ViewVC Help
View File | Revision Log | Show Annotations | Download File
/cvs/AnyEvent-HTTP/HTTP.pm
Revision: 1.34
Committed: Wed Oct 29 14:51:07 2008 UTC (15 years, 6 months ago) by root
Branch: MAIN
Changes since 1.33: +15 -9 lines
Log Message:
*** empty log message ***

File Contents

# Content
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 http_get "http://www.nethype.de/", sub { print $_[1] };
10
11 # ... do something else here
12
13 =head1 DESCRIPTION
14
15 This module is an L<AnyEvent> user, you need to make sure that you use and
16 run a supported event loop.
17
18 This module implements a simple, stateless and non-blocking HTTP
19 client. It supports GET, POST and other request methods, cookies and more,
20 all on a very low level. It can follow redirects supports proxies and
21 automatically limits the number of connections to the values specified in
22 the RFC.
23
24 It should generally be a "good client" that is enough for most HTTP
25 tasks. Simple tasks should be simple, but complex tasks should still be
26 possible as the user retains control over request and response headers.
27
28 The caller is responsible for authentication management, cookies (if
29 the simplistic implementation in this module doesn't suffice), referer
30 and other high-level protocol details for which this module offers only
31 limited support.
32
33 =head2 METHODS
34
35 =over 4
36
37 =cut
38
39 package AnyEvent::HTTP;
40
41 use strict;
42 no warnings;
43
44 use Carp;
45
46 use AnyEvent ();
47 use AnyEvent::Util ();
48 use AnyEvent::Socket ();
49 use AnyEvent::Handle ();
50
51 use base Exporter::;
52
53 our $VERSION = '1.05';
54
55 our @EXPORT = qw(http_get http_post http_head http_request);
56
57 our $USERAGENT = "Mozilla/5.0 (compatible; AnyEvent::HTTP/$VERSION; +http://software.schmorp.de/pkg/AnyEvent)";
58 our $MAX_RECURSE = 10;
59 our $MAX_PERSISTENT = 8;
60 our $PERSISTENT_TIMEOUT = 2;
61 our $TIMEOUT = 300;
62
63 # changing these is evil
64 our $MAX_PERSISTENT_PER_HOST = 2;
65 our $MAX_PER_HOST = 4;
66
67 our $PROXY;
68 our $ACTIVE = 0;
69
70 my %KA_COUNT; # number of open keep-alive connections per host
71 my %CO_SLOT; # number of open connections, and wait queue, per host
72
73 =item http_get $url, key => value..., $cb->($data, $headers)
74
75 Executes an HTTP-GET request. See the http_request function for details on
76 additional parameters and the return value.
77
78 =item http_head $url, key => value..., $cb->($data, $headers)
79
80 Executes an HTTP-HEAD request. See the http_request function for details
81 on additional parameters and the return value.
82
83 =item http_post $url, $body, key => value..., $cb->($data, $headers)
84
85 Executes an HTTP-POST request with a request body of C<$body>. See the
86 http_request function for details on additional parameters and the return
87 value.
88
89 =item http_request $method => $url, key => value..., $cb->($data, $headers)
90
91 Executes a HTTP request of type C<$method> (e.g. C<GET>, C<POST>). The URL
92 must be an absolute http or https URL.
93
94 When called in void context, nothing is returned. In other contexts,
95 C<http_request> returns a "cancellation guard" - you have to keep the
96 object at least alive until the callback get called. If the object gets
97 destroyed before the callbakc is called, the request will be cancelled.
98
99 The callback will be called with the response data as first argument
100 (or C<undef> if it wasn't available due to errors), and a hash-ref with
101 response headers as second argument.
102
103 All the headers in that hash are lowercased. In addition to the response
104 headers, the "pseudo-headers" C<HTTPVersion>, C<Status> and C<Reason>
105 contain the three parts of the HTTP Status-Line of the same name. The
106 pseudo-header C<URL> contains the original URL (which can differ from the
107 requested URL when following redirects).
108
109 If the server sends a header multiple times, then their contents will be
110 joined together with a comma (C<,>), as per the HTTP spec.
111
112 If an internal error occurs, such as not being able to resolve a hostname,
113 then C<$data> will be C<undef>, C<< $headers->{Status} >> will be C<599>
114 and the C<Reason> pseudo-header will contain an error message.
