Uuid v7 collisions about uuid HOT 9 CLOSED

I will do a PR.

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Running same code with "ramsey/uuid": "4.5.1" does not give any collisions. So the bug is in new UnixTimeGenerator.

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The new code in UnixTimeGenerator was mostly borrowed from symfony/uid. Can you reproduce the issue using their method for generating v7 UUIDs?

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Can you reproduce the issue using their method for generating v7 UUIDs?

Yes, done.

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See symfony/symfony#52367 for the fix

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Thanks, @nicolas-grekas!

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@ramsey @nicolas-grekas Hi! Have a question about uuid v7 collisions.

I need to replace 4-5 chars after generation uuid v7 with my specific characters (servers id or smth else).
At what positions would you advise me to change them so as not to greatly increase the chance of collisions?

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@fannyfan414 , you can use UUID v8, it allows to put arbitrary content.

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I would recommend using UUIDv8 for your use-case, by the way. It's intended for custom layouts like the one you're using.

To minimize chance of collision, I would probably place the server ID in the bytes to the far right of the UUID layout.

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