I'm over the moon with this series since this drops dozens of
megabytes of scratchpad use while providing tiny speedups along
the way.  For me, that's a 10-15% reduction in memory use under
public-inbox-netd w/ mwrap-perl[1] overhead.

This scratchpad use has been bothering me for a long time
(since I fixed all the other leaks, including one in the core
Encode module).

There's more coming, of course, but this series is big enough
and shown good results on https://yhbt.net/lore/

Also, it also provides a good pattern/guidance going forward
on how to efficiently implement future features.

I actually started out in this series trying to buffer
everything using gzip to avoid space-wasting uncompressed
strings living in memory.  Unfortunately,
Compress::Raw::Zlib::deflate calls proved too expensive to call
frequently for short strings.

Going back to `.=' ops via a ->zadd method brought back some of
the speed while consolidating the scratchpad to a single place;
but I didn't like the performance regression.

I kept those detours in the history presented here since I
figure it's worth showing

Finally relying on PerlIO::scalar with print|say ops proved to
be the fastest since OO ->method dispatch overhead can be avoided
and there's no scratchpad use at all from these, either.

As before, we still call C:R:Z:deflate after every full message
and flush to the socket periodically.

I may even consider using PerlIO::gzip in the future, but that's
a non-standard module.  However, I definitely took inspiration
from it since I saw that it would buffer uncompressed data into
memory before compressing it.

There's also a few small simplifications and speedups I noticed
along the way, and several other bugfixes I posted independently
while working on this series.

[1] I used https://80x24.org/mwrap-perl.git to check malloc use

Eric Wong (38):
  xt: fold perf-obfuscate into perf-msgview, future-proof
  www: gzip_filter: implicitly flush {obuf} on zmore/zflush
  view: rework single message page to compress earlier
  www_atom_stream: require 200 response
  www_stream: aresponse assumes 200, too
  www_text: reduce parameter passing for response header
  viewvcs: use shorter and simpler ctx->html_done
  www_listing: consolidate some ->zmore dispatches
  www_listing: avoid unnecessary work for common cases
  www: viewdiff: use return value for diff_hunk
  view: simplify _parent_headers
  view: eml_entry: reduce manipulation of ctx->{obuf}
  gzip_filter: ->translate can reuse zmore/zflush
  view: remove multipart_text_as_html
  view: reduce subroutine calls for submsg_hdr
  view: attach_link: reduce obuf manipulation
  viewdiff: reuse existing string in diff_before_or_after
  view: _th_index_lite: avoid one s///, improve symmetry
  view: _th_index_lite: use `//' defined-or op
  view: reduce ascii_html calls and {obuf} use
  view: html_footer: golf out a few lines
  view: html_footer: remove obuf dependency
  view: html_footer: avoid escaping " in a few places
  viewdiff: diff_hunk: shorten conditionals, slightly
  view: switch a few things to ctx->zmore
  www: drop {obuf} use entirely, for now
  www: switch to zadd for the majority of buffering
  www: use PerlIO::scalar (zfh) for buffering
  viewdiff: diff_before_or_after: avoid extra capture
  viewdiff: diff_header: shorten function, slightly
  www_static: switch to `print $zfh', and optimize
  httpd/async: describe which ->write subs it can call
  translate: support multiple buffer args
  gzip_filter: write: use multi-arg translate
  feed: new_html_i: switch from zmore to `print $zfh'
  mbox*: use multi-arg ->translate and ->write
  www_listing: switch to `print $zfh'
  viewvcs: switch to `print $zfh'

 Documentation/mknews.perl        |   3 +-
 MANIFEST                         |   1 -
 lib/PublicInbox/CompressNoop.pm  |   4 +-
 lib/PublicInbox/Feed.pm          |  12 +-
 lib/PublicInbox/GzipFilter.pm    |  62 +++---
 lib/PublicInbox/HTTPD/Async.pm   |   9 +-
 lib/PublicInbox/Mbox.pm          |  11 +-
 lib/PublicInbox/MboxGz.pm        |   3 +-
 lib/PublicInbox/SearchView.pm    |   8 +-
 lib/PublicInbox/View.pm          | 312 ++++++++++++-------------------
 lib/PublicInbox/ViewDiff.pm      | 115 +++++-------
 lib/PublicInbox/ViewVCS.pm       |  17 +-
 lib/PublicInbox/WwwAtomStream.pm |  19 +-
 lib/PublicInbox/WwwListing.pm    |  40 ++--
 lib/PublicInbox/WwwStatic.pm     |  32 ++--
 lib/PublicInbox/WwwStream.pm     |  23 ++-
 lib/PublicInbox/WwwText.pm       |  35 ++--
 t/psgi_v2.t                      |   4 +-
 xt/perf-msgview.t                |  10 +-
 xt/perf-obfuscate.t              |  66 -------
 20 files changed, 320 insertions(+), 466 deletions(-)
 delete mode 100644 xt/perf-obfuscate.t

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