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Revision: 1.33
Committed: Mon Oct 27 11:09:54 2008 UTC (15 years, 6 months ago) by root
Branch: MAIN
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# 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($$) {
237 push @{ $CO_SLOT{$_[0]}[1] }, $_[1];
238
239 _slot_schedule $_[0];
240 }
241
242 sub http_request($$@) {
243 my $cb = pop;
244 my ($method, $url, %arg) = @_;
245
246 my %hdr;
247
248 $method = uc $method;
249
250 if (my $hdr = $arg{headers}) {
251 while (my ($k, $v) = each %$hdr) {
252 $hdr{lc $k} = $v;
253 }
254 }
255
256 my $recurse = exists $arg{recurse} ? delete $arg{recurse} : $MAX_RECURSE;
257
258 return $cb->(undef, { Status => 599, Reason => "recursion limit reached", URL => $url })
259 if $recurse < 0;
260
261 my $proxy = $arg{proxy} || $PROXY;
262 my $timeout = $arg{timeout} || $TIMEOUT;
263
264 $hdr{"user-agent"} ||= $USERAGENT;
265
266 my ($uscheme, $uauthority, $upath, $query, $fragment) =
267 $url =~ m|(?:([^:/?#]+):)?(?://([^/?#]*))?([^?#]*)(?:\?([^#]*))?(?:#(.*))?|;
268
269 $uscheme = lc $uscheme;
270
271 my $uport = $uscheme eq "http" ? 80
272 : $uscheme eq "https" ? 443
273 : return $cb->(undef, { Status => 599, Reason => "only http and https URL schemes supported", URL => $url });
274
275 $hdr{referer} ||= "$uscheme://$uauthority$upath"; # leave out fragment and query string, just a heuristic
276
277 $uauthority =~ /^(?: .*\@ )? ([^\@:]+) (?: : (\d+) )?$/x
278 or return $cb->(undef, { Status => 599, Reason => "unparsable URL", URL => $url });
279
280 my $uhost = $1;
281 $uport = $2 if defined $2;
282
283 $uhost =~ s/^\[(.*)\]$/$1/;
284 $upath .= "?$query" if length $query;
285
286 $upath =~ s%^/?%/%;
287
288 # cookie processing
289 if (my $jar = $arg{cookie_jar}) {
290 %$jar = () if $jar->{version} != 1;
291
292 my @cookie;
293
294 while (my ($chost, $v) = each %$jar) {
295 if ($chost =~ /^\./) {
296 next unless $chost eq substr $uhost, -length $chost;
297 } elsif ($chost =~ /\./) {
298 next unless $chost eq $uhost;
299 } else {
300 next;
301 }
302
303 while (my ($cpath, $v) = each %$v) {
304 next unless $cpath eq substr $upath, 0, length $cpath;
305
306 while (my ($k, $v) = each %$v) {
307 next if $uscheme ne "https" && exists $v->{secure};
308 my $value = $v->{value};
309 $value =~ s/([\\"])/\\$1/g;
310 push @cookie, "$k=\"$value\"";
311 }
312 }
313 }
314
315 $hdr{cookie} = join "; ", @cookie
316 if @cookie;
317 }
318
319 my ($rhost, $rport, $rscheme, $rpath); # request host, port, path
320
321 if ($proxy) {
322 ($rhost, $rport, $rscheme, $rpath) = (@$proxy, $url);
323
324 # don't support https requests over https-proxy transport,
325 # can't be done with tls as spec'ed.
