You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
 
 
 
 
 

71 lines
1.9 KiB

/*
This file is part of cpp-ethereum.
cpp-ethereum 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, either version 3 of the License, or
(at your option) any later version.
cpp-ethereum 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 cpp-ethereum. If not, see <http://www.gnu.org/licenses/>.
*/
/** @file BloomFilter.cpp
* @author Vladislav Gluhovsky <vlad@ethdev.com>
* @date June 2015
*/
#include "BloomFilter.h"
using namespace std;
using namespace dev;
using namespace dev::shh;
bool BloomFilter::matches(AbridgedTopic const& _t) const
{
static unsigned const c_PerfectMatch = ~unsigned(0);
unsigned topic = AbridgedTopic::Arith(_t).convert_to<unsigned>();
unsigned matchingBits = m_filter & topic;
matchingBits |= ~topic;
return (c_PerfectMatch == matchingBits);
}
void SharedBloomFilter::add(AbridgedTopic const& _t)
{
unsigned const topic = AbridgedTopic::Arith(_t).convert_to<unsigned>();
m_filter |= topic;
unsigned nextBit = 1;
for (unsigned i = 0; i < ArrSize; ++i, nextBit <<= 1)
if (topic & nextBit)
if (m_refCounter[i] != numeric_limits<unsigned short>::max())
m_refCounter[i]++;
//else: overflow
// in order to encounter overflow, you have to set 65536 filters simultaneously.
// we assume, it will never happen.
}
void SharedBloomFilter::remove(AbridgedTopic const& _t)
{
unsigned const topic = AbridgedTopic::Arith(_t).convert_to<unsigned>();
unsigned nextBit = 1;
for (unsigned i = 0; i < ArrSize; ++i, nextBit <<= 1)
if (topic & nextBit)
{
if (m_refCounter[i])
m_refCounter[i]--;
if (!m_refCounter[i])
m_filter &= ~nextBit;
}
}