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Diffstat (limited to 'tests/ftruncate.c')
| -rw-r--r-- | tests/ftruncate.c | 195 |
1 files changed, 195 insertions, 0 deletions
diff --git a/tests/ftruncate.c b/tests/ftruncate.c new file mode 100644 index 00000000..f9c4ebad --- /dev/null +++ b/tests/ftruncate.c @@ -0,0 +1,195 @@ +/* ftruncate emulations for native Windows. + Copyright (C) 1992-2022 Free Software Foundation, Inc. + + 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. + + 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 <https://www.gnu.org/licenses/>. */ + +#include <config.h> + +/* Specification. */ +#include <unistd.h> + +#if HAVE__CHSIZE +/* A native Windows platform. */ + +# include <errno.h> + +# 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 <windows.h> declares GetFileSizeEx. */ +# if !defined _WIN32_WINNT || (_WIN32_WINNT < _WIN32_WINNT_WIN2K) +# undef _WIN32_WINNT +# define _WIN32_WINNT _WIN32_WINNT_WIN2K +# endif + +/* Get declarations of the native Windows API functions. */ +# define WIN32_LEAN_AND_MEAN +# include <windows.h> + +/* Get _get_osfhandle. */ +# if GNULIB_MSVC_NOTHROW +# include "msvc-nothrow.h" +# else +# include <io.h> +# endif + +static BOOL +SetFileSize (HANDLE h, LONGLONG size) +{ + 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; +} + +int +ftruncate (int fd, off_t length) +{ + HANDLE handle = (HANDLE) _get_osfhandle (fd); + + if (handle == INVALID_HANDLE_VALUE) + { + errno = EBADF; + return -1; + } + if (length < 0) + { + 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; +} + +# else + +# include <io.h> + +# 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); + } + CATCH_MSVC_INVAL + { + result = -1; + errno = EBADF; + } + DONE_MSVC_INVAL; + + return result; +} +# else +# define chsize_nothrow _chsize +# endif + +int +ftruncate (int fd, off_t length) +{ + return chsize_nothrow (fd, length); +} + +# endif +#endif |