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| author | Uwe Hermann <uwe@hermann-uwe.de> | 2012-07-11 22:19:31 +0200 |
|---|---|---|
| committer | Uwe Hermann <uwe@hermann-uwe.de> | 2012-07-11 23:13:36 +0200 |
| commit | 2fcd7c22852436c3226de9007e88cb305cce1b00 (patch) | |
| tree | b1681936eec81e3bd91eb43fb395fc2bcf908aba /decoders/i2c | |
| parent | b5d3ea69628d49ab5b26e064559f7a237b46c086 (diff) | |
| download | libsigrokdecode-2fcd7c22852436c3226de9007e88cb305cce1b00.tar.gz libsigrokdecode-2fcd7c22852436c3226de9007e88cb305cce1b00.zip | |
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 <lars@metafoo.de> for bringing this to our
attention.
Diffstat (limited to 'decoders/i2c')
| -rw-r--r-- | decoders/i2c/i2c.py | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/decoders/i2c/i2c.py b/decoders/i2c/i2c.py index 0e79497..53321eb 100644 --- a/decoders/i2c/i2c.py +++ b/decoders/i2c/i2c.py @@ -88,6 +88,7 @@ class Decoder(srd.Decoder): self.state = 'FIND START' self.oldscl = None self.oldsda = None + self.oldpins = None def start(self, metadata): self.out_proto = self.add(srd.OUTPUT_PROTO, 'i2c') @@ -198,7 +199,12 @@ class Decoder(srd.Decoder): super(Decoder, self).put(self.startsample, self.samplenum, output_id, data) def decode(self, ss, es, data): - for (self.samplenum, (scl, sda)) in data: + for (self.samplenum, pins) in data: + + # Ignore identical samples early on (for performance reasons). + if self.oldpins == pins: + continue + self.oldpins, (scl, sda) = pins, pins # First sample: Save SCL/SDA value. if self.oldscl == None: |