115
116 A typical callback might look like this:
117
118 sub {
119 my ($body, $hdr) = @_;
120
121 if ($hdr->{Status} =~ /^2/) {
122 ... everything should be ok
123 } else {
124 print "error, $hdr->{Status} $hdr->{Reason}\n";
125 }
126 }
127
128 Additional parameters are key-value pairs, and are fully optional. They
129 include:
130
131 =over 4
132
133 =item recurse => $count (default: $MAX_RECURSE)
134
135 Whether to recurse requests or not, e.g. on redirects, authentication
136 retries and so on, and how often to do so.
137
138 =item headers => hashref
139
140 The request headers to use. Currently, C<http_request> may provide its
141 own C<Host:>, C<Content-Length:>, C<Connection:> and C<Cookie:> headers
142 and will provide defaults for C<User-Agent:> and C<Referer:>.
143
144 =item timeout => $seconds
145
146 The time-out to use for various stages - each connect attempt will reset
147 the timeout, as will read or write activity. Default timeout is 5 minutes.
148
149 =item proxy => [$host, $port[, $scheme]] or undef
150
151 Use the given http proxy for all requests. If not specified, then the
152 default proxy (as specified by C<$ENV{http_proxy}>) is used.
153
154 C<$scheme> must be either missing or C<http> for HTTP, or C<https> for
155 HTTPS.
156
157 =item body => $string
158
159 The request body, usually empty. Will be-sent as-is (future versions of
160 this module might offer more options).
161
162 =item cookie_jar => $hash_ref
163
164 Passing this parameter enables (simplified) cookie-processing, loosely
165 based on the original netscape specification.
166
167 The C<$hash_ref> must be an (initially empty) hash reference which will
168 get updated automatically. It is possible to save the cookie_jar to
169 persistent storage with something like JSON or Storable, but this is not
170 recommended, as expire times are currently being ignored.
171
172 Note that this cookie implementation is not of very high quality, nor
173 meant to be complete. If you want complete cookie management you have to
174 do that on your own. C<cookie_jar> is meant as a quick fix to get some
175 cookie-using sites working. Cookies are a privacy disaster, do not use
176 them unless required to.
177
178 =back
179
180 Example: make a simple HTTP GET request for http://www.nethype.de/
181
182 http_request GET => "http://www.nethype.de/", sub {
183 my ($body, $hdr) = @_;
184 print "$body\n";
185 };
186
187 Example: make a HTTP HEAD request on https://www.google.com/, use a
188 timeout of 30 seconds.
189
190 http_request
191 GET => "https://www.google.com",
192 timeout => 30,
193 sub {
194 my ($body, $hdr) = @_;
195 use Data::Dumper;
196 print Dumper $hdr;
197 }
198 ;
199
200 Example: make another simple HTTP GET request, but immediately try to
201 cancel it.
202
203 my $request = http_request GET => "http://www.nethype.de/", sub {
204 my ($body, $hdr) = @_;
205 print "$body\n";
206 };
207
208 undef $request;
209
210 =cut
211
212 sub _slot_schedule;
213 sub _slot_schedule($) {
214 my $host = shift;
215
216 while ($CO_SLOT{$host}[0] < $MAX_PER_HOST) {
217 if (my $cb = shift @{ $CO_SLOT{$host}[1] }) {
218 # somebody wants that slot
219 ++$CO_SLOT{$host}[0];
220 ++$ACTIVE;
221
222 $cb->(AnyEvent::Util::guard {
223 --$ACTIVE;
224 --$CO_SLOT{$host}[0];
225 _slot_schedule $host;
226 });
227 } else {
228 # nobody wants the slot, maybe we can forget about it
229 delete $CO_SLOT{$host} unless $CO_SLOT{$host}[0];
230 last;
231 }
232 }
233 }
234
235 # wait for a free slot on host, call callback
236 sub _get_slot($$) {
237 push @{ $CO_SLOT{$_[0]}[1] }, $_[1];
238
239 _slot_schedule $_[0];
240 }
241
242 our $qr_nl = qr<\015?\012>;
243 our $qr_nlnl = qr<\015?\012\015?\012>;
244
245 sub http_request($$@) {
246 my $cb = pop;
247 my ($method, $url, %arg) = @_;
248
249 my %hdr;
250
251 $method = uc $method;
252
253 if (my $hdr = $arg{headers}) {
254 while (my ($k, $v) = each %$hdr) {
255 $hdr{lc $k} = $v;
256 }
257 }
258
259 my $recurse = exists $arg{recurse} ? delete $arg{recurse} : $MAX_RECURSE;
260
261 return $cb->(undef, { Status => 599, Reason => "recursion limit reached", URL => $url })
262 if $recurse < 0;
263
264 my $proxy = $arg{proxy} || $PROXY;
265 my $timeout = $arg{timeout} || $TIMEOUT;
266
267 $hdr{"user-agent"} ||= $USERAGENT;
268
269 my ($uscheme, $uauthority, $upath, $query, $fragment) =
