BIND 10 #1975: implement meta-or-container-of data source

[BIND 10 Development]

#1975: implement meta-or-container-of data source
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                   Reporter:         |                 Owner:  vorner
  jinmei                             |                Status:  reviewing
                       Type:  task   |             Milestone:
                   Priority:         |  Sprint-20120619
  medium                             |            Resolution:
                  Component:  data   |             Sensitive:  0
  source                             |           Sub-Project:  DNS
                   Keywords:         |  Estimated Difficulty:  9
            Defect Severity:  N/A    |           Total Hours:  0
Feature Depending on Ticket:         |
        Add Hours to Ticket:  0      |
                  Internal?:  0      |
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Comment (by jinmei):

 Replying to [comment:12 vorner]:

 This point first, as it may affect larger parts of the branch:

 > > - I see general confusion between the concept of "data sources" and of
 > >   "data source clients".
 >
 > The problem might be I'm not really clear about the difference myself.
 What is the difference between data source and data source client? Where
 can I meat the first one, if we have classes for the second only?
 >
 > I guess that if I myself am confused about the difference, it is
 projected to the code and comments I write. I might try to improve it
 after I understand.

 Actually, I'm afraid it's probably only me who differentiates them:-)
 See the first bullet of
 http://bind10.isc.org/wiki/DataSourceDesign#Otherrelativelyminororpossiblycontroversialnotes
 that was my intent when I first introduced the term "client".  In the
 case of in-memory or sqlite3 the difference may be quite moot because
 the "client" gets access to the actual "storage" quite directly, but
 considering a more generic case where we use a general purpose DB or
 something, I wanted to make clear that the actual "data source" is in
 the server side.

 But if this differentiation doesn't make sense to others or is
 difficult to make in coding, maybe we should simply call them "data
 source" (one advantage of this is that we'll have shorter
 class/variable names).

-- 
Ticket URL: <http://bind10.isc.org/ticket/1975#comment:13>
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