#!/usr/bin/perl

use strict;

use FCGI;
use IO::File;
use SL::Dispatcher;
use SL::FCGIFixes;
use SL::LXDebug;

sub _parse_number_with_unit {
  my ($number) = @_;

  return undef   unless defined $number;
  return $number unless $number =~ m{^ \s* (\d+) \s* ([kmg])b \s* $}xi;

  my %factors = (K => 1024, M => 1024 * 1024, G => 1024 * 1024 * 1024);

  return $1 * $factors{uc $2};
}

sub _memory_usage_is_too_high {
  return undef unless $::lx_office_conf{system};

  my %limits = (
    rss  => _parse_number_with_unit($::lx_office_conf{system}->{memory_limit_rss}),
    size => _parse_number_with_unit($::lx_office_conf{system}->{memory_limit_vsz}),
  );

  # $::lxdebug->dump(0, "limits", \%limits);

  return undef unless $limits{rss} || $limits{vsz};

  my %usage;

  my $in = IO::File->new("/proc/$$/status", "r") or return undef;

  while (<$in>) {
    chomp;
    $usage{lc $1} = _parse_number_with_unit($2) if m{^ vm(rss|size): \s* (\d+ \s* [kmg]b) \s* $}ix;
  }

  $in->close;

  # $::lxdebug->dump(0, "usage", \%usage);

  foreach my $type (keys %limits) {
    next if !$limits{$type};
    next if $limits{$type} >= ($usage{$type} // 0);

    $::lxdebug->message(LXDebug::WARN(), "Exiting due to memory size limit reached for type '${type}': limit " . $limits{$type} . " bytes, usage " . $usage{$type} . " bytes");

    return 1;
  }

  return 0;
}

our $dispatcher = SL::Dispatcher->new('FastCGI');
$dispatcher->pre_startup_setup;
SL::FCGIFixes::apply_fixes();
$dispatcher->pre_startup_checks;

my $request = FCGI::Request();
while ($request->Accept() >= 0) {
  $dispatcher->handle_request($request);
  exit if _memory_usage_is_too_high();
}

1;