added v3

venv/lib/python3.11/site-packages/paramiko/pipe.py

@@ -0,0 +1,148 @@
+# Copyright (C) 2003-2007  Robey Pointer <robeypointer@gmail.com>
+#
+# This file is part of paramiko.
+#
+# Paramiko is free software; you can redistribute it and/or modify it under the
+# terms of the GNU Lesser General Public License as published by the Free
+# Software Foundation; either version 2.1 of the License, or (at your option)
+# any later version.
+#
+# Paramiko is distributed in the hope that it will be useful, but WITHOUT ANY
+# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
+# A PARTICULAR PURPOSE.  See the GNU Lesser General Public License for more
+# details.
+#
+# You should have received a copy of the GNU Lesser General Public License
+# along with Paramiko; if not, write to the Free Software Foundation, Inc.,
+# 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301 USA.
+
+"""
+Abstraction of a one-way pipe where the read end can be used in
+`select.select`. Normally this is trivial, but Windows makes it nearly
+impossible.
+
+The pipe acts like an Event, which can be set or cleared. When set, the pipe
+will trigger as readable in `select <select.select>`.
+"""
+
+import sys
+import os
+import socket
+
+
+def make_pipe():
+    if sys.platform[:3] != "win":
+        p = PosixPipe()
+    else:
+        p = WindowsPipe()
+    return p
+
+
+class PosixPipe:
+    def __init__(self):
+        self._rfd, self._wfd = os.pipe()
+        self._set = False
+        self._forever = False
+        self._closed = False
+
+    def close(self):
+        os.close(self._rfd)
+        os.close(self._wfd)
+        # used for unit tests:
+        self._closed = True
+
+    def fileno(self):
+        return self._rfd
+
+    def clear(self):
+        if not self._set or self._forever:
+            return
+        os.read(self._rfd, 1)
+        self._set = False
+
+    def set(self):
+        if self._set or self._closed:
+            return
+        self._set = True
+        os.write(self._wfd, b"*")
+
+    def set_forever(self):
+        self._forever = True
+        self.set()
+
+
+class WindowsPipe:
+    """
+    On Windows, only an OS-level "WinSock" may be used in select(), but reads
+    and writes must be to the actual socket object.
+    """
+
+    def __init__(self):
+        serv = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+        serv.bind(("127.0.0.1", 0))
+        serv.listen(1)
+
+        # need to save sockets in _rsock/_wsock so they don't get closed
+        self._rsock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+        self._rsock.connect(("127.0.0.1", serv.getsockname()[1]))
+
+        self._wsock, addr = serv.accept()
+        serv.close()
+        self._set = False
+        self._forever = False
+        self._closed = False
+
+    def close(self):
+        self._rsock.close()
+        self._wsock.close()
+        # used for unit tests:
+        self._closed = True
+
+    def fileno(self):
+        return self._rsock.fileno()
+
+    def clear(self):
+        if not self._set or self._forever:
+            return
+        self._rsock.recv(1)
+        self._set = False
+
+    def set(self):
+        if self._set or self._closed:
+            return
+        self._set = True
+        self._wsock.send(b"*")
+
+    def set_forever(self):
+        self._forever = True
+        self.set()
+
+
+class OrPipe:
+    def __init__(self, pipe):
+        self._set = False
+        self._partner = None
+        self._pipe = pipe
+
+    def set(self):
+        self._set = True
+        if not self._partner._set:
+            self._pipe.set()
+
+    def clear(self):
+        self._set = False
+        if not self._partner._set:
+            self._pipe.clear()
+
+
+def make_or_pipe(pipe):
+    """
+    wraps a pipe into two pipe-like objects which are "or"d together to
+    affect the real pipe. if either returned pipe is set, the wrapped pipe
+    is set. when both are cleared, the wrapped pipe is cleared.
+    """
+    p1 = OrPipe(pipe)
+    p2 = OrPipe(pipe)
+    p1._partner = p2
+    p2._partner = p1
+    return p1, p2