BitUtil (Lucene 8.9.0 API)乐学网一站式学习平台

java.lang.Object
- org.apache.lucene.util.BitUtil

```
public final class BitUtil
extends Object
```
A variety of high efficiency bit twiddling routines.

NOTE: This API is for internal purposes only and might change in incompatible ways in the next release.

Method Summary

All Methods Static Methods Concrete Methods
Modifier and Type	Method and Description
`static long`	`deinterleave(long b)` Extract just the even-bits value as a long from the bit-interleaved value
`static long`	`flipFlop(long b)` flip flops odd with even bits
`static long`	`interleave(int even, int odd)` Interleaves the first 32 bits of each long value Adapted from: http://graphics.stanford.edu/~seander/bithacks.html#InterleaveBMN
`static int`	`nextHighestPowerOfTwo(int v)` returns the next highest power of two, or the current value if it's already a power of two or zero
`static long`	`nextHighestPowerOfTwo(long v)` returns the next highest power of two, or the current value if it's already a power of two or zero
`static long`	`pop_andnot(long[] arr1, long[] arr2, int wordOffset, int numWords)` Returns the popcount or cardinality of `A & ~B`.
`static long`	`pop_array(long[] arr, int wordOffset, int numWords)` Returns the number of set bits in an array of longs.
`static long`	`pop_intersect(long[] arr1, long[] arr2, int wordOffset, int numWords)` Returns the popcount or cardinality of the two sets after an intersection.
`static long`	`pop_union(long[] arr1, long[] arr2, int wordOffset, int numWords)` Returns the popcount or cardinality of the union of two sets.
`static long`	`pop_xor(long[] arr1, long[] arr2, int wordOffset, int numWords)` Returns the popcount or cardinality of A ^ B Neither array is modified.
`static int`	`zigZagDecode(int i)` Decode an int previously encoded with `zigZagEncode(int)`.
`static long`	`zigZagDecode(long l)` Decode a long previously encoded with `zigZagEncode(long)`.
`static int`	`zigZagEncode(int i)` Same as `zigZagEncode(long)` but on integers.
`static long`	`zigZagEncode(long l)` Zig-zag encode the provided long.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Method Detail
  - pop_array
```
public static long pop_array(long[] arr,
                             int wordOffset,
                             int numWords)
```
    Returns the number of set bits in an array of longs.
  - pop_intersect
```
public static long pop_intersect(long[] arr1,
                                 long[] arr2,
                                 int wordOffset,
                                 int numWords)
```
    Returns the popcount or cardinality of the two sets after an intersection. Neither array is modified.
  - pop_union
```
public static long pop_union(long[] arr1,
                             long[] arr2,
                             int wordOffset,
                             int numWords)
```
    Returns the popcount or cardinality of the union of two sets. Neither array is modified.
  - pop_andnot
```
public static long pop_andnot(long[] arr1,
                              long[] arr2,
                              int wordOffset,
                              int numWords)
```
    Returns the popcount or cardinality of A & ~B. Neither array is modified.
  - pop_xor
```
public static long pop_xor(long[] arr1,
                           long[] arr2,
                           int wordOffset,
                           int numWords)
```
    Returns the popcount or cardinality of A ^ B Neither array is modified.
  - nextHighestPowerOfTwo
```
public static int nextHighestPowerOfTwo(int v)
```
    returns the next highest power of two, or the current value if it's already a power of two or zero
  - nextHighestPowerOfTwo
```
public static long nextHighestPowerOfTwo(long v)
```
    returns the next highest power of two, or the current value if it's already a power of two or zero
  - interleave
```
public static long interleave(int even,
                              int odd)
```
    Interleaves the first 32 bits of each long value Adapted from: http://graphics.stanford.edu/~seander/bithacks.html#InterleaveBMN
  - deinterleave
```
public static long deinterleave(long b)
```
    Extract just the even-bits value as a long from the bit-interleaved value
  - flipFlop
```
public static long flipFlop(long b)
```
    flip flops odd with even bits
  - zigZagEncode
```
public static int zigZagEncode(int i)
```
    Same as zigZagEncode(long) but on integers.
  - zigZagEncode
```
public static long zigZagEncode(long l)
```
    Zig-zag encode the provided long. Assuming the input is a signed long whose absolute value can be stored on n bits, the returned value will be an unsigned long that can be stored on n+1 bits.
  - zigZagDecode
```
public static int zigZagDecode(int i)
```
    Decode an int previously encoded with zigZagEncode(int).
  - zigZagDecode
```
public static long zigZagDecode(long l)
```
    Decode a long previously encoded with zigZagEncode(long).

Class BitUtil

Method Summary

Methods inherited from class java.lang.Object

Method Detail

pop_array

pop_intersect

pop_union

pop_andnot

pop_xor

nextHighestPowerOfTwo

nextHighestPowerOfTwo

interleave

deinterleave

flipFlop

zigZagEncode

zigZagEncode

zigZagDecode

zigZagDecode