BIND 10 #2832: extend data source config to specify shmem segment params

[BIND 10 Development]

#2832: extend data source config to specify shmem segment params
-------------------------------------+-------------------------------------
            Reporter:  jinmei        |                        Owner:
                Type:  task          |                       Status:  new
            Priority:  medium        |                    Milestone:  Next-
           Component:  Unclassified  |  Sprint-Proposed
            Keywords:                |                   Resolution:
           Sensitive:  0             |                 CVSS Scoring:
         Sub-Project:  DNS           |              Defect Severity:  N/A
Estimated Difficulty:  2             |  Feature Depending on Ticket:
         Total Hours:  0             |  shared memory data source
                                     |          Add Hours to Ticket:  0
                                     |                    Internal?:  0
-------------------------------------+-------------------------------------

Comment (by jinmei):

 Replying to [comment:6 vorner]:
 > Just a small suggestion. The user probably should not be required to
 know about memory segments, that's our internal representation. What about
 {{{"cache-type": "SharedFile"}}}?
 >
 > The name is already being added in #2835.

 The main reason for specifying the type of the memory segment is that
 we might eventually want to other type of shared segment, such as
 non-file based one or Windows-specific one.  And, at least the file
 based segment is special in that we need to create and maintain files
 somewhere, so some kind of path information would have to be
 configured (even if it has some default and can be omitted).  If
 there's a better abstraction that meets such requirement and still
 hides lower level details, I'm okay with that.

-- 
Ticket URL: <https://bind10.isc.org/ticket/2832#comment:7>
BIND 10 Development <http://bind10.isc.org>
BIND 10 Development