AnyEvent-HTTP/HTTP.pm

=head1 NAME

AnyEvent::HTTP - simple but non-blocking HTTP/HTTPS client

=head1 SYNOPSIS

   use AnyEvent::HTTP;

=head1 DESCRIPTION

This module is an L<AnyEvent> user, you need to make sure that you use and
run a supported event loop.

=head2 METHODS

=over 4

=cut

package AnyEvent::HTTP;

use strict;
no warnings;

use Carp;

use AnyEvent ();
use AnyEvent::Util ();
use AnyEvent::Socket ();
use AnyEvent::Handle ();

use base Exporter::;

our $VERSION = '1.0';

our @EXPORT = qw(http_get http_request);

our $USERAGENT          = "Mozilla/5.0 (compatible; AnyEvent::HTTP/$VERSION; +http://software.schmorp.de/pkg/AnyEvent)";
our $MAX_REDIRECTS      =  10;
our $MAX_PERSISTENT     =   8;
our $PERSISTENT_TIMEOUT =   2;
our $TIMEOUT            = 300;

# changing these is evil
our $MAX_PERSISTENT_PER_HOST = 2;
our $MAX_PER_HOST       = 4; # not respected yet :(

our $PROXY;

my %KA_COUNT; # number of open keep-alive connections per host

=item http_get $url, key => value..., $cb->($data, $headers)

Executes an HTTP-GET request. See the http_request function for details on
additional parameters.

=item http_request $method => $url, key => value..., $cb->($data, $headers)

Executes a HTTP request of type C<$method> (e.g. C<GET>, C<POST>). The URL
must be an absolute http or https URL.

The callback will be called with the response data as first argument
(or C<undef> if it wasn't available due to errors), and a hash-ref with
response headers as second argument.

All the headers in that has are lowercased. In addition to the response
headers, the three "pseudo-headers" C<HTTPVersion>, C<Status> and
C<Reason> contain the three parts of the HTTP Status-Line of the same
name.

If an internal error occurs, such as not being able to resolve a hostname,
then C<$data> will be C<undef>, C<< $headers->{Status} >> will be C<599>
and the C<Reason> pseudo-header will contain an error message.

Additional parameters are key-value pairs, and are fully optional. They
include:

=over 4

=item recurse => $boolean (default: true)

Whether to recurse requests or not, e.g. on redirects, authentication
retries and so on.

=item headers => hashref

The request headers to use.

=item timeout => $seconds

The time-out to use for various stages - each connect attempt will reset
the timeout, as will read or write activity. Default timeout is 5 minutes.

=item proxy => [$host, $port[, $scheme]] or undef

Use the given http proxy for all requests. If not specified, then the
default proxy (as specified by C<$ENV{http_proxy}>) is used.

C<$scheme> must be either missing or C<http> for HTTP, or C<https> for
HTTPS.

=back

=back

=cut

sub http_request($$$;@) {
   my $cb = pop;
   my ($method, $url, %arg) = @_;

   my %hdr;

   if (my $hdr = delete $arg{headers}) {
      while (my ($k, $v) = each %$hdr) {
         $hdr{lc $k} = $v;
      }
   }

   my $proxy   = $arg{proxy}   || $PROXY;
   my $timeout = $arg{timeout} || $TIMEOUT;

   $hdr{"user-agent"} ||= $USERAGENT;

   my ($host, $port, $path, $scheme);

   if ($proxy) {
      ($host, $port, $scheme) = @$proxy;
      $path = $url;
   } else {
      ($scheme, my $authority, $path, my $query, my $fragment) =
         $url =~ m|(?:([^:/?#]+):)?(?://([^/?#]*))?([^?#]*)(?:\?([^#]*))?(?:#(.*))?|;

      $port = $scheme eq "http"  ?  80
            : $scheme eq "https" ? 443
            : croak "$url: only http and https URLs supported";

      $authority =~ /^(?: .*\@ )? ([^\@:]+) (?: : (\d+) )?$/x
         or croak "$authority: unparsable URL";

      $host = $1;
      $port = $2 if defined $2;

      $host =~ s/^\[(.*)\]$/$1/;
      $path .= "?$query" if length $query;

