#!/usr/bin/perl
=pod

=head1 NAME

Spline::Data - Per Message data

=head1 SYNOPSIS

    use Spline::Data;

    my $data = Spline::Data->new($ctx);
    my $value = $data->get($key);
    $data->set($key, $value);

    my $data = Spline::Data->load($ctx); 

=head1 DESCRIPTION

=cut

package Spline::Data;

use strict;
use warnings;

use Spline::Log qw(set_log_context);
use Data::Dumper;

use base 'Exporter';
our @EXPORT = qw();
our @EXPORT_OK = qw(); 

=head2 _generate_id

    my $id = _gernerate_id();

Generate a random string to tag interleaving log lines belonging to
the same message.

=cut

sub _generate_id() {
    my @chars = ('A'..'Z', 'a'..'z', '0'..'9');
    my $id = '';
    $id .= $chars[rand @chars] for 1..10;

    return $id;    
};

=head2 new

    my $data = Spline::Data::new($ctx);

=cut

sub new {
    my $class = shift;
    my $ctx = shift;

    my $id = _generate_id();
    my $self = {
        ctx => $ctx,
        data => {
            log_ctx => $id,
        }
    };
    set_log_context($id);

    return bless $self, $class;
}

=head2 get

    my $value = $data->get($key);

Get the matching value for the supplied key as scalar. If there is no
such key in the data, return undef.

=cut

sub get($$) {
    my $self = shift;
    my $key = shift;

    return $self->{data}->{$key} if defined $self->{data}->{$key};
    return undef;
}

=head2 set

    $data->set($key, $value);

Set the supplied value for the key and save the data in the Milter
context. This method will silently create new keys and overwrite
possible existent values.

=cut

sub set($$$) {
    my $self = shift;
    my ($key, $value) = @_;

    $self->{data}->{$key} = $value;
    $self->_save();
}

=head2 _save

    $data->_save();

Save the data in the Milter context.

=cut

sub _save($) {
    my $self = shift;

    $self->{ctx}->setpriv($self->{data}); 
}

=head2 load

    my $data = Spline::Data->load($ctx);

Get the data from the Milter context and return a Spline::Data object.
The data is saved again after receiving it, so that it will persist
even if no value is changed.

=cut

sub load {
    my $class = shift;
    my $ctx = shift;

    my $self = {
        ctx => $ctx,
        data => {},
    };
    $self->{data} = $ctx->getpriv();
    _save($self);

    if (defined $self->{data}->{log_ctx}) { 
        set_log_context($self->{data}->{log_ctx});
    }

    return bless $self, $class;
} 

=head1 AUTHOR

Alexander Sulfrian <alex@spline.inf.fu-berlin.de>

=cut

1;
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