/usr/share/perl5/LWP/Protocol.pm is in libwww-perl 6.03-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 | package LWP::Protocol;
require LWP::MemberMixin;
@ISA = qw(LWP::MemberMixin);
$VERSION = "6.00";
use strict;
use Carp ();
use HTTP::Status ();
use HTTP::Response;
my %ImplementedBy = (); # scheme => classname
sub new
{
my($class, $scheme, $ua) = @_;
my $self = bless {
scheme => $scheme,
ua => $ua,
# historical/redundant
max_size => $ua->{max_size},
}, $class;
$self;
}
sub create
{
my($scheme, $ua) = @_;
my $impclass = LWP::Protocol::implementor($scheme) or
Carp::croak("Protocol scheme '$scheme' is not supported");
# hand-off to scheme specific implementation sub-class
my $protocol = $impclass->new($scheme, $ua);
return $protocol;
}
sub implementor
{
my($scheme, $impclass) = @_;
if ($impclass) {
$ImplementedBy{$scheme} = $impclass;
}
my $ic = $ImplementedBy{$scheme};
return $ic if $ic;
return '' unless $scheme =~ /^([.+\-\w]+)$/; # check valid URL schemes
$scheme = $1; # untaint
$scheme =~ s/[.+\-]/_/g; # make it a legal module name
# scheme not yet known, look for a 'use'd implementation
$ic = "LWP::Protocol::$scheme"; # default location
$ic = "LWP::Protocol::nntp" if $scheme eq 'news'; #XXX ugly hack
no strict 'refs';
# check we actually have one for the scheme:
unless (@{"${ic}::ISA"}) {
# try to autoload it
eval "require $ic";
if ($@) {
if ($@ =~ /Can't locate/) { #' #emacs get confused by '
$ic = '';
}
else {
die "$@\n";
}
}
}
$ImplementedBy{$scheme} = $ic if $ic;
$ic;
}
sub request
{
my($self, $request, $proxy, $arg, $size, $timeout) = @_;
Carp::croak('LWP::Protocol::request() needs to be overridden in subclasses');
}
# legacy
sub timeout { shift->_elem('timeout', @_); }
sub max_size { shift->_elem('max_size', @_); }
sub collect
{
my ($self, $arg, $response, $collector) = @_;
my $content;
my($ua, $max_size) = @{$self}{qw(ua max_size)};
eval {
local $\; # protect the print below from surprises
if (!defined($arg) || !$response->is_success) {
$response->{default_add_content} = 1;
}
elsif (!ref($arg) && length($arg)) {
open(my $fh, ">", $arg) or die "Can't write to '$arg': $!";
binmode($fh);
push(@{$response->{handlers}{response_data}}, {
callback => sub {
print $fh $_[3] or die "Can't write to '$arg': $!";
1;
},
});
push(@{$response->{handlers}{response_done}}, {
callback => sub {
close($fh) or die "Can't write to '$arg': $!";
undef($fh);
},
});
}
elsif (ref($arg) eq 'CODE') {
push(@{$response->{handlers}{response_data}}, {
callback => sub {
&$arg($_[3], $_[0], $self);
1;
},
});
}
else {
die "Unexpected collect argument '$arg'";
}
$ua->run_handlers("response_header", $response);
if (delete $response->{default_add_content}) {
push(@{$response->{handlers}{response_data}}, {
callback => sub {
$_[0]->add_content($_[3]);
1;
},
});
}
my $content_size = 0;
my $length = $response->content_length;
my %skip_h;
while ($content = &$collector, length $$content) {
for my $h ($ua->handlers("response_data", $response)) {
next if $skip_h{$h};
unless ($h->{callback}->($response, $ua, $h, $$content)) {
# XXX remove from $response->{handlers}{response_data} if present
$skip_h{$h}++;
}
}
$content_size += length($$content);
$ua->progress(($length ? ($content_size / $length) : "tick"), $response);
if (defined($max_size) && $content_size > $max_size) {
$response->push_header("Client-Aborted", "max_size");
last;
}
}
};
my $err = $@;
delete $response->{handlers}{response_data};
delete $response->{handlers} unless %{$response->{handlers}};
if ($err) {
chomp($err);
$response->push_header('X-Died' => $err);
$response->push_header("Client-Aborted", "die");
return $response;
}
return $response;
}
sub collect_once
{
my($self, $arg, $response) = @_;
my $content = \ $_[3];
my $first = 1;
$self->collect($arg, $response, sub {
return $content if $first--;
return \ "";
});
}
1;
__END__
=head1 NAME
LWP::Protocol - Base class for LWP protocols
=head1 SYNOPSIS
package LWP::Protocol::foo;
require LWP::Protocol;
@ISA=qw(LWP::Protocol);
=head1 DESCRIPTION
This class is used a the base class for all protocol implementations
supported by the LWP library.
When creating an instance of this class using
C<LWP::Protocol::create($url)>, and you get an initialised subclass
appropriate for that access method. In other words, the
LWP::Protocol::create() function calls the constructor for one of its
subclasses.
All derived LWP::Protocol classes need to override the request()
method which is used to service a request. The overridden method can
make use of the collect() function to collect together chunks of data
as it is received.
The following methods and functions are provided:
=over 4
=item $prot = LWP::Protocol->new()
The LWP::Protocol constructor is inherited by subclasses. As this is a
virtual base class this method should B<not> be called directly.
=item $prot = LWP::Protocol::create($scheme)
Create an object of the class implementing the protocol to handle the
given scheme. This is a function, not a method. It is more an object
factory than a constructor. This is the function user agents should
use to access protocols.
=item $class = LWP::Protocol::implementor($scheme, [$class])
Get and/or set implementor class for a scheme. Returns '' if the
specified scheme is not supported.
=item $prot->request(...)
$response = $protocol->request($request, $proxy, undef);
$response = $protocol->request($request, $proxy, '/tmp/sss');
$response = $protocol->request($request, $proxy, \&callback, 1024);
Dispatches a request over the protocol, and returns a response
object. This method needs to be overridden in subclasses. Refer to
L<LWP::UserAgent> for description of the arguments.
=item $prot->collect($arg, $response, $collector)
Called to collect the content of a request, and process it
appropriately into a scalar, file, or by calling a callback. If $arg
is undefined, then the content is stored within the $response. If
$arg is a simple scalar, then $arg is interpreted as a file name and
the content is written to this file. If $arg is a reference to a
routine, then content is passed to this routine.
The $collector is a routine that will be called and which is
responsible for returning pieces (as ref to scalar) of the content to
process. The $collector signals EOF by returning a reference to an
empty sting.
The return value from collect() is the $response object reference.
B<Note:> We will only use the callback or file argument if
$response->is_success(). This avoids sending content data for
redirects and authentication responses to the callback which would be
confusing.
=item $prot->collect_once($arg, $response, $content)
Can be called when the whole response content is available as
$content. This will invoke collect() with a collector callback that
returns a reference to $content the first time and an empty string the
next.
=back
=head1 SEE ALSO
Inspect the F<LWP/Protocol/file.pm> and F<LWP/Protocol/http.pm> files
for examples of usage.
=head1 COPYRIGHT
Copyright 1995-2001 Gisle Aas.
This library is free software; you can redistribute it and/or
modify it under the same terms as Perl itself.
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