diff options
Diffstat (limited to 'ouroboros/_timespec.py')
| -rw-r--r-- | ouroboros/_timespec.py | 51 |
1 files changed, 23 insertions, 28 deletions
diff --git a/ouroboros/_timespec.py b/ouroboros/_timespec.py index 2fcf666..1656eb2 100644 --- a/ouroboros/_timespec.py +++ b/ouroboros/_timespec.py @@ -1,64 +1,59 @@ # -# Ouroboros - Copyright (C) 2016 - 2026 -# -# Internal helpers for translating float seconds <-> struct timespec. -# -# Dimitri Staessens <dimitri@ouroboros.rocks> -# -# This library is free software; you can redistribute it and/or -# modify it under the terms of the GNU Lesser General Public License -# version 2.1 as published by the Free Software Foundation. -# -# This library 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 this library; if not, write to the Free Software -# Foundation, Inc., http://www.fsf.org/about/contact/. +# SPDX-FileCopyrightText: 2016 - 2026 Dimitri Staessens +# SPDX-License-Identifier: LGPL-2.1-only # -"""Shared float-seconds <-> ``struct timespec *`` conversions. +""" +Shared float-seconds <-> ``struct timespec *`` conversions. -The dev and event modules both deal in seconds-as-float timeouts on -the Python side and pass ``struct timespec *`` to the C library. -The helpers take the caller's ``ffi`` instance as a parameter so the -returned CData is bound to the right CFFI module. +The caller passes its own ``ffi`` instance so the returned CData is +bound to the right CFFI extension module. """ from __future__ import annotations from math import modf -from typing import Optional +from typing import TYPE_CHECKING, Any, Optional + +if TYPE_CHECKING: + from cffi import FFI BILLION = 1000 * 1000 * 1000 -def fl_to_timespec(ffi, timeo: Optional[float]): - """Convert *timeo* (seconds, or None) to a ``struct timespec *``. +def fl_to_timespec(ffi: FFI, timeo: Optional[float]) -> Any: + """ + Convert *timeo* (seconds, or None) to a ``struct timespec *``. *None* yields ``ffi.NULL`` (block forever). A non-positive *timeo* yields a zeroed timespec (async / poll). """ + if timeo is None: return ffi.NULL + if timeo <= 0: return ffi.new("struct timespec *", [0, 0]) + frac, whole = modf(timeo) _timeo = ffi.new("struct timespec *") _timeo.tv_sec = int(whole) _timeo.tv_nsec = int(frac * BILLION) + return _timeo -def timespec_to_fl(ffi, _timeo) -> Optional[float]: - """Convert a ``struct timespec *`` to seconds-as-float. +def timespec_to_fl(ffi: FFI, _timeo: Any) -> Optional[float]: + """ + Convert a ``struct timespec *`` to seconds-as-float. ``ffi.NULL`` yields *None* (block forever). """ + if _timeo == ffi.NULL: return None + if _timeo.tv_sec <= 0 and _timeo.tv_nsec == 0: return 0.0 + return _timeo.tv_sec + _timeo.tv_nsec / BILLION |