154 lines
3.3 KiB
C++

/*
Copyright (c) 2010, 2013 Oracle and/or its affiliates. All rights reserved.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; version 2 of the License.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifndef NDB_SPARSE_BITMASK_H
#define NDB_SPARSE_BITMASK_H
#include <ndb_global.h>
#include <util/Vector.hpp>
#include <util/BaseString.hpp>
class SparseBitmask {
unsigned m_max_size;
Vector<unsigned> m_vec;
public:
STATIC_CONST( NotFound = (unsigned)-1 );
SparseBitmask(unsigned max_size = NotFound - 1) : m_max_size(max_size) {}
unsigned max_size() const { return m_max_size; }
/* Set bit n */
void set(unsigned n) {
assert(n <= m_max_size);
unsigned i = m_vec.size();
while (i > 0)
{
const unsigned j = m_vec[i-1];
if (n == j)
return; // Bit n already set
if (j < n)
break;
i--;
}
m_vec.push(n, i);
}
/* Get bit n */
bool get(unsigned n) const {
assert(n <= m_max_size);
for (unsigned i = 0; i < m_vec.size(); i++)
{
const unsigned j = m_vec[i];
if (j < n)
continue;
return (j == n);
}
return false;
}
/* Clear bit n */
int clear(unsigned n) {
assert(n <= m_max_size);
for (unsigned i = 0; i < m_vec.size(); i++)
{
const unsigned j = m_vec[i];
if (j != n)
continue;
m_vec.erase(i);
return 1;
}
return 0;
}
/* Clear all bits */
void clear(void) {
m_vec.clear();
}
/* Find first bit >= n */
unsigned find(unsigned n) const {
for (unsigned i = 0; i < m_vec.size(); i++)
{
const unsigned j = m_vec[i];
if (j >= n)
return j;
}
return NotFound;
}
/* Number of bits set */
unsigned count() const { return m_vec.size(); }
bool isclear() const { return count() == 0; }
unsigned getBitNo(unsigned n) const {
assert(n < m_vec.size());
return m_vec[n];
}
void print(void) const {
for (unsigned i = 0; i < m_vec.size(); i++)
{
const unsigned j = m_vec[i];
printf("[%u]: %u\n", i, j);
}
}
bool equal(const SparseBitmask& obj) const {
if (obj.count() != count())
return false;
for (unsigned i = 0; i<count(); i++)
if (!obj.get(m_vec[i]))
return false;
return true;
}
bool overlaps(const SparseBitmask& obj) const {
for (unsigned i = 0; i<count(); i++)
if (obj.get(m_vec[i]))
return true;
for (unsigned i = 0; i<obj.count(); i++)
if (get(obj.getBitNo(i)))
return true;
return false;
}
BaseString str() const {
BaseString tmp;
const char* sep="";
for (unsigned i = 0; i<m_vec.size(); i++)
{
tmp.appfmt("%s%u", sep, m_vec[i]);
sep=",";
}
return tmp;
}
};
#endif