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 #!/usr/bin/perl -w

 #

 # This Source Code Form is subject to the terms of the Mozilla Public

 # License, v. 2.0. If a copy of the MPL was not distributed with this

 # file, You can obtain one at http://mozilla.org/MPL/2.0/.

 # This program produces a ``class histogram'' of the live objects, one

 # line per class, with the total number of objects allocated, and

 # total number of bytes attributed to those objects.

 use 5.004;

 use strict;

 use Getopt::Long;

 # So we can find TraceMalloc.pm

 use FindBin;

 use lib "$FindBin::Bin";

 use TraceMalloc;

 # Collect program options

 $::opt_help = 0;

 $::opt_types = "${FindBin::Bin}/types.dat";

 GetOptions("help", "types=s");

 if ($::opt_help) {

     die "usage: histogram.pl [options] <dumpfile>

   --help          Display this message

   --types=<file>  Read type heuristics from <file>";

 }

 # Initialize type inference juju from the type file specified by

 # ``--types''.

 if ($::opt_types) {

     TraceMalloc::init_type_inference($::opt_types);

 }

 # Read the dump file, collecting count and size information for each

 # object that's detected.

 # This'll hold a record for each class that we detect

 $::Classes = { };

 sub collect_objects($) {

     my ($object) = @_;

     my $type = $object->{'type'};

     my $entry = $::Classes{$type};

     if (! $entry) {

         $entry = $::Classes{$type} = { '#count#' => 0, '#bytes#' => 0 };

     }

     $entry->{'#count#'} += 1;

     $entry->{'#bytes#'} += $object->{'size'};

 }

 TraceMalloc::read(\&collect_objects);

 # Print one line per class, sorted with the classes that accumulated

 # the most bytes first.

 foreach my $class (sort { $::Classes{$b}->{'#bytes#'} <=> $::Classes{$a}->{'#bytes#'} } keys %::Classes) {

     print "$class $::Classes{$class}->{'#count#'} $::Classes{$class}->{'#bytes#'}\n";

 }