#!/usr/bin/perl -w

use warnings;

use strict;

# unbuffered output.

$| = 1;

require LWP;

require LWP::UserAgent;

require HTTP::Status;

require HTTP::Date;

my $ua = new LWP::UserAgent; # we create a global UserAgent object

$ua->env_proxy;

sub dumpHttpHeads {

foreach (@_) {

my $url = $_;

my $request = HTTP::Request->new(HEAD => $url);

my $response = $ua->request($request);

if ($response->is_error()) {

print("HEAD request to $url failed.\n");

} else {

print("$url:\n");

my @keys = $response->header_field_names();

foreach (@keys) {

print(" $_: " . $response->header($_) . "\n");

}

print("\n\n");

}

}

}

sub loadMetadata {

my $fname = shift;

return undef if not open(FH, '<', $fname);

my %retval;

while (not eof(FH)) {

my $key = <FH>;

my $val = <FH>;

chomp($key) if (defined $key);

chomp($val) if (defined $val);

#print("'$key' == '$val'\n");

$retval{$key} = $val;

}

close(FH);

if (not defined $retval{'X-Offload-Hostname'}) {

$retval{'X-Offload-Hostname'} = 'icculus.org';

}

return(%retval);

}

sub usage {

die("USAGE: $0 <offloaddir> [--nukeshortfiles]\n")

}

my $nukeshortfiles = 0;

my $offloaddir = undef;

foreach (@ARGV) {

$nukeshortfiles = 1, next if ($_ eq '--nukeshortfiles');

$offloaddir = $_, next if not defined $offloaddir;

usage();

}

usage() if (not defined $offloaddir);

opendir(DIRH, $offloaddir) || die("Couldn't open directory [$offloaddir]: $!");

my $diskrecovered = 0;

my $filesseen = 0;

my $filesdelete = 0;

my $totalfilespace = 0;

while (my $f = readdir(DIRH)) {

# '7' is the file size info in stat().

my $filespace = 0;

$filesseen++;

if ($f =~ /\Adebug-/) {

print(" - Deleting debug file '$f'.\n");

my @statbuf = (stat($f));

my $size = 0;

$size = $statbuf[7] if @statbuf;

$diskrecovered += $size;

$totalfilespace += $size;

$filesdelete++;

unlink("$offloaddir/$f");

}

next if (not $f =~ /\A(meta|file)data-/);

my ($filetype, $etag) = ($f =~ /\A(meta|file)data-(.*)\Z/);

my $metadatapath = $offloaddir . '/metadata-' . $etag;

my $filedatapath = $offloaddir . '/filedata-' . $etag;

my $filecachesize = (stat($filedatapath))[7];

$filespace += (stat($metadatapath))[7] if (-f $metadatapath);

$filespace += $filecachesize if (-f $filedatapath);

$totalfilespace += $filespace;

if ((not -f $filedatapath) || (not -f $metadatapath)) {

unlink $metadatapath;

unlink $filedatapath;

$filesdelete++;

$diskrecovered += $filespace;

next;

}

next if ($filetype eq 'file');

my %metadata = loadMetadata($metadatapath);

next if (not %metadata);

my $tmp = $metadata{'ETag'};

$tmp = '"BOGUSSTRING"' if (not defined $tmp);

$tmp =~ s/\A\"(.*?)\"\Z/$1/;

if ($tmp ne $etag) {

print("File '$metadatapath' is bogus.\n");

$diskrecovered += $filespace;

unlink $metadatapath;

unlink $filedatapath;

$filesdelete++;

next;

}

my $len = $metadata{'Content-Length'};

my $hostname = $metadata{'X-Offload-Hostname'};

my $origurl = $metadata{'X-Offload-Orig-URL'};

my $url = 'http://' . $hostname . $origurl;

my $request = HTTP::Request->new(HEAD => $url);

my $response = $ua->request($request);

print(" - $url ($etag) ... ");

my $dokill = 0;

my $httpcode = $response->code();

if ($httpcode == 404) {

print("is no longer on base server.");

$dokill = 1;

} elsif ($response->is_error()) {

# everything else we ignore for now.

print("status unknown (HTTP error $httpcode).");

} elsif (($nukeshortfiles) && ($len != $filecachesize)) {

$dokill = 1;

print("Cached file is wrong size.");

} else {

my $hetag = $response->header('ETag');

$hetag = '' if (not defined $hetag);

$dokill = 1 if ($hetag ne "\"$etag\"");

# !!! FIXME: check other attributes...

print("out of date in some way.") if ($dokill);

}

if ($dokill) {

print(" DELETE!\n");

$diskrecovered += $filespace;

unlink $metadatapath;

unlink $filedatapath;

$filesdelete++;

} else {

print("KEEP!\n");

}

}

closedir(DIRH);

print("Recovered $diskrecovered bytes of $totalfilespace.\n");

print("$filesseen files seen, $filesdelete deleted.\n");

exit 0;