X-Git-Url: https://wimlib.net/git/?p=wimlib;a=blobdiff_plain;f=src%2Fwin32_replacements.c;h=0e1023f6113e11c87f5416e584f3cc7f1bc25f58;hp=4e9df0aee8a5a538676176fd74a3d20819222513;hb=e3dc3c76cf0896eb98f455f2538999d23f95b61a;hpb=da295f258b60e1593de305385c0669eac4b76644 diff --git a/src/win32_replacements.c b/src/win32_replacements.c index 4e9df0ae..0e1023f6 100644 --- a/src/win32_replacements.c +++ b/src/win32_replacements.c @@ -37,6 +37,7 @@ #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() */ @@ -57,7 +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) { @@ -66,6 +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. */ @@ -88,7 +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; } @@ -99,27 +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 */ @@ -234,31 +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) { @@ -301,6 +343,7 @@ win32_wglob(const wchar_t *pattern, int flags, HANDLE hFind; int ret; size_t nspaces; + int errno_save; const wchar_t *backslash, *end_slash; size_t prefix_len; @@ -330,9 +373,7 @@ win32_wglob(const wchar_t *pattern, int flags, errno = 0; return GLOB_NOMATCH; } else { - /* The other possible error codes for FindFirstFile() - * are undocumented. */ - errno = EIO; + set_errno_from_win32_error(err); return GLOB_ABORTED; } } @@ -366,22 +407,21 @@ win32_wglob(const wchar_t *pattern, int flags, } while (FindNextFileW(hFind, &dat)); err = GetLastError(); CloseHandle(hFind); - if (err == ERROR_NO_MORE_FILES) { - errno = 0; - return 0; - } else { - /* Other possible error codes for FindNextFile() are - * undocumented */ - errno = EIO; + 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; } @@ -390,8 +430,8 @@ globfree(glob_t *pglob) { size_t i; for (i = 0; i < pglob->gl_pathc; i++) - free(pglob->gl_pathv[i]); - free(pglob->gl_pathv); + FREE(pglob->gl_pathv[i]); + FREE(pglob->gl_pathv); } #endif /* __WIN32__ */