]> wimlib.net Git - wimlib/blobdiff - src/win32_replacements.c
wincfg: Add swapfile.sys
[wimlib] / src / win32_replacements.c
index d16936ceec299415b5b4b72b66dcb80ac112ffdf..0e1023f6113e11c87f5416e584f3cc7f1bc25f58 100644 (file)
 #  include "config.h"
 #endif
 
+#include <errno.h>
 #include <pthread.h>
 #include <shlwapi.h> /* for PathMatchSpecW() */
 #include "wimlib/win32_common.h"
 
 #include "wimlib/assert.h"
 #include "wimlib/file_io.h"
+#include "wimlib/glob.h"
 #include "wimlib/error.h"
+#include "wimlib/wildcard.h"
 #include "wimlib/util.h"
 
 /* Replacement for POSIX fsync() */
@@ -55,7 +58,7 @@ err:
        return -1;
 }
 
-/* Use the Win32 API to get the number of processors */
+/* Use the Win32 API to get the number of processors */
 unsigned
 win32_get_number_of_processors(void)
 {
@@ -64,6 +67,17 @@ win32_get_number_of_processors(void)
        return sysinfo.dwNumberOfProcessors;
 }
 
+/* Use the Win32 API to get the amount of available memory.  */
+u64
+win32_get_avail_memory(void)
+{
+       MEMORYSTATUSEX status = {
+               .dwLength = sizeof(status),
+       };
+       GlobalMemoryStatusEx(&status);
+       return status.ullTotalPhys;
+}
+
 /* Replacement for POSIX-2008 realpath().  Warning: partial functionality only
  * (resolved_path must be NULL).   Also I highly doubt that GetFullPathName
  * really does the right thing under all circumstances. */
@@ -86,7 +100,7 @@ realpath(const wchar_t *path, wchar_t *resolved_path)
        ret = GetFullPathNameW(path, ret, resolved_path, NULL);
        if (!ret) {
                err = GetLastError();
-               free(resolved_path);
+               FREE(resolved_path);
                resolved_path = NULL;
                goto fail_win32;
        }
@@ -97,27 +111,82 @@ out:
        return resolved_path;
 }
 
-/* rename() on Windows fails if the destination file exists.  And we need to
- * make it work on wide characters.  Fix it. */
+/* A quick hack to get reasonable rename() semantics on Windows, in particular
+ * deleting the destination file instead of failing with ERROR_FILE_EXISTS and
+ * working around any processes that may have the destination file open.
+ *
+ * Note: This is intended to be called when overwriting a regular file with an
+ * updated copy and is *not* a fully POSIX compliant rename().  For that you may
+ * wish to take a look at Cygwin's implementation, but be prepared...
+ *
+ * Return 0 on success, -1 on regular error, or 1 if the destination file was
+ * deleted but the source could not be renamed and therefore should not be
+ * deleted.
+ */
 int
-win32_rename_replacement(const wchar_t *oldpath, const wchar_t *newpath)
+win32_rename_replacement(const wchar_t *srcpath, const wchar_t *dstpath)
 {
-       if (MoveFileExW(oldpath, newpath, MOVEFILE_REPLACE_EXISTING)) {
+       wchar_t *tmpname;
+
+       /* Normally, MoveFileExW() with the MOVEFILE_REPLACE_EXISTING flag does
+        * what we want.  */
+
+       if (MoveFileExW(srcpath, dstpath, MOVEFILE_REPLACE_EXISTING))
                return 0;
-       } else {
+
+       /* MoveFileExW() failed.  One way this can happen is if any process has
+        * the destination file open, in which case ERROR_ACCESS_DENIED is
+        * produced.  This can commonly happen if there is a backup or antivirus
+        * program monitoring or scanning the files.  This behavior is very
+        * different from the behavior of POSIX rename(), which simply unlinks
+        * the destination file and allows other processes to keep it open!  */
+
+       if (GetLastError() != ERROR_ACCESS_DENIED)
+               goto err_set_errno;
+
+       /* We can work around the above-mentioned problem by renaming the
+        * destination file to yet another temporary file, then "deleting" it,
+        * which on Windows will in fact not actually delete it immediately but
+        * rather mark it for deletion when the last handle to it is closed.  */
+       {
+               static const wchar_t orig_suffix[5] = L".orig";
+               const size_t num_rand_chars = 9;
+               wchar_t *p;
+
+               size_t dstlen = wcslen(dstpath);
+
+               tmpname = alloca(sizeof(wchar_t) *
+                                (dstlen + ARRAY_LEN(orig_suffix) + num_rand_chars + 1));
+               p = tmpname;
+               p = wmempcpy(p, dstpath, dstlen);
+               p = wmempcpy(p, orig_suffix, ARRAY_LEN(orig_suffix));
+               randomize_char_array_with_alnum(p, num_rand_chars);
+               p += num_rand_chars;
+               *p = L'\0';
+       }
+
+       if (!MoveFile(dstpath, tmpname))
+               goto err_set_errno;
+
+       if (!DeleteFile(tmpname)) {
                set_errno_from_GetLastError();
-               return -1;
+               WARNING_WITH_ERRNO("Failed to delete original file "
+                                  "(moved to \"%ls\")", tmpname);
        }
-}
 
