changed signed handling

This commit is contained in:
Dave Schuyler 2005-04-21 00:28:46 +00:00
parent c0c9cb499e
commit d058dcfaff
2 changed files with 24 additions and 16 deletions

View File

@ -23,8 +23,9 @@ NetworkTimePrecision = 100.0
# These values are derived from the above.
NetworkTimeMask = (1 << NetworkTimeBits) - 1
NetworkTimeSignedMask = NetworkTimeMask >> 1 # the max absolute value bits.
NetworkTimeTopBits = 32 - NetworkTimeBits
MaxTimeDelta = (NetworkTimeMask / 2.0) / NetworkTimePrecision
MaxTimeDelta = NetworkTimeSignedMask / NetworkTimePrecision
# This is the maximum number of seconds by which we expect our clock
# (or the server's clock) to drift over an hour.
@ -65,7 +66,7 @@ class ClockDelta(DirectObject.DirectObject):
# uncertainty increases over time (due to relative clock
# drift).
self.lastResync = 0.0
self.accept("resetClock", self.__resetClock)
def getDelta(self):
@ -76,10 +77,10 @@ class ClockDelta(DirectObject.DirectObject):
# as a number of seconds plus or minus. Returns None,
# representing infinite uncertainty, if we have never received
# a time measurement.
if self.uncertainty == None:
return None
now = self.globalClock.getRealTime()
elapsed = now - self.lastResync
return self.uncertainty + elapsed * ClockDriftPerSecond
@ -88,7 +89,7 @@ class ClockDelta(DirectObject.DirectObject):
# Returns the local time at which we last resynchronized the
# clock delta.
return self.lastResync
def __resetClock(self, timeDelta):
"""
this is called when the global clock gets adjusted
@ -134,7 +135,7 @@ class ClockDelta(DirectObject.DirectObject):
value is negative if the test was not even considered (because
it happened too soon after another recent request).
"""
now = self.globalClock.getRealTime()
if now - self.lastResync < P2PResyncDelay:
# We can't process this request; it came in on the heels
@ -143,7 +144,7 @@ class ClockDelta(DirectObject.DirectObject):
# request is meaningless.
assert(self.notify.debug("Ignoring request for resync from %s within %.3f s." % (avId, now - self.lastResync)))
return -1
# The timestamp value will be a timestamp that we sent out
# previously, echoed back to us. Therefore we can confidently
# convert it back into our local time, even though we suspect
@ -168,7 +169,7 @@ class ClockDelta(DirectObject.DirectObject):
self.notify.info("Got sync +/- %.3f s, elapsed %.3f s, from %s." % (uncertainty, elapsed, avId))
delta -= elapsed / 2.0
uncertainty += elapsed / 2.0
gotSync = self.newDelta(local, delta, uncertainty, trustNew = 0)
return gotSync
@ -188,7 +189,7 @@ class ClockDelta(DirectObject.DirectObject):
# Our previous measurement was self.delta +/- oldUncertainty;
# our new measurement is newDelta +/- newUncertainty. Take
# the intersection of both.
oldLow = self.delta - oldUncertainty
oldHigh = self.delta + oldUncertainty
newLow = newDelta - newUncertainty
@ -196,20 +197,20 @@ class ClockDelta(DirectObject.DirectObject):
low = max(oldLow, newLow)
high = min(oldHigh, newHigh)
# If there is no intersection, whoops! Either the old
# measurement or the new measurement is completely wrong.
if low > high:
if not trustNew:
self.notify.info('discarding new delta.')
return 0
self.notify.info('discarding previous delta.')
else:
newDelta = (low + high) / 2.0
newUncertainty = (high - low) / 2.0
assert(self.notify.debug('intersection at %.3f s, +/- %.3f s.' % (newDelta, newUncertainty)))
self.delta = newDelta
self.uncertainty = newUncertainty
self.lastResync = localTime
@ -245,9 +246,9 @@ class ClockDelta(DirectObject.DirectObject):
# Assume the bits is either 16 or 32. If it's 32, no need
# to sign-extend. 32 bits gives us about 227 days of
# continuous timestamp.
diff = networkTime - ntime
return now + float(diff) / ticksPerSec
def localToNetworkTime(self, localTime, bits = 16,
@ -310,6 +311,13 @@ class ClockDelta(DirectObject.DirectObject):
Preserves the lower NetworkTimeBits of the networkTime value,
and extends the sign bit all the way up.
"""
return ((networkTime & NetworkTimeMask) << NetworkTimeTopBits) >> NetworkTimeTopBits
if networkTime < 0:
# flip the sign, mask it as if it were positive, flip the sign back:
r = (networkTime * -1 & NetworkTimeSignedMask) * -1
else:
r = networkTime & NetworkTimeSignedMask
assert -32768 <= r <= 32767
return r
globalClockDelta = ClockDelta()

View File

@ -1098,7 +1098,7 @@ def randInt32(rng=random.random):
"""
i = int(rng() * 0x7FFFFFFF)
if rng() < .5:
i += 0x80000000
i *= -1
return i
class Enum: