refactor(common): 重构 bitset 和 log 包
- 移除了 github.com/scylladb/termtables 依赖 - 修改了 bitset 包，移除了未使用的代码和测试 - 修改了 log 包，移除了未使用的代码和测试 - 更新了 go.work 文件，添加了 bitset 和 log 包
This commit is contained in:
963
common/serialize/bitset/bitset32.go
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963
common/serialize/bitset/bitset32.go
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@@ -0,0 +1,963 @@
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/*
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Package bitset implements bitsets, a mapping
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between non-negative integers and boolean values. It should be more
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efficient than map[uint] bool.
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It provides methods for setting, clearing, flipping, and testing
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individual integers.
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But it also provides set intersection, union, difference,
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complement, and symmetric operations, as well as tests to
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check whether any, all, or no bits are set, and querying a
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bitset's current length and number of positive bits.
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BitSets are expanded to the size of the largest set bit; the
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memory allocation is approximately Max bits, where Max is
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the largest set bit. BitSets are never shrunk. On creation,
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a hint can be given for the number of bits that will be used.
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Many of the methods, including Set,Clear, and Flip, return
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a BitSet pointer, which allows for chaining.
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Example use:
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import "bitset"
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var b BitSet
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b.Set(10).Set(11)
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if b.Test(1000) {
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b.Clear(1000)
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}
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if B.Intersection(bitset.New(100).Set(10)).Count() > 1 {
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fmt.Println("Intersection works.")
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}
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As an alternative to BitSets, one should check out the 'big' package,
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which provides a (less set-theoretical) view of bitsets.
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*/
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package bitset32
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import (
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"bufio"
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"bytes"
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"encoding/binary"
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"errors"
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"fmt"
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"io"
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"math/bits"
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"strconv"
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)
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// the wordSize of a bit set
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const wordSize = uint(32)
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// log2WordSize is lg(wordSize)
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const log2WordSize = uint(5)
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// allBits has every bit set
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const allBits uint32 = 0xffffffff
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// TODO BUGFIX
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// default binary BigEndian
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var binaryOrder binary.ByteOrder = binary.BigEndian
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// A BitSet is a set of bits. The zero value of a BitSet is an empty set of length 0.
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type BitSet32 struct {
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length uint
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set []uint32
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}
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// Error is used to distinguish errors (panics) generated in this package.
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type Error string
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// safeSet will fixup b.set to be non-nil and return the field value
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func (b *BitSet32) safeSet() []uint32 {
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if b.set == nil {
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b.set = make([]uint32, wordsNeeded(0))
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}
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return b.set
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}
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// SetBitsetFrom fills the bitset with an array of integers without creating a new BitSet instance
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func (b *BitSet32) SetBitsetFrom(buf []uint32) {
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b.length = uint(len(buf)) * 32
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b.set = buf
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}
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// From is a constructor used to create a BitSet from an array of integers
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func From(buf []uint32) *BitSet32 {
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return FromWithLength(uint(len(buf))*32, buf)
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}
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// FromWithLength constructs from an array of integers and length.
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func FromWithLength(len uint, set []uint32) *BitSet32 {
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return &BitSet32{len, set}
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}
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// Bytes returns the bitset as array of integers
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func (b *BitSet32) Bytes() []uint32 {
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return b.set
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}
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// wordsNeeded calculates the number of words needed for i bits
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func wordsNeeded(i uint) int {
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if i > (Cap() - wordSize + 1) {
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return int(Cap() >> log2WordSize)
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}
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return int((i + (wordSize - 1)) >> log2WordSize)
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}
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// wordsNeededUnbound calculates the number of words needed for i bits, possibly exceeding the capacity.
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// This function is useful if you know that the capacity cannot be exceeded (e.g., you have an existing bitmap).
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func wordsNeededUnbound(i uint) int {
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return int((i + (wordSize - 1)) >> log2WordSize)
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}
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// wordsIndex calculates the index of words in a `uint64`
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func wordsIndex(i uint) uint {
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return i & (wordSize - 1)
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}
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// New creates a new BitSet with a hint that length bits will be required
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func New(length uint) (bset *BitSet32) {
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defer func() {
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if r := recover(); r != nil {
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bset = &BitSet32{
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0,
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make([]uint32, 0),
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}
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}
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}()
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bset = &BitSet32{
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length,
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make([]uint32, wordsNeeded(length)),
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}
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return bset
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}
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// Cap returns the total possible capacity, or number of bits
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func Cap() uint {
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return ^uint(0)
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}
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// Len returns the number of bits in the BitSet.
