http://stxxl.sourceforge.net
<dementiev@mpi-sb.mpg.de>
<beckmann@cs.uni-frankfurt.de>
http://www.boost.org/LICENSE_1_0.txt
#include <limits>
#include <stxxl/priority_queue>
#include <stxxl/timer>
#define RECORD_SIZE 20
struct my_type
{
typedef int key_type;
key_type key;
char data[RECORD_SIZE - sizeof(key_type)];
my_type() { }
explicit my_type(key_type k) : key(k)
{
#ifdef STXXL_VALGRIND_AVOID_UNINITIALIZED_WRITE_ERRORS
memset(data, 0, sizeof(data));
#endif
}
};
std::ostream & operator << (std::ostream & o, const my_type & obj)
{
o << obj.key;
return o;
}
struct my_cmp : std::binary_function<my_type, my_type, bool>
{
bool operator () (const my_type & a, const my_type & b) const
{
return a.key > b.key;
}
my_type min_value() const
{
return my_type((std::numeric_limits<my_type::key_type>::max)());
}
};
int main()
{
const unsigned volume = 3 * 1024 * 1024;
const unsigned mem_for_queue = 256 * 1024 * 1024;
const unsigned mem_for_pools = 512 * 1024 * 1024;
typedef stxxl::PRIORITY_QUEUE_GENERATOR<my_type, my_cmp, mem_for_queue, volume / sizeof(my_type)> gen;
typedef gen::result pq_type;
typedef pq_type::block_type block_type;
STXXL_MSG("Block size: " << block_type::raw_size);
STXXL_MSG("AI: " << gen::AI);
STXXL_MSG("X : " << gen::X);
STXXL_MSG("N : " << gen::N);
STXXL_MSG("AE: " << gen::AE);
stxxl::timer Timer;
Timer.start();
pq_type p(mem_for_pools / 2, mem_for_pools / 2);
stxxl::int64 nelements = stxxl::int64(volume / sizeof(my_type)) * 1024, i;
STXXL_MSG("Internal memory consumption of the priority queue: " << p.mem_cons() << " B");
STXXL_MSG("Max elements: " << nelements);
for (i = 0; i < nelements; i++)
{
if ((i % (1024 * 1024)) == 0)
STXXL_MSG("Inserting element " << i);
p.push(my_type(nelements - i));
}
Timer.stop();
STXXL_MSG("Time spent for filling: " << Timer.seconds() << " s");
STXXL_MSG("Internal memory consumption of the priority queue: " << p.mem_cons() << " B");
Timer.reset();
Timer.start();
for (i = 0; i < (nelements); ++i)
{
assert(!p.empty());
assert(p.top().key == i + 1);
p.pop();
if ((i % (1024 * 1024)) == 0)
STXXL_MSG("Element " << i << " popped");
}
Timer.stop();
STXXL_MSG("Time spent for removing elements: " << Timer.seconds() << " s");
STXXL_MSG("Internal memory consumption of the priority queue: " << p.mem_cons() << " B");
}