* [PATCH 38/38] viewvcs: switch to `print $zfh'
2022-09-10 8:16 7% [PATCH 00/38] www: reduce memory usage Eric Wong
@ 2022-09-10 8:17 6% ` Eric Wong
0 siblings, 0 replies; 2+ results
From: Eric Wong @ 2022-09-10 8:17 UTC (permalink / raw)
To: meta
Again, ->zmore has proven expensive due to the overhead of
calling ->deflate on small strings, so print directly to the
file handle and let the PerlIO::scalar layer take care of
buffering. One of the ->zmore calls was a no-op, even, so
drop that entirely.
---
lib/PublicInbox/ViewVCS.pm | 11 +++++------
1 file changed, 5 insertions(+), 6 deletions(-)
diff --git a/lib/PublicInbox/ViewVCS.pm b/lib/PublicInbox/ViewVCS.pm
index 57ab378d..f740591d 100644
--- a/lib/PublicInbox/ViewVCS.pm
+++ b/lib/PublicInbox/ViewVCS.pm
@@ -189,7 +189,8 @@ href="$f.patch">patch</a>)\n <a href=#parent>parent</a> $P->[0]};
$x = ' (<a href=#root_commit>root commit</a>)';
}
PublicInbox::WwwStream::html_init($ctx);
- $ctx->zmore(<<EOM);
+ my $zfh = $ctx->zfh;
+ print $zfh <<EOM;
<pre> <a href=#commit>commit</a> $H$x
<a href=#tree>tree</a> <a href="$upfx$T/s/">$T</a>
author $au
@@ -197,16 +198,14 @@ committer $co
<b>$s</b>
EOM
- $ctx->zmore("\n", $ctx->{-linkify}->to_html($bdy)) if length($bdy);
+ print $zfh "\n", $ctx->{-linkify}->to_html($bdy) if length($bdy);
$bdy = '';
open my $fh, '<:utf8', "$ctx->{-tmp}/p" or
die "open $ctx->{-tmp}/p: $!";
if (-s $fh > $MAX_SIZE) {
- $ctx->zmore("---\n patch is too large to show\n");
+ print $zfh "---\n patch is too large to show\n";
} else { # prepare flush_diff:
read($fh, $x, -s _);
- $ctx->zmore($bdy);
- undef $bdy;
$ctx->{-apfx} = $ctx->{-spfx} = $upfx;
$x =~ s/\r?\n/\n/gs;
$ctx->{-anchors} = {} if $x =~ /^diff --git /sm;
@@ -228,7 +227,7 @@ EOM
$q = wrap('', '', $q);
my $rows = ($q =~ tr/\n/\n/) + 1;
$q = ascii_html($q);
- $ctx->zmore(<<EOM);
+ print $zfh <<EOM;
<hr><form action=$upfx
id=related><pre>find related emails, including ancestors/descendants/conflicts
<textarea name=q cols=${\PublicInbox::View::COLS} rows=$rows>$q</textarea>
^ permalink raw reply related [relevance 6%]
* [PATCH 00/38] www: reduce memory usage
@ 2022-09-10 8:16 7% Eric Wong
2022-09-10 8:17 6% ` [PATCH 38/38] viewvcs: switch to `print $zfh' Eric Wong
0 siblings, 1 reply; 2+ results
From: Eric Wong @ 2022-09-10 8:16 UTC (permalink / raw)
To: meta
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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