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authorDylan William Hardison <dylan@hardison.net>2016-12-22 22:18:23 +0100
committerGitHub <noreply@github.com>2016-12-22 22:18:23 +0100
commit1a5dacd60904a20abf13b1995a4bbb46fccbf739 (patch)
tree2f1a315886002135d496f3a3c096e9156b562c54 /Bugzilla
parent52d2e6ff05ad4c3db3eb97beb68bd8ae83abdb60 (diff)
downloadbugzilla-1a5dacd60904a20abf13b1995a4bbb46fccbf739.tar.gz
bugzilla-1a5dacd60904a20abf13b1995a4bbb46fccbf739.tar.xz
Bug 1299855 - Implement token-bucket rate limiting on top of memcached (#23)
* cleanup
Diffstat (limited to 'Bugzilla')
-rw-r--r--Bugzilla/Memcached.pm22
1 files changed, 22 insertions, 0 deletions
diff --git a/Bugzilla/Memcached.pm b/Bugzilla/Memcached.pm
index a1b8a5ac7..6ada1adf8 100644
--- a/Bugzilla/Memcached.pm
+++ b/Bugzilla/Memcached.pm
@@ -13,6 +13,7 @@ use warnings;
use Bugzilla::Error;
use Scalar::Util qw(blessed);
+use List::Util qw(sum);
use Bugzilla::Util qw(trick_taint);
use URI::Escape;
use Encode;
@@ -20,6 +21,7 @@ use Sys::Syslog qw(:DEFAULT);
# memcached keys have a maximum length of 250 bytes
use constant MAX_KEY_LENGTH => 250;
+use constant RATE_LIMIT_PREFIX => "rate:";
sub _new {
my $invocant = shift;
@@ -157,6 +159,26 @@ sub clear {
}
}
+sub should_rate_limit {
+ my ($self, $name, $rate_max, $rate_seconds, $tries) = @_;
+ my $prefix = RATE_LIMIT_PREFIX . $name . ':';
+ my $memcached = $self->{memcached};
+
+ $tries //= 3;
+
+ for (0 .. $tries) {
+ my $now = time;
+ my ($key, @keys) = map { $prefix . ( $now - $_ ) } 0 .. $rate_seconds;
+ $memcached->add($key, 0, $rate_seconds+1);
+ my $tokens = $memcached->get_multi(@keys);
+ my $cas = $memcached->gets($key);
+ $tokens->{$key} = $cas->[1]++;
+ return 1 if sum(values %$tokens) >= $rate_max;
+ return 0 if $memcached->cas($key, @$cas, $rate_seconds+1);
+ }
+ return 1;
+}
+
sub clear_all {
my ($self) = @_;
return unless $self->{memcached};