      $path = "/" unless $path;

      $hdr{host} = $host = lc $host;
   }

   $scheme = lc $scheme;

   my %state;

   my $body = "";
   $state{body} = $body;

   $hdr{"content-length"} = length $body;

   $state{connect_guard} = AnyEvent::Socket::tcp_connect $host, $port, sub {
      $state{fh} = shift
         or return $cb->(undef, { Status => 599, Reason => "$!" });

      delete $state{connect_guard}; # reduce memory usage, save a tree

      # get handle
      $state{handle} = new AnyEvent::Handle
         fh => $state{fh},
         ($scheme eq "https" ? (tls => "connect") : ());

      # limit the number of persistent connections
      if ($KA_COUNT{$_[1]} < $MAX_PERSISTENT_PER_HOST) {
         ++$KA_COUNT{$_[1]};
         $state{handle}{ka_count_guard} = AnyEvent::Util::guard { --$KA_COUNT{$_[1]} };
         $hdr{connection} = "keep-alive";
         delete $hdr{connection}; # keep-alive not yet supported
      } else {
         delete $hdr{connection};
      }

      # (re-)configure handle
      $state{handle}->timeout ($timeout);
      $state{handle}->on_error (sub {
         %state = ();
         $cb->(undef, { Status => 599, Reason => "$!" });
      });
      $state{handle}->on_eof (sub {
         %state = ();
         $cb->(undef, { Status => 599, Reason => "unexpected end-of-file" });
      });

      # send request
      $state{handle}->push_write (
         "\U$method\E $path HTTP/1.0\015\012"
         . (join "", map "$_: $hdr{$_}\015\012", keys %hdr)
         . "\015\012"
         . (delete $state{body})
      );

      %hdr = (); # reduce memory usage, save a kitten

      # status line
      $state{handle}->push_read (line => qr/\015?\012/, sub {
         $_[1] =~ /^HTTP\/([0-9\.]+) \s+ ([0-9]{3}) \s+ ([^\015\012]+)/ix
            or return (%state = (), $cb->(undef, { Status => 599, Reason => "invalid server response ($_[1])" }));

         my %hdr = ( # response headers
            HTTPVersion => ",$1",
            Status      => ",$2",
            Reason      => ",$3",
         );

         # headers, could be optimized a bit
         $state{handle}->unshift_read (line => qr/\015?\012\015?\012/, sub {
            for ("$_[1]\012") {
               # we support spaces in field names, as lotus domino
               # creates them.
               $hdr{lc $1} .= ",$2"
                  while /\G
                        ([^:\000-\037]+):
                        [\011\040]*
                        ((?: [^\015\012]+ | \015?\012[\011\040] )*)
                        \015?\012
                     /gxc;

               /\G$/
                 or return $cb->(undef, { Status => 599, Reason => "garbled response headers" });
            }

            substr $_, 0, 1, ""
               for values %hdr;

            if (exists $hdr{"content-length"}) {
               $_[0]->unshift_read (chunk => $hdr{"content-length"}, sub {
                  # could cache persistent connection now
                  if ($hdr{connection} =~ /\bkeep-alive\b/i) {
                     # but we don't, due to misdesigns, this is annoyingly complex
                  };

                  %state = ();
                  $cb->($_[1], \%hdr);
               });
            } else {
               # too bad, need to read until we get an error or EOF,
               # no way to detect winged data.
               $_[0]->on_error (sub {
                  %state = ();
                  $cb->($_[0]{rbuf}, \%hdr);
               });
               $_[0]->on_eof (undef);
               $_[0]->on_read (sub { });
            }
         });
      });
   }, sub {
      $timeout
   };

   defined wantarray && AnyEvent::Util::guard { %state = () }
}

sub http_get($$;@) {
   unshift @_, "GET";
   &http_request
}

=head2 GLOBAL FUNCTIONS AND VARIABLES

=over 4

=item AnyEvent::HTTP::set_proxy "proxy-url"

Sets the default proxy server to use. The proxy-url must begin with a
string of the form C<http://host:port> (optionally C<https:...>).

=item $AnyEvent::HTTP::MAX_REDIRECTS

The default value for the C<max_redirects> request parameter
(default: C<10>).

