fileperblock_file.cpp

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/***************************************************************************
 *  foxxll/io/fileperblock_file.cpp
 *
 *  Part of FOXXLL. See http://foxxll.org
 *
 *  Copyright (C) 2008, 2009 Johannes Singler <[email protected]>
 *  Copyright (C) 2008 Andreas Beckmann <[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 <cassert>
#include <cstdio>
#include <iomanip>
#include <sstream>
#include <string>

#include <tlx/counting_ptr.hpp>
#include <tlx/logger/core.hpp>
#include <tlx/unused.hpp>

#include <foxxll/common/aligned_alloc.hpp>
#include <foxxll/common/error_handling.hpp>
#include <foxxll/common/exceptions.hpp>
#include <foxxll/config.hpp>
#include <foxxll/io/disk_queued_file.hpp>
#include <foxxll/io/file.hpp>
#include <foxxll/io/fileperblock_file.hpp>
#include <foxxll/io/mmap_file.hpp>
#include <foxxll/io/request.hpp>
#include <foxxll/io/serving_request.hpp>
#include <foxxll/io/syscall_file.hpp>
#include <foxxll/io/ufs_platform.hpp>
#include <foxxll/io/wincall_file.hpp>

namespace foxxll {

template <class base_file_type>
fileperblock_file<base_file_type>::fileperblock_file(
    const std::string& filename_prefix,
    int mode,
    int queue_id,
    int allocator_id,
    unsigned int device_id)
    : file(device_id),
      disk_queued_file(queue_id, allocator_id),
      filename_prefix_(filename_prefix),
      mode_(mode),
      current_size_(0)
{ }

template <class base_file_type>
fileperblock_file<base_file_type>::~fileperblock_file()
{
    if (lock_file_)
        lock_file_->close_remove();
}

template <class base_file_type>
std::string fileperblock_file<base_file_type>::filename_for_block(offset_type offset)
{
    std::ostringstream name;
    //enough for 1 billion blocks
    name << filename_prefix_ << "_fpb_" << std::setw(20) << std::setfill('0') << offset;
    return name.str();
}

template <class base_file_type>
void fileperblock_file<base_file_type>::serve(
    void* buffer, offset_type offset,
    size_type bytes, request::read_or_write op)
{
    base_file_type base_file(filename_for_block(offset), mode_, get_queue_id(),
                             NO_ALLOCATOR, DEFAULT_DEVICE_ID, file_stats_);
    base_file.set_size(bytes);
    base_file.serve(buffer, 0, bytes, op);
}

template <class base_file_type>
void fileperblock_file<base_file_type>::lock()
{
    if (!lock_file_)
    {
        lock_file_ = tlx::make_counting<base_file_type>(
                filename_prefix_ + "_fpb_lock", mode_, get_queue_id()
            );

        //create lock file and fill it with one page, an empty file cannot be locked
        const int page_size = BlockAlignment;
        void* one_page = aligned_alloc<BlockAlignment>(page_size);
#if FOXXLL_WITH_VALGRIND
        memset(one_page, 0, page_size);
#endif
        lock_file_->set_size(page_size);
        request_ptr r = lock_file_->awrite(one_page, 0, page_size);
        r->wait();
        aligned_dealloc<BlockAlignment>(one_page);
    }
    lock_file_->lock();
}

template <class base_file_type>
void fileperblock_file<base_file_type>::discard(offset_type offset, offset_type length)
{
    tlx::unused(length);
#ifdef FOXXLL_FILEPERBLOCK_NO_DELETE
    if (::truncate(filename_for_block(offset).c_str(), 0) != 0)
        TLX_LOG1 << "truncate() error on path=" << filename_for_block(offset)
                 << " error=" << strerror(errno);
#else
    if (::remove(filename_for_block(offset).c_str()) != 0)
        TLX_LOG1 << "remove() error on path=" << filename_for_block(offset)
                 << " error=" << strerror(errno);
#endif

    TLX_LOG << "discard " << offset << " + " << length;
}

template <class base_file_type>
void fileperblock_file<base_file_type>::export_files(offset_type offset, offset_type length, std::string filename)
{
    std::string original(filename_for_block(offset));
    filename.insert(0, original.substr(0, original.find_last_of("/") + 1));
    if (::remove(filename.c_str()) != 0)
        TLX_LOG1 << "remove() error on path=" << filename
                 << " error=" << strerror(errno);

    if (::rename(original.c_str(), filename.c_str()) != 0)
        TLX_LOG1 << "rename() error on path=" << filename
                 << " to=" << original << " error=" << strerror(errno);

#if !FOXXLL_WINDOWS
    //TODO: implement on Windows
    if (::truncate(filename.c_str(), as_signed(length)) != 0) {
        FOXXLL_THROW_ERRNO(io_error, "Error doing truncate()");
    }
#else
    tlx::unused(length);
#endif
}

template <class base_file_type>
const char* fileperblock_file<base_file_type>::io_type() const
{
    return "fileperblock";
}

////////////////////////////////////////////////////////////////////////////

template class fileperblock_file<syscall_file>;

#if FOXXLL_HAVE_MMAP_FILE
template class fileperblock_file<mmap_file>;
#endif

#if FOXXLL_HAVE_WINCALL_FILE
template class fileperblock_file<wincall_file>;
#endif

} // namespace foxxll

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