1559988 - Make extension hooks faster

Status: RESOLVED FIXED

(bugzilla.mozilla.org :: General, enhancement)

Description

[Dylan Hardison [:dylan] (he/him)]

Every hook is $NUMBER_OF_HOOKS calls to ->can().
Some hooks can be called thousands of times per request, or more.

This patch changes how Bugzilla::Hook works. After all extensions are
loaded, the list of packages is passed to Bugzilla::Hook::finalize,
which builds a cache that maps hook names to lists of functions.

Calling a hook is just simple iteration over that list, which is much
faster. In addition, unused hooks have virtually no cost.

Benchmarking

diff --git a/extensions/BMO/Extension.pm b/extensions/BMO/Extension.pm
index dbab0e5..9bc3f18 100644
--- a/extensions/BMO/Extension.pm
+++ b/extensions/BMO/Extension.pm
@@ -2805,6 +2805,10 @@ sub tf_search_operator_field_override {
   }
 }

+sub hello_world {
+       say "hello world";
+}
+
 sub app_startup {
   my ($self, $args) = @_;
   my $app = $args->{app};

The runtime can be tested like so:

perl bugzilla.pl eval 'use ojo; n { Bugzilla::Hook::process("hello_world") } 20_000' >/dev/null
0.213981 wallclock secs ( 0.21 usr +  0.00 sys =  0.21 CPU) @ 95238.10/s (n=20000)

After this change:

perl bugzilla.pl eval 'use ojo; n { Bugzilla::Hook::process("hello_world") } 20_000' >/dev/null
0.0158732 wallclock secs ( 0.01 usr +  0.00 sys =  0.01 CPU) @ 2000000.00/s (n=20000)

Comment 1

[Dylan Hardison [:dylan] (he/him)]

This is about 12 times faster.

Comment 2

[Dylan Hardison [:dylan] (he/him)]

Attachment: GitHub Pull Request

Comment 3

[David Lawrence [:dkl]]

Merged to master.