package VCP::Filter ;
=head1 NAME
VCP::Filter - A base class for filters
=head1 SYNOPSIS
use VCP::Filter;
@ISA = qw( VCP::Filter );
...
=head1 DESCRIPTION
A VPC::Filter is a VCP::Plugin that is placed between the source
and the destination and allows the stream of revisions to be altered.
For instance, the Map: option in vcp files is implemented by
VCP::Filter::Map
By default a filter is a pass-through.
=cut
$VERSION = 0.1 ;
use strict;
use Carp ();
use VCP::Debug qw( :debug );
use VCP::Logger qw( lg BUG );
use VCP::Utils qw( shell_quote );
use fields (
'DEST', ## Points to the next filter.
);
sub dest {
my VCP::Filter $self = shift;
$self->{DEST} = shift if @_;
return $self->{DEST};
}
###############################################################################
=head1 SUBCLASSING
This class uses the fields pragma, so you'll need to use base and
possibly fields in any subclasses.
=over
=item parse_rules_list
Used in VCP::Filter::*map and VCP::Filter::*edit to parse lists of rules
where every rule is a set of N "words". The value of N is computed from
the number of labels passed in and the labels are used when printing an
error message:
@rules = $self->parse_rules( $options, "Pattern", "Replacement" );
=cut
sub parse_rules_list {
my $self = shift;
my $options = shift;
my $default = @_ && ref $_[-1] ? pop : [];
my @labels = @_;
my $expression_count = @labels;
BUG "No expression labels passed" unless $expression_count;
BUG "No options " unless $options;
my @rule;
my $rules;
while ( @$options ) {
my $v = shift @$options;
last if $v eq "--";
push @rule, $v;
push @$rules, [splice @rule] if @rule == $expression_count;
}
push @$rules, \@rule if @rule;
$rules = $default unless $rules || @rule;
my @out = map [
map shell_quote( $_ ), @$_
], @$rules;
my @w;
for ( \@labels, @out ) {
for my $i (0..$#$_) {
$w[$i] = length $_->[$i]
if ! defined $w[$i] || length $_->[$i] > $w[$i];
}
}
( my $filter_type = ref $self ) =~ s/.*://;
my $format = join " ", map "%-${_}s", @w;
my @msg = (
sprintf( "# $format\n", @labels ),
sprintf( "# $format\n", map "=" x $_, @w ),
map(
sprintf( " $format\n", map defined $_ ? $_ : "", @$_ ),
@out
)
);
die "incomplete rule in $filter_type:\n\n", @msg, "\n" if @rule;
lg "$filter_type rules:\n", @msg;
return $rules;
}
=item last_rev_in_filebranch
(passthru; see L<VCP::Dest|VCP::Dest>)
=cut
sub last_rev_in_filebranch {
shift->dest->last_rev_in_filebranch( @_ );
}
=item backfill
(passthru; see L<VCP::Dest|VCP::Dest>)
=cut
sub backfill {
shift->dest->backfill( @_ );
}
=item is_sort_filter
Sort filters should return a 1 in this method, see L<VCP::Plugin> for details.
=cut
## inherited
=item handle_header
(passthru)
=cut
sub handle_header {
shift->dest->handle_header( @_ );
}
=item handle_rev
(passthru)
=cut
sub handle_rev {
shift->dest->handle_rev( @_ );
}
=item handle_footer
(passthru)
=cut
sub handle_footer {
shift->dest->handle_footer( @_ );
}
=back
=head1 COPYRIGHT
Copyright 2000, Perforce Software, Inc. All Rights Reserved.
This module and the VCP package are licensed according to the terms given in
the file LICENSE accompanying this distribution, a copy of which is included in
L<vcp>.
=head1 AUTHOR
Barrie Slaymaker <barries@slaysys.com>
=cut
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