source: gsdl/trunk/perllib/plugin.pm@ 16300

###########################################################################
#
# plugin.pm -- functions to handle using plugins
# A component of the Greenstone digital library software
# from the New Zealand Digital Library Project at the 
# University of Waikato, New Zealand.
#
# Copyright (C) 1999 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.
#
###########################################################################

package plugin;

use strict; # to pick up typos and undeclared variables...
no strict 'refs'; # ...but allow filehandles to be variables and vice versa
no strict 'subs';

require util;
use gsprintf 'gsprintf';

# mapping from old plugin names to new ones for backwards compatibility
# can remove at sometime in future when we no longer want to support old xxPlug plugins
my $plugin_name_map = {
    'ArcPlug' => 'ArchivesInfPlugin',
    'RecPlug' => 'DirectoryPlugin',
    'TEXTPlug' => 'TextPlugin',
    'EMAILPlug' => 'EmailPlugin',
    'SRCPlug' => 'SourceCodePlugin',
    'NULPlug' => 'NulPlugin',
    'W3ImgPlug' => 'W3ImagePlugin',
    'PagedImgPlug' => 'PagedImagePlugin'
    };

# global variables
my $stats = {'num_processed' => 0,
         'num_blocked' => 0,
         'num_not_processed' => 0,
         'num_not_recognised' => 0,
         'num_archives' => 0
         };

#globaloptions contains any options that should be passed to all plugins
my ($verbosity, $outhandle, $failhandle, $globaloptions);

sub get_valid_pluginname {
    my ($pluginname) = @_;
    my $valid_name = $pluginname;
    if (defined $plugin_name_map->{$pluginname}) {
    $valid_name = $plugin_name_map->{$pluginname};
    } elsif ($pluginname =~ /Plug$/) {
    $valid_name =~ s/Plug/Plugin/;
    
    }
    return $valid_name;
}
sub load_plugin_require
{
    my ($pluginname) = @_;

    my @check_list = ();

    # pp_plugname shorthand for 'perllib' 'plugin' '$pluginname.pm' 
    my $pp_plugname 
    = &util::filename_cat('perllib', 'plugins', "${pluginname}.pm");
    my $collectdir = $ENV{'GSDLCOLLECTDIR'};

    # find the plugin
    if (defined($ENV{'GSDLCOLLECTION'}))
    {
    my $customplugname 
        = &util::filename_cat($collectdir, "custom",$ENV{'GSDLCOLLECTION'},
                  $pp_plugname);
    push(@check_list,$customplugname);
    }

    my $colplugname = &util::filename_cat($collectdir, $pp_plugname);
    push(@check_list,$colplugname);

    if (defined $ENV{'GSDLEXTS'}) {

    my $ext_prefix = &util::filename_cat($ENV{'GSDLHOME'}, "ext");

    my @extensions = split(/:/,$ENV{'GSDLEXTS'});
    foreach my $e (@extensions) {
        my $extplugname = &util::filename_cat($ext_prefix, $e, $pp_plugname);
        push(@check_list,$extplugname);

    }
    }


    my $mainplugname = &util::filename_cat($ENV{'GSDLHOME'}, $pp_plugname);
    push(@check_list,$mainplugname);

    my $success=0;
    foreach my $plugname (@check_list) {
    if (-e $plugname) {
        require $plugname;
        $success=1;
        last;
    }
    }

    if (!$success) {
    &gsprintf(STDERR, "{plugin.could_not_find_plugin}\n",
          $pluginname);
    die "\n";
    }
}

sub load_plugin_for_info {
    my ($pluginname) = shift @_;
    $pluginname = &get_valid_pluginname($pluginname);
    load_plugin_require($pluginname);

