Tim Peters wrote:
ZODB has a TimeStamp type that uses a 32-bit unsigned integer to store year, month,, day, hour, and minute in a way that makes it dirt simple to extract a component.
You really think so? It's a mixed-radix scheme:
so requires lots of expensive integer division and remainder operations to pick apart again (the trend in CPUs is to make these relatively more expensive, not less, and e.g. Itanium doesn't even have an integer division instruction).
Compared to storing date-times as offsets from an epoch, this is much simpler and cheaper.
If we had this to do over again, I'd strongly suggest assigning 12 bits to the year, 4 to the month, 5 each to day and hour, and 6 to the minute. The components would then be truly dirt simple and dirt cheap to extract, and we wouldn't even have to bother switching between 0-based and 1-based for the months and days (let 'em stay 1-based). They would still sort and compare correctly in packed format. The only downside I can see is that not pursuing every last drop of potential compression would shrink the dynamic range from 8000+ years to 4000+ years, but we're likely to have much worse problems in Zope by the year 5900 anyway <wink>.
Sounds good to me.