From 15a8a05595c72d328abdea8e3b23f1b558cc46bf Mon Sep 17 00:00:00 2001 From: Gerhard Sittig Date: Sun, 28 Jan 2018 20:49:48 +0100 Subject: graycode, morse, pwm, usb_request, wiegand: cope with absent sample rate Improve robustness of some more protocol decoders. Few of them never checked for the availability of a sample rate in the first place, others checked for the presence of a spec but would not cope with a value of 0. Some checked the value only after processing it, which could result in runtime errors. This change is motivated by bug #1118. --- decoders/wiegand/pd.py | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) (limited to 'decoders/wiegand') diff --git a/decoders/wiegand/pd.py b/decoders/wiegand/pd.py index ea873ea..c494789 100644 --- a/decoders/wiegand/pd.py +++ b/decoders/wiegand/pd.py @@ -19,6 +19,9 @@ import sigrokdecode as srd +class SamplerateError(Exception): + pass + class Decoder(srd.Decoder): api_version = 3 id = 'wiegand' @@ -51,6 +54,7 @@ class Decoder(srd.Decoder): self.reset() def reset(self): + self.samplerate = None self._samples_per_bit = 10 self._d0_prev = None @@ -73,9 +77,11 @@ class Decoder(srd.Decoder): def metadata(self, key, value): 'Receive decoder metadata about the data stream.' if key == srd.SRD_CONF_SAMPLERATE: - ms_per_sample = 1000 * (1.0 / value) - ms_per_bit = float(self.options['bitwidth_ms']) - self._samples_per_bit = int(max(1, int(ms_per_bit / ms_per_sample))) + self.samplerate = value + if self.samplerate: + ms_per_sample = 1000 * (1.0 / self.samplerate) + ms_per_bit = float(self.options['bitwidth_ms']) + self._samples_per_bit = int(max(1, int(ms_per_bit / ms_per_sample))) def _update_state(self, state, bit=None): 'Update state and bit values when they change.' @@ -106,6 +112,8 @@ class Decoder(srd.Decoder): self._bits = [] def decode(self): + if not self.samplerate: + raise SamplerateError('Cannot decode without samplerate.') while True: # TODO: Come up with more appropriate self.wait() conditions. (d0, d1) = self.wait() -- cgit v1.2.3-70-g09d2