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// Note the difference to method Count, see example.
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func (b *BitSet32) Len() uint {
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return b.length
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}
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// extendSet adds additional words to incorporate new bits if needed
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func (b *BitSet32) extendSet(i uint) {
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if i >= Cap() {
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panic("You are exceeding the capacity")
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}
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nsize := wordsNeeded(i + 1)
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if b.set == nil {
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b.set = make([]uint32, nsize)
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} else if cap(b.set) >= nsize {
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b.set = b.set[:nsize] // fast resize
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} else if len(b.set) < nsize {
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newset := make([]uint32, nsize, 2*nsize) // increase capacity 2x
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copy(newset, b.set)
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b.set = newset
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}
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b.length = i + 1
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}
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// Test whether bit i is set.
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func (b *BitSet32) Test(i uint) bool {
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if i >= b.length {
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return false
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}
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return b.set[i>>log2WordSize]&(1<<wordsIndex(i)) != 0
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}
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// Set bit i to 1, the capacity of the bitset is automatically
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// increased accordingly.
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// If i>= Cap(), this function will panic.
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// Warning: using a very large value for 'i'
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// may lead to a memory shortage and a panic: the caller is responsible
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// for providing sensible parameters in line with their memory capacity.
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func (b *BitSet32) Set(i uint) *BitSet32 {
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if i >= b.length { // if we need more bits, make 'em
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b.extendSet(i)
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}
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b.set[i>>log2WordSize] |= 1 << wordsIndex(i)
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return b
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}
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// Clear bit i to 0
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func (b *BitSet32) Clear(i uint) *BitSet32 {
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if i >= b.length {
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return b
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}
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b.set[i>>log2WordSize] &^= 1 << wordsIndex(i)
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return b
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}
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// SetTo sets bit i to value.
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// If i>= Cap(), this function will panic.
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// Warning: using a very large value for 'i'
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// may lead to a memory shortage and a panic: the caller is responsible
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// for providing sensible parameters in line with their memory capacity.
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func (b *BitSet32) SetTo(i uint, value bool) *BitSet32 {
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if value {
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return b.Set(i)
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}
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return b.Clear(i)
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}
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// Flip bit at i.
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// If i>= Cap(), this function will panic.
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// Warning: using a very large value for 'i'
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// may lead to a memory shortage and a panic: the caller is responsible
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// for providing sensible parameters in line with their memory capacity.
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func (b *BitSet32) Flip(i uint) *BitSet32 {
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if i >= b.length {
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return b.Set(i)
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}
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b.set[i>>log2WordSize] ^= 1 << wordsIndex(i)
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return b
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}
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// FlipRange bit in [start, end).
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// If end>= Cap(), this function will panic.
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// Warning: using a very large value for 'end'
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// may lead to a memory shortage and a panic: the caller is responsible
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// for providing sensible parameters in line with their memory capacity.
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func (b *BitSet32) FlipRange(start, end uint) *BitSet32 {
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if start >= end {
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return b
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}
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if end-1 >= b.length { // if we need more bits, make 'em
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b.extendSet(end - 1)
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}
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var startWord uint = start >> log2WordSize
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var endWord uint = end >> log2WordSize
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b.set[startWord] ^= ^(^uint32(0) << wordsIndex(start))
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for i := startWord; i < endWord; i++ {
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b.set[i] = ^b.set[i]
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}
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if end&(wordSize-1) != 0 {
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b.set[endWord] ^= ^uint32(0) >> wordsIndex(-end)
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}
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return b
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}
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// Shrink shrinks BitSet so that the provided value is the last possible
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// set value. It clears all bits > the provided index and reduces the size
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// and length of the set.
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//
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// Note that the parameter value is not the new length in bits: it is the
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// maximal value that can be stored in the bitset after the function call.
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// The new length in bits is the parameter value + 1. Thus it is not possible
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// to use this function to set the length to 0, the minimal value of the length
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// after this function call is 1.
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//
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// A new slice is allocated to store the new bits, so you may see an increase in
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// memory usage until the GC runs. Normally this should not be a problem, but if you
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// have an extremely large BitSet its important to understand that the old BitSet will
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// remain in memory until the GC frees it.
