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reducing time overhead of text display (in 1.1)

Clim 1.1 in Lucid (and MCL2.0 occasionally)

We've been having serious performance problems with the display of
long texts in CLIM. At first, suspecting that indenting output and
formatting output were individually or collectively to blame, I wrote
my own indenting&formatting code for writing strings. However, the
only advantage seems to be that my code displays incrementally -- it
still takes about as long (subjectively) to complete the process.  So
I timed my indenting&formatting function writing to the lisp listener
*standard-output*:

  Elapsed Real Time = 4.86 seconds
  Total Run Time    = 1.95 seconds
  User Run Time     = 1.44 seconds
  System Run Time   = 0.52 seconds
  Process Page Faults    =          7
  Dynamic Bytes Consed   =          0
  Ephemeral Bytes Consed =    850,176
  There was 1 ephemeral GC

and writing into the main display of our application-frame:

  Elapsed Real Time = 6.88 seconds
  Total Run Time    = 6.73 seconds
  User Run Time     = 5.61 seconds
  System Run Time   = 1.12 seconds
  Process Page Faults    =          6
  Dynamic Bytes Consed   =          0
  Ephemeral Bytes Consed =    962,896
  There was 1 ephemeral GC

The difference in total run time makes me wonder: what overhead is
associated with writing strings into CLIM streams and how can I
minimize it?

Unfortunately the above is not the bulk of the problem. The above
writes did not involve any presentations, but most of our texts are
segmented into dozens (or more) of nested parts that each require a
presentation. If I write the segmented version of this string it takes
longer. For example, the stats for a text of similar character length
but highly segmented are:

  Elapsed Real Time = 26.48 seconds
  Total Run Time    = 26.21 seconds
  User Run Time     = 19.24 seconds
  System Run Time   = 6.97 seconds
  Process Page Faults    =         12
  Dynamic Bytes Consed   =          0
  Ephemeral Bytes Consed =  2,972,208
  There were 6 ephemeral GCs

So our users have to wait half a minute every time they modify the
text (or something in the same pane)! Any comments on reducing the
overhead of creating presentations from the CLIM end of things? (We
will of course continue to scrutinize our own code.)
--------------------------------------------------
 Dan Suthers           | LRDC, room 505A
 suthers+@pitt.edu     | 3939 O'Hara Street
 (412) 624-7036 office | University of Pittsburgh
 (412) 624-9149 fax    | Pittsburgh, PA 15260
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