def test_fromParentTicks(self):
mockTime = self.mockTime
b = self.newSysClock(tickRate=2000000)
mockTime.timeNow = 1000.0
c = CorrelatedClock(b, 1000, correlation=Correlation(50, 300))
self.assertAlmostEqual(c.fromParentTicks(50 + (400 - 300) * 2000),
400,
places=5)
c = CorrelatedClock(b, 1000, correlation=Correlation(50, 300), speed=0)
self.assertEquals(c.fromParentTicks(50), 300)
self.assertEquals(c.fromParentTicks(100), 300)
def test_differentBranches(self):
a = SysClock(tickRate=1000000)
a1 = CorrelatedClock(a, tickRate=100, correlation=(50,0))
a2 = CorrelatedClock(a1, tickRate=78, correlation=(28,999))
a3 = CorrelatedClock(a2, tickRate=178, correlation=(5,1003))
a4 = CorrelatedClock(a3, tickRate=28, correlation=(17,9))
b3 = CorrelatedClock(a2, tickRate=1000, correlation=(10,20))
b4 = CorrelatedClock(b3, tickRate=2000, correlation=(15,90))
v = a4.toParentTicks(500)
v = a3.toParentTicks(v)
v = b3.fromParentTicks(v)
v = b4.fromParentTicks(v)
self.assertEquals(a4.toOtherClockTicks(b4, 500), v)
def test_fromParentTicks(self):
mockTime = self.mockTime
mockTime.timeNow = 1000.0
b = SysClock(tickRate=2000000)
c = CorrelatedClock(b, 1000, correlation=(50,300))
self.assertAlmostEqual(c.fromParentTicks(50 + (400-300)*2000), 400, places=5 )
def algorithm(self):
candidateClock = CorrelatedClock(self.clock.getParent(),
tickRate=self.clock.tickRate,
correlation=self.clock.correlation)
while True:
update = False
cumulativeOffset = None
candidate = (yield self.timeoutSecs)
t = self.clock.ticks
currentDispersion = self.clock.dispersionAtTime(t)
if candidate is not None:
candidateClock.correlation = candidate.calcCorrelationFor(
self.clock, self.localMaxFreqErrorPpm)
candidateDispersion = candidateClock.dispersionAtTime(t)
update = candidateDispersion < currentDispersion
if update:
pt = self.clock.toParentTicks(t)
adjustment = candidateClock.fromParentTicks(pt) - t
if cumulativeOffset is None:
cumulativeOffset = 0
else:
cumulativeOffset += adjustment
self.clock.correlation = candidateClock.correlation
self.onClockAdjusted(
self.clock.ticks, adjustment,
1000000000 * currentDispersion,
1000000000 * candidateDispersion,
self.clock.correlation.errorGrowthRate)
else:
pass
# update worst dispersion seen so far
self.worstDispersion = max(self.worstDispersion,
currentDispersion,
candidateDispersion)
co = cumulativeOffset or 0 # convert None to 0
self.log.info(
"Old / New dispersion (millis) is %.5f / %.5f ... offset=%20d new best candidate? %s\n"
% (1000 * currentDispersion, 1000 * candidateDispersion,
co, str(update)))
else:
self.log.info("Timeout. Dispersion (millis) is %.5f\n" %
(1000 * currentDispersion, ))
# retry more quickly if we didn't get an improved candidate
if update:
time.sleep(self.repeatSecs)
else:
time.sleep(self.timeoutSecs)
def test_differentBranches(self):
a = self.newSysClock(tickRate=1000000)
a1 = CorrelatedClock(a, tickRate=100, correlation=Correlation(50, 0))
a2 = CorrelatedClock(a1, tickRate=78, correlation=Correlation(28, 999))
a3 = CorrelatedClock(a2,
tickRate=178,
correlation=Correlation(5, 1003))
a4 = CorrelatedClock(a3, tickRate=28, correlation=Correlation(17, 9))
b3 = CorrelatedClock(a2,
tickRate=1000,
correlation=Correlation(10, 20))
b4 = CorrelatedClock(b3,
tickRate=2000,
correlation=Correlation(15, 90))
v = a4.toParentTicks(500)
v = a3.toParentTicks(v)
v = b3.fromParentTicks(v)
v = b4.fromParentTicks(v)
self.assertEquals(a4.toOtherClockTicks(b4, 500), v)