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func (b *BitSet32) Shrink(lastbitindex uint) *BitSet32 {
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length := lastbitindex + 1
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idx := wordsNeeded(length)
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if idx > len(b.set) {
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return b
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}
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shrunk := make([]uint32, idx)
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copy(shrunk, b.set[:idx])
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b.set = shrunk
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b.length = length
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lastWordUsedBits := length % 32
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if lastWordUsedBits != 0 {
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b.set[idx-1] &= allBits >> uint32(32-wordsIndex(lastWordUsedBits))
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}
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return b
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}
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// Compact shrinks BitSet to so that we preserve all set bits, while minimizing
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// memory usage. Compact calls Shrink.
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func (b *BitSet32) Compact() *BitSet32 {
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idx := len(b.set) - 1
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for ; idx >= 0 && b.set[idx] == 0; idx-- {
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}
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newlength := uint((idx + 1) << log2WordSize)
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if newlength >= b.length {
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return b // nothing to do
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}
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if newlength > 0 {
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return b.Shrink(newlength - 1)
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}
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// TODO: FIX
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// We preserve one word
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return b.Shrink(31)
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}
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// InsertAt takes an index which indicates where a bit should be
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// inserted. Then it shifts all the bits in the set to the left by 1, starting
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// from the given index position, and sets the index position to 0.
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//
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// Depending on the size of your BitSet, and where you are inserting the new entry,
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// this method could be extremely slow and in some cases might cause the entire BitSet
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// to be recopied.
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func (b *BitSet32) InsertAt(idx uint) *BitSet32 {
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insertAtElement := idx >> log2WordSize
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// if length of set is a multiple of wordSize we need to allocate more space first
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if b.isLenExactMultiple() {
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b.set = append(b.set, uint32(0))
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}
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var i uint
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for i = uint(len(b.set) - 1); i > insertAtElement; i-- {
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// all elements above the position where we want to insert can simply by shifted
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b.set[i] <<= 1
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// we take the most significant bit of the previous element and set it as
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// the least significant bit of the current element
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// TODO: FIX
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b.set[i] |= (b.set[i-1] & 0x80000000) >> 31
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}
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// generate a mask to extract the data that we need to shift left
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// within the element where we insert a bit
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dataMask := uint32(1)<<uint32(wordsIndex(idx)) - 1
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// extract that data that we'll shift
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data := b.set[i] & (^dataMask)
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// set the positions of the data mask to 0 in the element where we insert
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b.set[i] &= dataMask
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// shift data mask to the left and insert its data to the slice element
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b.set[i] |= data << 1
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// add 1 to length of BitSet
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b.length++
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return b
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}
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// String creates a string representation of the Bitmap
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func (b *BitSet32) String() string {
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// follows code from https://github.com/RoaringBitmap/roaring
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var buffer bytes.Buffer
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start := []byte("{")
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buffer.Write(start)
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counter := 0
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i, e := b.NextSet(0)
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for e {
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counter = counter + 1
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// to avoid exhausting the memory
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if counter > 0x40000 {
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buffer.WriteString("...")
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break
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}
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buffer.WriteString(strconv.FormatInt(int64(i), 10))
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i, e = b.NextSet(i + 1)
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if e {
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buffer.WriteString(",")
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}
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}
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buffer.WriteString("}")
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return buffer.String()
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}
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// DeleteAt deletes the bit at the given index position from
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// within the bitset
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// All the bits residing on the left of the deleted bit get
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// shifted right by 1
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// The running time of this operation may potentially be
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// relatively slow, O(length)
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func (b *BitSet32) DeleteAt(i uint) *BitSet32 {
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// the index of the slice element where we'll delete a bit
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deleteAtElement := i >> log2WordSize
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// generate a mask for the data that needs to be shifted right
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// within that slice element that gets modified
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dataMask := ^((uint32(1) << wordsIndex(i)) - 1)
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// extract the data that we'll shift right from the slice element
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data := b.set[deleteAtElement] & dataMask
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// set the masked area to 0 while leaving the rest as it is
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b.set[deleteAtElement] &= ^dataMask
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// shift the previously extracted data to the right and then
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// set it in the previously masked area
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b.set[deleteAtElement] |= (data >> 1) & dataMask
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// loop over all the consecutive slice elements to copy each
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// lowest bit into the highest position of the previous element,
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// then shift the entire content to the right by 1
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for i := int(deleteAtElement) + 1; i < len(b.set); i++ {
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b.set[i-1] |= (b.set[i] & 1) << 31
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b.set[i] >>= 1
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}
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b.length = b.length - 1
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return b
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}
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// NextSet returns the next bit set from the specified index,
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// including possibly the current index
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// along with an error code (true = valid, false = no set bit found)
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// for i,e := v.NextSet(0); e; i,e = v.NextSet(i + 1) {...}
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//
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// Users concerned with performance may want to use NextSetMany to
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// retrieve several values at once.
