#! perl -slw
use strict;
use threads;
use Thread::Queue;

my $LOGDIR = "./logs";
my $WORKERS = 4;

## The basis of the communications
my $Qwork = new Thread::Queue;

## Minimal error handling for posting
sub compress_log {
	require Compress::ZLib;
	
	while( ( my $workitem = $Qwork->dequeue ) != 'DONE' ) {
		
		open IN, '<', $workitem 
			or warn $! and next;
			
		open OUT, '> :raw', "$workitem.gz" 
			or warn $! and next;
		
		## Slurp the file, compress it and write it out.
		print OUT Compress::Zlib::memGzip( 
            do{ $/ = \-s( IN ); <IN> } 
        );
		
		close OUT;
		close IN;
		
		unlink $workitem;
	}
}

## Set up a method of terminating the process cleanly.
## The main loop below will terminate on ^C/^Break (on win32) 
## Set appropriate SIG vales for your OS / usage.
my $monitoring = 1;
$SIG{INT} = $SIG{QUIT} = sub{ $monitoring = 0; };

## start the compressor threads.
my @workers = map{ threads->new( \&compress_log ) } 1 .. $WORKERS;

## Monitor the directory for new .log files

my %seen; ## Track which files we have already queued.
while( $monitoring ) {
	## Grab the latest logs (exluding those we've already queued)
	my @newfiles = grep{ !defined $seen{ $_ }++ } glob( "$LOGDIR/*.log" );
	
	## And queue them for compression
	$Qwork->enqueue( @newfiles );
	
	## sleep a while before looking again
	sleep 10;
} 

## You can wait for existing work items to be processed here?
## The timeout chosen appropriate to your requirements
my $timeout = 60;
sleep 1 while --$timeout and $Qwork->pending;

## Empty any remaining items from the work queue -- Do something with them?
$Qwork->dequeue while $Qwork->pending;

## Post 'Done' messages one per worker
$Qwork->enqueue( ('DONE') x $WORKERS );

## And wait for them to complete
$_->join for @workers;

## Bye.
exit;