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premiere-libtorrent/src/file.cpp

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/*
Copyright (c) 2003, Arvid Norberg
All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:
* Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
* Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in
the documentation and/or other materials provided with the distribution.
* Neither the name of the author nor the names of its
contributors may be used to endorse or promote products derived
from this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
POSSIBILITY OF SUCH DAMAGE.
*/
#include "libtorrent/pch.hpp"
#include "libtorrent/config.hpp"
#include "libtorrent/alloca.hpp"
#include <boost/scoped_ptr.hpp>
#ifdef TORRENT_WINDOWS
// windows part
#include "libtorrent/utf8.hpp"
#include <windows.h>
#include <winioctl.h>
#else
// posix part
#define _FILE_OFFSET_BITS 64
#include <unistd.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/statvfs.h>
#include <errno.h>
#include <boost/static_assert.hpp>
// make sure the _FILE_OFFSET_BITS define worked
// on this platform. It's supposed to make file
// related functions support 64-bit offsets.
// this test makes sure lseed() returns a type
// at least 64 bits wide
BOOST_STATIC_ASSERT(sizeof(lseek(0, 0, 0)) >= 8);
#endif
#include <boost/filesystem/operations.hpp>
#include "libtorrent/file.hpp"
#include <cstring>
#include <vector>
// for convert_to_wstring and convert_to_native
#include "libtorrent/escape_string.hpp"
#include "libtorrent/assert.hpp"
#ifdef TORRENT_DEBUG
BOOST_STATIC_ASSERT((libtorrent::file::rw_mask & libtorrent::file::no_buffer) == 0);
BOOST_STATIC_ASSERT((libtorrent::file::rw_mask & libtorrent::file::attribute_mask) == 0);
BOOST_STATIC_ASSERT((libtorrent::file::no_buffer & libtorrent::file::attribute_mask) == 0);
#endif
namespace libtorrent
{
namespace fs = boost::filesystem;
file::file()
#ifdef TORRENT_WINDOWS
: m_file_handle(INVALID_HANDLE_VALUE)
#else
: m_fd(-1)
#endif
, m_open_mode(0)
#if defined TORRENT_WINDOWS || defined TORRENT_LINUX
, m_sector_size(0)
#endif
{}
file::file(fs::path const& path, int mode, error_code& ec)
#ifdef TORRENT_WINDOWS
: m_file_handle(INVALID_HANDLE_VALUE)
#else
: m_fd(-1)
#endif
, m_open_mode(0)
{
open(path, mode, ec);
}
file::~file()
{
close();
}
bool file::open(fs::path const& path, int mode, error_code& ec)
{
close();
#ifdef TORRENT_WINDOWS
struct open_mode_t
{
DWORD rw_mode;
DWORD share_mode;
DWORD create_mode;
DWORD flags;
};
const static open_mode_t mode_array[] =
{
// read_only
{GENERIC_READ, FILE_SHARE_READ, OPEN_EXISTING, FILE_FLAG_RANDOM_ACCESS},
// write_only
{GENERIC_WRITE, FILE_SHARE_READ, OPEN_ALWAYS, FILE_FLAG_RANDOM_ACCESS},
// read_write
{GENERIC_WRITE | GENERIC_READ, FILE_SHARE_READ, OPEN_ALWAYS, FILE_FLAG_RANDOM_ACCESS},
// invalid option
{0,0,0,0},
// read_only no_buffer
{GENERIC_READ, FILE_SHARE_READ, OPEN_EXISTING, FILE_FLAG_RANDOM_ACCESS | FILE_FLAG_OVERLAPPED | FILE_FLAG_NO_BUFFERING },
// write_only no_buffer