    # create a plugin object
    my ($plugobj);
    my $options = "-gsdlinfo";
    
    eval ("\$plugobj = new \$pluginname([],[$options])");
    die "$@" if $@;

    return $plugobj;
}

sub load_plugins {
    my ($plugin_list) = shift @_;
    my $incremental;
    ($verbosity, $outhandle, $failhandle, $globaloptions, $incremental) = @_; # globals
    my @plugin_objects = ();
    $incremental = 0 unless (defined $incremental && $incremental == 1);
    $verbosity = 2 unless defined $verbosity;
    $outhandle = 'STDERR' unless defined $outhandle;
    $failhandle = 'STDERR' unless defined $failhandle;

    my $colplugindir = &util::filename_cat($ENV{'GSDLCOLLECTDIR'},"perllib/plugins");
     unshift (@INC, $colplugindir);  

    map { $_ = "\"$_\""; } @$globaloptions;
    my $globals = join (",", @$globaloptions);

    foreach my $pluginoptions (@$plugin_list) {
    my $pluginname = shift @$pluginoptions;
    next unless defined $pluginname;
    $pluginname = &get_valid_pluginname($pluginname);
    load_plugin_require($pluginname);

    # create a plugin object
    my ($plugobj);
    map { $_ = "\"$_\""; } @$pluginoptions;
    my $options = join (",", @$pluginoptions);
    if ($globals) {
        if (@$pluginoptions) {
        $options .= ",";
        }
        $options .= "$globals";
    }
    $options =~ s/\$/\\\$/g;

    eval ("\$plugobj = new \$pluginname([],[$options])");
    die "$@" if $@;
    
    # initialize plugin
    $plugobj->init($verbosity, $outhandle, $failhandle);
    
    $plugobj->set_incremental($incremental);

    # add this object to the list
    push (@plugin_objects, $plugobj);
    }

    return \@plugin_objects;
}


sub begin {
    my ($pluginfo, $base_dir, $processor, $maxdocs, $gli) = @_;

    map { $_->{'gli'} = $gli; } @$pluginfo;
    map { $_->begin($pluginfo, $base_dir, $processor, $maxdocs); } @$pluginfo;
}


sub metadata_read {
    my ($pluginfo, $base_dir, $file, $metadata, $extrametakeys, $extrametadata, $processor, $maxdocs, $gli, $aux) = @_;

    $maxdocs = -1 unless defined $maxdocs && $maxdocs =~ /\d/;
    $gli = 0 unless defined $gli;

    my $rv = 0;
    my $glifile = $file;
    
    $glifile =~ s/^[\/\\]+//; # file sometimes starts with a / so get rid of it
    
    # Announce to GLI that we are handling a file
    print STDERR "<File n='$glifile'>\n" if $gli;
    
    # the .kill file is a handy (if not very elegant) way of aborting 
    # an import.pl or buildcol.pl process
    if (-e &util::filename_cat ($ENV{'GSDLCOLLECTDIR'}, ".kill")) {
    gsprintf($outhandle, "{plugin.kill_file}\n");
    die "\n";
    }

    my $had_error = 0;
    # pass this file by each of the plugins in turn until one
    # is found which will process it
    # read must return:
    # undef - could not recognise
    # -1 - tried but error
    # 0 - blocked
    # anything else for successful processing
    
    foreach my $plugobj (@$pluginfo) {

    $rv = $plugobj->metadata_read($pluginfo, $base_dir, $file, 
                 $metadata, $extrametakeys, $extrametadata, $processor, $maxdocs, $gli, $aux);

    if (defined $rv) {
        if ($rv == -1) {
            # an error has occurred
        $had_error = 1;
        print STDERR "<ProcessingError n='$glifile'>\n" if $gli;
        } else {
            return $rv;
        }
    } # else undefined - was not recognised by the plugin
    }

    return 0;
}

sub read {
    my ($pluginfo, $base_dir, $file, $metadata, $processor, $maxdocs, $total_count, $gli, $aux) = @_;

    $maxdocs = -1 unless defined $maxdocs && $maxdocs =~ /\d/;
    $total_count = 0 unless defined $total_count && $total_count =~ /\d/;
    $gli = 0 unless defined $gli;

    my $rv = 0;
    my $glifile = $file;
    
