2 * win32_replacements.c - Replacements for various functions not available on
3 * Windows, such as fsync().
7 * Copyright (C) 2013 Eric Biggers
9 * This file is part of wimlib, a library for working with WIM files.
11 * wimlib is free software; you can redistribute it and/or modify it under the
12 * terms of the GNU General Public License as published by the Free
13 * Software Foundation; either version 3 of the License, or (at your option)
16 * wimlib is distributed in the hope that it will be useful, but WITHOUT ANY
17 * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
18 * A PARTICULAR PURPOSE. See the GNU General Public License for more
21 * You should have received a copy of the GNU General Public License
22 * along with wimlib; if not, see http://www.gnu.org/licenses/.
33 #include <io.h> /* for _get_osfhandle() */
34 #include <shlwapi.h> /* for PathMatchSpecW() */
36 #include "wimlib/win32_common.h"
38 #include "wimlib/assert.h"
39 #include "wimlib/file_io.h"
40 #include "wimlib/glob.h"
41 #include "wimlib/error.h"
42 #include "wimlib/wildcard.h"
43 #include "wimlib/util.h"
45 /* Replacement for POSIX fsync() */
51 h = (HANDLE)_get_osfhandle(fd);
52 if (h == INVALID_HANDLE_VALUE)
54 if (!FlushFileBuffers(h))
58 set_errno_from_GetLastError();
63 /* Use the Win32 API to get the number of processors. */
65 win32_get_number_of_processors(void)
68 GetSystemInfo(&sysinfo);
69 return sysinfo.dwNumberOfProcessors;
72 /* Use the Win32 API to get the amount of available memory. */
74 win32_get_avail_memory(void)
76 MEMORYSTATUSEX status = {
77 .dwLength = sizeof(status),
79 GlobalMemoryStatusEx(&status);
80 return status.ullTotalPhys;
83 /* Replacement for POSIX-2008 realpath(). Warning: partial functionality only
84 * (resolved_path must be NULL). Also I highly doubt that GetFullPathName
85 * really does the right thing under all circumstances. */
87 realpath(const wchar_t *path, wchar_t *resolved_path)
91 wimlib_assert(resolved_path == NULL);
93 ret = GetFullPathNameW(path, 0, NULL, NULL);
99 resolved_path = MALLOC(ret * sizeof(wchar_t));
102 ret = GetFullPathNameW(path, ret, resolved_path, NULL);
104 err = GetLastError();
106 resolved_path = NULL;
111 set_errno_from_win32_error(err);
113 return resolved_path;
116 /* A quick hack to get reasonable rename() semantics on Windows, in particular
117 * deleting the destination file instead of failing with ERROR_FILE_EXISTS and
118 * working around any processes that may have the destination file open.
120 * Note: This is intended to be called when overwriting a regular file with an
121 * updated copy and is *not* a fully POSIX compliant rename(). For that you may
122 * wish to take a look at Cygwin's implementation, but be prepared...
124 * Return 0 on success, -1 on regular error, or 1 if the destination file was
125 * deleted but the source could not be renamed and therefore should not be
129 win32_rename_replacement(const wchar_t *srcpath, const wchar_t *dstpath)
133 /* Normally, MoveFileExW() with the MOVEFILE_REPLACE_EXISTING flag does
136 if (MoveFileExW(srcpath, dstpath, MOVEFILE_REPLACE_EXISTING))
139 /* MoveFileExW() failed. One way this can happen is if any process has
140 * the destination file open, in which case ERROR_ACCESS_DENIED is
141 * produced. This can commonly happen if there is a backup or antivirus
142 * program monitoring or scanning the files. This behavior is very
143 * different from the behavior of POSIX rename(), which simply unlinks
144 * the destination file and allows other processes to keep it open! */
146 if (GetLastError() != ERROR_ACCESS_DENIED)
149 /* We can work around the above-mentioned problem by renaming the
150 * destination file to yet another temporary file, then "deleting" it,
151 * which on Windows will in fact not actually delete it immediately but
152 * rather mark it for deletion when the last handle to it is closed. */
154 static const wchar_t orig_suffix[5] = L".orig";
155 const size_t num_rand_chars = 9;
158 size_t dstlen = wcslen(dstpath);
160 tmpname = alloca(sizeof(wchar_t) *
161 (dstlen + ARRAY_LEN(orig_suffix) + num_rand_chars + 1));
163 p = wmempcpy(p, dstpath, dstlen);
164 p = wmempcpy(p, orig_suffix, ARRAY_LEN(orig_suffix));
165 randomize_char_array_with_alnum(p, num_rand_chars);
170 if (!MoveFile(dstpath, tmpname))
173 if (!DeleteFile(tmpname)) {
174 set_errno_from_GetLastError();
175 WARNING_WITH_ERRNO("Failed to delete original file "
176 "(moved to \"%ls\")", tmpname);
179 if (!MoveFile(srcpath, dstpath)) {
180 set_errno_from_GetLastError();
181 WARNING_WITH_ERRNO("Atomic semantics not respected in "
182 "failed rename() (new file is at \"%ls\")",
190 set_errno_from_GetLastError();
194 /* truncate() replacement */