{GENERIC_WRITE, FILE_SHARE_READ | FILE_SHARE_WRITE, OPEN_ALWAYS, FILE_FLAG_RANDOM_ACCESS | FILE_FLAG_OVERLAPPED | FILE_FLAG_NO_BUFFERING },
// read_write no_buffer
{GENERIC_WRITE | GENERIC_READ, FILE_SHARE_READ | FILE_SHARE_WRITE, OPEN_ALWAYS, FILE_FLAG_RANDOM_ACCESS | FILE_FLAG_OVERLAPPED | FILE_FLAG_NO_BUFFERING },
// invalid option
{0,0,0,0}
};
const static DWORD attrib_array[] =
{
FILE_ATTRIBUTE_NORMAL, // no attrib
FILE_ATTRIBUTE_HIDDEN, // hidden
FILE_ATTRIBUTE_NORMAL, // executable
FILE_ATTRIBUTE_HIDDEN, // hidden + executable
};
#if TORRENT_USE_WPATH
m_path = convert_to_wstring(path.external_file_string());
#else
m_path = convert_to_native(path.external_file_string());
#endif
TORRENT_ASSERT((mode & mode_mask) < sizeof(mode_array)/sizeof(mode_array[0]));
open_mode_t const& m = mode_array[mode & mode_mask];
DWORD a = attrib_array[(mode & attribute_mask) >> 12];
m_file_handle = CreateFile(m_path.c_str(), m.rw_mode, m.share_mode, 0
, m.create_mode, m.flags | (a ? a : FILE_ATTRIBUTE_NORMAL), 0);
if (m_file_handle == INVALID_HANDLE_VALUE)
{
ec = error_code(GetLastError(), get_system_category());
return false;
}
// try to make the file sparse if supported
if (mode & file::sparse)
{
DWORD temp;
::DeviceIoControl(m_file_handle, FSCTL_SET_SPARSE, 0, 0
, 0, 0, &temp, 0);
}
#else
// rely on default umask to filter x and w permissions
// for group and others
int permissions = S_IRUSR | S_IWUSR
| S_IRGRP | S_IWGRP
| S_IROTH | S_IWOTH;
if (mode & attribute_executable)
permissions |= S_IXGRP | S_IXOTH | S_IXUSR;
static const int mode_array[] = {O_RDONLY, O_WRONLY | O_CREAT, O_RDWR | O_CREAT};
#ifdef O_DIRECT
static const int no_buffer_flag[] = {0, O_DIRECT};
#else
static const int no_buffer_flag[] = {0, 0};
#endif
m_fd = ::open(convert_to_native(path.external_file_string()).c_str()
, mode_array[mode & rw_mask] | no_buffer_flag[(mode & no_buffer) >> 2], permissions);
#ifdef TORRENT_LINUX
// workaround for linux bug
// https://bugs.launchpad.net/ubuntu/+source/linux/+bug/269946
if (m_fd == -1 && (mode & no_buffer) && errno == EINVAL)
{
mode &= ~no_buffer;
m_fd = ::open(path.external_file_string().c_str()
, mode & (rw_mask | no_buffer), permissions);
}
#endif
if (m_fd == -1)
{
ec = error_code(errno, get_posix_category());
TORRENT_ASSERT(ec);
return false;
}
#ifdef F_NOCACHE
if (mode & no_buffer)
{
int yes = 1;
fcntl(m_fd, F_NOCACHE, &yes);
}
#endif
#ifdef POSIX_FADV_RANDOM
// disable read-ahead
posix_fadvise(m_fd, 0, 0, POSIX_FADV_RANDOM);
#endif
#endif
m_open_mode = mode;
TORRENT_ASSERT(is_open());
return true;
}
bool file::is_open() const
{
#ifdef TORRENT_WINDOWS
return m_file_handle != INVALID_HANDLE_VALUE;
#else
return m_fd != -1;
#endif
}
int file::pos_alignment() const
{
// on linux and windows, file offsets needs
// to be aligned to the disk sector size
#if defined TORRENT_LINUX
if (m_sector_size == 0)
{
struct statvfs fs;
if (fstatvfs(m_fd, &fs) == 0)
m_sector_size = fs.f_bsize;
else
m_sector_size = 4096;
}
return m_sector_size;
#elif defined TORRENT_WINDOWS
if (m_sector_size == 0)
