Ok, thanks. I'm moving values to start at 10^8 instead of zero, and it seems to work fine.
On Apr 6, 7:18 pm, "Ikai L (Google)" <[email protected]> wrote: > I'm looking at the standard memcached documentation: > > http://github.com/memcached/memcached/blob/master/doc/protocol.txt > > <http://github.com/memcached/memcached/blob/master/doc/protocol.txt>"Note > that underflow in the "decr" command is caught: if a client tries > > to decrease the value below 0, the new value will be 0. Overflow in > the "incr" command will wrap around the 64 bit mark." > > I'm not sure why our version of memcached behaves the way it does. I suspect > it has to do with storing numbers as either signed or unsigned ints > depending on what you first set the value to, with unsigned ints being the > 90% case. > > When in doubt, use the solution that results in the least confusion. And > document. > > > > On Tue, Apr 6, 2010 at 9:09 AM, Nacho Coloma <[email protected]> wrote: > > Hi all, > > > I am trying to use memcache.increment to move to negative values, > > starting at 0. According to the javadoc[1]: > > > "To facilitate use as an atomic countdown, incrementing by a negative > > value (i.e. decrementing) will not go below zero: incrementing 2 by -5 > > will return 0, not -3. However, due to the way numbers are stored, > > decrementing -3 by -5 will result in -8; so the zero-floor rule only > > applies to decrementing numbers that were positive." > > > What is the rationale behind this, and why is 0 considered positive? I > > may have missed something, but I did not understand a similar behavior > > in python's memcache.decr() docs. If my counter can hold positive or > > negative values, what options do I have apart from initializing at > > 2^30? > > > -- Nacho > > > [1] > > >http://code.google.com/appengine/docs/java/javadoc/com/google/appengi...) > > > -- > > You received this message because you are subscribed to the Google Groups > > "Google App Engine for Java" group. > > To post to this group, send email to > > [email protected]. > > To unsubscribe from this group, send email to > > [email protected]<google-appengine-java%[email protected]> > > . > > For more options, visit this group at > >http://groups.google.com/group/google-appengine-java?hl=en. > > -- > Ikai Lan > Developer Programs Engineer, Google App > Enginehttp://googleappengine.blogspot.com|http://twitter.com/app_engine -- You received this message because you are subscribed to the Google Groups "Google App Engine for Java" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/google-appengine-java?hl=en.