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func (b *BitSet32) NextSet(i uint) (uint, bool) {
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x := int(i >> log2WordSize)
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if x >= len(b.set) {
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return 0, false
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}
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w := b.set[x]
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w = w >> wordsIndex(i)
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if w != 0 {
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return i + uint(bits.TrailingZeros32(w)), true
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}
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x = x + 1
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for x < len(b.set) {
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if b.set[x] != 0 {
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return uint(x)*wordSize + uint(bits.TrailingZeros32(b.set[x])), true
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}
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x = x + 1
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}
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return 0, false
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}
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// NextSetMany returns many next bit sets from the specified index,
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// including possibly the current index and up to cap(buffer).
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// If the returned slice has len zero, then no more set bits were found
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//
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// buffer := make([]uint, 256) // this should be reused
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// j := uint(0)
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// j, buffer = bitmap.NextSetMany(j, buffer)
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// for ; len(buffer) > 0; j, buffer = bitmap.NextSetMany(j,buffer) {
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// for k := range buffer {
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// do something with buffer[k]
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// }
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// j += 1
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// }
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//
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// It is possible to retrieve all set bits as follow:
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//
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// indices := make([]uint, bitmap.Count())
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// bitmap.NextSetMany(0, indices)
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//
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// However if bitmap.Count() is large, it might be preferable to
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// use several calls to NextSetMany, for performance reasons.
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func (b *BitSet32) NextSetMany(i uint, buffer []uint) (uint, []uint) {
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myanswer := buffer
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capacity := cap(buffer)
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x := int(i >> log2WordSize)
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if x >= len(b.set) || capacity == 0 {
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return 0, myanswer[:0]
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}
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skip := wordsIndex(i)
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word := b.set[x] >> skip
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myanswer = myanswer[:capacity]
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size := int(0)
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for word != 0 {
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r := uint(bits.TrailingZeros32(word))
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t := word & ((^word) + 1)
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myanswer[size] = r + i
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size++
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if size == capacity {
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goto End
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}
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word = word ^ t
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}
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x++
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||||
for idx, word := range b.set[x:] {
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for word != 0 {
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||||
r := uint(bits.TrailingZeros32(word))
|
||||
t := word & ((^word) + 1)
|
||||
myanswer[size] = r + (uint(x+idx) << 6)
|
||||
size++
|
||||
if size == capacity {
|
||||
goto End
|
||||
}
|
||||
word = word ^ t
|
||||
}
|
||||
}
|
||||
End:
|
||||
if size > 0 {
|
||||
return myanswer[size-1], myanswer[:size]
|
||||
}
|
||||
return 0, myanswer[:0]
|
||||
}
|
||||
|
||||
// NextClear returns the next clear bit from the specified index,
|
||||
// including possibly the current index
|
||||
// along with an error code (true = valid, false = no bit found i.e. all bits are set)
|
||||
func (b *BitSet32) NextClear(i uint) (uint, bool) {
|
||||
x := int(i >> log2WordSize)
|
||||
if x >= len(b.set) {
|
||||
return 0, false
|
||||
}
|
||||
w := b.set[x]
|
||||
w = w >> wordsIndex(i)
|
||||
wA := allBits >> wordsIndex(i)
|
||||
index := i + uint(bits.TrailingZeros32(^w))
|
||||
if w != wA && index < b.length {
|
||||
return index, true
|
||||
}
|
||||
x++
|
||||
for x < len(b.set) {
|
||||
index = uint(x)*wordSize + uint(bits.TrailingZeros32(^b.set[x]))
|
||||
if b.set[x] != allBits && index < b.length {
|
||||
return index, true
|
||||
}
|
||||
x++
|
||||
}
|
||||
return 0, false
|
||||
}
|
||||
|
||||
// ClearAll clears the entire BitSet
|
||||
func (b *BitSet32) ClearAll() *BitSet32 {
|
||||
if b != nil && b.set != nil {
|
||||
for i := range b.set {
|
||||
b.set[i] = 0
|
||||
}
|
||||
}
|
||||
return b
|
||||
}
|
||||
|
||||
// wordCount returns the number of words used in a bit set
|
||||
func (b *BitSet32) wordCount() int {
|
||||
return wordsNeededUnbound(b.length)
|
||||
}
|
||||
|
||||
// Clone this BitSet
|
||||
func (b *BitSet32) Clone() *BitSet32 {
|
||||
c := New(b.length)
|
||||
if b.set != nil { // Clone should not modify current object
|
||||
copy(c.set, b.set)
|
||||
}
|
||||
return c
|
||||
}
|
||||
|
||||
// Copy into a destination BitSet using the Go array copy semantics:
|
||||
// the number of bits copied is the minimum of the number of bits in the current
|
||||
// BitSet (Len()) and the destination Bitset.