270 $url =~ m|(?:([^:/?#]+):)?(?://([^/?#]*))?([^?#]*)(?:\?([^#]*))?(?:#(.*))?|;
271
272 $uscheme = lc $uscheme;
273
274 my $uport = $uscheme eq "http" ? 80
275 : $uscheme eq "https" ? 443
276 : return $cb->(undef, { Status => 599, Reason => "only http and https URL schemes supported", URL => $url });
277
278 $hdr{referer} ||= "$uscheme://$uauthority$upath"; # leave out fragment and query string, just a heuristic
279
280 $uauthority =~ /^(?: .*\@ )? ([^\@:]+) (?: : (\d+) )?$/x
281 or return $cb->(undef, { Status => 599, Reason => "unparsable URL", URL => $url });
282
283 my $uhost = $1;
284 $uport = $2 if defined $2;
285
286 $uhost =~ s/^\[(.*)\]$/$1/;
287 $upath .= "?$query" if length $query;
288
289 $upath =~ s%^/?%/%;
290
291 # cookie processing
292 if (my $jar = $arg{cookie_jar}) {
293 %$jar = () if $jar->{version} != 1;
294
295 my @cookie;
296
297 while (my ($chost, $v) = each %$jar) {
298 if ($chost =~ /^\./) {
299 next unless $chost eq substr $uhost, -length $chost;
300 } elsif ($chost =~ /\./) {
301 next unless $chost eq $uhost;
302 } else {
303 next;
304 }
305
306 while (my ($cpath, $v) = each %$v) {
307 next unless $cpath eq substr $upath, 0, length $cpath;
308
309 while (my ($k, $v) = each %$v) {
310 next if $uscheme ne "https" && exists $v->{secure};
311 my $value = $v->{value};
312 $value =~ s/([\\"])/\\$1/g;
313 push @cookie, "$k=\"$value\"";
314 }
315 }
316 }
317
318 $hdr{cookie} = join "; ", @cookie
319 if @cookie;
320 }
321
322 my ($rhost, $rport, $rscheme, $rpath); # request host, port, path
323
324 if ($proxy) {
325 ($rhost, $rport, $rscheme, $rpath) = (@$proxy, $url);
326
327 # don't support https requests over https-proxy transport,
328 # can't be done with tls as spec'ed.
329 $rscheme = "http" if $uscheme eq "https" && $rscheme eq "https";
330 } else {
331 ($rhost, $rport, $rscheme, $rpath) = ($uhost, $uport, $uscheme, $upath);
332 }
333
334 $hdr{host} = $uhost;
335 $hdr{"content-length"} = length $arg{body};
336
337 my %state = (connect_guard => 1);
338
339 _get_slot $uhost, sub {
340 $state{slot_guard} = shift;
341
342 return unless $state{connect_guard};
343
344 $state{connect_guard} = AnyEvent::Socket::tcp_connect $rhost, $rport, sub {
345 $state{fh} = shift
346 or return $cb->(undef, { Status => 599, Reason => "$!", URL => $url });
347 pop; # free memory, save a tree
348
349 return unless delete $state{connect_guard};
350
351 # get handle
352 $state{handle} = new AnyEvent::Handle
353 fh => $state{fh},
354 timeout => $timeout;
355
356 # limit the number of persistent connections
357 # keepalive not yet supported
358 if ($KA_COUNT{$_[1]} < $MAX_PERSISTENT_PER_HOST) {
359 ++$KA_COUNT{$_[1]};
360 $state{handle}{ka_count_guard} = AnyEvent::Util::guard {
361 --$KA_COUNT{$_[1]}
362 };
363 $hdr{connection} = "keep-alive";
364 } else {
365 delete $hdr{connection};
366 }
367
368 # (re-)configure handle
369 $state{handle}->on_error (sub {
370 my $errno = "$!";
371 %state = ();
372 $cb->(undef, { Status => 599, Reason => $errno, URL => $url });
373 });
374 $state{handle}->on_eof (sub {
375 %state = ();
376 $cb->(undef, { Status => 599, Reason => "unexpected end-of-file", URL => $url });
377 });
378
379 $state{handle}->starttls ("connect") if $rscheme eq "https";
380
381 # handle actual, non-tunneled, request
382 my $handle_actual_request = sub {
383 $state{handle}->starttls ("connect") if $uscheme eq "https" && !exists $state{handle}{tls};
384
385 # send request
386 $state{handle}->push_write (
387 "$method $rpath HTTP/1.0\015\012"
388 . (join "", map "\u$_: $hdr{$_}\015\012", keys %hdr)
389 . "\015\012"
390 . (delete $arg{body})
391 );
392
393 %hdr = (); # reduce memory usage, save a kitten
394
395 # status line
396 $state{handle}->push_read (line => $qr_nl, sub {
397 $_[1] =~ /^HTTP\/([0-9\.]+) \s+ ([0-9]{3}) (?: \s+ ([^\015\012]*) )?/ix
398 or return (%state = (), $cb->(undef, { Status => 599, Reason => "invalid server response ($_[1])", URL => $url }));
399
400 my %hdr = ( # response headers
401 HTTPVersion => ",$1",
402 Status => ",$2",
403 Reason => ",$3",
404 URL => ",$url"
405 );
406
407 # headers, could be optimized a bit
408 $state{handle}->unshift_read (line => $qr_nlnl, sub {
409 for ("$_[1]\012") {
410 y/\015//d; # weed out any \015, as they show up in the weirdest of places.
