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/uart/uart.py | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) (limited to 'decoders/uart') diff --git a/decoders/uart/uart.py b/decoders/uart/uart.py index bb4d9e6..92c105c 100644 --- a/decoders/uart/uart.py +++ b/decoders/uart/uart.py @@ -103,6 +103,7 @@ class Decoder(srd.Decoder): self.startsample = [-1, -1] self.state = ['WAIT FOR START BIT', 'WAIT FOR START BIT'] self.oldbit = [None, None] + self.oldpins = None def start(self, metadata): self.samplerate = metadata['samplerate'] @@ -265,7 +266,12 @@ class Decoder(srd.Decoder): def decode(self, ss, es, data): # TODO: Either RX or TX could be omitted (optional probe). - for (self.samplenum, (rx, tx)) in data: + for (self.samplenum, pins) in data: + + # Ignore identical samples early on (for performance reasons). + if self.oldpins == pins: + continue + self.oldpins, (rx, tx) = pins, pins # First sample: Save RX/TX value. if self.oldbit[RX] == None: -- cgit v1.2.3-70-g09d2