[
https://issues.apache.org/jira/browse/OPENJPA-361?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#action_12526250
]
Kevin Sutter commented on OPENJPA-361:
--------------------------------------
Looks like a good catch, Albert. I went back and looked at the Apache Sandbox
code that this implementation was based off of and, sure enough, the constant
for GREG_OFFSET should have been 12,219,292,800,000 (ms) or 0xB1D 069B 5400
(ms). We should go ahead with this change.
> Incorrect GREG_OFFSET offset or inconsistent usage in UUIDGenerator
> -------------------------------------------------------------------
>
> Key: OPENJPA-361
> URL: https://issues.apache.org/jira/browse/OPENJPA-361
> Project: OpenJPA
> Issue Type: Bug
> Components: lib
> Affects Versions: 1.0.0
> Environment: All platforms
> Reporter: Albert Lee
> Assignee: Albert Lee
> Priority: Trivial
> Attachments: OPENJPA-361.patch
>
>
> In UUIDGenerator, GREG_OFFSET is defined as
> // offset to move from 1/1/1970, which is 0-time for Java, to gregorian
> // 0-time 10/15/1582, and multiplier to go from 100nsec to msec units
> private static final long GREG_OFFSET = 0x01b21dd213814000L;
> This constant is used as:
> // calculate time as current millis plus offset times 100 ns ticks
> long currentTime = (_currentMillis + GREG_OFFSET) * MILLI_MULT;
> Based of the usage, GREG_OFFSET should be in msec unit and this value should
> be
> (1970-1582) * 365.25 * 24 * 3600 * 1000 (ms) = 12,219,292,800,000 (ms) =
> 0xB1D 069B 5400 (ms)
> The defined constant value 0x1b21dd213814000L is the last value in 100ns unit
> not ms.
> This also offsets the currentTime calculation off by a factor of 10**4.
> To correct the discrepency, either:
> 1) GREG_OFFSET should assign the value of 0xB1D 069B 5400L instead of 0x1b2
> 1dd2 1381 4000L, or
> 2) long currentTime = (_currentMillis * MILLI_MULT ) + GREG_OFFSET ;
> Since UUID is an arbituary value, therefore I don't believe the current
> implementation is "incorrect" but just inconsistent in its implementation
> description.
> Please comment on if:
> 1) the suggested change will have any undesirable side-effect for UUID
> 2) there is any legacy/backward compatibility problem
> 3) this is worth to change at all.
> If there is no objection, I'll correct the "problem" early next week.
> Albert Lee.
--
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.