196 win32_truncate_replacement(const wchar_t *path, off_t size)
198 DWORD err = NO_ERROR;
199 LARGE_INTEGER liOffset;
201 HANDLE h = win32_open_existing_file(path, GENERIC_WRITE);
202 if (h == INVALID_HANDLE_VALUE)
205 liOffset.QuadPart = size;
206 if (!SetFilePointerEx(h, liOffset, NULL, FILE_BEGIN))
207 goto fail_close_handle;
209 if (!SetEndOfFile(h))
210 goto fail_close_handle;
215 err = GetLastError();
219 err = GetLastError();
220 set_errno_from_win32_error(err);
225 /* This really could be replaced with _wcserror_s, but this doesn't seem to
226 * actually be available in MSVCRT.DLL on Windows XP (perhaps it's statically
227 * linked in by Visual Studio...?). */
229 win32_strerror_r_replacement(int errnum, wchar_t *buf, size_t buflen)
231 static pthread_mutex_t strerror_lock = PTHREAD_MUTEX_INITIALIZER;
233 pthread_mutex_lock(&strerror_lock);
234 mbstowcs(buf, strerror(errnum), buflen);
235 buf[buflen - 1] = '\0';
236 pthread_mutex_unlock(&strerror_lock);
241 do_pread_or_pwrite(int fd, void *buf, size_t count, off_t offset,
245 LARGE_INTEGER orig_offset;
246 DWORD bytes_read_or_written;
247 LARGE_INTEGER relative_offset;
248 OVERLAPPED overlapped;
251 h = (HANDLE)_get_osfhandle(fd);
252 if (h == INVALID_HANDLE_VALUE)
255 if (GetFileType(h) == FILE_TYPE_PIPE) {
260 /* Get original position */
261 relative_offset.QuadPart = 0;
262 if (!SetFilePointerEx(h, relative_offset, &orig_offset, FILE_CURRENT))
265 memset(&overlapped, 0, sizeof(overlapped));
266 overlapped.Offset = offset;
267 overlapped.OffsetHigh = offset >> 32;
269 /* Do the read or write at the specified offset */
271 bret = WriteFile(h, buf, count, &bytes_read_or_written, &overlapped);
273 bret = ReadFile(h, buf, count, &bytes_read_or_written, &overlapped);
277 /* Restore the original position */
278 if (!SetFilePointerEx(h, orig_offset, NULL, FILE_BEGIN))
281 return bytes_read_or_written;
283 set_errno_from_GetLastError();
288 /* Dumb Windows implementation of pread(). It temporarily changes the file
289 * offset, so it is not safe to use with readers/writers on the same file
292 pread(int fd, void *buf, size_t count, off_t offset)
294 return do_pread_or_pwrite(fd, buf, count, offset, false);
297 /* Dumb Windows implementation of pwrite(). It temporarily changes the file
298 * offset, so it is not safe to use with readers/writers on the same file
301 pwrite(int fd, const void *buf, size_t count, off_t offset)
303 return do_pread_or_pwrite(fd, (void*)buf, count, offset, true);
307 win32_get_file_and_vol_ids(const wchar_t *path, u64 *ino_ret, u64 *dev_ret)
310 BY_HANDLE_FILE_INFORMATION file_info;
314 h = win32_open_existing_file(path, FILE_READ_ATTRIBUTES);
315 if (h == INVALID_HANDLE_VALUE) {
316 ret = WIMLIB_ERR_OPEN;
320 if (!GetFileInformationByHandle(h, &file_info)) {
321 ret = WIMLIB_ERR_STAT;
323 *ino_ret = ((u64)file_info.nFileIndexHigh << 32) |
324 (u64)file_info.nFileIndexLow;
325 *dev_ret = file_info.dwVolumeSerialNumber;
328 err = GetLastError();
332 set_errno_from_GetLastError();
336 /* Replacement for glob() in Windows native builds that operates on wide
339 win32_wglob(const wchar_t *pattern, int flags,
340 int (*errfunc)(const wchar_t *epath, int eerrno),
343 WIN32_FIND_DATAW dat;
350 const wchar_t *backslash, *end_slash;
353 backslash = wcsrchr(pattern, L'\\');
354 end_slash = wcsrchr(pattern, L'/');
356 if (backslash > end_slash)
357 end_slash = backslash;
360 prefix_len = end_slash - pattern + 1;
364 /* This function does not support all functionality of the POSIX glob(),
365 * so make sure the parameters are consistent with supported
367 wimlib_assert(errfunc == NULL);
368 wimlib_assert((flags & GLOB_ERR) == GLOB_ERR);
369 wimlib_assert((flags & ~(GLOB_NOSORT | GLOB_ERR)) == 0);
371 hFind = FindFirstFileW(pattern, &dat);
372 if (hFind == INVALID_HANDLE_VALUE) {
373 err = GetLastError();
374 if (err == ERROR_FILE_NOT_FOUND) {
378 set_errno_from_win32_error(err);
383 pglob->gl_pathv = NULL;
387 if (pglob->gl_pathc == nspaces) {
391 new_nspaces = nspaces * 2 + 1;
392 pathv = REALLOC(pglob->gl_pathv,
393 new_nspaces * sizeof(pglob->gl_pathv[0]));
396 pglob->gl_pathv = pathv;
397 nspaces = new_nspaces;
399 size_t filename_len = wcslen(dat.cFileName);
400 size_t len_needed = prefix_len + filename_len;
402 path = MALLOC((len_needed + 1) * sizeof(wchar_t));
406 wmemcpy(path, pattern, prefix_len);
407 wmemcpy(path + prefix_len, dat.cFileName, filename_len + 1);
408 pglob->gl_pathv[pglob->gl_pathc++] = path;
409 } while (FindNextFileW(hFind, &dat));
410 err = GetLastError();
412 if (err != ERROR_NO_MORE_FILES) {
413 set_errno_from_win32_error(err);
431 globfree(glob_t *pglob)
434 for (i = 0; i < pglob->gl_pathc; i++)
435 FREE(pglob->gl_pathv[i]);
436 FREE(pglob->gl_pathv);
439 #endif /* __WIN32__ */