411
412 # we support spaces in field names, as lotus domino
413 # creates them (actually spaces around seperators
414 # are strictly allowed in http, they are a security issue).
415 $hdr{lc $1} .= ",$2"
416 while /\G
417 ([^:\000-\037]+):
418 [\011\040]*
419 ((?: [^\012]+ | \012[\011\040] )*)
420 \012
421 /gxc;
422
423 /\G$/
424 or return (%state = (), $cb->(undef, { Status => 599, Reason => "garbled response headers", URL => $url }));
425 }
426
427 substr $_, 0, 1, ""
428 for values %hdr;
429
430 my $finish = sub {
431 # TODO: use destroy method, when/if available
432 #$state{handle}->destroy;
433 $state{handle}->on_eof (undef);
434 $state{handle}->on_error (undef);
435 %state = ();
436
437 # set-cookie processing
438 if ($arg{cookie_jar}) {
439 for ($hdr{"set-cookie"}) {
440 # parse NAME=VALUE
441 my @kv;
442
443 while (/\G\s* ([^=;,[:space:]]+) \s*=\s* (?: "((?:[^\\"]+|\\.)*)" | ([^=;,[:space:]]*) )/gcxs) {
444 my $name = $1;
445 my $value = $3;
446
447 unless ($value) {
448 $value = $2;
449 $value =~ s/\\(.)/$1/gs;
450 }
451
452 push @kv, $name => $value;
453
454 last unless /\G\s*;/gc;
455 }
456
457 last unless @kv;
458
459 my $name = shift @kv;
460 my %kv = (value => shift @kv, @kv);
461
462 my $cdom;
463 my $cpath = (delete $kv{path}) || "/";
464
465 if (exists $kv{domain}) {
466 $cdom = delete $kv{domain};
467
468 $cdom =~ s/^\.?/./; # make sure it starts with a "."
469
470 next if $cdom =~ /\.$/;
471
472 # this is not rfc-like and not netscape-like. go figure.
473 my $ndots = $cdom =~ y/.//;
474 next if $ndots < ($cdom =~ /\.[^.][^.]\.[^.][^.]$/ ? 3 : 2);
475 } else {
476 $cdom = $uhost;
477 }
478
479 # store it
480 $arg{cookie_jar}{version} = 1;
481 $arg{cookie_jar}{$cdom}{$cpath}{$name} = \%kv;
482
483 redo if /\G\s*,/gc;
484 }
485 }
486
487 # microsoft and other shitheads don't give a shit for following standards,
488 # try to support some common forms of broken Location headers.
489 if ($_[1]{location} !~ /^(?: $ | [^:\/?\#]+ : )/x) {
490 $_[1]{location} =~ s/^\.\/+//;
491
492 my $url = "$rscheme://$uhost:$uport";
493
494 unless ($_[1]{location} =~ s/^\///) {
495 $url .= $upath;
496 $url =~ s/\/[^\/]*$//;
497 }
498
499 $_[1]{location} = "$url/$_[1]{location}";
500 }
501
502 if ($_[1]{Status} =~ /^30[12]$/ && $recurse && $method ne "POST") {
503 # apparently, mozilla et al. just change POST to GET here
504 # more research is needed before we do the same
505 http_request ($method, $_[1]{location}, %arg, recurse => $recurse - 1, $cb);
506 } elsif ($_[1]{Status} == 303 && $recurse) {
507 # even http/1.1 is unclear on how to mutate the method
508 $method = "GET" unless $method eq "HEAD";
509 http_request ($method => $_[1]{location}, %arg, recurse => $recurse - 1, $cb);
510 } elsif ($_[1]{Status} == 307 && $recurse && $method =~ /^(?:GET|HEAD)$/) {
511 http_request ($method => $_[1]{location}, %arg, recurse => $recurse - 1, $cb);
512 } else {
513 $cb->($_[0], $_[1]);
514 }
515 };
516
517 if ($hdr{Status} =~ /^(?:1..|204|304)$/ or $method eq "HEAD") {
518 $finish->(undef, \%hdr);
519 } else {
520 if (exists $hdr{"content-length"}) {
521 $_[0]->unshift_read (chunk => $hdr{"content-length"}, sub {
522 # could cache persistent connection now
523 if ($hdr{connection} =~ /\bkeep-alive\b/i) {
524 # but we don't, due to misdesigns, this is annoyingly complex
525 };
526
527 $finish->($_[1], \%hdr);
528 });
529 } else {
530 # too bad, need to read until we get an error or EOF,
531 # no way to detect winged data.