-/* Replacement for POSIX fnmatch() (partial functionality only) */
-int
-fnmatch(const wchar_t *pattern, const wchar_t *string, int flags)
-{
-       if (PathMatchSpecW(string, pattern))
-               return 0;
-       else
-               return FNM_NOMATCH;
+       if (!MoveFile(srcpath, dstpath)) {
+               set_errno_from_GetLastError();
+               WARNING_WITH_ERRNO("Atomic semantics not respected in "
+                                  "failed rename() (new file is at \"%ls\")",
+                                  srcpath);
+               return 1;
+       }
+
+       return 0;
+
+err_set_errno:
+       set_errno_from_GetLastError();
+       return -1;
 }
 
 /* truncate() replacement */
@@ -232,31 +301,6 @@ pwrite(int fd, const void *buf, size_t count, off_t offset)
        return do_pread_or_pwrite(fd, (void*)buf, count, offset, true);
 }
 
-/* Dumb Windows implementation of writev().  It writes the vectors one at a
- * time. */
-ssize_t writev(int fd, const struct iovec *iov, int iovcnt)
-{
-       ssize_t total_bytes_written = 0;
-
-       if (iovcnt <= 0) {
-               errno = EINVAL;
-               return -1;
-       }
-       for (int i = 0; i < iovcnt; i++) {
-               ssize_t bytes_written;
-
-               bytes_written = write(fd, iov[i].iov_base, iov[i].iov_len);
-               if (bytes_written >= 0)
-                       total_bytes_written += bytes_written;
-               if (bytes_written != iov[i].iov_len) {
-                       if (total_bytes_written == 0)
-                               total_bytes_written = -1;
-                       break;
-               }
-       }
-       return total_bytes_written;
-}
-
 int
 win32_get_file_and_vol_ids(const wchar_t *path, u64 *ino_ret, u64 *dev_ret)
 {
@@ -279,7 +323,6 @@ win32_get_file_and_vol_ids(const wchar_t *path, u64 *ino_ret, u64 *dev_ret)
                *dev_ret = file_info.dwVolumeSerialNumber;
                ret = 0;
        }
-out_close_handle:
        err = GetLastError();
        CloseHandle(h);
        SetLastError(err);
@@ -288,5 +331,107 @@ out:
        return ret;
 }
 
+/* Replacement for glob() in Windows native builds that operates on wide
+ * characters.  */
+int
+win32_wglob(const wchar_t *pattern, int flags,
+           int (*errfunc)(const wchar_t *epath, int eerrno),
+           glob_t *pglob)
+{
+       WIN32_FIND_DATAW dat;
+       DWORD err;
+       HANDLE hFind;
+       int ret;
+       size_t nspaces;
+       int errno_save;
+
+       const wchar_t *backslash, *end_slash;
+       size_t prefix_len;
+
+       backslash = wcsrchr(pattern, L'\\');
+       end_slash = wcsrchr(pattern, L'/');
+
+       if (backslash > end_slash)
+               end_slash = backslash;
+
+       if (end_slash)
+               prefix_len = end_slash - pattern + 1;
+       else
+               prefix_len = 0;
+
+       /* This function does not support all functionality of the POSIX glob(),
+        * so make sure the parameters are consistent with supported
+        * functionality. */
+       wimlib_assert(errfunc == NULL);
+       wimlib_assert((flags & GLOB_ERR) == GLOB_ERR);
+       wimlib_assert((flags & ~(GLOB_NOSORT | GLOB_ERR)) == 0);
+
+       hFind = FindFirstFileW(pattern, &dat);
+       if (hFind == INVALID_HANDLE_VALUE) {
+               err = GetLastError();
+               if (err == ERROR_FILE_NOT_FOUND) {
+                       errno = 0;
+                       return GLOB_NOMATCH;
+               } else {
+                       set_errno_from_win32_error(err);
+                       return GLOB_ABORTED;
+               }
+       }
+       pglob->gl_pathc = 0;
+       pglob->gl_pathv = NULL;
+       nspaces = 0;
+       do {
+               wchar_t *path;
+               if (pglob->gl_pathc == nspaces) {
+                       size_t new_nspaces;
+                       wchar_t **pathv;
+
+                       new_nspaces = nspaces * 2 + 1;
+                       pathv = REALLOC(pglob->gl_pathv,
+                                       new_nspaces * sizeof(pglob->gl_pathv[0]));
+                       if (!pathv)
+                               goto oom;
+                       pglob->gl_pathv = pathv;
+                       nspaces = new_nspaces;
+               }
+               size_t filename_len = wcslen(dat.cFileName);
+               size_t len_needed = prefix_len + filename_len;
+
+               path = MALLOC((len_needed + 1) * sizeof(wchar_t));
+               if (!path)
+                       goto oom;
+
+               wmemcpy(path, pattern, prefix_len);
+               wmemcpy(path + prefix_len, dat.cFileName, filename_len + 1);
+               pglob->gl_pathv[pglob->gl_pathc++] = path;
+       } while (FindNextFileW(hFind, &dat));
+       err = GetLastError();
+       CloseHandle(hFind);
+       if (err != ERROR_NO_MORE_FILES) {
+               set_errno_from_win32_error(err);
+               ret = GLOB_ABORTED;
+               goto fail_globfree;
+       }
+       return 0;
+
+oom:
+       CloseHandle(hFind);
+       errno = ENOMEM;
+       ret = GLOB_NOSPACE;
+fail_globfree:
+       errno_save = errno;
+       globfree(pglob);
+       errno = errno_save;
+       return ret;
+}
+
+void
+globfree(glob_t *pglob)
+{
+       size_t i;
+       for (i = 0; i < pglob->gl_pathc; i++)
+               FREE(pglob->gl_pathv[i]);
+       FREE(pglob->gl_pathv);
+}
 
 #endif /* __WIN32__ */