mirror of
https://github.com/zeek/zeek.git
synced 2025-10-02 14:48:21 +00:00
58 lines
1.2 KiB
C++
58 lines
1.2 KiB
C++
// A simple but fast data structure for sets of integers.
|
|
// Only supported operations are insert, remove and membership test.
|
|
//
|
|
// It's implemented via a bitmap so the memory usage increases linearly
|
|
// with max(set).
|
|
|
|
#pragma once
|
|
|
|
#include <cstring>
|
|
|
|
namespace zeek::detail {
|
|
|
|
class IntSet {
|
|
public:
|
|
// n is a hint for the value of the largest integer.
|
|
explicit IntSet(unsigned int n = 1);
|
|
~IntSet();
|
|
|
|
void Insert(unsigned int i);
|
|
void Remove(unsigned int i);
|
|
bool Contains(unsigned int i) const;
|
|
|
|
void Clear();
|
|
|
|
private:
|
|
void Expand(unsigned int i);
|
|
|
|
unsigned int size;
|
|
unsigned char* set;
|
|
};
|
|
|
|
inline IntSet::IntSet(unsigned int n) {
|
|
size = n / 8 + 1;
|
|
set = new unsigned char[size];
|
|
memset(set, 0, size);
|
|
}
|
|
|
|
inline IntSet::~IntSet() { delete[] set; }
|
|
|
|
inline void IntSet::Insert(unsigned int i) {
|
|
if ( i / 8 >= size )
|
|
Expand(i);
|
|
|
|
set[i / 8] |= (1 << (i % 8));
|
|
}
|
|
|
|
inline void IntSet::Remove(unsigned int i) {
|
|
if ( i / 8 >= size )
|
|
Expand(i);
|
|
else
|
|
set[i / 8] &= ~(1 << (i % 8));
|
|
}
|
|
|
|
inline bool IntSet::Contains(unsigned int i) const { return i / 8 < size ? set[i / 8] & (1 << (i % 8)) : false; }
|
|
|
|
inline void IntSet::Clear() { memset(set, 0, size); }
|
|
|
|
} // namespace zeek::detail
|