{
DWORD sectors_per_cluster;
DWORD bytes_per_sector;
DWORD free_clusters;
DWORD total_clusters;
#if TORRENT_USE_WPATH
wchar_t backslash = L'\\';
#else
char backslash = '\\';
#endif
if (GetDiskFreeSpace(m_path.substr(0, m_path.find_first_of(backslash)+1).c_str()
, &sectors_per_cluster, &bytes_per_sector
, &free_clusters, &total_clusters))
m_sector_size = bytes_per_sector;
else
m_sector_size = 4096;
}
return m_sector_size;
#else
return 1;
#endif
}
int file::buf_alignment() const
{
#if defined TORRENT_WINDOWS
init_file();
return m_page_size;
#else
return pos_alignment();
#endif
}
int file::size_alignment() const
{
#if defined TORRENT_WINDOWS
init_file();
return m_page_size;
#else
return pos_alignment();
#endif
}
void file::close()
{
#if defined TORRENT_WINDOWS || defined TORRENT_LINUX
m_sector_size = 0;
#endif
#ifdef TORRENT_WINDOWS
if (m_file_handle == INVALID_HANDLE_VALUE) return;
CloseHandle(m_file_handle);
m_file_handle = INVALID_HANDLE_VALUE;
m_path.clear();
#else
if (m_fd == -1) return;
::close(m_fd);
m_fd = -1;
#endif
m_open_mode = 0;
}
// defined in storage.cpp
int bufs_size(file::iovec_t const* bufs, int num_bufs);
#if defined TORRENT_WINDOWS || defined TORRENT_LINUX || defined TORRENT_DEBUG
int file::m_page_size = 0;
void file::init_file()
{
if (m_page_size != 0) return;
#ifdef TORRENT_WINDOWS
SYSTEM_INFO si;
GetSystemInfo(&si);
m_page_size = si.dwPageSize;
#else
m_page_size = sysconf(_SC_PAGESIZE);
#endif
}
#endif
size_type file::readv(size_type file_offset, iovec_t const* bufs, int num_bufs, error_code& ec)
{
TORRENT_ASSERT((m_open_mode & rw_mask) == read_only || (m_open_mode & rw_mask) == read_write);
TORRENT_ASSERT(bufs);
TORRENT_ASSERT(num_bufs > 0);
TORRENT_ASSERT(is_open());
#if defined TORRENT_WINDOWS || defined TORRENT_LINUX || defined TORRENT_DEBUG
// make sure m_page_size is initialized
init_file();
#endif
#ifdef TORRENT_DEBUG
if (m_open_mode & no_buffer)
{
bool eof = false;
int size = 0;
// when opened in no_buffer mode, the file_offset must
// be aligned to pos_alignment()
TORRENT_ASSERT((file_offset & (pos_alignment()-1)) == 0);
for (file::iovec_t const* i = bufs, *end(bufs + num_bufs); i < end; ++i)
{
TORRENT_ASSERT((uintptr_t(i->iov_base) & (buf_alignment()-1)) == 0);
// every buffer must be a multiple of the page size
// except for the last one
TORRENT_ASSERT((i->iov_len & (size_alignment()-1)) == 0 || i == end-1);
if ((i->iov_len & (size_alignment()-1)) != 0) eof = true;
size += i->iov_len;
}
error_code code;
if (eof) TORRENT_ASSERT(file_offset + size >= get_size(code));
}
#endif
#ifdef TORRENT_WINDOWS
DWORD ret = 0;
// since the ReadFileScatter requires the file to be opened
// with no buffering, and no buffering requires page aligned
// buffers, open the file in non-buffered mode in case the
// buffer is not aligned. Most of the times the buffer should
// be aligned though
if ((m_open_mode & no_buffer) == 0)
{
// this means the buffer base or the buffer size is not aligned
// to the page size. Use a regular file for this operation.
