[mythtv-commits] Ticket #10161: Speed up loading of Watch Recordings screen

[MythTV]

#10161: Speed up loading of Watch Recordings screen
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 Reporter:  Jim Stichnoth <stichnot@…>          |           Type:  Patch -
   Status:  new                                 |  Feature
Milestone:  unknown                             |       Priority:  minor
  Version:  Trunk Head                          |      Component:  MythTV -
 Keywords:                                      |  General
                                                |       Severity:  medium
                                                |  Ticket locked:  0
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 The attached patch improves the initial loading time of the Watch
 Recordings screen (PlaybackBox), in cases where there are a large number
 of recordings to display and the frontend has a relatively weak CPU such
 as an Atom.

 This is accomplished through lazy creation of many of the program
 attribute strings in ProgramInfo::ToMap(), particularly ones that involve
 expensive computation like string rendering of dates.  ToMap() creates 68
 such attribute strings for each program, the majority of which are
 unlikely to be used by a given theme.

 On my system (an ION frontend, about 2000 recordings, and using the Blue
 Abstract theme), lazy computation saves about 1 millisecond per program,
 reducing the total wall-clock load time from about 6 seconds down to about
 4 seconds.  The patch includes some logging (which should ultimately be
 removed) to help with performance comparisons.

 If developers feel this is a reasonable direction, then I would also
 advocate converting all other uses of InfoMap to use the lazy data
 structure, which would remove the code duplication in the
 SetTextFromLazyMap() methods.  Also, it would be useful to consolidate the
 3 separate typedefs of InfoMap, and clean up multiple spots where QHash<>
 is used directly instead of InfoMap.

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Ticket URL: <http://code.mythtv.org/trac/ticket/10161>
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