#!/usr/bin/perl -w
#
# files.pl	Print file sizes in folded format, for a flame graph.
#
# This helps you understand storage consumed by a file system, by creating
# a flame graph visualization of space consumed. This is basically a Perl
# version of the "find" command, which emits in folded format for piping
# into flamegraph.pl.
#
# Copyright (c) 2017 Brendan Gregg.
# Licensed under the Apache License, Version 2.0 (the "License")
#
# 03-Feb-2017   Brendan Gregg   Created this.

use strict;
use File::Find;

sub usage {
	print STDERR "USAGE: $0 [--xdev] [DIRECTORY]...\n";
	print STDERR "   eg, $0 /Users\n";
	print STDERR "   To not descend directories on other filesystems:";
	print STDERR "   eg, $0 --xdev /\n";
	print STDERR "Intended to be piped to flamegraph.pl. Full example:\n";
	print STDERR "   $0 /Users | flamegraph.pl " .
	    "--hash --countname=bytes > files.svg\n";
	print STDERR "   $0 /usr /home /root /etc | flamegraph.pl " .
	    "--hash --countname=bytes > files.svg\n";
	print STDERR "   $0 --xdev / | flamegraph.pl " .
	    "--hash --countname=bytes > files.svg\n";
	exit 1;
}

usage() if @ARGV == 0 or $ARGV[0] eq "--help" or $ARGV[0] eq "-h";

my $filter_xdev = 0;
my $xdev_id;

foreach my $dir (@ARGV) {
	if ($dir eq "--xdev") {
	    $filter_xdev = 1;
	} else {
	    find(\&wanted, $dir);
	}
}

sub wanted {
	my ($dev,$ino,$mode,$nlink,$uid,$gid,$rdev,$size) = lstat($_);
	return unless defined $size;
	if ($filter_xdev) {
		if (!$xdev_id) {
			$xdev_id = $dev;
		} elsif ($xdev_id ne $dev) {
			$File::Find::prune = 1;
			return;
		}
	}
	my $path = $File::Find::name;
	$path =~ tr/\//;/;		# delimiter
	$path =~ tr/;.a-zA-Z0-9-/_/c;	# ditch whitespace and other chars
	$path =~ s/^;//;
	print "$path $size\n";
}