Ausgabe der neuen DB Einträge

venv/lib/python3.9/site-packages/twisted/python/systemd.py

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+# -*- test-case-name: twisted.python.test.test_systemd -*-
+# Copyright (c) Twisted Matrix Laboratories.
+# See LICENSE for details.
+
+"""
+Integration with systemd.
+
+Currently only the minimum APIs necessary for using systemd's socket activation
+feature are supported.
+"""
+
+from __future__ import division, absolute_import
+
+__all__ = ['ListenFDs']
+
+from os import getpid
+
+
+class ListenFDs(object):
+    """
+    L{ListenFDs} provides access to file descriptors inherited from systemd.
+
+    Typically L{ListenFDs.fromEnvironment} should be used to construct a new
+    instance of L{ListenFDs}.
+
+    @cvar _START: File descriptors inherited from systemd are always
+        consecutively numbered, with a fixed lowest "starting" descriptor.  This
+        gives the default starting descriptor.  Since this must agree with the
+        value systemd is using, it typically should not be overridden.
+    @type _START: C{int}
+
+    @ivar _descriptors: A C{list} of C{int} giving the descriptors which were
+        inherited.
+    """
+    _START = 3
+
+    def __init__(self, descriptors):
+        """
+        @param descriptors: The descriptors which will be returned from calls to
+            C{inheritedDescriptors}.
+        """
+        self._descriptors = descriptors
+
+
+    @classmethod
+    def fromEnvironment(cls, environ=None, start=None):
+        """
+        @param environ: A dictionary-like object to inspect to discover
+            inherited descriptors.  By default, L{None}, indicating that the
+            real process environment should be inspected.  The default is
+            suitable for typical usage.
+
+        @param start: An integer giving the lowest value of an inherited
+            descriptor systemd will give us.  By default, L{None}, indicating
+            the known correct (that is, in agreement with systemd) value will be
+            used.  The default is suitable for typical usage.
+
+        @return: A new instance of C{cls} which can be used to look up the
+            descriptors which have been inherited.
+        """
+        if environ is None:
+            from os import environ
+        if start is None:
+            start = cls._START
+
+        descriptors = []
+
+        try:
+            pid = int(environ['LISTEN_PID'])
+        except (KeyError, ValueError):
+            pass
+        else:
+            if pid == getpid():
+                try:
+                    count = int(environ['LISTEN_FDS'])
+                except (KeyError, ValueError):
+                    pass
+                else:
+                    descriptors = range(start, start + count)
+                    del environ['LISTEN_PID'], environ['LISTEN_FDS']
+
+        return cls(descriptors)
+
+
+    def inheritedDescriptors(self):
+        """
+        @return: The configured list of descriptors.
+        """
+        return list(self._descriptors)