|
||||
// We return the number of bits copied in the destination BitSet.
|
||||
func (b *BitSet32) Copy(c *BitSet32) (count uint) {
|
||||
if c == nil {
|
||||
return
|
||||
}
|
||||
if b.set != nil { // Copy should not modify current object
|
||||
copy(c.set, b.set)
|
||||
}
|
||||
count = c.length
|
||||
if b.length < c.length {
|
||||
count = b.length
|
||||
}
|
||||
// Cleaning the last word is needed to keep the invariant that other functions, such as Count, require
|
||||
// that any bits in the last word that would exceed the length of the bitmask are set to 0.
|
||||
c.cleanLastWord()
|
||||
return
|
||||
}
|
||||
|
||||
// CopyFull copies into a destination BitSet such that the destination is
|
||||
// identical to the source after the operation, allocating memory if necessary.
|
||||
func (b *BitSet32) CopyFull(c *BitSet32) {
|
||||
if c == nil {
|
||||
return
|
||||
}
|
||||
c.length = b.length
|
||||
if len(b.set) == 0 {
|
||||
if c.set != nil {
|
||||
c.set = c.set[:0]
|
||||
}
|
||||
} else {
|
||||
if cap(c.set) < len(b.set) {
|
||||
c.set = make([]uint32, len(b.set))
|
||||
} else {
|
||||
c.set = c.set[:len(b.set)]
|
||||
}
|
||||
copy(c.set, b.set)
|
||||
}
|
||||
}
|
||||
|
||||
// Count (number of set bits).
|
||||
// Also known as "popcount" or "population count".
|
||||
func (b *BitSet32) Count() uint {
|
||||
if b != nil && b.set != nil {
|
||||
return uint(popcntSlice(b.set))
|
||||
}
|
||||
return 0
|
||||
}
|
||||
|
||||
// Equal tests the equivalence of two BitSets.
|
||||
// False if they are of different sizes, otherwise true
|
||||
// only if all the same bits are set
|
||||
func (b *BitSet32) Equal(c *BitSet32) bool {
|
||||
if c == nil || b == nil {
|
||||
return c == b
|
||||
}
|
||||
if b.length != c.length {
|
||||
return false
|
||||
}
|
||||
if b.length == 0 { // if they have both length == 0, then could have nil set
|
||||
return true
|
||||
}
|
||||
wn := b.wordCount()
|
||||
for p := 0; p < wn; p++ {
|
||||
if c.set[p] != b.set[p] {
|
||||
return false
|
||||
}
|
||||
}
|
||||
return true
|
||||
}
|
||||
|
||||
func panicIfNull(b *BitSet32) {
|
||||
if b == nil {
|
||||
panic(Error("BitSet must not be null"))
|
||||
}
|
||||
}
|
||||
|
||||
// Difference of base set and other set
|
||||
// This is the BitSet equivalent of &^ (and not)
|
||||
func (b *BitSet32) Difference(compare *BitSet32) (result *BitSet32) {
|
||||
panicIfNull(b)
|
||||
panicIfNull(compare)
|
||||
result = b.Clone() // clone b (in case b is bigger than compare)
|
||||
l := int(compare.wordCount())
|
||||
if l > int(b.wordCount()) {
|
||||
l = int(b.wordCount())
|
||||
}
|
||||
for i := 0; i < l; i++ {
|
||||
result.set[i] = b.set[i] &^ compare.set[i]
|
||||
}
|
||||
return
|
||||
}
|
||||
|
||||
// DifferenceCardinality computes the cardinality of the differnce
|
||||
func (b *BitSet32) DifferenceCardinality(compare *BitSet32) uint {
|
||||
panicIfNull(b)
|
||||
panicIfNull(compare)
|
||||
l := int(compare.wordCount())
|
||||
if l > int(b.wordCount()) {
|
||||
l = int(b.wordCount())
|
||||
}
|
||||
cnt := uint64(0)
|
||||
cnt += popcntMaskSlice(b.set[:l], compare.set[:l])
|
||||
cnt += popcntSlice(b.set[l:])
|
||||
return uint(cnt)
|
||||
