From 4b666bd2d82a51f1c809b2703a91679789c1ec01 Mon Sep 17 00:00:00 2001 From: Joran Dirk Greef Date: Wed, 27 Sep 2017 15:03:00 +0200 Subject: [PATCH] unix,win: add fs open flags, map O_DIRECT|O_DSYNC Define stable cross-platform file open constants so that users can pass `UV_FS_O_RDWR` rather than `_O_RDWR` (win) or `O_RDWR` (unix). Map `UV_FS_O_DIRECT`, `UV_FS_O_DSYNC` and `UV_FS_O_SYNC` to `FILE_FLAG_NO_BUFFERING` and `FILE_FLAG_WRITE_THROUGH` (win). Fixes: https://github.com/libuv/libuv/issues/1550 PR-URL: https://github.com/libuv/libuv/pull/1567 Reviewed-By: Bartosz Sosnowski --- docs/src/fs.rst | 151 ++++++++++++++++++++++++++++++++++++++++++++++ include/uv-unix.h | 93 ++++++++++++++++++++++++++++ include/uv-win.h | 25 ++++++++ src/win/fs.c | 59 +++++++++++------- 4 files changed, 306 insertions(+), 22 deletions(-) diff --git a/docs/src/fs.rst b/docs/src/fs.rst index 2db915bc..f46c4e76 100644 --- a/docs/src/fs.rst +++ b/docs/src/fs.rst @@ -353,3 +353,154 @@ Helper functions any attempts to close it or to use it after closing the fd may lead to malfunction. .. versionadded:: 1.12.0 + +File open constants +------------------- + +.. c:macro:: UV_FS_O_APPEND + + The file is opened in append mode. Before each write, the file offset is + positioned at the end of the file. + +.. c:macro:: UV_FS_O_CREAT + + The file is created if it does not already exist. + +.. c:macro:: UV_FS_O_DIRECT + + File I/O is done directly to and from user-space buffers, which must be + aligned. Buffer size and address should be a multiple of the physical sector + size of the block device. + + .. note:: + `UV_FS_O_DIRECT` is supported on Linux, and on Windows via + `FILE_FLAG_NO_BUFFERING `_. + `UV_FS_O_DIRECT` is not supported on macOS. + +.. c:macro:: UV_FS_O_DIRECTORY + + If the path is not a directory, fail the open. + + .. note:: + `UV_FS_O_DIRECTORY` is not supported on Windows. + +.. c:macro:: UV_FS_O_DSYNC + + The file is opened for synchronous I/O. Write operations will complete once + all data and a minimum of metadata are flushed to disk. + + .. note:: + `UV_FS_O_DSYNC` is supported on Windows via + `FILE_FLAG_WRITE_THROUGH `_. + +.. c:macro:: UV_FS_O_EXCL + + If the `O_CREAT` flag is set and the file already exists, fail the open. + + .. note:: + In general, the behavior of `O_EXCL` is undefined if it is used without + `O_CREAT`. There is one exception: on Linux 2.6 and later, `O_EXCL` can + be used without `O_CREAT` if pathname refers to a block device. If the + block device is in use by the system (e.g., mounted), the open will fail + with the error `EBUSY`. + +.. c:macro:: UV_FS_O_EXLOCK + + Atomically obtain an exclusive lock. + + .. note:: + `UV_FS_O_EXLOCK` is only supported on macOS. + +.. c:macro:: UV_FS_O_NOATIME + + Do not update the file access time when the file is read. + + .. note:: + `UV_FS_O_NOATIME` is not supported on Windows. + +.. c:macro:: UV_FS_O_NOCTTY + + If the path identifies