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::Utils qw( shell_quote ); use VCP::Debug qw( :debug ); use base "VCP::Plugin"; 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 @labels = @_; my $expression_count = @labels; Carp::confess "No expression labels passed" unless $expression_count; my @rule; my @rules; while ( @$options ) { my $v = shift @$options; last if $v eq "--"; push @rule, $v; push @rules, [splice @rule] if @rule == $expression_count; } if ( debugging $self ) { require Data::Dumper; debug( "vcp: ", Data::Dumper->Dump( [ \@rules ], [ ref ( $self ) . "_rules" ] ) ); } if ( @rule ) { push @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; die "Incomplete rule in $filter_type:\n\n", sprintf( "# $format\n", @labels ), sprintf( "# $format\n", map "=" x $_, @w ), map( sprintf( " $format\n", map defined $_ ? $_ : "", @$_ ), @out ), "\n"; } return \@rules; } =item last_rev_in_filebranch (passthru; see L) =cut sub last_rev_in_filebranch { shift->dest->last_rev_in_filebranch( @_ ); } =item metadata_only (passthru; see L) =cut sub metadata_only { shift->dest->metadata_only( @_ ); } =item sort_revs (passthru) =cut sub sort_revs { shift->dest->sort_revs( @_ ); } =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. =head1 AUTHOR Barrie Slaymaker =cut 1