table.pm

普通的ETL工具

# vim:ts=4 sw=4
# ----------------------------------------------------------------------------------------------------
#  Name		: ETL::Pequel3::Type::Section::Table.pm
#  Created	: 22 June 2006
#  Author	: Mario Gaffiero (gaffie)
#
# Copyright 1999-2007 Mario Gaffiero.
# 
# This file is part of Pequel(TM).
# 
# Pequel 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; version 2 of the License.
# 
# Pequel 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 Pequel; if not, write to the Free Software
# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
# ----------------------------------------------------------------------------------------------------
# Modification History
# When          Version     Who     What
# ----------------------------------------------------------------------------------------------------
package ETL::Pequel3::Type::Section::Table;
require 5.005_62;
use strict;
use warnings;
use ETL::Pequel3::Type::Section;
# ----------------------------------------------------------------------------------------------------
{
	package ETL::Pequel3::Type::Section::Table;
	use base qw(ETL::Pequel3::Type::Section::Abstract);
	use Class::STL::ClassMembers
		qw( 
			table_name
			table_ref
		),
		Class::STL::ClassMembers::DataMember->new(name => 'target_mem_name', default => 'table_name'),
		Class::STL::ClassMembers::DataMember->new(name => 'section_name', default => 'table'),
		Class::STL::ClassMembers::DataMember->new(name => 'item_type', default => __PACKAGE__ . '::Item'),
		Class::STL::ClassMembers::DataMember->new(name => 'element_type', default => "@{[ __PACKAGE__ ]}"),
		Class::STL::ClassMembers::DataMember->new(name => 'description', default => "Tables are a powerfull feature in F<pequel>. They provide functionality to access data from additional, secondary data streams. Table data is accessed via unique key lookup. The data for tables is pre-loaded at the start of the generated program execution, that is, before the main transformation process begins. Be aware that tables are memory intensive since the data is pre-loaded into memory -- it is up to the user to manage memory requirements.\n\n\nThe table consists of one or more rows consisting of key, value(s) pairs. Each row within the table will have a unique key. During table loading, only the first record for a key will be loaded.\n\n\nTables are global. All tables are loaded at the start of program execution. The same table name may be referenced across all sub and main pequel scripts.");
	use Class::STL::ClassMembers::Constructor;
	sub new_extra
	{
		my $self = shift;
		$self->attributes()->push_back(
			$self->attributes()->factory(name => 'table_name', required => 1),
			ETL::Pequel3::Type::Properties::TableType->new(required => 1),
			ETL::Pequel3::Type::Properties::DataSetSpec->new(required => 1),
			$self->attributes()->factory(name => 'static'),
			$self->attributes()->factory(name => 'key_field', required => 1),
			$self->attributes()->factory(name => 'key_type'),
			$self->attributes()->factory(name => 'field_map'), # =fname:col,fname:col,...
		);
	}
	sub prepare
	{
		my $self = shift;
		return if ($self->pequel_ref()->user_tables()->exists($self->table_name()));
		$self->table_ref($self->pequel_ref()->user_tables()->factory(
			name => $self->table_name(),
			table_type => $self->attributes()->table_type(),
			static => $self->attributes()->static(),
			dataset_spec => $self->attributes()->dataset_spec(),
			key_field => $self->attributes()->key_field(),
			key_type => $self->attributes()->key_type(),
			field_map => $self->attributes()->field_map(),
			pequel_ref => $self->pequel_ref(),
		));
		$self->table_ref()->prepare($self->items());
		$self->pequel_ref()->user_tables()->push_back($self->table_ref());
	}
	sub select
	{
		my $self = shift;
		my %p = @_;
		$self->err()->user_error(10211, "Section '@{[ 
			$self->section_name() ]}' select() function requires '@{[ $self->target_mem_name() ]}' parameter!")
			unless (exists($p{$self->target_mem_name()}));
		my $s = $self->exists($p{$self->target_mem_name()});
		return $s if (ref($s));
		$self->add(%p);
		$self->back()->attributes()->set(@_);
		return $self->back();
	}

	package ETL::Pequel3::Type::Section::Table::Item;
	use base qw(ETL::Pequel3::Type::Section::Item::Abstract);
	use Class::STL::ClassMembers;
	use Class::STL::ClassMembers::Constructor;
	sub new_extra
	{
		my $self = shift;
		$self->attributes()->push_back(
			$self->attributes()->factory(name => 'key_value'),
			$self->attributes()->factory(name => 'data_values'),
		);
	}
}
# ----------------------------------------------------------------------------------------------------
1;