Ausgabe der neuen DB Einträge

venv/lib/python3.9/site-packages/twisted/internet/fdesc.py

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+# -*- test-case-name: twisted.test.test_fdesc -*-
+# Copyright (c) Twisted Matrix Laboratories.
+# See LICENSE for details.
+
+
+"""
+Utility functions for dealing with POSIX file descriptors.
+"""
+
+import os
+import errno
+try:
+    import fcntl
+except ImportError:
+    fcntl = None
+
+# twisted imports
+from twisted.internet.main import CONNECTION_LOST, CONNECTION_DONE
+
+
+def setNonBlocking(fd):
+    """
+    Set the file description of the given file descriptor to non-blocking.
+    """
+    flags = fcntl.fcntl(fd, fcntl.F_GETFL)
+    flags = flags | os.O_NONBLOCK
+    fcntl.fcntl(fd, fcntl.F_SETFL, flags)
+
+
+def setBlocking(fd):
+    """
+    Set the file description of the given file descriptor to blocking.
+    """
+    flags = fcntl.fcntl(fd, fcntl.F_GETFL)
+    flags = flags & ~os.O_NONBLOCK
+    fcntl.fcntl(fd, fcntl.F_SETFL, flags)
+
+
+if fcntl is None:
+    # fcntl isn't available on Windows.  By default, handles aren't
+    # inherited on Windows, so we can do nothing here.
+    _setCloseOnExec = _unsetCloseOnExec = lambda fd: None
+else:
+    def _setCloseOnExec(fd):
+        """
+        Make a file descriptor close-on-exec.
+        """
+        flags = fcntl.fcntl(fd, fcntl.F_GETFD)
+        flags = flags | fcntl.FD_CLOEXEC
+        fcntl.fcntl(fd, fcntl.F_SETFD, flags)
+
+
+    def _unsetCloseOnExec(fd):
+        """
+        Make a file descriptor close-on-exec.
+        """
+        flags = fcntl.fcntl(fd, fcntl.F_GETFD)
+        flags = flags & ~fcntl.FD_CLOEXEC
+        fcntl.fcntl(fd, fcntl.F_SETFD, flags)
+
+
+def readFromFD(fd, callback):
+    """
+    Read from file descriptor, calling callback with resulting data.
+
+    If successful, call 'callback' with a single argument: the
+    resulting data.
+
+    Returns same thing FileDescriptor.doRead would: CONNECTION_LOST,
+    CONNECTION_DONE, or None.
+
+    @type fd: C{int}
+    @param fd: non-blocking file descriptor to be read from.
+    @param callback: a callable which accepts a single argument. If
+    data is read from the file descriptor it will be called with this
+    data. Handling exceptions from calling the callback is up to the
+    caller.
+
+    Note that if the descriptor is still connected but no data is read,
+    None will be returned but callback will not be called.
+
+    @return: CONNECTION_LOST on error, CONNECTION_DONE when fd is
+    closed, otherwise None.
+    """
+    try:
+        output = os.read(fd, 8192)
+    except (OSError, IOError) as ioe:
+        if ioe.args[0] in (errno.EAGAIN, errno.EINTR):
+            return
+        else:
+            return CONNECTION_LOST
+    if not output:
+        return CONNECTION_DONE
+    callback(output)
+
+
+def writeToFD(fd, data):
+    """
+    Write data to file descriptor.
+
+    Returns same thing FileDescriptor.writeSomeData would.
+
+    @type fd: C{int}
+    @param fd: non-blocking file descriptor to be written to.
+    @type data: C{str} or C{buffer}
+    @param data: bytes to write to fd.
+
+    @return: number of bytes written, or CONNECTION_LOST.
+    """
+    try:
+        return os.write(fd, data)
+    except (OSError, IOError) as io:
+        if io.errno in (errno.EAGAIN, errno.EINTR):
+            return 0
+        return CONNECTION_LOST
+
+
+__all__ = ["setNonBlocking", "setBlocking", "readFromFD", "writeToFD"]