sample14.cpp

Exmaple demonstrates bitvector serialization/deserialization and set-operations on searialized BLOBs.

Exmaple demonstrates bitvector serialization/deserialization and set-operations on searialized BLOBs

See also
  bm::serializer
  bm::deserialize

/*
Copyright(c) 2002-2017 Anatoliy Kuznetsov(anatoliy_kuznetsov at yahoo.com)
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
For more information please visit: http://bitmagic.io
*/
/** \example sample14.cpp
Exmaple demonstrates bitvector serialization/deserialization and set-operations on
searialized BLOBs
\sa bm::serializer
\sa bm::deserialize
*/
/*! \file sample14.cpp
\brief Example: bvector<> set operations on serialized/compressed BLOBs
*/
#include <stdlib.h>
#include <iostream>
#include <vector>
#include "bm.h"
#include "bmserial.h"
#include "bmundef.h" /* clear the pre-proc defines from BM */
using namespace std;
const unsigned MAX_VALUE = 1000000;
static
void fill_bvector(bm::bvector<>* bv)
{
for (unsigned i = 0; i < MAX_VALUE; ++i)
{
if ((rand() % 10))
{
bv->set(i);
}
}
}
int main(void)
{
bm::operation_deserializer<bm::bvector<> > od;
try
{
bm::bvector<> bv1;
bm::bvector<> bv2;
fill_bvector(&bv1);
fill_bvector(&bv2);
cout << "bv1 count = " << bv1.count() << endl;
cout << "bv2 count = " << bv2.count() << endl;
// Prepare a serializer class
// for best performance - create serilizer once and reuse it
//
BM_DECLARE_TEMP_BLOCK(tb)
bm::serializer<bm::bvector<> > bvs(tb);
bvs.set_compression_level(4);
bm::bvector<>::statistics st1;
bm::bvector<>::statistics st2;
// compress bit-vectors and compute statistics
// (later re-used in serialization)
//
bv1.optimize(tb, bm::bvector<>::opt_compress, &st1);
bv1.optimize(tb, bm::bvector<>::opt_compress, &st2);
// declare serialization buffers
bm::serializer<bm::bvector<> >::buffer sbuf1;
bm::serializer<bm::bvector<> >::buffer sbuf2;
// perform serialization
//
bvs.serialize(bv1, sbuf1, &st1);
bvs.serialize(bv2, sbuf2, &st2);
// Serialized bvectors (sbuf1 and sbuf2) now ready to be
// saved to a database, file or send over a network.
// to simulate this we just copy content to std::vector<>
//
std::vector<unsigned char> vect1;
std::vector<unsigned char> vect2;
vect1.resize(sbuf1.size());
vect2.resize(sbuf2.size());
::memcpy(vect1.data(), sbuf1.buf(), sbuf1.size());
::memcpy(vect2.data(), sbuf2.buf(), sbuf2.size());
// Simple deserialization.
//
bm::bvector<> bv3;
// As a result of desrialization bv3 will contain all bits from
// bv1 and bv3:
// bv3 = bv1 OR bv2
bm::deserialize(bv3, sbuf1.buf());
bm::deserialize(bv3, sbuf2.buf());
bv3.optimize(tb);
// A few examples of operation deserializations
// set algebraic operation over bit-vector and a BLOB
//
bm::bvector<> bv4(bv3);
// bv4 = (bv1 OR bv2) AND bv1
// this must be equal to bv1 ?
//
od.deserialize(bv4, vect1.data(), bm::set_AND);
cout << "bv4 count = " << bv4.count() << endl;
bool eq = bv1.equal(bv4);
if (!eq)
{
cerr << "Logical error detected!" << endl;
return 1;
}
else
cout << "bv4 is equal to bv1" << endl;
bm::bvector<> bv5(bv3);
// if we need just set count, we can get it faster
// via set_COUNT_ operations
// use of COUNT operations does not materialize a target vector
//
// POPCNT((bv1 OR bv2) MINUS bv1)
auto cnt_sub =
od.deserialize(bv3, sbuf1.buf(), bm::set_COUNT_SUB_AB);
cout << "minus count = " << cnt_sub << endl;
// or we can actually perform the operation and get the full vector
// bv5 = (bv1 OR bv2) MINUS bv1
//
od.deserialize(bv5, sbuf1.buf(), tb, bm::set_SUB);
auto bv5_cnt = bv5.count();
cout << "bv5 count = " << bv5_cnt << endl;
if (cnt_sub != bv5_cnt)
{
cerr << "Logical error!" << endl;
return 1;
}
}
catch(std::exception& ex)
{
std::cerr << ex.what() << std::endl;
return 1;
}
return 0;
}
bm.h
Compressed bit-vector bvector<> container, set algebraic methods, traversal iterators.
BM_DECLARE_TEMP_BLOCK
#define BM_DECLARE_TEMP_BLOCK(x)
Definition bm.h:47
bmserial.h
Serialization / compression of bvector<>. Set theoretical operations on compressed BLOBs.
bmundef.h
pre-processor un-defines to avoid global space pollution (internal)
bm::bvector
Bitvector Bit-vector container with runtime compression of bits.
Definition bm.h:115
bm::bvector::opt_compress
@ opt_compress
compress blocks when possible (GAP/prefix sum)
Definition bm.h:137
bm::bvector::equal
bool equal(const bvector< Alloc > &bvect) const BMNOEXCEPT
Equal comparison with an agr bit-vector.
Definition bm.h:2017
bm::bvector::count
size_type count() const BMNOEXCEPT
population count (count of ON bits)
Definition bm.h:2401
bm::bvector::set
bvector< Alloc > & set(size_type n, bool val=true)
Sets bit n if val is true, clears bit n if val is false.
Definition bm.h:4188
bm::bvector::optimize
void optimize(bm::word_t *temp_block=0, optmode opt_mode=opt_compress, statistics *stat=0)
Optimize memory bitvector's memory allocation.
Definition bm.h:3635
bm::operation_deserializer
Deserializer, performs logical operations between bit-vector and serialized bit-vector.
Definition bmserial.h:927
bm::operation_deserializer::deserialize
size_type deserialize(bvector_type &bv, const unsigned char *buf, set_operation op, bool exit_on_one=false)
Deserialize bvector using buffer as set operation argument.
Definition bmserial.h:6581
bm::serializer
Bit-vector serialization class.
Definition bmserial.h:76
bm::serializer::serialize
size_type serialize(const BV &bv, unsigned char *buf, size_t buf_size)
Bitvector serialization into memory block.
Definition bmserial.h:2703
bm::set_COUNT_SUB_AB
@ set_COUNT_SUB_AB
Definition bmconst.h:178
bm::set_SUB
@ set_SUB
Definition bmconst.h:171
bm::set_AND
@ set_AND
Definition bmconst.h:169
bm::deserialize
size_t deserialize(BV &bv, const unsigned char *buf, bm::word_t *temp_block=0, const bm::bv_ref_vector< BV > *ref_vect=0)
Bitvector deserialization from a memory BLOB.
Definition bmserial.h:3137
main
int main(void)
Definition sample1.cpp:43
fill_bvector
static void fill_bvector(bm::bvector<> *bv1, bm::bvector<> *bv2)
Definition sample3.cpp:48
MAX_VALUE
const unsigned MAX_VALUE
Definition sample3.cpp:42
bm::bvector::statistics
Statistical information about bitset's memory allocation details.
Definition bm.h:125