gh-130843: expose 48-bit timestamp for UUIDv7

[picnixz]

(skip news because the feature was added in the latest alpha and thus it wouldn't really make sense to have a separate news entry; if we can't make it in 3.14, I'll add a NEWS entry though)

• Issue: Customize UUIDv7 generation for database partitioning #130843

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📚 Documentation preview 📚: https://cpython-previews--131838.org.readthedocs.build/

[vstinner]

LGTM

[vstinner]

What is the timestamp unit? Seconds? Is it using UNIX timestamp Epoch (1970-01-01 at 00:00)? You don't have to document it if it's complicated, I'm just curious.

[picnixz]

I'll repost here for posterity:

There is no "unit" here and the caller is responsible to handle it as it depends on the version. What's important is that we can recover the timestamp that was generated during UUID construction without having to do bits operations ourselves (for UUIDv7 it's easy because it's 48 first bits of the UUID but for UUIDv1 and v6, the timestamp is split into multiple chunks and those chunks are put in different places of the resulting UUID object).

[bedevere-bot]

⚠️⚠️⚠️ Buildbot failure ⚠️⚠️⚠️

Hi! The buildbot AMD64 Debian root 3.x (tier-1) has failed when building commit ba11f45.

What do you need to do:

1. Don't panic.
2. Check the buildbot page in the devguide if you don't know what the buildbots are or how they work.
3. Go to the page of the buildbot that failed (https://buildbot.python.org/#/builders/345/builds/10761) and take a look at the build logs.
4. Check if the failure is related to this commit (ba11f45) or if it is a false positive.
5. If the failure is related to this commit, please, reflect that on the issue and make a new Pull Request with a fix.

You can take a look at the buildbot page here:

https://buildbot.python.org/#/builders/345/builds/10761

Summary of the results of the build (if available):

==

Click to see traceback logs

Traceback (most recent call last):
  File "/root/buildarea/3.x.angelico-debian-amd64/build/Lib/test/test_ftplib.py", line 935, in tearDown
    self.server = None
ResourceWarning: unclosed <ssl.SSLSocket fd=6, family=2, type=1, proto=0, laddr=('127.0.0.1', 58787), raddr=('127.0.0.1', 58568)>
k


Traceback (most recent call last):
  File "/root/buildarea/3.x.angelico-debian-amd64/build/Lib/test/test_ftplib.py", line 935, in tearDown
    self.server = None
ResourceWarning: unclosed <ssl.SSLSocket fd=5, family=2, type=1, proto=0, laddr=('127.0.0.1', 40921), raddr=('127.0.0.1', 55662)>
k

[picnixz]

I doubtz this has something to do with my change