    $glifile =~ s/^[\/\\]+//; # file sometimes starts with a / so get rid of it
    
    # Announce to GLI that we are handling a file
    print STDERR "<File n='$glifile'>\n" if $gli;
    
    # the .kill file is a handy (if not very elegant) way of aborting 
    # an import.pl or buildcol.pl process
    if (-e &util::filename_cat ($ENV{'GSDLCOLLECTDIR'}, ".kill")) {
    gsprintf($outhandle, "{plugin.kill_file}\n");
    die "\n";
    }

    my $had_error = 0;
    # pass this file by each of the plugins in turn until one
    # is found which will process it
    # read must return:
    # undef - could not recognise
    # -1 - tried but error
    # 0 - blocked
    # anything else for successful processing
    
    foreach my $plugobj (@$pluginfo) {

        $rv = $plugobj->read($pluginfo, $base_dir, $file, 
                 $metadata, $processor, $maxdocs, $total_count, $gli, $aux);

    if (defined $rv) {
        if ($rv == -1) {
            # an error has occurred
        $had_error = 1;
        } else {
            return $rv;
        }
    } # else undefined - was not recognised by the plugin
    }

    if ($had_error) {
    # was recognised but couldn't be processed
    if ($verbosity >= 2) {
        gsprintf($outhandle, "{plugin.no_plugin_could_process}\n", $file);
    }
    # tell the GLI that it was not processed
    print STDERR "<NonProcessedFile n='$glifile'>\n" if $gli;
      
    gsprintf($failhandle, "$file: {plugin.no_plugin_could_process_this_file}\n");
    $stats->{'num_not_processed'} ++;
    } else {
    # was not recognised
    if ($verbosity >= 2) {
        gsprintf($outhandle, "{plugin.no_plugin_could_recognise}\n",$file);
    }
    # tell the GLI that it was not processed
    print STDERR "<NonRecognisedFile n='$glifile'>\n" if $gli;
    
    gsprintf($failhandle, "$file: {plugin.no_plugin_could_recognise_this_file}\n");
    $stats->{'num_not_recognised'} ++;
    }
    return 0;
}

# write out some general stats that the plugins have compiled - note that
# the buildcol.pl process doesn't currently call this process so the stats
# are only output after import.pl -
sub write_stats {
    my ($pluginfo, $statshandle, $faillog, $gli) = @_;

    $gli = 0 unless defined $gli;

    foreach my $plugobj (@$pluginfo) {
    $plugobj->compile_stats($stats);
    }

    my $total = $stats->{'num_processed'} + $stats->{'num_blocked'} + 
    $stats->{'num_not_processed'} + $stats->{'num_not_recognised'};

    print STDERR "<ImportComplete considered='$total' processed='$stats->{'num_processed'}' blocked='$stats->{'num_blocked'}' ignored='$stats->{'num_not_recognised'}' failed='$stats->{'num_not_processed'}'>\n" if $gli;

    if ($total == 1) {
    gsprintf($statshandle, "* {plugin.one_considered}\n");
    } else {
    gsprintf($statshandle, "* {plugin.n_considered}\n", $total);
    }
    if ($stats->{'num_archives'}) {
    if ($stats->{'num_archives'} == 1) {
        gsprintf($statshandle, "   ({plugin.including_archive})\n");
    }
    else {
        gsprintf($statshandle, "   ({plugin.including_archives})\n",
             $stats->{'num_archives'});
    }
    }
    if ($stats->{'num_processed'} == 1) {
    gsprintf($statshandle, "* {plugin.one_included}\n");
    } else {
    gsprintf($statshandle, "* {plugin.n_included}\n", $stats->{'num_processed'});
    }
    if ($stats->{'num_not_recognised'}) {
    if ($stats->{'num_not_recognised'} == 1) {
        gsprintf($statshandle, "* {plugin.one_unrecognised}\n");
    } else {
        gsprintf($statshandle, "* {plugin.n_unrecognised}\n",
             $stats->{'num_not_recognised'});
    }

    }
    if ($stats->{'num_not_processed'}) {
    if ($stats->{'num_not_processed'} == 1) {
        gsprintf($statshandle, "* {plugin.one_rejected}\n");
    } else {
        gsprintf($statshandle, "* {plugin.n_rejected}\n",
             $stats->{'num_not_processed'});
    }
    }
    if ($stats->{'num_not_processed'} || $stats->{'num_not_recognised'}) {
    gsprintf($statshandle, " {plugin.see_faillog}\n", $faillog);
    }
}

sub end {
    my ($pluginfo, $processor) = @_;
    map { $_->end($processor); } @$pluginfo;
}

sub deinit {
    my ($pluginfo, $processor) = @_;
   

    map { $_->deinit($processor); } @$pluginfo;
}

1;