BitMagic-C++
sample18.cpp
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1 /*
2 Copyright(c) 2002-2017 Anatoliy Kuznetsov(anatoliy_kuznetsov at yahoo.com)
3 
4 Licensed under the Apache License, Version 2.0 (the "License");
5 you may not use this file except in compliance with the License.
6 You may obtain a copy of the License at
7 
8  http://www.apache.org/licenses/LICENSE-2.0
9 
10 Unless required by applicable law or agreed to in writing, software
11 distributed under the License is distributed on an "AS IS" BASIS,
12 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 See the License for the specific language governing permissions and
14 limitations under the License.
15 
16 For more information please visit: http://bitmagic.io
17 */
18 
19 /** \example sample18.cpp
20  Example of bulk insert iterator
21  \sa bm::bvector::insert_iterator
22  \sa bm::bvector::bulk_insert_iterator
23 
24 */
25 
26 /*! \file sample18.cpp
27  \brief Example: bulk insert iterator
28 
29  Bulk insert iterator uses internal buffer to accumulate a batch
30  of bit indexes and flush it faster.
31  This delay makes its behavior different from classic
32  deterministic STL iterators.
33 */
34 
35 #include <stdlib.h>
36 #include <iostream>
37 
38 #include "bm.h"
39 
40 using namespace std;
41 
42 int main(void)
43 {
44  try
45  {
46  bm::bvector<> bv;
47 
48  // use regular insert iterator to add bits to vector
50  for (unsigned i = 5; i != 0; --i)
51  {
52  iit = i;
53  cout << bv.count() << ", "; // note that bits are added immediately
54  }
55  cout << endl;
56 
57  bv.clear(); // clear the vector
58 
59  // bulk insert adds bits faster (on sorted data), but provides no guarantee
60  // that it happens immediately. Instead it uses an internal buffer to accumulate it first
61  // and periodically flushes it into the bit-vector.
62  //
63  {
65  for (bm::bvector<>::size_type i = 5; i != 0; --i)
66  {
67  bulk_iit = i;
68  cout << bv.count() << ", "; // note that bits are NOT added immediately
69  }
70  cout << endl;
71  } // <= scope is a point when data flush happens (on destruction)
72  cout << bv.count() << endl; // now all bits are added
73 
74  bv.clear();
75 
76  // bulk content flash can be forced, before going out-of-scope
77  // which may be problematic due to possible exceptions from the destructor.
78  //
79  {
81  for (bm::bvector<>::size_type i = 0; i < 5; ++i)
82  bulk_iit = i;
83  cout << bv.count() << endl; // not added yet
84  bulk_iit.flush(); // force bulk iterator to submit the data
85  cout << bv.count() << endl; // now added!
86  }
87 
88  }
89  catch(std::exception& ex)
90  {
91  std::cerr << ex.what() << std::endl;
92  return 1;
93  }
94 
95  return 0;
96 }
97 
98 
bm::bvector::count
size_type count() const
population cout (count of ON bits)
Definition: bm.h:2487
bm::bvector::insert_iterator
Output iterator iterator designed to set "ON" bits based on input sequence of integers (bit indeces).
Definition: bm.h:369
main
int main(void)
Definition: sample18.cpp:42
bm::bvector<>
bm::bvector::clear
void clear(const size_type *ids, size_type ids_size, bm::sort_order so=bm::BM_UNKNOWN)
clear list of bits in this bitset
Definition: bm.h:3504
bm::bvector::inserter
insert_iterator inserter()
Definition: bm.h:1647
bm::bvector::bulk_insert_iterator::flush
void flush()
Definition: bm.h:554
bm::bvector::bulk_insert_iterator
Output iterator iterator designed to set "ON" bits based on input sequence of integers.
Definition: bm.h:453
bm::bvector::size_type
bm::id_t size_type
Definition: bm.h:117
bm.h
Compressed bit-vector bvector<> container, set algebraic methods, traversal iterators.