LARGE_INTEGER offs;
offs.QuadPart = file_offset;
if (SetFilePointerEx(m_file_handle, offs, &offs, FILE_BEGIN) == FALSE)
{
ec = error_code(GetLastError(), get_system_category());
return -1;
}
for (file::iovec_t const* i = bufs, *end(bufs + num_bufs); i < end; ++i)
{
DWORD intermediate = 0;
if (ReadFile(m_file_handle, (char*)i->iov_base
, (DWORD)i->iov_len, &intermediate, 0) == FALSE)
{
ec = error_code(GetLastError(), get_system_category());
return -1;
}
ret += intermediate;
}
return ret;
}
int size = bufs_size(bufs, num_bufs);
// number of pages for the read. round up
int num_pages = (size + m_page_size - 1) / m_page_size;
// allocate array of FILE_SEGMENT_ELEMENT for ReadFileScatter
FILE_SEGMENT_ELEMENT* segment_array = TORRENT_ALLOCA(FILE_SEGMENT_ELEMENT, num_pages + 1);
FILE_SEGMENT_ELEMENT* cur_seg = segment_array;
for (file::iovec_t const* i = bufs, *end(bufs + num_bufs); i < end; ++i)
{
for (int k = 0; k < i->iov_len; k += m_page_size)
{
cur_seg->Buffer = ((char*)i->iov_base) + k;
++cur_seg;
}
}
// terminate the array
cur_seg->Buffer = 0;
OVERLAPPED ol;
ol.Internal = 0;
ol.InternalHigh = 0;
ol.OffsetHigh = file_offset >> 32;
ol.Offset = file_offset & 0xffffffff;
ol.hEvent = CreateEvent(0, true, false, 0);
ret += size;
size = num_pages * m_page_size;
if (ReadFileScatter(m_file_handle, segment_array, size, 0, &ol) == 0)
{
DWORD last_error = GetLastError();
if (last_error != ERROR_IO_PENDING)
{
ec = error_code(GetLastError(), get_system_category());
CloseHandle(ol.hEvent);
return -1;
}
if (GetOverlappedResult(m_file_handle, &ol, &ret, true) == 0)
{
ec = error_code(GetLastError(), get_system_category());
CloseHandle(ol.hEvent);
return -1;
}
}
CloseHandle(ol.hEvent);
return ret;
#else // TORRENT_WINDOWS
size_type ret = lseek(m_fd, file_offset, SEEK_SET);
if (ret < 0)
{
ec = error_code(errno, get_posix_category());
return -1;
}
#if TORRENT_USE_READV
#ifdef TORRENT_LINUX
bool aligned = false;
int size = 0;
// if we're not opened in no-buffer mode, we don't need alignment
if ((m_open_mode & no_buffer) == 0) aligned = true;
if (!aligned)
{
size = bufs_size(bufs, num_bufs);
if (size & (size_alignment()-1) == 0) aligned = true;
}
if (aligned)
#endif // TORRENT_LINUX
{
ret = ::readv(m_fd, bufs, num_bufs);
if (ret < 0)
{
ec = error_code(errno, get_posix_category());
return -1;
}
return ret;
}
#ifdef TORRENT_LINUX
file::iovec_t* temp_bufs = TORRENT_ALLOCA(file::iovec_t, num_bufs);
memcpy(temp_bufs, bufs, sizeof(file::iovec_t) * num_bufs);
iovec_t& last = temp_bufs[num_bufs-1];
last.iov_len = (last.iov_len & ~(size_alignment()-1)) + m_page_size;
ret = ::readv(m_fd, temp_bufs, num_bufs);
if (ret < 0)
{
ec = error_code(errno, get_posix_category());
return -1;
}
return (std::min)(ret, size_type(size));
#endif // TORRENT_LINUX
#else // TORRENT_USE_READV
ret = 0;
for (file::iovec_t const* i = bufs, *end(bufs + num_bufs); i < end; ++i)
{
int tmp = read(m_fd, i->iov_base, i->iov_len);
if (tmp < 0)
{
ec = error_code(errno, get_posix_category());
return -1;
}
ret += tmp;
if (tmp < i->iov_len) break;
