#!/usr/bin/perl
#
#*******************************************************************************
#
#Copyright (c) 2009, Perforce Software, Inc.  All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are met:
# 
# 1.  Redistributions of source code must retain the above copyright
# notice, this list of conditions and the following disclaimer.
# 
# 2.  Redistributions in binary form must reproduce the above copyright
# notice, this list of conditions and the following disclaimer in the
# documentation and/or other materials provided with the distribution.
# 
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
# ARE DISCLAIMED. IN NO EVENT SHALL PERFORCE SOFTWARE, INC. BE LIABLE FOR ANY
# DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
# (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
# LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
# ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
# SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#*******************************************************************************
#
#Author: Stephen Moon
#
#Date: May 25, 2010
#Program: Truncates a large size journal or text file 
#
#*******************************************************************************

use warnings;
use strict;
use POSIX qw/floor/;
use Benchmark;

sub main() {

my $argc = @ARGV;

if ($argc !=2) { die "Usage: truncJnl.pl <journal_name> <split_number>\n"; }

my $jnl = $ARGV[0];
my $splits = int($ARGV[1]);

my $start = new Benchmark;

open(IN,"$jnl") or die "Unable to open $jnl: $!\n";
my $count = 0;
while(<IN>) { $count++; }
close(IN);

print "Total line count of $jnl: " . $count . "\n";
print "The line count of each splited $jnl is " . floor($count/int($splits)) . "\n\n";

my $chunk = floor($count/int($splits));

open(IN,"$jnl") or die "Unable to open $jnl: $!\n";

my ($jnl_ct,$chunk_bk) = 0;
my $total_size = 0;
my $line_ct = 0;
while(<IN>) {

  if($line_ct == 0 || $chunk_bk == 0) {
     if($line_ct == 0) {
        &findJournalCtr($_);
     }

     ($line_ct,$jnl,$jnl_ct,$total_size,$chunk_bk,$chunk) =
      &createFile($line_ct,$jnl,$jnl_ct,$total_size,$chunk_bk,$chunk);
  } elsif($line_ct == 1 && $_ =~ /^\@ex\@\s\d+\s(\d+).*$/) {
       print "Journal created on " . &unix2local($1) . "\n";
  }

  print OUT $_;
  $total_size = $total_size + length($_);

  $line_ct++;
  $chunk_bk--;
}
close(IN);

my $end = new Benchmark;

my $diff = timediff($end, $start);
print "Time taken was ", timestr($diff, 'nop'), "\n";
}

#find out the journal counter value of the input journal
sub findJournalCtr() {

my $firstLine = shift;

#print "test: " . $_ . "\n";
if($firstLine =~ 
	/^\@vv\@ \d+ \@db.counters\@ \@journal\@ \@(\d+)\@.*$/) {
   print "Journal # is " . $1 . "\n";
}

#convert unix time to local time
}

sub unix2local() {

my $unixTime = shift;

my $time_local = localtime $unixTime;

return $time_local;

}

#helper function to create a new file
sub createFile() {

my $line_ct = shift;
my $jnl = shift;
my $jnl_ct = shift;
my $total_size = shift;
my $chunk_bk = shift;
my $chunk = shift;

if($line_ct == 0) {
   $total_size = 0; 
} else {
   printf("Done with %s.%d\tFile Size: %.0f Kbytes\n",
	$jnl,$jnl_ct,$total_size/1024);
   close(OUT);
   $total_size = 0;
}

$chunk_bk = $chunk;
$jnl_ct++;
open(OUT,"> $jnl.$jnl_ct") or die "Unable to open $jnl.$jnl_ct\n";

return ($line_ct,$jnl,$jnl_ct,$total_size,$chunk_bk,$chunk);

}

#run main here
#

&main()