Current File : //data/old/usr/share/perl5/vendor_perl/Net/FTPServer/DBeg1/IOBlob.pm
# -*- perl -*-
# Net::FTPServer A Perl FTP Server
# Copyright (C) 2000 Bibliotech Ltd., Unit 2-3, 50 Carnwath Road,
# London, SW6 3EG, United Kingdom.
#
# 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
=pod
=head1 NAME
Net::FTPServer::DBeg1::IOBlob - The example DB FTP server personality
=head1 SYNOPSIS
use Net::FTPServer::DBeg1::IOBlob;
=head1 METHODS
=cut
package Net::FTPServer::DBeg1::IOBlob;
use strict;
use vars qw($VERSION);
( $VERSION ) = '$Revision: 1.1 $ ' =~ /\$Revision:\s+([^\s]+)/;
use DBI;
use Carp qw(confess croak);
=pod
=over 4
=item $io = Net::FTPServer::DBeg1::IOBlob ('r', $dbh, $blob_id);
=item $io = Net::FTPServer::DBeg1::IOBlob ('w', $dbh, $blob_id);
Create an IO handle for reading or writing a PostgreSQL blob.
=cut
sub new
{
my $class = shift;
my $mode = shift;
my $dbh = shift;
my $blob_id = shift;
# XXX For some reason PostgreSQL (6.4) fails when you call lo_open
# the first time. But if you retry a second time it succeeds. Therefore
# there is this hack. [RWMJ]
my $blob_fd;
for (my $retries = 0; !$blob_fd && $retries < 3; ++$retries)
{
$blob_fd = $dbh->func ($blob_id,
$mode eq 'r' ? $dbh->{pg_INV_READ} : $dbh->{pg_INV_WRITE},
'lo_open');
}
die "failed to open blob $blob_id: ", $dbh->errstr
unless $blob_fd;
my $self = {
mode => $mode,
dbh => $dbh,
blob_id => $blob_id,
blob_fd => $blob_fd
};
bless $self, $class;
return $self;
}
=item $io->getc ();
Read 1 byte from the buffer and return it
=cut
sub getc
{
my $self = shift;
my $buffer;
if (defined $self->read ($buffer, 1)) {
return $buffer;
} else {
return undef;
}
}
=item $io->read ($buffer, $nbytes, [$offset]);
=item $io->sysread ($buffer, $nbytes, [$offset]);
Read C<$nbytes> from the handle and place them in C<$buffer>
at offset C<$offset>.
=cut
sub read
{
my $self = shift;
my $nbytes = $_[1];
my $offset = $_[2] || 0;
$self->{dbh}->func ($self->{blob_fd}, substr ($_[0], $offset), $nbytes, 'lo_read');
return $nbytes;
}
sub sysread
{
my $self = shift;
my $nbytes = $_[1];
my $offset = $_[2] || 0;
$self->{dbh}->func ($self->{blob_fd}, substr ($_[0], $offset), $nbytes, 'lo_read');
return $nbytes;
}
=item $io->write ($buffer, $nbytes, [$offset]);
=item $io->syswrite ($buffer, $nbytes, [$offset]);
Write C<$nbytes> to the handle from C<$buffer> offset C<$offset>.
=cut
sub write
{
my $self = shift;
my $nbytes = $_[1];
my $offset = $_[2] || 0;
my $buffer = substr $_[0], $offset, $nbytes;
$self->{dbh}->func ($self->{blob_fd}, $buffer, length $buffer, 'lo_write');
return $nbytes;
}
sub syswrite
{
my $self = shift;
my $nbytes = $_[1];
my $offset = $_[2] || 0;
my $buffer = substr $_[0], $offset, $nbytes;
$self->{dbh}->func ($self->{blob_fd}, $buffer, length $buffer, 'lo_write');
return $nbytes;
}
=item $io->print ($buffer);
=cut
sub print
{
my $self = shift;
my $buffer = join "", @_;
return $self->write ($buffer, length $buffer);
}
=item $io->close;
Close the IO handle.
=cut
sub close
{
my $self = shift;
if ($self->{dbh})
{
$self->{dbh}->func ($self->{blob_fd}, 'lo_close');
delete $self->{dbh};
}
return 1;
}
sub DESTROY
{
shift->close;
}
1 # So that the require or use succeeds.
__END__
=back
=head1 AUTHORS
Richard Jones (rich@annexia.org).
=head1 COPYRIGHT
Copyright (C) 2000 Biblio@Tech Ltd., Unit 2-3, 50 Carnwath Road,
London, SW6 3EG, UK
=head1 SEE ALSO
C<Net::FTPServer(3)>, C<perl(1)>
=cut
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