package Net::HTTP::NB;# $Id: NB.pm,v 1.6 2004/11/12 16:18:11 gisle Exp $use strict;use vars qw($VERSION @ISA);$VERSION = "0.03";require Net::HTTP;@ISA=qw(Net::HTTP);sub sysread {    my $self = $_[0];    if (${*$self}{'httpnb_read_count'}++) {	${*$self}{'http_buf'} = ${*$self}{'httpnb_save'};	die "Multi-read\n";    }    my $buf;    my $offset = $_[3] || 0;    my $n = sysread($self, $_[1], $_[2], $offset);    ${*$self}{'httpnb_save'} .= substr($_[1], $offset);    return $n;}sub read_response_headers {    my $self = shift;    ${*$self}{'httpnb_read_count'} = 0;    ${*$self}{'httpnb_save'} = ${*$self}{'http_buf'};    my @h = eval { $self->SUPER::read_response_headers(@_) };    if ($@) {	return if $@ eq "Multi-read\n";	die;    }    return @h;}sub read_entity_body {    my $self = shift;    ${*$self}{'httpnb_read_count'} = 0;    ${*$self}{'httpnb_save'} = ${*$self}{'http_buf'};    # XXX I'm not so sure this does the correct thing in case of    # transfer-encoding tranforms    my $n = eval { $self->SUPER::read_entity_body(@_); };    if ($@) {	$_[0] = "";	return -1;    }    return $n;}1;__END__=head1 NAMENet::HTTP::NB - Non-blocking HTTP client=head1 SYNOPSIS use Net::HTTP::NB; my $s = Net::HTTP::NB->new(Host => "www.perl.com") || die $@; $s->write_request(GET => "/"); use IO::Select; my $sel = IO::Select->new($s); READ_HEADER: {    die "Header timeout" unless $sel->can_read(10);    my($code, $mess, %h) = $s->read_response_headers;    redo READ_HEADER unless $code; } while (1) {    die "Body timeout" unless $sel->can_read(10);    my $buf;    my $n = $s->read_entity_body($buf, 1024);    last unless $n;    print $buf; }=head1 DESCRIPTIONSame interface as C<Net::HTTP> but it will never try multiple readswhen the read_response_headers() or read_entity_body() methods areinvoked.  This make it possible to multiplex multiple Net::HTTP::NBusing select without risk blocking.If read_response_headers() did not see enough data to complete theheaders an empty list is returned.If read_entity_body() did not see new entity data in its readthe value -1 is returned.=head1 SEE ALSOL<Net::HTTP>=head1 COPYRIGHTCopyright 2001 Gisle Aas.This library is free software; you can redistribute it and/ormodify it under the same terms as Perl itself.=cut