}
return ret;
#endif // TORRENT_USE_READV
#endif // TORRENT_WINDOWS
}
size_type file::writev(size_type file_offset, iovec_t const* bufs, int num_bufs, error_code& ec)
{
TORRENT_ASSERT((m_open_mode & rw_mask) == write_only || (m_open_mode & rw_mask) == read_write);
TORRENT_ASSERT(bufs);
TORRENT_ASSERT(num_bufs > 0);
TORRENT_ASSERT(is_open());
#if defined TORRENT_WINDOWS || defined TORRENT_LINUX || defined TORRENT_DEBUG
// make sure m_page_size is initialized
init_file();
#endif
#ifdef TORRENT_DEBUG
if (m_open_mode & no_buffer)
{
bool eof = false;
int size = 0;
// when opened in no_buffer mode, the file_offset must
// be aligned to pos_alignment()
TORRENT_ASSERT((file_offset & (pos_alignment()-1)) == 0);
for (file::iovec_t const* i = bufs, *end(bufs + num_bufs); i < end; ++i)
{
TORRENT_ASSERT((uintptr_t(i->iov_base) & (buf_alignment()-1)) == 0);
// every buffer must be a multiple of the page size
// except for the last one
TORRENT_ASSERT((i->iov_len & (size_alignment()-1)) == 0 || i == end-1);
if ((i->iov_len & (size_alignment()-1)) != 0) eof = true;
size += i->iov_len;
}
error_code code;
if (eof) TORRENT_ASSERT(file_offset + size >= get_size(code));
}
#endif
#ifdef TORRENT_WINDOWS
DWORD ret = 0;
// since the ReadFileScatter requires the file to be opened
// with no buffering, and no buffering requires page aligned
// buffers, open the file in non-buffered mode in case the
// buffer is not aligned. Most of the times the buffer should
// be aligned though
if ((m_open_mode & no_buffer) == 0)
{
// this means the buffer base or the buffer size is not aligned
// to the page size. Use a regular file for this operation.
LARGE_INTEGER offs;
offs.QuadPart = file_offset;
if (SetFilePointerEx(m_file_handle, offs, &offs, FILE_BEGIN) == FALSE)
{
ec = error_code(GetLastError(), get_system_category());
return -1;
}
for (file::iovec_t const* i = bufs, *end(bufs + num_bufs); i < end; ++i)
{
DWORD intermediate = 0;
if (WriteFile(m_file_handle, (char const*)i->iov_base
, (DWORD)i->iov_len, &intermediate, 0) == FALSE)
{
ec = error_code(GetLastError(), get_system_category());
return -1;
}
ret += intermediate;
}
return ret;
}
int size = bufs_size(bufs, num_bufs);
// number of pages for the write. round up
int num_pages = (size + m_page_size - 1) / m_page_size;
// allocate array of FILE_SEGMENT_ELEMENT for WriteFileGather
FILE_SEGMENT_ELEMENT* segment_array = TORRENT_ALLOCA(FILE_SEGMENT_ELEMENT, num_pages + 1);
FILE_SEGMENT_ELEMENT* cur_seg = segment_array;
for (file::iovec_t const* i = bufs, *end(bufs + num_bufs); i < end; ++i)
{
for (int k = 0; k < i->iov_len; k += m_page_size)
{
cur_seg->Buffer = ((char*)i->iov_base) + k;
++cur_seg;
}
}
// terminate the array
cur_seg->Buffer = 0;
OVERLAPPED ol;
ol.Internal = 0;
ol.InternalHigh = 0;
ol.OffsetHigh = file_offset >> 32;
ol.Offset = file_offset & 0xffffffff;
ol.hEvent = CreateEvent(0, true, false, 0);
ret += size;
// if file_size is > 0, the file will be opened in unbuffered
// mode after the write completes, and truncate the file to
// file_size.
