mng/test_buf_streams.cpp

This is an example of use of stxxl::buf_istream and stxxl::buf_ostream

/***************************************************************************
 * mng/test_buf_streams.cpp
 *
 * Part of the STXXL. See http://stxxl.sourceforge.net
 *
 * Copyright (C) 2002 Roman Dementiev <[email protected]>
 *
 * Distributed under the Boost Software License, Version 1.0.
 * (See accompanying file LICENSE_1_0.txt or copy at
 * http://www.boost.org/LICENSE_1_0.txt)
 **************************************************************************/


#include <iostream>
#include <stxxl/mng>
#include <stxxl/bits/mng/buf_ostream.h>
#include <stxxl/bits/mng/buf_istream.h>


#define BLOCK_SIZE (1024 * 512)

typedef stxxl::typed_block<BLOCK_SIZE, unsigned> block_type;
typedef stxxl::buf_ostream<block_type, stxxl::BIDArray<BLOCK_SIZE>::iterator> buf_ostream_type;
typedef stxxl::buf_istream<block_type, stxxl::BIDArray<BLOCK_SIZE>::iterator> buf_istream_type;

int main()
{
 const unsigned nblocks = 64;
 const unsigned nelements = nblocks * block_type::size;
 stxxl::BIDArray<BLOCK_SIZE> bids(nblocks);

 stxxl::block_manager * bm = stxxl::block_manager::get_instance();
 bm->new_blocks(stxxl::striping(), bids.begin(), bids.end());
 {
 buf_ostream_type out(bids.begin(), 2);
 for (unsigned i = 0; i < nelements; i++)
 out << i;
 }
 {
 buf_istream_type in(bids.begin(), bids.end(), 2);
 for (unsigned i = 0; i < nelements; i++)
 {
 unsigned value;
 in >> value;
 if (value != i)
 {
 STXXL_ERRMSG("Error at position " << std::hex << i << " (" << value << ") block " << (i / block_type::size));
 }
 }
 }
 bm->delete_blocks(bids.begin(), bids.end());
}