bpo-41625: Expose the splice() system call in the os module (GH-21947)
diff --git a/Modules/clinic/posixmodule.c.h b/Modules/clinic/posixmodule.c.h
index f5826e3..ee4ee8c 100644
--- a/Modules/clinic/posixmodule.c.h
+++ b/Modules/clinic/posixmodule.c.h
@@ -5674,6 +5674,106 @@ os_copy_file_range(PyObject *module, PyObject *const *args, Py_ssize_t nargs, Py
#endif /* defined(HAVE_COPY_FILE_RANGE) */
+#if defined(HAVE_SPLICE)
+
+PyDoc_STRVAR(os_splice__doc__,
+"splice($module, /, src, dst, count, offset_src=None, offset_dst=None,\n"
+" flags=0)\n"
+"--\n"
+"\n"
+"Transfer count bytes from one pipe to a descriptor or vice versa.\n"
+"\n"
+" src\n"
+" Source file descriptor.\n"
+" dst\n"
+" Destination file descriptor.\n"
+" count\n"
+" Number of bytes to copy.\n"
+" offset_src\n"
+" Starting offset in src.\n"
+" offset_dst\n"
+" Starting offset in dst.\n"
+" flags\n"
+" Flags to modify the semantics of the call.\n"
+"\n"
+"If offset_src is None, then src is read from the current position;\n"
+"respectively for offset_dst. The offset associated to the file\n"
+"descriptor that refers to a pipe must be None.");
+
+#define OS_SPLICE_METHODDEF \
+ {"splice", (PyCFunction)(void(*)(void))os_splice, METH_FASTCALL|METH_KEYWORDS, os_splice__doc__},
+
+static PyObject *
+os_splice_impl(PyObject *module, int src, int dst, Py_ssize_t count,
+ PyObject *offset_src, PyObject *offset_dst,
+ unsigned int flags);
+
+static PyObject *
+os_splice(PyObject *module, PyObject *const *args, Py_ssize_t nargs, PyObject *kwnames)
+{
+ PyObject *return_value = NULL;
+ static const char * const _keywords[] = {"src", "dst", "count", "offset_src", "offset_dst", "flags", NULL};
+ static _PyArg_Parser _parser = {NULL, _keywords, "splice", 0};
+ PyObject *argsbuf[6];
+ Py_ssize_t noptargs = nargs + (kwnames ? PyTuple_GET_SIZE(kwnames) : 0) - 3;
+ int src;
+ int dst;
+ Py_ssize_t count;
+ PyObject *offset_src = Py_None;
+ PyObject *offset_dst = Py_None;
+ unsigned int flags = 0;
+
+ args = _PyArg_UnpackKeywords(args, nargs, NULL, kwnames, &_parser, 3, 6, 0, argsbuf);
+ if (!args) {
+ goto exit;
+ }
+ src = _PyLong_AsInt(args[0]);
+ if (src == -1 && PyErr_Occurred()) {
+ goto exit;
+ }
+ dst = _PyLong_AsInt(args[1]);
+ if (dst == -1 && PyErr_Occurred()) {
+ goto exit;
+ }
+ {
+ Py_ssize_t ival = -1;
+ PyObject *iobj = _PyNumber_Index(args[2]);
+ if (iobj != NULL) {
+ ival = PyLong_AsSsize_t(iobj);
+ Py_DECREF(iobj);
+ }
+ if (ival == -1 && PyErr_Occurred()) {
+ goto exit;
+ }
+ count = ival;
+ }
+ if (!noptargs) {
+ goto skip_optional_pos;
+ }
+ if (args[3]) {
+ offset_src = args[3];
+ if (!--noptargs) {
+ goto skip_optional_pos;
+ }
+ }
+ if (args[4]) {
+ offset_dst = args[4];
+ if (!--noptargs) {
+ goto skip_optional_pos;
+ }
+ }
+ if (!_PyLong_UnsignedInt_Converter(args[5], &flags)) {
+ goto exit;
+ }
+skip_optional_pos:
+ return_value = os_splice_impl(module, src, dst, count, offset_src, offset_dst, flags);
+
+exit:
+ return return_value;
+}
+
+#endif /* defined(HAVE_SPLICE) */
+
#if defined(HAVE_MKFIFO)
PyDoc_STRVAR(os_mkfifo__doc__,
@@ -8864,6 +8964,10 @@ os_waitstatus_to_exitcode(PyObject *module, PyObject *const *args, Py_ssize_t na
#define OS_COPY_FILE_RANGE_METHODDEF
#endif /* !defined(OS_COPY_FILE_RANGE_METHODDEF) */
+#ifndef OS_SPLICE_METHODDEF
+ #define OS_SPLICE_METHODDEF
+#endif /* !defined(OS_SPLICE_METHODDEF) */
+
#ifndef OS_MKFIFO_METHODDEF
#define OS_MKFIFO_METHODDEF
#endif /* !defined(OS_MKFIFO_METHODDEF) */
@@ -9059,4 +9163,4 @@ 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=49b7ed768242ef7c input=a9049054013a1b77]*/
+/*[clinic end generated code: output=8a59e91178897267 input=a9049054013a1b77]*/
diff --git a/Modules/posixmodule.c b/Modules/posixmodule.c
index 0764453..ecab147 100644
--- a/Modules/posixmodule.c
+++ b/Modules/posixmodule.c
@@ -6521,7 +6521,6 @@ os_spawnve_impl(PyObject *module, int mode, path_t *path, PyObject *argv,
#endif /* HAVE_SPAWNV */
-
#ifdef HAVE_FORK
/* Helper function to validate arguments.