532 $_[0]->on_error (sub {
533 $finish->($_[0]{rbuf}, \%hdr);
534 });
535 $_[0]->on_eof (undef);
536 $_[0]->on_read (sub { });
537 }
538 }
539 });
540 });
541 };
542
543 # now handle proxy-CONNECT method
544 if ($proxy && $uscheme eq "https") {
545 # oh dear, we have to wrap it into a connect request
546
547 # maybe re-use $uauthority with patched port?
548 $state{handle}->push_write ("CONNECT $uhost:$uport HTTP/1.0\015\012Host: $uhost\015\012\015\012");
549 $state{handle}->push_read (line => $qr_nlnl, sub {
550 $_[1] =~ /^HTTP\/([0-9\.]+) \s+ ([0-9]{3}) (?: \s+ ([^\015\012]*) )?/ix
551 or return (%state = (), $cb->(undef, { Status => 599, Reason => "invalid proxy connect response ($_[1])", URL => $url }));
552
553 if ($2 == 200) {
554 $rpath = $upath;
555 &$handle_actual_request;
556 } else {
557 %state = ();
558 $cb->(undef, { Status => $2, Reason => $3, URL => $url });
559 }
560 });
561 } else {
562 &$handle_actual_request;
563 }
564
565 }, sub {
566 $timeout
567 };
568 };
569
570 defined wantarray && AnyEvent::Util::guard { %state = () }
571 }
572
573 sub http_get($@) {
574 unshift @_, "GET";
575 &http_request
576 }
577
578 sub http_head($@) {
579 unshift @_, "HEAD";
580 &http_request
581 }
582
583 sub http_post($$@) {
584 my $url = shift;
585 unshift @_, "POST", $url, "body";
586 &http_request
587 }
588
589 =back
590
591 =head2 GLOBAL FUNCTIONS AND VARIABLES
592
593 =over 4
594
595 =item AnyEvent::HTTP::set_proxy "proxy-url"
596
597 Sets the default proxy server to use. The proxy-url must begin with a
598 string of the form C<http://host:port> (optionally C<https:...>).
599
600 =item $AnyEvent::HTTP::MAX_RECURSE
601
602 The default value for the C<recurse> request parameter (default: C<10>).
603
604 =item $AnyEvent::HTTP::USERAGENT
605
606 The default value for the C<User-Agent> header (the default is
607 C<Mozilla/5.0 (compatible; AnyEvent::HTTP/$VERSION; +http://software.schmorp.de/pkg/AnyEvent)>).
608
609 =item $AnyEvent::HTTP::MAX_PERSISTENT
610
611 The maximum number of persistent connections to keep open (default: 8).
612
613 Not implemented currently.
614
615 =item $AnyEvent::HTTP::PERSISTENT_TIMEOUT
616
617 The maximum time to cache a persistent connection, in seconds (default: 2).
618
619 Not implemented currently.
620
621 =item $AnyEvent::HTTP::ACTIVE
622
623 The number of active connections. This is not the number of currently
624 running requests, but the number of currently open and non-idle TCP
625 connections. This number of can be useful for load-leveling.
626
627 =back
628
629 =cut
630
631 sub set_proxy($) {
632 $PROXY = [$2, $3 || 3128, $1] if $_[0] =~ m%^(https?):// ([^:/]+) (?: : (\d*) )?%ix;
633 }
634
635 # initialise proxy from environment
636 set_proxy $ENV{http_proxy};
637
638 =head1 SEE ALSO
639
640 L<AnyEvent>.
641
642 =head1 AUTHOR
643
644 Marc Lehmann <schmorp@schmorp.de>
645 http://home.schmorp.de/
646
647 =cut
648
649 1
650