BIND 10 #2052: dns::LabelSequence::compare()

[BIND 10 Development]

#2052: dns::LabelSequence::compare()
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                   Reporter:         |                 Owner:  vorner
  jinmei                             |                Status:  reviewing
                       Type:  task   |             Milestone:
                   Priority:         |  Sprint-20120703
  medium                             |            Resolution:
                  Component:         |             Sensitive:  0
  libdns++                           |           Sub-Project:  DNS
                   Keywords:         |  Estimated Difficulty:  4
            Defect Severity:  N/A    |           Total Hours:  0
Feature Depending on Ticket:         |
        Add Hours to Ticket:  0      |
                  Internal?:  0      |
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Changes (by muks):

 * owner:  muks => vorner


Comment:

 Hi vorner

 Replying to [comment:5 vorner]:
 > First, I'd like to ask ‒ there's no relation between absolute and non-
 absolute name. But what about two non-absolute ones? Comparing "www" to
 "www" will return NONE. Is it what we want?

 It seems this is not we want after discussion with Jinmei on jabber. I've
 added several more unit tests and updated the code to compare non-absolute
 label sequences properly.

 > Also, this comment is not true (in the documentation of
 `partial_compare`):
 > {{{#!c++
 > /// This method never throws an exception.
 > }}}
 >
 > because of this:
 > {{{#!c++
 > if ((first_label > labelcount_) ||
 >     (first_label_other > other.labelcount_)) {
 >     isc_throw(BadValue, "Bad first label indices were passed");
 > }
 > }}}

 Fixed. :)

 > And, finally, I wanted to point out that we planned to extend the
 LabelSequence so it would be possible to be built on top of raw data
 instead of the Name object. I think we'll be using these in the new in-
 memory implementation. But then, this will not work. Would it be possible
 to modify the Name and the LabelSequence so that the `partial_match` code
 works both for the Name and for the internal data structures of
 LabelSequence, so the LabelSequence::compare would not use the Name object
 there?

 There is no current internal data structure of LabelSequence specific to
 it (it uses Name). This is why Name's `compare()` was modified to
 `partial_compare()` and reused. I think suggested changes are best done
 after LabelSequence is itself modified as part of the larger changes. The
 changes required at that point would be straightforward.

-- 
Ticket URL: <http://bind10.isc.org/ticket/2052#comment:7>
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