@@ -10370,6 +10369,75 @@ os_copy_file_range_impl(PyObject *module, int src, int dst, Py_ssize_t count,
}
#endif /* HAVE_COPY_FILE_RANGE*/
+#ifdef HAVE_SPLICE
+/*[clinic input]
+
+os.splice
+ src: int
+ Source file descriptor.
+ dst: int
+ Destination file descriptor.
+ count: Py_ssize_t
+ Number of bytes to copy.
+ offset_src: object = None
+ Starting offset in src.
+ offset_dst: object = None
+ Starting offset in dst.
+ flags: unsigned_int = 0
+ Flags to modify the semantics of the call.
+
+Transfer count bytes from one pipe to a descriptor or vice versa.
+
+If offset_src is None, then src is read from the current position;
+respectively for offset_dst. The offset associated to the file
+descriptor that refers to a pipe must be None.
+[clinic start generated code]*/
+
+static PyObject *
+os_splice_impl(PyObject *module, int src, int dst, Py_ssize_t count,
+ PyObject *offset_src, PyObject *offset_dst,
+ unsigned int flags)
+/*[clinic end generated code: output=d0386f25a8519dc5 input=047527c66c6d2e0a]*/
+{
+ off_t offset_src_val, offset_dst_val;
+ off_t *p_offset_src = NULL;
+ off_t *p_offset_dst = NULL;
+ Py_ssize_t ret;
+ int async_err = 0;
+
+ if (count < 0) {
+ PyErr_SetString(PyExc_ValueError, "negative value for 'count' not allowed");
+ return NULL;
+ }
+
+ if (offset_src != Py_None) {
+ if (!Py_off_t_converter(offset_src, &offset_src_val)) {
+ return NULL;
+ }
+ p_offset_src = &offset_src_val;
+ }
+
+ if (offset_dst != Py_None) {
+ if (!Py_off_t_converter(offset_dst, &offset_dst_val)) {
+ return NULL;
+ }
+ p_offset_dst = &offset_dst_val;
+ }
+
+ do {
+ Py_BEGIN_ALLOW_THREADS
+ ret = splice(src, p_offset_src, dst, p_offset_dst, count, flags);
+ Py_END_ALLOW_THREADS
+ } while (ret < 0 && errno == EINTR && !(async_err = PyErr_CheckSignals()));
+
+ if (ret < 0) {
+ return (!async_err) ? posix_error() : NULL;
+ }
+
+ return PyLong_FromSsize_t(ret);
+}
+#endif /* HAVE_SPLICE*/
+
#ifdef HAVE_MKFIFO
/*[clinic input]
os.mkfifo
@@ -14550,6 +14618,7 @@ static PyMethodDef posix_methods[] = {
OS_POSIX_SPAWNP_METHODDEF
OS_READLINK_METHODDEF
OS_COPY_FILE_RANGE_METHODDEF
+ OS_SPLICE_METHODDEF
OS_RENAME_METHODDEF
OS_REPLACE_METHODDEF
OS_RMDIR_METHODDEF
@@ -15072,6 +15141,13 @@ all_ins(PyObject *m)
if (PyModule_AddIntConstant(m, "RWF_APPEND", RWF_APPEND)) return -1;
#endif
+/* constants for splice */
+#ifdef HAVE_SPLICE
+ if (PyModule_AddIntConstant(m, "SPLICE_F_MOVE", SPLICE_F_MOVE)) return -1;
+ if (PyModule_AddIntConstant(m, "SPLICE_F_NONBLOCK", SPLICE_F_NONBLOCK)) return -1;
+ if (PyModule_AddIntConstant(m, "SPLICE_F_MORE", SPLICE_F_MORE)) return -1;
+#endif
+
/* constants for posix_spawn */
#ifdef HAVE_POSIX_SPAWN
if (PyModule_AddIntConstant(m, "POSIX_SPAWN_OPEN", POSIX_SPAWN_OPEN)) return -1;