#!/usr/bin/perl

use strict;
use DBI;
use LWP::Simple;
use Parallel::ForkManager;

my $dbh=DBI->connect("dbi:mysql:shsearch","","", {RaiseError=>1});

my $sth=$dbh->prepare("select siteid, imageurl from big_ass_table grou
+p by siteid, imageurl");
$sth->execute();
my ($siteid, $imageurl, $type, $size, $flag, %sites, $count, $counter)
+;

$count=0;
$sth->bind_columns(\($siteid, $imageurl));
while($sth->fetch()) {
 $sites{$siteid}=$imageurl;
 $count++;
}

$dbh->disconnect();

my $pm=new Parallel::ForkManager(30);

print "Ready to fetch headers ($count to process)...\n";

open(FILE, ">sql.torun") || die "Cannot open file for writting: $!";
print FILE "update big_ass_table set imagedown=0;\n";

$counter=0;
foreach $siteid (sort{$a <=> $b} keys %sites) {
 $imageurl=$sites{$siteid};
 $counter++;
 $pm->start and next;
 print "($counter of $count) Checking $imageurl for site $siteid...";

 if(($type, $size)=(head($imageurl))[0,1]) {
  if($size < 25600) {
   if($type =~ /image\/(gif|jpeg)/) {
    print "OK ($size bytes, $type)\n";
    $flag=1;
   } else {
    $flag=0;
    print "Wrong file type ($type, must be image/gif or image/jpeg)\n"
+;
   }
  } else {
   $flag=0;
   print "Image size exceeded ($size bytes, should be < 25600)\n";
  }
 } else {
  print "Error\n";
  $flag=0;
 }

 if($flag==0) {
  print FILE "update big_ass_table set imagedown=imagedown+1 where sit
+eid=$siteid and imageurl='$imageurl';\n";
 } else {
  print FILE "update big_ass_table set imagedown=0 where siteid=$sitei
+d and imageurl='$imageurl';\n";
 }

 $pm->finish();
} 

$pm->wait_all_children();
close(FILE);
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