[Xapian-tickets] [Xapian] #280: Review storage of parameters in Query

[Xapian]

#280: Review storage of parameters in Query
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 Reporter:  richard      |       Owner:  olly     
     Type:  enhancement  |      Status:  assigned 
 Priority:  low          |   Milestone:  1.3.0    
Component:  Library API  |     Version:  SVN trunk
 Severity:  normal       |    Keywords:           
Blockedby:               |    Platform:  All      
 Blocking:               |  
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Changes (by olly):

  * milestone:  1.1.7 => 1.3.0


Comment:

 While Query::Internal is a bit of an ugly mess overall, it does work
 currently (except for some remaining issues with the O() behaviour of
 pairwise construction which affects unusually large queries).  So a
 rewrite would be good, but is potentially destabilising at a point where
 we really want to avoid that, and the only real direct benefit to users
 would be that Query objects would need less memory.

 Added a layer of indirection would allow us to tidy up during 1.2.x, but
 there's a small time and space penalty for that change right now, and even
 with smaller internals, there's still the time and code overhead of the
 indirection, and an extra memory allocation per Query object for the
 indirecting object.

 Adding a double member to house the scaling factor for OP_SCALE_WEIGHT
 would add a space overhead for every Query object, but make use of
 OP_SCALE_WEIGHT a little faster (though note that if you use the remote
 backend, you don't save any time as then we're essentially eagerly
 converting the scale factor to its serialised form).

 So I think the "least worst" action is probably to postpone this ticket to
 the next development series - I've added a new 1.3.0 milestone for this
 purpose.

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Ticket URL: <http://trac.xapian.org/ticket/280#comment:8>
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