}
|
||||
|
||||
// InPlaceDifference computes the difference of base set and other set
|
||||
// This is the BitSet equivalent of &^ (and not)
|
||||
func (b *BitSet32) InPlaceDifference(compare *BitSet32) {
|
||||
panicIfNull(b)
|
||||
panicIfNull(compare)
|
||||
l := int(compare.wordCount())
|
||||
if l > int(b.wordCount()) {
|
||||
l = int(b.wordCount())
|
||||
}
|
||||
for i := 0; i < l; i++ {
|
||||
b.set[i] &^= compare.set[i]
|
||||
}
|
||||
}
|
||||
|
||||
// Convenience function: return two bitsets ordered by
|
||||
// increasing length. Note: neither can be nil
|
||||
func sortByLength(a *BitSet32, b *BitSet32) (ap *BitSet32, bp *BitSet32) {
|
||||
if a.length <= b.length {
|
||||
ap, bp = a, b
|
||||
} else {
|
||||
ap, bp = b, a
|
||||
}
|
||||
return
|
||||
}
|
||||
|
||||
// Intersection of base set and other set
|
||||
// This is the BitSet equivalent of & (and)
|
||||
func (b *BitSet32) Intersection(compare *BitSet32) (result *BitSet32) {
|
||||
panicIfNull(b)
|
||||
panicIfNull(compare)
|
||||
b, compare = sortByLength(b, compare)
|
||||
result = New(b.length)
|
||||
for i, word := range b.set {
|
||||
result.set[i] = word & compare.set[i]
|
||||
}
|
||||
return
|
||||
}
|
||||
|
||||
// IntersectionCardinality computes the cardinality of the union
|
||||
func (b *BitSet32) IntersectionCardinality(compare *BitSet32) uint {
|
||||
panicIfNull(b)
|
||||
panicIfNull(compare)
|
||||
b, compare = sortByLength(b, compare)
|
||||
cnt := popcntAndSlice(b.set, compare.set)
|
||||
return uint(cnt)
|
||||
}
|
||||
|
||||
// InPlaceIntersection destructively computes the intersection of
|
||||
// base set and the compare set.
|
||||
// This is the BitSet equivalent of & (and)
|
||||
func (b *BitSet32) InPlaceIntersection(compare *BitSet32) {
|
||||
panicIfNull(b)
|
||||
panicIfNull(compare)
|
||||
l := int(compare.wordCount())
|
||||
if l > int(b.wordCount()) {
|
||||
l = int(b.wordCount())
|
||||
}
|
||||
for i := 0; i < l; i++ {
|
||||
b.set[i] &= compare.set[i]
|
||||
}
|
||||
for i := l; i < len(b.set); i++ {
|
||||
b.set[i] = 0
|
||||
}
|
||||
if compare.length > 0 {
|
||||
if compare.length-1 >= b.length {
|
||||
b.extendSet(compare.length - 1)
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
// Union of base set and other set
|
||||
// This is the BitSet equivalent of | (or)
|
||||
func (b *BitSet32) Union(compare *BitSet32) (result *BitSet32) {
|
||||
panicIfNull(b)
|
||||
panicIfNull(compare)
|
||||
b, compare = sortByLength(b, compare)
|
||||
result = compare.Clone()
|
||||
for i, word := range b.set {
|
||||
result.set[i] = word | compare.set[i]
|
||||
}
|
||||
return
|
||||
}
|
||||
|
||||
// UnionCardinality computes the cardinality of the uniton of the base set
|
||||
// and the compare set.
|
||||
func (b *BitSet32) UnionCardinality(compare *BitSet32) uint {
|
||||
panicIfNull(b)
|
||||
panicIfNull(compare)
|
||||
b, compare = sortByLength(b, compare)
|
||||
cnt := popcntOrSlice(b.set, compare.set)
|
||||
if len(compare.set) > len(b.set) {
|
||||
cnt += popcntSlice(compare.set[len(b.set):])
|
||||
}
|
||||
return uint(cnt)
|
||||
}
|
||||
|
||||
// InPlaceUnion creates the destructive union of base set and compare set.
