1 files changed, 110 insertions, 0 deletions
diff --git a/ouroboros/qos.py b/ouroboros/qos.py
new file mode 100644
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+++ b/ouroboros/qos.py
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+#
+# Ouroboros - Copyright (C) 2016 - 2020
+#
+# Python API for applications - QoS
+#
+#    Dimitri Staessens <[email protected]>
+#
+# 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/.
+#
+
+from _ouroboros_cffi import ffi
+from math import modf
+from typing import Optional
+
+# Some constants
+MILLION = 1000 * 1000
+BILLION = 1000 * 1000 * 1000
+
+
+class QoSSpec:
+    """
+    delay:        In ms, default 1000s
+    bandwidth:    In bits / s, default 0
+    availability: Class of 9s, default 0
+    loss:         Packet loss in ppm, default MILLION
+    ber:          Bit error rate, errors per billion bits. default BILLION
+    in_order:     In-order delivery, enables FRCT, default 0
+    max_gap:      Maximum interruption in ms, default MILLION
+    cypher_s:     Requested encryption strength in bits
+    """
+
+    def __init__(self,
+                 delay: int = MILLION,
+                 bandwidth: int = 0,
+                 availability: int = 0,
+                 loss: int = 1,
+                 ber: int = MILLION,
+                 in_order: int = 0,
+                 max_gap: int = MILLION,
+                 cypher_s: int = 0):
+        self.delay = delay
+        self.bandwidth = bandwidth
+        self.availability = availability
+        self.loss = loss
+        self.ber = ber
+        self.in_order = in_order
+        self.max_gap = max_gap
+        self.cypher_s = cypher_s
+
+
+def _fl_to_timespec(timeo: float):
+    if timeo is None:
+        return ffi.NULL
+    elif timeo <= 0:
+        return ffi.new("struct timespec *", [0, 0])
+    else:
+        frac, whole = modf(timeo)
+        _timeo = ffi.new("struct timespec *")
+        _timeo.tv_sec = whole
+        _timeo.tv_nsec = frac * BILLION
+        return _timeo
+
+
+def _timespec_to_fl(_timeo) -> Optional[float]:
+    if _timeo is ffi.NULL:
+        return None
+    elif _timeo.tv_sec <= 0 and _timeo.tv_nsec == 0:
+        return 0
+    else:
+        return _timeo.tv_sec + _timeo.tv_nsec / BILLION
+
+
+def _qos_to_qosspec(qos: QoSSpec):
+    if qos is None:
+        return ffi.NULL
+    else:
+        return ffi.new("qosspec_t *",
+                       [qos.delay,
+                        qos.bandwidth,
+                        qos.availability,
+                        qos.loss,
+                        qos.ber,
+                        qos.in_order,
+                        qos.max_gap,
+                        qos.cypher_s])
+
+
+def _qosspec_to_qos(_qos) -> Optional[QoSSpec]:
+    if _qos is ffi.NULL:
+        return None
+    else:
+        return QoSSpec(delay=_qos.delay,
+                       bandwidth=_qos.bandwidth,
+                       availability=_qos.availability,
+                       loss=_qos.loss,
+                       ber=_qos.ber,
+                       in_order=_qos.in_order,
+                       max_gap=_qos.max_gap,
+                       cypher_s=_qos.cypher_s)