BIND 10 #2572: extend MasterLexer to provide current/total bytes of source(s)

[BIND 10 Development]

#2572: extend MasterLexer to provide current/total bytes of source(s)
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            Reporter:  jinmei        |                        Owner:
                Type:  task          |  jinmei
            Priority:  medium        |                       Status:
           Component:  libdns++      |  accepted
            Keywords:                |                    Milestone:
           Sensitive:  0             |  Sprint-20130122
         Sub-Project:  DNS           |                   Resolution:
Estimated Difficulty:  4             |                 CVSS Scoring:
         Total Hours:  0             |              Defect Severity:  N/A
                                     |  Feature Depending on Ticket:
                                     |  loadzone-ng
                                     |          Add Hours to Ticket:  0
                                     |                    Internal?:  0
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Comment (by jinmei):

 trac2572 is ready for review.

 It was actually easier than I originally anticipated.  getting the
 "size" of istream works via seekg() and tellg(), so we can treat
 both istream and file-name cases transparently.

 I've added one note to `MasterLexer::pushSource`: that istream must be
 complete at the time of push; otherwise getting its size won't work.
 But I believe this was actually already implicitly assumed, and in any
 case this restriction is reasonable.

 I don't plan to add a changelog entry for this task. This is an
 extension to public API, but the intended use of it is mostly
 internal.

-- 
Ticket URL: <http://bind10.isc.org/ticket/2572#comment:3>
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