|
||||
// This is the BitSet equivalent of | (or).
|
||||
func (b *BitSet32) InPlaceUnion(compare *BitSet32) {
|
||||
panicIfNull(b)
|
||||
panicIfNull(compare)
|
||||
l := int(compare.wordCount())
|
||||
if l > int(b.wordCount()) {
|
||||
l = int(b.wordCount())
|
||||
}
|
||||
if compare.length > 0 && compare.length-1 >= b.length {
|
||||
b.extendSet(compare.length - 1)
|
||||
}
|
||||
for i := 0; i < l; i++ {
|
||||
b.set[i] |= compare.set[i]
|
||||
}
|
||||
if len(compare.set) > l {
|
||||
for i := l; i < len(compare.set); i++ {
|
||||
b.set[i] = compare.set[i]
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
// SymmetricDifference of base set and other set
|
||||
// This is the BitSet equivalent of ^ (xor)
|
||||
func (b *BitSet32) SymmetricDifference(compare *BitSet32) (result *BitSet32) {
|
||||
panicIfNull(b)
|
||||
panicIfNull(compare)
|
||||
b, compare = sortByLength(b, compare)
|
||||
// compare is bigger, so clone it
|
||||
result = compare.Clone()
|
||||
for i, word := range b.set {
|
||||
result.set[i] = word ^ compare.set[i]
|
||||
}
|
||||
return
|
||||
}
|
||||
|
||||
// SymmetricDifferenceCardinality computes the cardinality of the symmetric difference
|
||||
func (b *BitSet32) SymmetricDifferenceCardinality(compare *BitSet32) uint {
|
||||
panicIfNull(b)
|
||||
panicIfNull(compare)
|
||||
b, compare = sortByLength(b, compare)
|
||||
cnt := popcntXorSlice(b.set, compare.set)
|
||||
if len(compare.set) > len(b.set) {
|
||||
cnt += popcntSlice(compare.set[len(b.set):])
|
||||
}
|
||||
return uint(cnt)
|
||||
}
|
||||
|
||||
// InPlaceSymmetricDifference creates the destructive SymmetricDifference of base set and other set
|
||||
// This is the BitSet equivalent of ^ (xor)
|
||||
func (b *BitSet32) InPlaceSymmetricDifference(compare *BitSet32) {
|
||||
panicIfNull(b)
|
||||
panicIfNull(compare)
|
||||
l := int(compare.wordCount())
|
||||
if l > int(b.wordCount()) {
|
||||
l = int(b.wordCount())
|
||||
}
|
||||
if compare.length > 0 && compare.length-1 >= b.length {
|
||||
b.extendSet(compare.length - 1)
|
||||
}
|
||||
for i := 0; i < l; i++ {
|
||||
b.set[i] ^= compare.set[i]
|
||||
}
|
||||
if len(compare.set) > l {
|
||||
for i := l; i < len(compare.set); i++ {
|
||||
b.set[i] = compare.set[i]
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
// Is the length an exact multiple of word sizes?
|
||||
func (b *BitSet32) isLenExactMultiple() bool {
|
||||
return wordsIndex(b.length) == 0
|
||||
}
|
||||
|
||||
// Clean last word by setting unused bits to 0
|
||||
func (b *BitSet32) cleanLastWord() {
|
||||
if !b.isLenExactMultiple() {
|
||||
b.set[len(b.set)-1] &= allBits >> (wordSize - wordsIndex(b.length))
|
||||
}
|
||||
}
|
||||
|
||||
// Complement computes the (local) complement of a bitset (up to length bits)
|
||||
func (b *BitSet32) Complement() (result *BitSet32) {
|
||||
panicIfNull(b)
|
||||
result = New(b.length)
|
||||
for i, word := range b.set {
|
||||
result.set[i] = ^word
|
||||
}
|
||||
result.cleanLastWord()
|
||||
return
|
||||
}
|
||||
|
||||
// All returns true if all bits are set, false otherwise. Returns true for
|
||||
// empty sets.
|
||||
func (b *BitSet32) All() bool {
|
||||
panicIfNull(b)
|
||||
return b.Count() == b.length
|
||||
}
|
||||
|
||||
// None returns true if no bit is set, false otherwise. Returns true for
|
||||
// empty sets.
