This is an example of use of <stxxl>
files, requests, and completion tracking mechanisms, i.e. stxxl::file
, stxxl::request
/*************************************************************************** * io/test_io.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 <stxxl/io> #include <stxxl/aligned_alloc> using stxxl::file; struct my_handler { void operator () (stxxl::request * ptr) { STXXL_MSG("Request completed: " << ptr); } }; namespace stxxl { std::string hr(uint64, const char *); } int main() { std::cout << sizeof(void *) << std::endl; const int size = 1024 * 384; char * buffer = (char *)stxxl::aligned_alloc<4096>(size); memset(buffer, 0, size); #ifdef BOOST_MSVC const char * paths[2] = { "data1", "data2" }; #else const char * paths[2] = { "/var/tmp/data1", "/var/tmp/data2" }; stxxl::mmap_file file1(paths[0], file::CREAT | file::RDWR /* | file::DIRECT */, 0); file1.set_size(size * 1024); #endif stxxl::syscall_file file2(paths[1], file::CREAT | file::RDWR /* | file::DIRECT */, 1); stxxl::request_ptr req[16]; unsigned i = 0; for ( ; i < 16; i++) req[i] = file2.awrite(buffer, i * size, size, my_handler()); wait_all(req, 16); stxxl::aligned_dealloc<4096>(buffer); std::cout << *(stxxl::stats::get_instance()); stxxl::uint64 sz = 123; for (i = 0; i < 20; ++i, sz *= 10) STXXL_MSG(stxxl::hr(sz, "B")); STXXL_MSG(stxxl::hr((std::numeric_limits<stxxl::uint64>::max)(), "B")); unlink(paths[0]); unlink(paths[1]); return 0; }