idx > bm.size {
return
}
subscript := idx / 8
var pos = uint64(idx % 8)
bm.bits[subscript] = (bm.bits[subscript] | 1<<pos)
}
func (bm *BitMap) Has(idx int64) bool {
if idx > bm.size {
return false
}
subscript := idx / 8
var pos = uint64(idx % 8)
return bm.bits[subscript]&(1<<pos) > 0
}
func (bm *BitMap) Clean(idx int64) {
if idx > bm.size {
return
}
subscript := idx / 8
var pos = uint64(idx % 8)
bm.bits[subscript] &= ^(1 << pos)
}
func NewBitMap(size int64) *BitMap {
bits := make([]byte, (size>>3)+1)
return &BitMap{bits: bits, size: size}
}