###############################################################################
#
# parallelmgbuilder.pm -- inherits from the MGBuilder object but adds parallel
# indexing capability by way of a function that generates the 'recipe' for
# indexing. This recipe including information on precedence and can be used by
# a controller (such as OpenMPI) to parallelize parts of the recipe.
#
# A component of the Greenstone digital library software
# from the New Zealand Digital Library Project at the
# University of Waikato, New Zealand.
#
# Copyright (C) 2013 New Zealand Digital Library Project
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
#
###########################################################################

# @author John Thompson [jmt12], Waikato DL Research group

package parallelmgbuilder;

use mgbuilder;
use parallelbasebuilder;
use strict;

BEGIN
{
  # multiple inheritence FTW
  @parallelmgbuilder::ISA = ('mgbuilder', 'parallelbasebuilder');
}

# /** @function new()
#  */
sub new
{
    my $class = shift(@_);
    my $self = new mgbuilder(@_);
    return bless($self, $class);
}
# /** new() **/

# /** @function prepareIndexRecipe()
#  * MG is the most 'complex' recipe we currently support. While the compress
#  * text and infodb phases can be run in parallel, the indexes cannot be built
#  * until after the compress text phase is complete.
#  * @param $self
#  * @param $collection
#  * @param $recipe a reference to an array of recipe 'steps'
#  * @author jmt12
#  */
sub prepareIndexRecipe
{
  my ($self, $collection, $recipe) = @_;
  my $outhandle = $self->{'outhandle'};
  my $verbosity = $self->{'verbosity'};
  # 1. We start by building up the array of indexes, as we'll need to add them
  #    as child tasks to the compress text phase
  my $index_tasks = ();
  my $indexes = $self->{'collect_cfg'}->{'indexes'};
  foreach my $index (@{$indexes})
  {
    push(@{$index_tasks}, {'command'=>'buildcol.pl -keepold -verbosity ' . $verbosity . ' -mode build_index -indexname ' . $index . ' ' . $collection});
  }
  # 2. Compressing the text - this time with dependent tasks
  push(@{$recipe}, {'command'=>'buildcol.pl -keepold -verbosity ' . $verbosity . ' -mode compress_text ' . $collection, 'children'=>$index_tasks});
  # 3. Info database building
  push(@{$recipe}, {'command'=>'buildcol.pl -keepold -verbosity ' . $verbosity . ' -mode infodb ' . $collection});
  # Complete!
}
# /** prepareIndexRecipe() **/

1;