size_type file_size = 0;
if ((size & (m_page_size-1)) != 0)
{
// if size is not an even multiple, this must be the tail
// of the file. Write the whole page and then open a new
// file without FILE_FLAG_NO_BUFFERING and set the
// file size to file_offset + size
file_size = file_offset + size;
size = num_pages * m_page_size;
}
if (WriteFileGather(m_file_handle, segment_array, size, 0, &ol) == 0)
{
if (GetLastError() != ERROR_IO_PENDING)
{
ec = error_code(GetLastError(), get_system_category());
CloseHandle(ol.hEvent);
return -1;
}
DWORD tmp;
if (GetOverlappedResult(m_file_handle, &ol, &tmp, true) == 0)
{
ec = error_code(GetLastError(), get_system_category());
CloseHandle(ol.hEvent);
return -1;
}
if (tmp < ret) ret = tmp;
}
CloseHandle(ol.hEvent);
if (file_size > 0)
{
HANDLE f = CreateFile(m_path.c_str(), GENERIC_WRITE
, FILE_SHARE_READ | FILE_SHARE_WRITE, 0, OPEN_EXISTING
, FILE_ATTRIBUTE_NORMAL | FILE_FLAG_RANDOM_ACCESS, 0);
if (f == INVALID_HANDLE_VALUE)
{
ec = error_code(GetLastError(), get_system_category());
return -1;
}
LARGE_INTEGER offs;
offs.QuadPart = file_size;
if (SetFilePointerEx(f, offs, &offs, FILE_BEGIN) == FALSE)
{
CloseHandle(f);
ec = error_code(GetLastError(), get_system_category());
return -1;
}
if (::SetEndOfFile(f) == FALSE)
{
ec = error_code(GetLastError(), get_system_category());
CloseHandle(f);
return -1;
}
CloseHandle(f);
}
return ret;
#else
size_type ret = lseek(m_fd, file_offset, SEEK_SET);
if (ret < 0)
{
ec = error_code(errno, get_posix_category());
return -1;
}
#if TORRENT_USE_WRITEV
#ifdef TORRENT_LINUX
bool aligned = false;
int size = 0;
// if we're not opened in no-buffer mode, we don't need alignment
if ((m_open_mode & no_buffer) == 0) aligned = true;
if (!aligned)
{
size = bufs_size(bufs, num_bufs);
if (size & (size_alignment()-1) == 0) aligned = true;
}
if (aligned)
#endif
{
ret = ::writev(m_fd, bufs, num_bufs);
if (ret < 0)
{
ec = error_code(errno, get_posix_category());
return -1;
}
return ret;
}
#ifdef TORRENT_LINUX
file::iovec_t* temp_bufs = TORRENT_ALLOCA(file::iovec_t, num_bufs);
memcpy(temp_bufs, bufs, sizeof(file::iovec_t) * num_bufs);
iovec_t& last = temp_bufs[num_bufs-1];
last.iov_len = (last.iov_len & ~(size_alignment()-1)) + size_alignment();
ret = ::writev(m_fd, temp_bufs, num_bufs);
if (ret < 0)
{
ec = error_code(errno, get_posix_category());
return -1;
}
if (ftruncate(m_fd, file_offset + size) < 0)
{
ec = error_code(errno, get_posix_category());
return -1;
}
return (std::min)(ret, size_type(size));
#endif // TORRENT_LINUX
#else // TORRENT_USE_WRITEV
ret = 0;
for (file::iovec_t const* i = bufs, *end(bufs + num_bufs); i < end; ++i)
{
int tmp = write(m_fd, i->iov_base, i->iov_len);
if (tmp < 0)
{
ec = error_code(errno, get_posix_category());
return -1;
}
ret += tmp;
if (tmp < i->iov_len) break;
}
return ret;