=item $AnyEvent::HTTP::USERAGENT

The default value for the C<User-Agent> header (the default is
C<Mozilla/5.0 (compatible; AnyEvent::HTTP/$VERSION; +http://software.schmorp.de/pkg/AnyEvent)>).

=item $AnyEvent::HTTP::MAX_PERSISTENT

The maximum number of persistent connections to keep open (default: 8).

=item $AnyEvent::HTTP::PERSISTENT_TIMEOUT

The maximum time to cache a persistent connection, in seconds (default: 2).

=back

=cut

sub set_proxy($) {
   $PROXY = [$2, $3 || 3128, $1] if $_[0] =~ m%^(https?):// ([^:/]+) (?: : (\d*) )?%ix;
}

# initialise proxy from environment
set_proxy $ENV{http_proxy};

=head1 SEE ALSO

L<AnyEvent>.

=head1 AUTHOR

 Marc Lehmann <schmorp@schmorp.de>
 http://home.schmorp.de/

=cut

1

Revision:	1.2
Committed:	Wed Jun 4 11:37:41 2008 UTC (15 years, 11 months ago) by root
Branch:	MAIN
Changes since 1.1:	+69 -19 lines
Log Message:	* empty log message *
#	User	Rev	Content
1	root	1.1	=head1 NAME
2
3			AnyEvent::HTTP - simple but non-blocking HTTP/HTTPS client
4
5			=head1 SYNOPSIS
6
7			use AnyEvent::HTTP;
8
9			=head1 DESCRIPTION
10
11			This module is an L<AnyEvent> user, you need to make sure that you use and
12			run a supported event loop.
13
14			=head2 METHODS
15
16			=over 4
17
18			=cut
19
20			package AnyEvent::HTTP;
21
22			use strict;
23			no warnings;
24
25			use Carp;
26
27			use AnyEvent ();
28			use AnyEvent::Util ();
29			use AnyEvent::Socket ();
30			use AnyEvent::Handle ();
31
32			use base Exporter::;
33
34			our $VERSION = '1.0';
35
36			our @EXPORT = qw(http_get http_request);
37
38			our $USERAGENT = "Mozilla/5.0 (compatible; AnyEvent::HTTP/$VERSION; +http://software.schmorp.de/pkg/AnyEvent)";
39	root	1.2	our $MAX_REDIRECTS = 10;
40			our $MAX_PERSISTENT = 8;
41			our $PERSISTENT_TIMEOUT = 2;
42			our $TIMEOUT = 300;
43	root	1.1
44			# changing these is evil
45			our $MAX_PERSISTENT_PER_HOST = 2;
46			our $MAX_PER_HOST = 4; # not respected yet :(
47
48	root	1.2	our $PROXY;
49
50	root	1.1	my %KA_COUNT; # number of open keep-alive connections per host
51
52			=item http_get $url, key => value..., $cb->($data, $headers)
53
54			Executes an HTTP-GET request. See the http_request function for details on
55			additional parameters.
56
57			=item http_request $method => $url, key => value..., $cb->($data, $headers)
58
59			Executes a HTTP request of type C<$method> (e.g. C<GET>, C<POST>). The URL
60			must be an absolute http or https URL.
61
62	root	1.2	The callback will be called with the response data as first argument
63			(or C<undef> if it wasn't available due to errors), and a hash-ref with
64			response headers as second argument.
65
66			All the headers in that has are lowercased. In addition to the response
67			headers, the three "pseudo-headers" C<HTTPVersion>, C<Status> and
68			C<Reason> contain the three parts of the HTTP Status-Line of the same
69			name.
70
71			If an internal error occurs, such as not being able to resolve a hostname,
72			then C<$data> will be C<undef>, C<< $headers->{Status} >> will be C<599>
73			and the C<Reason> pseudo-header will contain an error message.
74
75	root	1.1	Additional parameters are key-value pairs, and are fully optional. They
76			include:
77
78			=over 4
79
80			=item recurse => $boolean (default: true)
81
82			Whether to recurse requests or not, e.g. on redirects, authentication
