[Python-checkins] bpo-37129: Add os.RWF_APPEND flag for os.pwritev() (GH-20336)

[YoSTEALTH]

https://github.com/python/cpython/commit/76ef255bde772005bbd0761399b274c2240e61d3
commit: 76ef255bde772005bbd0761399b274c2240e61d3
branch: master
author: YoSTEALTH <35307184+YoSTEALTH at users.noreply.github.com>
committer: GitHub <noreply at github.com>
date: 2020-05-27T23:32:22+02:00
summary:

bpo-37129: Add os.RWF_APPEND flag for os.pwritev() (GH-20336)

files:
A Misc/NEWS.d/next/Library/2020-05-23-04-18-00.bpo-37129.YoYoYo.rst
M Doc/library/os.rst
M Modules/clinic/posixmodule.c.h
M Modules/posixmodule.c

diff --git a/Doc/library/os.rst b/Doc/library/os.rst
index 6d5fb314a8e39..275b2d390e7cf 100644
--- a/Doc/library/os.rst
+++ b/Doc/library/os.rst
@@ -1211,6 +1211,7 @@ or `the MSDN <https://msdn.microsoft.com/en-us/library/z0kc8e3z.aspx>`_ on Windo
 
    - :data:`RWF_DSYNC`
    - :data:`RWF_SYNC`
+   - :data:`RWF_APPEND`
 
    Return the total number of bytes actually written.
 
@@ -1228,8 +1229,8 @@ or `the MSDN <https://msdn.microsoft.com/en-us/library/z0kc8e3z.aspx>`_ on Windo
 
 .. data:: RWF_DSYNC
 
-   Provide a per-write equivalent of the :data:`O_DSYNC` ``open(2)`` flag. This
-   flag effect applies only to the data range written by the system call.
+   Provide a per-write equivalent of the :data:`O_DSYNC` :func:`os.open` flag.
+   This flag effect applies only to the data range written by the system call.
 
    .. availability:: Linux 4.7 and newer.
 
@@ -1238,14 +1239,28 @@ or `the MSDN <https://msdn.microsoft.com/en-us/library/z0kc8e3z.aspx>`_ on Windo
 
 .. data:: RWF_SYNC
 
-   Provide a per-write equivalent of the :data:`O_SYNC` ``open(2)`` flag. This
-   flag effect applies only to the data range written by the system call.
+   Provide a per-write equivalent of the :data:`O_SYNC` :func:`os.open` flag.
+   This flag effect applies only to the data range written by the system call.
 
    .. availability:: Linux 4.7 and newer.
 
    .. versionadded:: 3.7
 
 
+.. data:: RWF_APPEND
+
+    Provide a per-write equivalent of the :data:`O_APPEND` :func:`os.open`
+    flag. This flag is meaningful only for :func:`os.pwritev`, and its
+    effect applies only to the data range written by the system call. The
+    *offset* argument does not affect the write operation; the data is always
+    appended to the end of the file. However, if the *offset* argument is
+    ``-1``, the current file *offset* is updated.
+
+   .. availability:: Linux 4.16 and newer.
+
+   .. versionadded:: 3.10
+
+
 .. function:: read(fd, n)
 
    Read at most *n* bytes from file descriptor *fd*.
diff --git a/Misc/NEWS.d/next/Library/2020-05-23-04-18-00.bpo-37129.YoYoYo.rst b/Misc/NEWS.d/next/Library/2020-05-23-04-18-00.bpo-37129.YoYoYo.rst
new file mode 100644
index 0000000000000..e025e96f4f1c0
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2020-05-23-04-18-00.bpo-37129.YoYoYo.rst
@@ -0,0 +1 @@
+Add a new :data:`os.RWF_APPEND` flag for :func:`os.pwritev`.
diff --git a/Modules/clinic/posixmodule.c.h b/Modules/clinic/posixmodule.c.h
index 6f180abd25495..96ea02035ea41 100644
--- a/Modules/clinic/posixmodule.c.h
+++ b/Modules/clinic/posixmodule.c.h
@@ -5517,6 +5517,7 @@ PyDoc_STRVAR(os_pwritev__doc__,
 "\n"
 "- RWF_DSYNC\n"
 "- RWF_SYNC\n"
+"- RWF_APPEND\n"
 "\n"
 "Using non-zero flags requires Linux 4.7 or newer.");
 
@@ -8876,4 +8877,4 @@ os_waitstatus_to_exitcode(PyObject *module, PyObject *const *args, Py_ssize_t na
 #ifndef OS_WAITSTATUS_TO_EXITCODE_METHODDEF
     #define OS_WAITSTATUS_TO_EXITCODE_METHODDEF
 #endif /* !defined(OS_WAITSTATUS_TO_EXITCODE_METHODDEF) */
-/*[clinic end generated code: output=b97bbc8cb5078540 input=a9049054013a1b77]*/
+/*[clinic end generated code: output=9623b9e6f3809842 input=a9049054013a1b77]*/
diff --git a/Modules/posixmodule.c b/Modules/posixmodule.c
index 59ac47de1a709..47ae7a8c22ac2 100644
--- a/Modules/posixmodule.c
+++ b/Modules/posixmodule.c
@@ -9778,6 +9778,7 @@ The flags argument contains a bitwise OR of zero or more of the following flags:
 
 - RWF_DSYNC
 - RWF_SYNC
+- RWF_APPEND
 
 Using non-zero flags requires Linux 4.7 or newer.
 [clinic start generated code]*/
@@ -9785,7 +9786,7 @@ Using non-zero flags requires Linux 4.7 or newer.
 static Py_ssize_t
 os_pwritev_impl(PyObject *module, int fd, PyObject *buffers, Py_off_t offset,
                 int flags)
-/*[clinic end generated code: output=e3dd3e9d11a6a5c7 input=803dc5ddbf0cfd3b]*/
+/*[clinic end generated code: output=e3dd3e9d11a6a5c7 input=35358c327e1a2a8e]*/
 {
     Py_ssize_t cnt;
     Py_ssize_t result;
@@ -14509,6 +14510,9 @@ all_ins(PyObject *m)
 #ifdef RWF_NOWAIT
     if (PyModule_AddIntConstant(m, "RWF_NOWAIT", RWF_NOWAIT)) return -1;
 #endif
+#ifdef RWF_APPEND
+    if (PyModule_AddIntConstant(m, "RWF_APPEND", RWF_APPEND)) return -1;
+#endif
 
 /* constants for posix_spawn */
 #ifdef HAVE_POSIX_SPAWN