X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;ds=sidebyside;f=lib%2Fftruncate.c;h=db7f7ddf40cf176db29d987db8689b5df09664ef;hb=c96bab3fee48a9df55e7366344f838e1fc785c28;hp=17d263d512144e9df9d97ae8aa497134f4551690;hpb=d87c39464604e74f580c7fae835be31a4c125c36;p=gnulib.git diff --git a/lib/ftruncate.c b/lib/ftruncate.c index 17d263d51..db7f7ddf4 100644 --- a/lib/ftruncate.c +++ b/lib/ftruncate.c @@ -1,72 +1,188 @@ -/* ftruncate emulations that work on some System V's. - This file is in the public domain. */ +/* ftruncate emulations for native Windows. + Copyright (C) 1992-2013 Free Software Foundation, Inc. -#include -#include + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 3, or (at your option) + any later version. -#ifdef F_CHSIZE -int -ftruncate (fd, length) - int fd; - off_t length; -{ - return fcntl (fd, F_CHSIZE, length); -} -#else -#ifdef F_FREESP -/* The following function was written by - kucharsk@Solbourne.com (William Kucharski) */ + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License along + with this program; if not, see . */ + +#include -#include -#include +/* Specification. */ #include -int -ftruncate (fd, length) - int fd; - off_t length; +#if HAVE_CHSIZE +/* A native Windows platform. */ + +# include + +# if _GL_WINDOWS_64_BIT_OFF_T + +/* Large File Support: off_t is 64-bit, but chsize() takes only a 32-bit + argument. So, define a 64-bit safe SetFileSize function ourselves. */ + +/* Ensure that declares GetFileSizeEx. */ +# undef _WIN32_WINNT +# define _WIN32_WINNT 0x500 + +/* Get declarations of the native Windows API functions. */ +# define WIN32_LEAN_AND_MEAN +# include + +/* Get _get_osfhandle. */ +# include "msvc-nothrow.h" + +static BOOL +SetFileSize (HANDLE h, LONGLONG size) { - struct flock fl; - struct stat filebuf; + LARGE_INTEGER old_size; + + if (!GetFileSizeEx (h, &old_size)) + return FALSE; + + if (size != old_size.QuadPart) + { + /* Duplicate the handle, so we are free to modify its file position. */ + HANDLE curr_process = GetCurrentProcess (); + HANDLE tmph; + + if (!DuplicateHandle (curr_process, /* SourceProcessHandle */ + h, /* SourceHandle */ + curr_process, /* TargetProcessHandle */ + (PHANDLE) &tmph, /* TargetHandle */ + (DWORD) 0, /* DesiredAccess */ + FALSE, /* InheritHandle */ + DUPLICATE_SAME_ACCESS)) /* Options */ + return FALSE; + + if (size < old_size.QuadPart) + { + /* Reduce the size. */ + LONG size_hi = (LONG) (size >> 32); + if (SetFilePointer (tmph, (LONG) size, &size_hi, FILE_BEGIN) + == INVALID_SET_FILE_POINTER + && GetLastError() != NO_ERROR) + { + CloseHandle (tmph); + return FALSE; + } + if (!SetEndOfFile (tmph)) + { + CloseHandle (tmph); + return FALSE; + } + } + else + { + /* Increase the size by adding zero bytes at the end. */ + static char zero_bytes[1024]; + LONG pos_hi = 0; + LONG pos_lo = SetFilePointer (tmph, (LONG) 0, &pos_hi, FILE_END); + LONGLONG pos; + if (pos_lo == INVALID_SET_FILE_POINTER + && GetLastError() != NO_ERROR) + { + CloseHandle (tmph); + return FALSE; + } + pos = ((LONGLONG) pos_hi << 32) | (ULONGLONG) (ULONG) pos_lo; + while (pos < size) + { + DWORD written; + LONGLONG count = size - pos; + if (count > sizeof (zero_bytes)) + count = sizeof (zero_bytes); + if (!WriteFile (tmph, zero_bytes, (DWORD) count, &written, NULL) + || written == 0) + { + CloseHandle (tmph); + return FALSE; + } + pos += (ULONGLONG) (ULONG) written; + } + } + /* Close the handle. */ + CloseHandle (tmph); + } + return TRUE; +} - if (fstat (fd, &filebuf) < 0) - return -1; +int +ftruncate (int fd, off_t length) +{ + HANDLE handle = (HANDLE) _get_osfhandle (fd); - if (filebuf.st_size < length) + if (handle == INVALID_HANDLE_VALUE) + { + errno = EBADF; + return -1; + } + if (length < 0) { - /* Extend file length. */ - if (lseek (fd, (length - 1), SEEK_SET) < 0) - return -1; + errno = EINVAL; + return -1; + } + if (!SetFileSize (handle, length)) + { + switch (GetLastError ()) + { + case ERROR_ACCESS_DENIED: + errno = EACCES; + break; + case ERROR_HANDLE_DISK_FULL: + case ERROR_DISK_FULL: + case ERROR_DISK_TOO_FRAGMENTED: + errno = ENOSPC; + break; + default: + errno = EIO; + break; + } + return -1; + } + return 0; +} - /* Write a "0" byte. */ - if (write (fd, "", 1) != 1) - return -1; +# else + +# include + +# if HAVE_MSVC_INVALID_PARAMETER_HANDLER +# include "msvc-inval.h" +static int +chsize_nothrow (int fd, long length) +{ + int result; + + TRY_MSVC_INVAL + { + result = chsize (fd, length); } - else + CATCH_MSVC_INVAL { - /* Truncate length. */ - fl.l_whence = 0; - fl.l_len = 0; - fl.l_start = length; - fl.l_type = F_WRLCK; /* Write lock on file space. */ - - /* This relies on the UNDOCUMENTED F_FREESP argument to - fcntl, which truncates the file so that it ends at the - position indicated by fl.l_start. - Will minor miracles never cease? */ - if (fcntl (fd, F_FREESP, &fl) < 0) - return -1; + result = -1; + errno = EBADF; } + DONE_MSVC_INVAL; - return 0; + return result; } -#else +# define chsize chsize_nothrow +# endif + int -ftruncate (fd, length) - int fd; - off_t length; +ftruncate (int fd, off_t length) { return chsize (fd, length); } -#endif + +# endif #endif