a terminal device, opening the path will not cause + that terminal to become the controlling terminal for the process (if the + process does not already have one). + + .. note:: + `UV_FS_O_NOCTTY` is not supported on Windows. + +.. c:macro:: UV_FS_O_NOFOLLOW + + If the path is a symbolic link, fail the open. + + .. note:: + `UV_FS_O_NOFOLLOW` is not supported on Windows. + +.. c:macro:: UV_FS_O_NONBLOCK + + Open the file in nonblocking mode if possible. + + .. note:: + `UV_FS_O_NONBLOCK` is not supported on Windows. + +.. c:macro:: UV_FS_O_RANDOM + + Access is intended to be random. The system can use this as a hint to + optimize file caching. + + .. note:: + `UV_FS_O_RANDOM` is only supported on Windows via + `FILE_FLAG_RANDOM_ACCESS `_. + +.. c:macro:: UV_FS_O_RDONLY + + Open the file for read-only access. + +.. c:macro:: UV_FS_O_RDWR + + Open the file for read-write access. + +.. c:macro:: UV_FS_O_SEQUENTIAL + + Access is intended to be sequential from beginning to end. The system can + use this as a hint to optimize file caching. + + .. note:: + `UV_FS_O_SEQUENTIAL` is only supported on Windows via + `FILE_FLAG_SEQUENTIAL_SCAN `_. + +.. c:macro:: UV_FS_O_SHORT_LIVED + + The file is temporary and should not be flushed to disk if possible. + + .. note:: + `UV_FS_O_SHORT_LIVED` is only supported on Windows via + `FILE_ATTRIBUTE_TEMPORARY `_. + +.. c:macro:: UV_FS_O_SYMLINK + + Open the symbolic link itself rather than the resource it points to. + +.. c:macro:: UV_FS_O_SYNC + + The file is opened for synchronous I/O. Write operations will complete once + all data and all metadata are flushed to disk. + + .. note:: + `UV_FS_O_SYNC` is supported on Windows via + `FILE_FLAG_WRITE_THROUGH `_. + +.. c:macro:: UV_FS_O_TEMPORARY + + The file is temporary and should not be flushed to disk if possible. + + .. note:: + `UV_FS_O_TEMPORARY` is only supported on Windows via + `FILE_ATTRIBUTE_TEMPORARY `_. + +.. c:macro:: UV_FS_O_TRUNC + + If the file exists and is a regular file, and the file is opened + successfully for write access, its length shall be truncated to zero. + +.. c:macro:: UV_FS_O_WRONLY + + Open the file for write-only access. diff --git a/include/uv-unix.h b/include/uv-unix.h index d7754509..e0494f0c 100644 --- a/include/uv-unix.h +++ b/include/uv-unix.h @@ -365,4 +365,97 @@ typedef struct { uv_fs_event_cb cb; \ UV_PLATFORM_FS_EVENT_FIELDS \ +/* fs open() flags supported on this platform: */ +#if defined(O_APPEND) +# define UV_FS_O_APPEND O_APPEND +#else +# define UV_FS_O_APPEND 0 +#endif +#if defined(O_CREAT) +# define UV_FS_O_CREAT O_CREAT +#else +# define UV_FS_O_CREAT 0 +#endif +#if defined(O_DIRECT) +# define UV_FS_O_DIRECT O_DIRECT +#else +# define UV_FS_O_DIRECT 0 +#endif +#if defined(O_DIRECTORY) +# define UV_FS_O_DIRECTORY O_DIRECTORY +#else +# define UV_FS_O_DIRECTORY 0 +#endif +#if defined(O_DSYNC) +# define UV_FS_O_DSYNC O_DSYNC +#else +# define UV_FS_O_DSYNC 0 +#endif +#if defined(O_EXCL) +# define UV_FS_O_EXCL O_EXCL +#else +# define UV_FS_O_EXCL 0 +#endif +#if defined(O_EXLOCK) +# define UV_FS_O_EXLOCK O_EXLOCK +#else +# define UV_FS_O_EXLOCK 0 +#endif +#if defined(O_NOATIME) +# define UV_FS_O_NOATIME O_NOATIME +#else +# define UV_FS_O_NOATIME 0 +#endif +#if defined(O_NOCTTY) +# define UV_FS_O_NOCTTY O_NOCTTY +#else +# define UV_FS_O_NOCTTY 0 +#endif +#if defined(O_NOFOLLOW) +# define UV_FS_O_NOFOLLOW O_NOFOLLOW +#else +# define UV_FS_O_NOFOLLOW 0 +#endif +#if defined(O_NONBLOCK) +# define UV_FS_O_NONBLOCK O_NONBLOCK +#else +# define UV_FS_O_NONBLOCK 0 +#endif +#if defined(O_RDONLY) +# define UV_FS_O_RDONLY O_RDONLY +#else +# define UV_FS_O_RDONLY 0 +#endif +#if defined(O_RDWR) +# define UV_FS_O_RDWR O_RDWR +#else +# define UV_FS_O_RDWR 0 +#endif +#if defined(O_SYMLINK) +# define UV_FS_O_SYMLINK O_SYMLINK +#else +# define UV_FS_O_SYMLINK 0 +#endif +#if defined(O_SYNC) +# define UV_FS_O_SYNC O_SYNC +#else +# define UV_FS_O_SYNC 0 +#endif +#if defined(O_TRUNC) +# define UV_FS_O_TRUNC O_TRUNC +#else +# define UV_FS_O_TRUNC 0 +#endif +#if defined(O_WRONLY) +# define UV_FS_O_WRONLY O_WRONLY +#else +# define UV_FS_O_WRONLY 0 +#endif + +/* fs open() flags supported on other platforms: */ +#define UV_FS_O_RANDOM 0 +#define UV_FS_O_SHORT_LIVED 0 +#define UV_FS_O_SEQUENTIAL 0 +#define UV_FS_O_TEMPORARY 0 + #endif /* UV_UNIX_H */ diff --git a/include/uv-win.h b/include/uv-win.h index 9677ff16..e9605cd3 100644 --- a/include/uv-win.h +++ b/include/uv-win.h @@ -648,3 +648,28 @@ RB_HEAD(uv_timer_tree_s, uv_timer_s); #ifndef X_OK #define X_OK 1 #endif + +/* fs open() flags supported on this platform: */ +#define UV_FS_O_APPEND _O_APPEND +#define UV_FS_O_CREAT _O_CREAT +#define UV_FS_O_EXCL _O_EXCL +#define UV_FS_O_RANDOM _O_RANDOM +#define UV_FS_O_RDONLY _O_RDONLY +#define UV_FS_O_RDWR _O_RDWR +#define UV_FS_O_SEQUENTIAL _O_SEQUENTIAL +#define UV_FS_O_SHORT_LIVED _O_SHORT_LIVED +#define UV_FS_O_TEMPORARY _O_TEMPORARY +#define UV_FS_O_TRUNC _O_TRUNC +#define UV_FS_O_WRONLY _O_WRONLY + +/* fs open() flags supported on other platforms (or mapped on this platform): */ +#define UV_FS_O_DIRECT 0x2000000 /* FILE_FLAG_NO_BUFFERING */ +#define UV_FS_O_DIRECTORY 0 +#define UV_FS_O_DSYNC 0x4000000 /* FILE_FLAG_WRITE_THROUGH */ +#define UV_FS_O_EXLOCK 0 +#define UV_FS_O_NOATIME 0 +#define UV_FS_O_NOCTTY 0 +#define UV_FS_O_NOFOLLOW 0 +#define UV_FS_O_NONBLOCK 0 +#define UV_FS_O_SYMLINK 0 +#define UV_FS_O_SYNC 0x8000000 /* FILE_FLAG_WRITE_THROUGH */ diff --git a/src/win/fs.c b/src/win/fs.c index 51afac28..e732cd24 100644 --- a/src/win/fs.c +++ b/src/win/fs.c @@ -415,21 +415,21 @@ void fs__open(uv_fs_t* req) { umask(current_umask); /* convert flags and mode to CreateFile parameters */ - switch (flags & (_O_RDONLY | _O_WRONLY | _O_RDWR)) { - case _O_RDONLY: + switch (flags & (UV_FS_O_RDONLY | UV_FS_O_WRONLY | UV_FS_O_RDWR)) { + case UV_FS_O_RDONLY: access = FILE_GENERIC_READ; break; - case _O_WRONLY: + case UV_FS_O_WRONLY: access = FILE_GENERIC_WRITE; break; - case _O_RDWR: + case UV_FS_O_RDWR: access = FILE_GENERIC_READ | FILE_GENERIC_WRITE; break; default: goto einval; } - if (flags & _O_APPEND) { + if (flags & UV_FS_O_APPEND) { access &= ~FILE_WRITE_DATA; access |= FILE_APPEND_DATA; } @@ -442,23 +442,23 @@ void fs__open(uv_fs_t* req) { */ share = FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE; - switch (flags & (_O_CREAT | _O_EXCL | _O_TRUNC)) { + switch (flags & (UV_FS_O_CREAT | UV_FS_O_EXCL | UV_FS_O_TRUNC)) { case 0: - case _O_EXCL: + case UV_FS_O_EXCL: disposition = OPEN_EXISTING; break; - case _O_CREAT: + case UV_FS_O_CREAT: disposition = OPEN_ALWAYS; break; - case _O_CREAT | _O_EXCL: - case _O_CREAT | _O_TRUNC | _O_EXCL: + case UV_FS_O_CREAT | UV_FS_O_EXCL: + case UV_FS_O_CREAT | UV_FS_O_TRUNC | UV_FS_O_EXCL: disposition = CREATE_NEW; break; - case _O_TRUNC: - case _O_TRUNC | _O_EXCL: + case UV_FS_O_TRUNC: + case UV_FS_O_TRUNC | UV_FS_O_EXCL: disposition = TRUNCATE_EXISTING; break; - case _O_CREAT | _O_TRUNC: + case UV_FS_O_CREAT | UV_FS_O_TRUNC: disposition = CREATE_ALWAYS; break; default: @@ -466,34 +466,49 @@ void fs__open(uv_fs_t* req) { } attributes |= FILE_ATTRIBUTE_NORMAL; - if (flags & _O_CREAT) { + if (flags & UV_FS_O_CREAT) { if (!((req->fs.info.mode & ~current_umask) & _S_IWRITE)) { attributes |= FILE_ATTRIBUTE_READONLY; } } - if (flags & _O_TEMPORARY ) { + if (flags & UV_FS_O_TEMPORARY ) { attributes |= FILE_FLAG_DELETE_ON_CLOSE | FILE_ATTRIBUTE_TEMPORARY; access |= DELETE; } - if (flags & _O_SHORT_LIVED) { + if (flags & UV_FS_O_SHORT_LIVED) { attributes |= FILE_ATTRIBUTE_TEMPORARY; } - switch (flags & (_O_SEQUENTIAL | _O_RANDOM)) { + switch (flags & (UV_FS_O_SEQUENTIAL | UV_FS_O_RANDOM)) { case 0: break; - case _O_SEQUENTIAL: + case UV_FS_O_SEQUENTIAL: attributes |= FILE_FLAG_SEQUENTIAL_SCAN; break; - case _O_RANDOM: + case UV_FS_O_RANDOM: attributes |= FILE_FLAG_RANDOM_ACCESS; break; default: goto einval; } + if (flags & UV_FS_O_DIRECT) { + attributes |= FILE_FLAG_NO_BUFFERING; + } + + switch (flags & (UV_FS_O_DSYNC | UV_FS_O_SYNC)) { + case 0: + break; + case UV_FS_O_DSYNC: + case UV_FS_O_SYNC: + attributes |= FILE_FLAG_WRITE_THROUGH; + break; + default: + goto einval; + } + /* Setting this flag makes it possible to open a directory. */ attributes |= FILE_FLAG_BACKUP_SEMANTICS; @@ -506,9 +521,9 @@ void fs__open(uv_fs_t* req) { NULL); if (file == INVALID_HANDLE_VALUE) { DWORD error = GetLastError(); - if (error == ERROR_FILE_EXISTS && (flags & _O_CREAT) && - !(flags & _O_EXCL)) { - /* Special case: when ERROR_FILE_EXISTS happens and O_CREAT was */ + if (error == ERROR_FILE_EXISTS && (flags & UV_FS_O_CREAT) && + !(flags & UV_FS_O_EXCL)) { + /* Special case: when ERROR_FILE_EXISTS happens and UV_FS_O_CREAT was */ /* specified, it means the path referred to a directory. */ SET_REQ_UV_ERROR(req, UV_EISDIR, error); } else {