|
||||
func (b *BitSet32) None() bool {
|
||||
panicIfNull(b)
|
||||
if b != nil && b.set != nil {
|
||||
for _, word := range b.set {
|
||||
if word > 0 {
|
||||
return false
|
||||
}
|
||||
}
|
||||
}
|
||||
return true
|
||||
}
|
||||
|
||||
// Any returns true if any bit is set, false otherwise
|
||||
func (b *BitSet32) Any() bool {
|
||||
panicIfNull(b)
|
||||
return !b.None()
|
||||
}
|
||||
|
||||
// IsSuperSet returns true if this is a superset of the other set
|
||||
func (b *BitSet32) IsSuperSet(other *BitSet32) bool {
|
||||
for i, e := other.NextSet(0); e; i, e = other.NextSet(i + 1) {
|
||||
if !b.Test(i) {
|
||||
return false
|
||||
}
|
||||
}
|
||||
return true
|
||||
}
|
||||
|
||||
// IsStrictSuperSet returns true if this is a strict superset of the other set
|
||||
func (b *BitSet32) IsStrictSuperSet(other *BitSet32) bool {
|
||||
return b.Count() > other.Count() && b.IsSuperSet(other)
|
||||
}
|
||||
|
||||
// DumpAsBits dumps a bit set as a string of bits
|
||||
func (b *BitSet32) DumpAsBits() string {
|
||||
if b.set == nil {
|
||||
return "."
|
||||
}
|
||||
buffer := bytes.NewBufferString("")
|
||||
i := len(b.set) - 1
|
||||
for ; i >= 0; i-- {
|
||||
fmt.Fprintf(buffer, "%064b.", b.set[i])
|
||||
}
|
||||
return buffer.String()
|
||||
}
|
||||
|
||||
// BinaryStorageSize returns the binary storage requirements
|
||||
func (b *BitSet32) BinaryStorageSize() int {
|
||||
nWords := b.wordCount()
|
||||
return binary.Size(uint64(0)) + binary.Size(b.set[:nWords])
|
||||
}
|
||||
|
||||
// WriteTo writes a BitSet to a stream
|
||||
func (b *BitSet32) WriteTo(stream io.Writer) (int64, error) {
|
||||
length := uint64(b.length)
|
||||
|
||||
// Write length
|
||||
err := binary.Write(stream, binaryOrder, length)
|
||||
if err != nil {
|
||||
return 0, err
|
||||
}
|
||||
|
||||
// Write set
|
||||
// current implementation of bufio.Writer is more memory efficient than
|
||||
// binary.Write for large set
|
||||
writer := bufio.NewWriter(stream)
|
||||
var item = make([]byte, binary.Size(uint32(0))) // for serializing one uint32
|
||||
nWords := b.wordCount()
|
||||
for i := range b.set[:nWords] {
|
||||
binaryOrder.PutUint32(item, b.set[i])
|
||||
if nn, err := writer.Write(item); err != nil {
|
||||
return int64(i*binary.Size(uint32(0)) + nn), err
|
||||
}
|
||||
}
|
||||
|
||||
err = writer.Flush()
|
||||
return int64(b.BinaryStorageSize()), err
|
||||
}
|
||||
|
||||
// ReadFrom reads a BitSet from a stream written using WriteTo
|
||||
func (b *BitSet32) ReadFrom(stream io.Reader) (int64, error) {
|
||||
var length uint64
|
||||
|
||||
// Read length first
|
||||
err := binary.Read(stream, binaryOrder, &length)
|
||||
if err != nil {
|
||||
if err == io.EOF {
|
||||
err = io.ErrUnexpectedEOF
|
||||
}
|
||||
return 0, err
|
||||
}
|
||||
newset := New(uint(length))
|
||||
|
||||
if uint64(newset.length) != length {
|
||||
return 0, errors.New("unmarshalling error: type mismatch")
|
||||
}
|
||||
|
||||
var item [4]byte
|
||||
nWords := wordsNeeded(uint(length))
|
||||
reader := bufio.NewReader(io.LimitReader(stream, 4*int64(nWords)))
|
||||
for i := 0; i < nWords; i++ {
|
||||
if _, err := io.ReadFull(reader, item[:]); err != nil {
|
||||
if err == io.EOF {
|
||||
err = io.ErrUnexpectedEOF
|
||||
}
|
||||
return 0, err
|
||||
}
|
||||
newset.set[i] = binaryOrder.Uint32(item[:])
|
||||
}
|
||||
|
||||
*b = *newset
|
||||
return int64(b.BinaryStorageSize()), nil
|
||||
}
|
||||
Reference in New Issue
Block a user