bpo-32410: Implement loop.sock_sendfile() (#4976)

1 files changed, 30 insertions, 0 deletions

diff --git a/Doc/library/asyncio-eventloop.rst b/Doc/library/asyncio-eventloop.rst
index 4fbbcd8..e63180b 100644
--- a/Doc/library/asyncio-eventloop.rst
+++ b/Doc/library/asyncio-eventloop.rst
@@ -701,6 +701,36 @@ Low-level socket operations
 
       :meth:`AbstractEventLoop.create_server` and :func:`start_server`.
 
+.. coroutinemethod:: AbstractEventLoop.sock_sendfile(sock, file, \
+                                                     offset=0, count=None, \
+                                                     *, fallback=True)
+
+   Send a file using high-performance :mod:`os.sendfile` if possible
+   and return the total number of bytes which were sent.
+
+   Asynchronous version of :meth:`socket.socket.sendfile`.
+
+   *sock* must be non-blocking :class:`~socket.socket` of
+   :const:`socket.SOCK_STREAM` type.
+
+   *file* must be a regular file object opened in binary mode.
+
+   *offset* tells from where to start reading the file. If specified,
+   *count* is the total number of bytes to transmit as opposed to
+   sending the file until EOF is reached. File position is updated on
+   return or also in case of error in which case :meth:`file.tell()
+   <io.IOBase.tell>` can be used to figure out the number of bytes
+   which were sent.
+
+   *fallback* set to ``True`` makes asyncio to manually read and send
+   the file when the platform does not support the sendfile syscall
+   (e.g. Windows or SSL socket on Unix).
+
+   Raise :exc:`RuntimeError` if the system does not support
+   *sendfile* syscall and *fallback* is ``False``.
+
+   .. versionadded:: 3.7
+
 
 Resolve host name
 -----------------