新增对连续buff内存中指定索引位打标记函数

This commit is contained in:
orgin
2022-09-27 16:49:11 +08:00
parent 7a8d312aeb
commit 7f93aa5ff9
2 changed files with 98 additions and 0 deletions

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@@ -0,0 +1,61 @@
package algorithms
import (
"errors"
"unsafe"
)
type BitNumber interface {
int | int8 | int16 | int32 | int64 | uint | uint8 | uint16 | uint32 | uint64 | uintptr
}
type UnsignedNumber interface {
uint | uint8 | uint16 | uint32 | uint64 | uintptr
}
func getBitTagIndex[Number BitNumber, UNumber UnsignedNumber](bitBuff []Number, bitPositionIndex UNumber) (uintptr, uintptr, bool) {
sliceIndex := uintptr(bitPositionIndex) / (8 * unsafe.Sizeof(bitBuff[0]))
sliceBitIndex := uintptr(bitPositionIndex) % (8 * unsafe.Sizeof(bitBuff[0]))
//位index不能越界
if uintptr(bitPositionIndex) >= uintptr(len(bitBuff))*unsafe.Sizeof(bitBuff[0])*8 {
return 0, 0, false
}
return sliceIndex, sliceBitIndex, true
}
func setBitTagByIndex[Number BitNumber, UNumber UnsignedNumber](bitBuff []Number, bitPositionIndex UNumber, setTag bool) bool {
sliceIndex, sliceBitIndex, ret := getBitTagIndex(bitBuff, bitPositionIndex)
if ret == false {
return ret
}
if setTag {
bitBuff[sliceIndex] = bitBuff[sliceIndex] | 1<<sliceBitIndex
} else {
bitBuff[sliceIndex] = bitBuff[sliceIndex] &^ (1 << sliceBitIndex)
}
return true
}
func GetBitwiseTag[Number BitNumber, UNumber UnsignedNumber](bitBuff []Number, bitPositionIndex UNumber) (bool, error) {
sliceIndex, sliceBitIndex, ret := getBitTagIndex(bitBuff, bitPositionIndex)
if ret == false {
return false, errors.New("Invalid parameter")
}
return (bitBuff[sliceIndex] & (1 << sliceBitIndex)) > 0, nil
}
func SetBitwiseTag[Number BitNumber, UNumber UnsignedNumber](bitBuff []Number, bitPositionIndex UNumber) bool {
return setBitTagByIndex(bitBuff, bitPositionIndex, true)
}
func ClearBitwiseTag[Number BitNumber, UNumber UnsignedNumber](bitBuff []Number, bitPositionIndex UNumber) bool {
return setBitTagByIndex(bitBuff, bitPositionIndex, false)
}
func GetBitwiseNum[Number BitNumber](bitBuff []Number) int {
return len(bitBuff) * int(unsafe.Sizeof(bitBuff[0])*8)
}

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package algorithms
import "testing"
func Test_Bitwise(t *testing.T) {
//1.预分配10个byte切片用于存储位标识
byteBuff := make([]byte, 10)
//2.获取buff总共位数
bitNum := GetBitwiseNum(byteBuff)
t.Log(bitNum)
//3..对索引79位打标记注意是从0开始79即为最后一个位
idx := uint(79)
//4.对byteBuff索引idx位置打上标记
SetBitwiseTag(byteBuff, idx)
//5.获取索引idx位置标记
isTag, ret := GetBitwiseTag(byteBuff, idx)
t.Log("set index ", idx, " :", isTag, ret)
if isTag != true {
t.Fatal("error")
}
//6.清除掉索引idx位标记
ClearBitwiseTag(byteBuff, idx)
//7.获取索引idx位置标记
isTag, ret = GetBitwiseTag(byteBuff, idx)
t.Log("get index ", idx, " :", isTag, ret)
if isTag != false {
t.Fatal("error")
}
}