# Vend::Table::InMemory - Store an Interchange table in memory
#
# $Id: InMemory.pm,v 2.13 2005/11/08 18:14:48 jon Exp $
#
# Copyright (C) 2002-2005 Interchange Development Group
# Copyright (C) 1996-2002 Red Hat, Inc.
#
# This program was originally based on Vend 0.2 and 0.3
# Copyright 1995 by Andrew M. Wilcox <amw@wilcoxsolutions.com>
#
# 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., 59 Temple Place, Suite 330, Boston,
# MA  02111-1307  USA.

package Vend::Table::InMemory;
use Vend::Table::Common qw(!config !columns);
@ISA = qw/Vend::Table::Common/;
$VERSION = substr(q$Revision: 2.13 $, 10);
use strict;

# 0: column names
# 1: column index
# 2: tie hash
# 3: configuration

use vars qw($FILENAME
			$COLUMN_NAMES
			$COLUMN_INDEX
			$KEY_INDEX
			$TIE_HASH
			$DBM
			$CONFIG
			$EACH
			);
(
	$CONFIG,
	$FILENAME,
	$COLUMN_NAMES,
	$COLUMN_INDEX,
	$KEY_INDEX,
	$TIE_HASH,
	$DBM,
	$EACH
	) = (0 .. 7);

sub config {
	my ($self, $key, $value) = @_;
	return $self->[$CONFIG]{$key} unless defined $value;
	$self->[$CONFIG]{$key} = $value;
}

sub import_db {
	return shift;
}

sub create {
	my ($class, $config, $columns) = @_;

	$config = {} unless defined $config;

	undef $config->{Transactions};

	die ::errmsg("columns argument %s is not an array ref", $columns)
		unless CORE::ref($columns) eq 'ARRAY';

	my $column_index = Vend::Table::Common::create_columns($columns, $config);
	$config->{_Auto_number} = 1 if $config->{AUTO_NUMBER};

	my $tie = {};
	my $s = [
				$config,
				undef,
				$columns,
				$column_index,
				$config->{KEY_INDEX},
				$tie,
				1
			];
#::logDebug("Create database $config->{name}: " . ::uneval($s));
	bless $s, $class;
}

sub new {
	my ($class, $obj) = @_;
	bless [$obj], $class;
}

sub close_table {
	my $s = shift;
	return 1 unless $s->[$CONFIG]{_Dirty};
	Vend::Data::export_database($s->[$CONFIG]{name});
	delete $s->[$CONFIG]{_Dirty};
}

sub row {
	my ($s, $key) = @_;
	my $a = $s->[$TIE_HASH]{$key};
    die $s->log_error(
					"There is no row with index '%s' in database %s",
					$key,
					$s->[$FILENAME],
			) unless defined $a;
	return @$a;
}

sub row_hash {
	my ($s, $key) = @_;
	my $a = $s->[$TIE_HASH]{$key}
		or return undef;
#::logDebug("here is row $key: " . ::uneval($a));
	my %row;
	@row{ @{$s->[$COLUMN_NAMES]} } = @$a;
	return \%row;
}

*row_array = \&row;

sub columns {
	my ($s) = @_;
	return @{$s->[$COLUMN_NAMES]};
}


sub field_settor {
	my ($s, $column) = @_;
	my $index = $s->column_index($column);
	return sub {
		my ($key, $value) = @_;
		my $a = $s->[$TIE_HASH]{$key};
		$a = $s->[$TIE_HASH]{$key} = [] unless defined $a;
		$a->[$index] = $value;
		$s->[$CONFIG]{_Dirty} = 1;
		return undef;
	};
}

sub set_row {
	my ($s, @fields) = @_;
	my $key = $fields[$s->[$KEY_INDEX]];
	$s->[$CONFIG]{_Dirty} = 1;
	$s->[$TIE_HASH]{$key} = [@fields];
}

sub inc_field {
	my ($s, $key, $column, $adder) = @_;
	my $a = $s->[$TIE_HASH]{$key};
	$a = $s->[$TIE_HASH]{$key} = [] unless defined $a;
	$a->[$s->column_index($column)] += $adder;
}

sub each_record {
	my ($s) = @_;
	my $key;

#::logDebug("reached each_record InMemory");
	return $s->each_sorted() if defined $s->[$EACH];
	for (;;) {
		$key = each %{$s->[$TIE_HASH]};
		return () unless defined $key;
		return ($key, $s->row($key));
	}
}

sub each_nokey {
	my ($s) = @_;
#::logDebug("reached each_nokey InMemory");
	$s = $s->import_db() if ! defined $s->[$TIE_HASH];
	my $key;

	for (;;) {
		$key = each %{$s->[$TIE_HASH]};
		return () unless defined $key;
		return [ $s->row($key) ];
	}
}


#sub each_record {
#	my ($s) = @_;
#	my @e = each %{$s->[$TIE_HASH]};
#	if (@e) {
#		return ($e[0], @{$e[1]});
#	}
#	else {
#		return ();
#	}
#}

sub record_exists {
	my ($s, $key) = @_;
#::logDebug("$key exist test");
	return exists($s->[$TIE_HASH]{$key});
}

*test_record = \&record_exists;

sub delete_record {
	my ($s, $key) = @_;
	delete($s->[$TIE_HASH]{$key});
}

sub clear_table {
	my ($s) = @_;
	%{$s->[$TIE_HASH]} = ();
}

sub touch {
	1
}

sub isopen {
	1
}

sub ref {
	return $_[0];
}

# Unfortunate hack need for Safe searches
*test_column	= \&Vend::Table::Common::test_column;
*column_index	= \&Vend::Table::Common::column_index;
*errstr     	= \&Vend::Table::Common::errstr;
*field			= \&Vend::Table::Common::field;
*log_error  	= \&Vend::Table::Common::log_error;
*name			= \&Vend::Table::Common::name;
*numeric		= \&Vend::Table::Common::numeric;
*set_field		= \&Vend::Table::Common::set_field;
*suicide		= \&Vend::Table::Common::suicide;
*set_slice		= \&Vend::Table::Common::set_slice;

1;
