On Mon, 10 Jul 2006, Grant Baillie wrote:
Thanks for looking at that code: Most of your comments are right on the
money. IMAP has restrictions on what UIDs can be, though: see below.
On 7 Jul, 2006, at 11:00, Andi Vajda wrote:
...
validityUID = schema.One(
schema.Integer,
doc = 'The unique id number of this mailbox.',
initialValue = random.randint(1000000, 9999999),
) [EMAIL PROTECTED] why not use a UUID ?
[EMAIL PROTECTED] from chandlerdb.util.c import UUID()
[EMAIL PROTECTED] initialValue = UUID()
[EMAIL PROTECTED] also, maybe this should be in __init__() so that all
mailboxes
[EMAIL PROTECTED] don't endup with the same UID
[EMAIL PROTECTED] (an initial value is not required, by the way)
In IMAP, a mailbox uid (a.k.a. "UIDVALIDITY value") has to be a non-zero
32-bit unsigned value. It's also supposed to be unique for the mailbox at
that path (i.e. deleting & recreating the mailbox should give a new UID). So,
a UUID (128 bits IIRC) won't work here: Most implementations use a timestamp
(an increasing sequence of integers is also possible).
Understood. I guess the word UID confused me.
However, as you point out, an initialValue isn't really required, either, and
doesn't have the right behaviour w.r.t. deletion and recreation. Also, a
random int could theoretically collide. Maybe the best thing is to override
__init__ to make validityUID a computed value (like a timestamp).
In that case, a random number can work or, the hash value of a UUID.
hash(UUID()) is a 32 bit number.
A similar comment applies to your comments about UUIDs for uidNext & UIDs:
these also have to be 32-bit positive unsigned ints, and have the additionial
requirement of increasing monotonically as messages are added to the mailbox.
There, hash(UUID()) wouldn't work. The hash value cannot be predicted with
regards to its order and can be negative. Oh well. Back to timestamps... with
all the bugs that this may imply.
Andi..
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