create_file.cpp

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/***************************************************************************
 * lib/io/create_file.cpp
 *
 * Part of the STXXL. See http://stxxl.sourceforge.net
 *
 * Copyright (C) 2002 Roman Dementiev <[email protected]>
 * Copyright (C) 2008, 2010 Andreas Beckmann <[email protected]>
 * Copyright (C) 2008, 2009 Johannes Singler <[email protected]>
 * Copyright (C) 2013 Timo Bingmann <[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/bits/common/error_handling.h>
#include <stxxl/bits/common/exceptions.h>
#include <stxxl/bits/io/create_file.h>
#include <stxxl/bits/io/io.h>
#include <stxxl/bits/mng/config.h>

#include <ostream>
#include <stdexcept>


STXXL_BEGIN_NAMESPACE

file * create_file(const std::string& io_impl,
 const std::string& filename,
 int options, int physical_device_id, int disk_allocator_id)
{
 // construct temporary disk_config structure
 disk_config cfg(filename, 0, io_impl);
 cfg.queue = physical_device_id;
 cfg.direct =
 (options& file::REQUIRE_DIRECT) ? disk_config::DIRECT_ON :
 (options& file::DIRECT) ? disk_config::DIRECT_TRY :
 disk_config::DIRECT_OFF;

 return create_file(cfg, options, disk_allocator_id);
}

file * create_file(disk_config& cfg, int mode, int disk_allocator_id)
{
 // apply disk_config settings to open mode

 mode &= ~(file::DIRECT | file::REQUIRE_DIRECT); // clear DIRECT and REQUIRE_DIRECT

 switch (cfg.direct) {
 case disk_config::DIRECT_OFF:
 break;
 case disk_config::DIRECT_TRY:
 mode |= file::DIRECT;
 break;
 case disk_config::DIRECT_ON:
 mode |= file::DIRECT | file::REQUIRE_DIRECT;
 break;
 }

 // *** Select fileio Implementation

 if (cfg.io_impl == "syscall")
 {
 ufs_file_base* result =
 new syscall_file(cfg.path, mode, cfg.queue, disk_allocator_id);
 result->lock();

 // if marked as device but file is not -> throw!
 if (cfg.raw_device && !result->is_device())
 {
 delete result;
 STXXL_THROW(io_error, "Disk " << cfg.path << " was expected to be raw block device, but it is a normal file!");
 }

 // if is raw_device -> get size and remove some flags.
 if (result->is_device())
 {
 // if device
 cfg.raw_device = true;
 cfg.size = result->size();
 cfg.autogrow = cfg.delete_on_exit = cfg.unlink_on_open = false;
 }

 if (cfg.unlink_on_open)
 result->unlink();

 return result;
 }
 else if (cfg.io_impl == "fileperblock_syscall")
 {
 fileperblock_file<syscall_file>* result =
 new fileperblock_file<syscall_file>(cfg.path, mode, cfg.queue, disk_allocator_id);
 result->lock();
 return result;
 }
 else if (cfg.io_impl == "memory")
 {
 mem_file* result = new mem_file(cfg.queue, disk_allocator_id);
 result->lock();
 return result;
 }
#if STXXL_HAVE_MMAP_FILE
 else if (cfg.io_impl == "mmap")
 {
 ufs_file_base* result =
 new mmap_file(cfg.path, mode, cfg.queue, disk_allocator_id);
 result->lock();

 if (cfg.unlink_on_open)
 result->unlink();

 return result;
 }
 else if (cfg.io_impl == "fileperblock_mmap")
 {
 fileperblock_file<mmap_file>* result =
 new fileperblock_file<mmap_file>(cfg.path, mode, cfg.queue, disk_allocator_id);
 result->lock();
 return result;
 }
#endif
#if STXXL_HAVE_SIMDISK_FILE
 else if (cfg.io_impl == "simdisk")
 {
 mode &= ~(file::DIRECT | file::REQUIRE_DIRECT); // clear the DIRECT flag, this file is supposed to be on tmpfs
 ufs_file_base* result =
 new sim_disk_file(cfg.path, mode, cfg.queue, disk_allocator_id);
 result->lock();
 return result;
 }
#endif
#if STXXL_HAVE_WINCALL_FILE
 else if (cfg.io_impl == "wincall")
 {
 wfs_file_base* result =
 new wincall_file(cfg.path, mode, cfg.queue, disk_allocator_id);
 result->lock();
 return result;
 }
 else if (cfg.io_impl == "fileperblock_wincall")
 {
 fileperblock_file<wincall_file>* result =
 new fileperblock_file<wincall_file>(cfg.path, mode, cfg.queue, disk_allocator_id);
 result->lock();
 return result;
 }
#endif
#if STXXL_HAVE_BOOSTFD_FILE
 else if (cfg.io_impl == "boostfd")
 {
 boostfd_file* result =
 new boostfd_file(cfg.path, mode, cfg.queue, disk_allocator_id);
 result->lock();
 return result;
 }
 else if (cfg.io_impl == "fileperblock_boostfd")
 {
 fileperblock_file<boostfd_file>* result =
 new fileperblock_file<boostfd_file>(cfg.path, mode, cfg.queue, disk_allocator_id);
 result->lock();
 return result;
 }
#endif
#if STXXL_HAVE_WBTL_FILE
 else if (cfg.io_impl == "wbtl")
 {
 ufs_file_base* backend =
 new syscall_file(cfg.path, mode, -1, -1); // FIXME: ID
 wbtl_file* result =
 new stxxl::wbtl_file(backend, 16 * 1024 * 1024, 2, cfg.queue, disk_allocator_id);
 result->lock();

 if (cfg.unlink_on_open)
 backend->unlink();

 return result;
 }
#endif

 STXXL_THROW(std::runtime_error,
 "Unsupported disk I/O implementation '" << cfg.io_impl << "'.");
}

STXXL_END_NAMESPACE
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