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#ifndef BLOOMFILTERWINDOW_H
#define BLOOMFILTERWINDOW_H 1
#include "Bloom.h"
#include "BloomFilter.h"
#include "Common/HashFunction.h"
#include "Common/Kmer.h"
#include "Common/IOUtil.h"
#include <algorithm>
#include <vector>
#include <iostream>
/**
* A bloom filter that represents a window
* within a larger bloom filter.
*/
class BloomFilterWindow : public Konnector::BloomFilter
{
public:
/** Constructor. */
BloomFilterWindow() : Konnector::BloomFilter() { };
/** Constructor.
*
* @param fullBloomSize size in bits of the containing bloom filter
* @param startBitPos index of first bit in the window
* @param endBitPos index of last bit in the window
*/
BloomFilterWindow(size_t fullBloomSize, size_t startBitPos,
size_t endBitPos, size_t hashSeed=0) :
Konnector::BloomFilter(endBitPos - startBitPos + 1, hashSeed),
m_fullBloomSize(fullBloomSize),
m_startBitPos(startBitPos),
m_endBitPos(endBitPos)
{
assert(startBitPos < fullBloomSize);
assert(endBitPos < fullBloomSize);
assert(startBitPos <= endBitPos);
}
/**
* Get the full size (in bits) of the bloom filter that
* this window is a part of.
*/
size_t fullBloomSize()
{
return m_fullBloomSize;
}
/** Get the start bit position for the window. */
size_t startBitPos()
{
return m_startBitPos;
}
/** Get the end bit position for the window. */
size_t endBitPos()
{
return m_endBitPos;
}
/** Return the size of the bit array. */
size_t size() const
{
return Konnector::BloomFilter::size();
}
/** Return the number of elements with count >= max_count. */
size_t popcount() const
{
return Konnector::BloomFilter::popcount();
}
/** Return the estimated false positive rate */
double FPR() const
{
return Konnector::BloomFilter::FPR();
}
/** Return whether the specified bit is set. */
bool operator[](size_t i) const
{
if (i >= m_startBitPos && i <= m_endBitPos)
return Konnector::BloomFilter::operator[](i - m_startBitPos);
return false;
}
/** Return whether the object is present in this set. */
bool operator[](const Bloom::key_type& key) const
{
return (*this)[Bloom::hash(key, m_hashSeed) % m_fullBloomSize];
}
/** Add the object with the specified index to this set. */
void insert(size_t i)
{
if (i >= m_startBitPos && i <= m_endBitPos)
Konnector::BloomFilter::insert(i - m_startBitPos);
}
/** Add the object to this set. */
void insert(const Bloom::key_type& key)
{
insert(Bloom::hash(key, m_hashSeed) % m_fullBloomSize);
}
/** Operator for reading a bloom filter from a stream. */
friend std::istream& operator>>(std::istream& in, BloomFilterWindow& o)
{
o.read(in, BITWISE_OVERWRITE);
return in;
}
/** Operator for writing the bloom filter to a stream. */
friend std::ostream& operator<<(std::ostream& out, const BloomFilterWindow& o)
{
o.write(out);
return out;
}
/** Read a bloom filter window from a stream. */
void read(std::istream& in, BitwiseOp readOp = BITWISE_OVERWRITE)
{
Bloom::FileHeader header = Bloom::readHeader(in);
assert(in);
m_fullBloomSize = header.fullBloomSize;
m_startBitPos = header.startBitPos;
m_endBitPos = header.endBitPos;
if (m_hashSeed != header.hashSeed) {
if (readOp == BITWISE_OVERWRITE) {
m_hashSeed = header.hashSeed;
} else {
std::cerr << "error: can't union/intersect bloom filters with "
<< "different hash seed values\n";
exit(EXIT_FAILURE);
}
}
size_t bits = header.endBitPos - header.startBitPos + 1;
if (m_size != bits) {
if (readOp == BITWISE_OVERWRITE) {
Konnector::BloomFilter::resize(bits);
} else {
std::cerr << "error: can't union/intersect bloom filters with "
<< "different sizes\n";
exit(EXIT_FAILURE);
}
}
readBits(in, m_array, bits, 0, readOp);
assert(in);
}
/** Write a bloom filter window to a stream. */
void write(std::ostream& out) const
{
Bloom::FileHeader header;
header.fullBloomSize = m_fullBloomSize;
header.startBitPos = m_startBitPos;
header.endBitPos = m_endBitPos;
header.hashSeed = m_hashSeed;
Bloom::writeHeader(out, header);
assert(out);
size_t windowSize = m_endBitPos - m_startBitPos + 1;
out.write(m_array, (windowSize + 7)/8);
assert(out);
}
private:
size_t m_fullBloomSize;
size_t m_startBitPos, m_endBitPos;
};
#endif
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