#endif // TORRENT_USE_WRITEV
#endif // TORRENT_WINDOWS
}
bool file::set_size(size_type s, error_code& ec)
{
TORRENT_ASSERT(is_open());
TORRENT_ASSERT(s >= 0);
#ifdef TORRENT_WINDOWS
LARGE_INTEGER offs;
offs.QuadPart = s;
if (SetFilePointerEx(m_file_handle, offs, &offs, FILE_BEGIN) == FALSE)
{
ec = error_code(GetLastError(), get_system_category());
return false;
}
#if _WIN32_WINNT >= 0x501
if ((m_open_mode & sparse) == 0)
{
// if the user has permissions, avoid filling
// the file with zeroes, but just fill it with
// garbage instead
SetFileValidData(m_file_handle, offs.QuadPart);
}
#endif
if (::SetEndOfFile(m_file_handle) == FALSE)
{
ec = error_code(GetLastError(), get_system_category());
return false;
}
#else
if (ftruncate(m_fd, s) < 0)
{
ec = error_code(errno, get_posix_category());
return false;
}
if ((m_open_mode & sparse) == 0)
{
// if we're not in sparse mode, allocate the storage
#ifdef F_PREALLOCATE
fstore_t f = {F_ALLOCATECONTIG, F_PEOFPOSMODE, 0, s, 0};
if (fcntl(m_fd, F_PREALLOCATE, &f) < 0)
{
ec = error_code(errno, get_posix_category());
return false;
}
#else
int ret = posix_fallocate(m_fd, 0, s);
if (ret != 0)
{
ec = error_code(ret, get_posix_category());
return false;
}
#endif
}
#endif
return true;
}
size_type file::get_size(error_code& ec) const
{
#ifdef TORRENT_WINDOWS
LARGE_INTEGER file_size;
if (!GetFileSizeEx(m_file_handle, &file_size))
{
ec = error_code(GetLastError(), get_system_category());
return -1;
}
return file_size.QuadPart;
#else
struct stat fs;
if (fstat(m_fd, &fs) != 0)
{
ec = error_code(errno, get_posix_category());
return -1;
}
return fs.st_size;
#endif
}
size_type file::sparse_end(size_type start) const
{
#ifdef TORRENT_WINDOWS
FILE_ALLOCATED_RANGE_BUFFER buffer;
DWORD bytes_returned = 0;
FILE_ALLOCATED_RANGE_BUFFER in;
error_code ec;
size_type file_size = get_size(ec);
if (ec) return start;
in.FileOffset.QuadPart = start;
in.Length.QuadPart = file_size - start;
if (!DeviceIoControl(m_file_handle, FSCTL_QUERY_ALLOCATED_RANGES
, &in, sizeof(FILE_ALLOCATED_RANGE_BUFFER)
, &buffer, sizeof(FILE_ALLOCATED_RANGE_BUFFER), &bytes_returned, 0))
{
int err = GetLastError();
if (GetLastError() != ERROR_INSUFFICIENT_BUFFER) return start;
}
// if there are no allocated regions within the rest
// of the file, return the end of the file
if (bytes_returned == 0) return file_size;
// assume that this range overlaps the start of the
// region we were interested in, and that start actually
// resides in an allocated region.
if (buffer.FileOffset.QuadPart < start) return start;
// return the offset to the next allocated region
return buffer.FileOffset.QuadPart;
#elif defined SEEK_DATA
// this is supported on solaris
size_type ret = lseek(m_fd, start, SEEK_DATA);
if (ret < 0) return start;
#else
return start;
#endif
}
}
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