[Xapian-tickets] [Xapian] #295: Add support for multi and remote databases with PostingSources

[Xapian]

#295: Add support for multi and remote databases with PostingSources
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 Reporter:  richard      |        Owner:  richard 
     Type:  enhancement  |       Status:  assigned
 Priority:  normal       |    Milestone:  1.1.0   
Component:  Matcher      |      Version:  SVN HEAD
 Severity:  normal       |   Resolution:          
 Keywords:               |    Blockedby:          
 Platform:  All          |     Blocking:          
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Comment(by richard):

 Attached a new version of the patch - this time, clone() is optional again
 (default implementation returns NULL).  I've had to add some tracking of
 whether the Query() owns the supplied posting source again.

 Still to do:
  - should the Query constructor call clone on the posting source to get an
 owned copy (falling back to having a non-owned copy if clone returns
 NULL), or just assume that the supplied object remains valid indefinitely.
 I'm tending towards the latter (and that's what in this patch), but this
 does mean that if clone() is costly but implemented, it's called 1 more
 time than it needs to be.
  - Haven't looked into setting the database in clone() - note that it
 would also need to be able to be passed to unserialise() as well as
 clone(), of course.
  - Can we avoid the const_cast() when making the database object to pass
 to reset()?
  - general review of patch.

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Ticket URL: <http://trac.xapian.org/ticket/295#comment:4>
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