83			retries and so on.
84
85			=item headers => hashref
86
87			The request headers to use.
88
89			=item timeout => $seconds
90
91			The time-out to use for various stages - each connect attempt will reset
92	root	1.2	the timeout, as will read or write activity. Default timeout is 5 minutes.
93
94			=item proxy => [$host, $port[, $scheme]] or undef
95
96			Use the given http proxy for all requests. If not specified, then the
97			default proxy (as specified by C<$ENV{http_proxy}>) is used.
98
99			C<$scheme> must be either missing or C<http> for HTTP, or C<https> for
100			HTTPS.
101	root	1.1
102			=back
103
104			=back
105
106			=cut
107
108			sub http_request($$$;@) {
109			my $cb = pop;
110			my ($method, $url, %arg) = @_;
111
112			my %hdr;
113
114			if (my $hdr = delete $arg{headers}) {
115			while (my ($k, $v) = each %$hdr) {
116			$hdr{lc $k} = $v;
117			}
118			}
119
120	root	1.2	my $proxy = $arg{proxy} \|\| $PROXY;
121	root	1.1	my $timeout = $arg{timeout} \|\| $TIMEOUT;
122
123			$hdr{"user-agent"} \|\|= $USERAGENT;
124
125	root	1.2	my ($host, $port, $path, $scheme);
126
127			if ($proxy) {
128			($host, $port, $scheme) = @$proxy;
129			$path = $url;
130			} else {
131			($scheme, my $authority, $path, my $query, my $fragment) =
132			$url =~ m\|(?:([^:/?#]+):)?(?://([^/?#]))?([^?#])(?:\?([^#]))?(?:#(.))?\|;
133	root	1.1
134	root	1.2	$port = $scheme eq "http" ? 80
135	root	1.1	: $scheme eq "https" ? 443
136			: croak "$url: only http and https URLs supported";
137
138	root	1.2	$authority =~ /^(?: .*\@ )? ([^\@:]+) (?: : (\d+) )?$/x
139			or croak "$authority: unparsable URL";
140
141			$host = $1;
142			$port = $2 if defined $2;
143	root	1.1
144	root	1.2	$host =~ s/^\[(.*)\]$/$1/;
145			$path .= "?$query" if length $query;
146	root	1.1
147	root	1.2	$path = "/" unless $path;
148	root	1.1
149	root	1.2	$hdr{host} = $host = lc $host;
150			}
151
152			$scheme = lc $scheme;
153	root	1.1
154			my %state;
155
156			my $body = "";
157			$state{body} = $body;
158
159			$hdr{"content-length"} = length $body;
160
161			$state{connect_guard} = AnyEvent::Socket::tcp_connect $host, $port, sub {
162			$state{fh} = shift
163			or return $cb->(undef, { Status => 599, Reason => "$!" });
164
165			delete $state{connect_guard}; # reduce memory usage, save a tree
166
167			# get handle
168			$state{handle} = new AnyEvent::Handle
169			fh => $state{fh},
170			($scheme eq "https" ? (tls => "connect") : ());
171
172			# limit the number of persistent connections
173			if ($KA_COUNT{$_[1]} < $MAX_PERSISTENT_PER_HOST) {
174			++$KA_COUNT{$_[1]};
175			$state{handle}{ka_count_guard} = AnyEvent::Util::guard { --$KA_COUNT{$_[1]} };
176			$hdr{connection} = "keep-alive";
177	root	1.2	delete $hdr{connection}; # keep-alive not yet supported
178	root	1.1	} else {
179			delete $hdr{connection};
180			}
181
182			# (re-)configure handle
183			$state{handle}->timeout ($timeout);
184			$state{handle}->on_error (sub {
185			%state = ();
186			$cb->(undef, { Status => 599, Reason => "$!" });
187			});
188			$state{handle}->on_eof (sub {
189			%state = ();
190			$cb->(undef, { Status => 599, Reason => "unexpected end-of-file" });
191			});
192
193			# send request
194			$state{handle}->push_write (
195			"\U$method\E $path HTTP/1.0\015\012"
196			. (join "", map "$_: $hdr{$_}\015\012", keys %hdr)
