From 2fcd7c22852436c3226de9007e88cb305cce1b00 Mon Sep 17 00:00:00 2001 From: Uwe Hermann Date: Wed, 11 Jul 2012 22:19:31 +0200 Subject: srd: Performance improvements for various PDs. Ignore/skip identical samples in most (low-level) PDs, as we're usually (but not necessarily always) only interested in pin changes. This yields a significant performance improvement for the PDs. The mechanism was already used in the 'i2s', 'jtag', and 'lpc' PDs, but not yet in all supported low-level decoders. The following PDs now also use this mechanism: 'dcf77', 'i2c', 'spi', 'uart', and 'usb_signalling'. Thanks Lars-Peter Clausen for bringing this to our attention. --- decoders/spi/spi.py | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) (limited to 'decoders/spi/spi.py') diff --git a/decoders/spi/spi.py b/decoders/spi/spi.py index 2f10ef4..1085786 100644 --- a/decoders/spi/spi.py +++ b/decoders/spi/spi.py @@ -74,6 +74,7 @@ class Decoder(srd.Decoder): self.samplenum = -1 self.cs_was_deasserted_during_data_word = 0 self.oldcs = -1 + self.oldpins = None def start(self, metadata): self.out_proto = self.add(srd.OUTPUT_PROTO, 'spi') @@ -84,7 +85,12 @@ class Decoder(srd.Decoder): def decode(self, ss, es, data): # TODO: Either MISO or MOSI could be optional. CS# is optional. - for (self.samplenum, (miso, mosi, sck, cs)) in data: + for (self.samplenum, pins) in data: + + # Ignore identical samples early on (for performance reasons). + if self.oldpins == pins: + continue + self.oldpins, (miso, mosi, sck, cs) = pins, pins if self.oldcs != cs: # Send all CS# pin value changes. -- cgit v1.2.3-70-g09d2