197			. "\015\012"
198			. (delete $state{body})
199			);
200
201			%hdr = (); # reduce memory usage, save a kitten
202
203			# status line
204			$state{handle}->push_read (line => qr/\015?\012/, sub {
205			$_[1] =~ /^HTTP\/([0-9\.]+) \s+ ([0-9]{3}) \s+ ([^\015\012]+)/ix
206			or return (%state = (), $cb->(undef, { Status => 599, Reason => "invalid server response ($_[1])" }));
207
208			my %hdr = ( # response headers
209			HTTPVersion => ",$1",
210			Status => ",$2",
211			Reason => ",$3",
212			);
213
214			# headers, could be optimized a bit
215			$state{handle}->unshift_read (line => qr/\015?\012\015?\012/, sub {
216			for ("$_[1]\012") {
217	root	1.2	# we support spaces in field names, as lotus domino
218			# creates them.
219	root	1.1	$hdr{lc $1} .= ",$2"
220			while /\G
221	root	1.2	([^:\000-\037]+):
222	root	1.1	[\011\040]*
223			((?: [^\015\012]+ \| \015?\012[\011\040] )*)
224			\015?\012
225			/gxc;
226
227			/\G$/
228			or return $cb->(undef, { Status => 599, Reason => "garbled response headers" });
229			}
230
231			substr $_, 0, 1, ""
232			for values %hdr;
233
234			if (exists $hdr{"content-length"}) {
235			$_[0]->unshift_read (chunk => $hdr{"content-length"}, sub {
236			# could cache persistent connection now
237			if ($hdr{connection} =~ /\bkeep-alive\b/i) {
238	root	1.2	# but we don't, due to misdesigns, this is annoyingly complex
239	root	1.1	};
240
241			%state = ();
242			$cb->($_[1], \%hdr);
243			});
244			} else {
245			# too bad, need to read until we get an error or EOF,
246			# no way to detect winged data.
247			$_[0]->on_error (sub {
248			%state = ();
249			$cb->($_[0]{rbuf}, \%hdr);
250			});
251			$_[0]->on_eof (undef);
252			$_[0]->on_read (sub { });
253			}
254			});
255			});
256			}, sub {
257			$timeout
258			};
259
260			defined wantarray && AnyEvent::Util::guard { %state = () }
261			}
262
263			sub http_get($$;@) {
264			unshift @_, "GET";
265			&http_request
266			}
267
268	root	1.2	=head2 GLOBAL FUNCTIONS AND VARIABLES
269	root	1.1
270			=over 4
271
272	root	1.2	=item AnyEvent::HTTP::set_proxy "proxy-url"
273
274			Sets the default proxy server to use. The proxy-url must begin with a
275			string of the form C<http://host:port> (optionally C<https:...>).
276
277	root	1.1	=item $AnyEvent::HTTP::MAX_REDIRECTS
278
279			The default value for the C<max_redirects> request parameter
280			(default: C<10>).
281
282			=item $AnyEvent::HTTP::USERAGENT
283
284			The default value for the C<User-Agent> header (the default is
285			C<Mozilla/5.0 (compatible; AnyEvent::HTTP/$VERSION; +http://software.schmorp.de/pkg/AnyEvent)>).
286
287			=item $AnyEvent::HTTP::MAX_PERSISTENT
288
289			The maximum number of persistent connections to keep open (default: 8).
290
291			=item $AnyEvent::HTTP::PERSISTENT_TIMEOUT
292
293	root	1.2	The maximum time to cache a persistent connection, in seconds (default: 2).
294	root	1.1
295			=back
296
297			=cut
298
299	root	1.2	sub set_proxy($) {
300			$PROXY = [$2, $3 \|\| 3128, $1] if $_[0] =~ m%^(https?):// ([^:/]+) (?: : (\d*) )?%ix;
301			}
302
303			# initialise proxy from environment
304			set_proxy $ENV{http_proxy};
305
306	root	1.1	=head1 SEE ALSO
307
308			L<AnyEvent>.
309
310			=head1 AUTHOR
311
312			Marc Lehmann <schmorp@schmorp.de>
313			http://home.schmorp.de/
314
315			=cut
316
317			1
318