326 $rscheme = "http" if $uscheme eq "https" && $rscheme eq "https";
327 } else {
328 ($rhost, $rport, $rscheme, $rpath) = ($uhost, $uport, $uscheme, $upath);
329 }
330
331 $hdr{host} = $uhost;
332 $hdr{"content-length"} = length $arg{body};
333
334 my %state = (connect_guard => 1);
335
336 _get_slot $uhost, sub {
337 $state{slot_guard} = shift;
338
339 return unless $state{connect_guard};
340
341 $state{connect_guard} = AnyEvent::Socket::tcp_connect $rhost, $rport, sub {
342 $state{fh} = shift
343 or return $cb->(undef, { Status => 599, Reason => "$!", URL => $url });
344
345 delete $state{connect_guard}; # reduce memory usage, save a tree
346
347 # get handle
348 $state{handle} = new AnyEvent::Handle
349 fh => $state{fh};
350
351 # limit the number of persistent connections
352 if ($KA_COUNT{$_[1]} < $MAX_PERSISTENT_PER_HOST) {
353 ++$KA_COUNT{$_[1]};
354 $state{handle}{ka_count_guard} = AnyEvent::Util::guard { --$KA_COUNT{$_[1]} };
355 $hdr{connection} = "keep-alive";
356 delete $hdr{connection}; # keep-alive not yet supported
357 } else {
358 delete $hdr{connection};
359 }
360
361 # (re-)configure handle
362 $state{handle}->timeout ($timeout);
363 $state{handle}->on_error (sub {
364 my $errno = "$!";
365 %state = ();
366 $cb->(undef, { Status => 599, Reason => $errno, URL => $url });
367 });
368 $state{handle}->on_eof (sub {
369 %state = ();
370 $cb->(undef, { Status => 599, Reason => "unexpected end-of-file", URL => $url });
371 });
372
373 $state{handle}->starttls ("connect") if $rscheme eq "https";
374
375 # handle actual, non-tunneled, request
376 my $handle_actual_request = sub {
377 $state{handle}->starttls ("connect") if $uscheme eq "https";
378
379 # send request
380 $state{handle}->push_write (
381 "$method $rpath HTTP/1.0\015\012"
382 . (join "", map "\u$_: $hdr{$_}\015\012", keys %hdr)
383 . "\015\012"
384 . (delete $arg{body})
385 );
386
387 %hdr = (); # reduce memory usage, save a kitten
388
389 # status line
390 $state{handle}->push_read (line => qr/\015?\012/, sub {
391 $_[1] =~ /^HTTP\/([0-9\.]+) \s+ ([0-9]{3}) (?: \s+ ([^\015\012]*) )?/ix
392 or return (%state = (), $cb->(undef, { Status => 599, Reason => "invalid server response ($_[1])", URL => $url }));
393
394 my %hdr = ( # response headers
395 HTTPVersion => ",$1",
396 Status => ",$2",
397 Reason => ",$3",
398 URL => ",$url"
399 );
400
401 # headers, could be optimized a bit
402 $state{handle}->unshift_read (line => qr/\015?\012\015?\012/, sub {
403 for ("$_[1]\012") {
404 y/\015//d; # weed out any \015, as they show up in the weirdest of places.
405
406 # we support spaces in field names, as lotus domino
407 # creates them (actually spaces around seperators
408 # are strictly allowed in http, they are a security issue).
409 $hdr{lc $1} .= ",$2"
410 while /\G
411 ([^:\000-\037]+):
412 [\011\040]*
413 ((?: [^\012]+ | \012[\011\040] )*)
414 \012
415 /gxc;
416
417 /\G$/
418 or return (%state = (), $cb->(undef, { Status => 599, Reason => "garbled response headers", URL => $url }));
419 }
420
421 substr $_, 0, 1, ""
422 for values %hdr;
423
424 my $finish = sub {
425 # TODO: use destroy method, when/if available
426 #$state{handle}->destroy;
427 $state{handle}->on_eof (undef);
428 $state{handle}->on_error (undef);
429 %state = ();
430
431 # set-cookie processing
432 if ($arg{cookie_jar}) {
433 for ($hdr{"set-cookie"}) {
434 # parse NAME=VALUE
435 my @kv;
436
437 while (/\G\s* ([^=;,[:space:]]+) \s*=\s* (?: "((?:[^\\"]+|\\.)*)" | ([^=;,[:space:]]*) )/gcxs) {
438 my $name = $1;
439 my $value = $3;
440
441 unless ($value) {
442 $value = $2;
443 $value =~ s/\\(.)/$1/gs;
444 }
445
446 push @kv, $name => $value;
447
448 last unless /\G\s*;/gc;
449 }
450
451 last unless @kv;
452
453 my $name = shift @kv;
454 my %kv = (value => shift @kv, @kv);
455
456 my $cdom;
457 my $cpath = (delete $kv{path}) || "/";
458
459 if (exists $kv{domain}) {
460 $cdom = delete $kv{domain};
461
462 $cdom =~ s/^\.?/./; # make sure it starts with a "."
463
464 next if $cdom =~ /\.$/;
465
466 # this is not rfc-like and not netscape-like. go figure.
467 my $ndots = $cdom =~ y/.//;
468 next if $ndots < ($cdom =~ /\.[^.][^.]\.[^.][^.]$/ ? 3 : 2);
469 } else {
470 $cdom = $uhost;
471 }
472
473 # store it
474 $arg{cookie_jar}{version} = 1;
475 $arg{cookie_jar}{$cdom}{$cpath}{$name} = \%kv;
476
477 redo if /\G\s*,/gc;
478 }
479 }
480
481 # microsoft and other shitheads don't give a shit for following standards,
482 # try to support some common forms of broken Location headers.
483 if ($_[1]{location} !~ /^(?: $ | [^:\/?\#]+ : )/x) {
484 $_[1]{location} =~ s/^\.\/+//;
485
486 my $url = "$rscheme://$uhost:$uport";
487
488 unless ($_[1]{location} =~ s/^\///) {
489 $url .= $upath;
490 $url =~ s/\/[^\/]*$//;
491 }
492
493 $_[1]{location} = "$url/$_[1]{location}";
494 }
495
496 if ($_[1]{Status} =~ /^30[12]$/ && $recurse && $method ne "POST") {
497 # apparently, mozilla et al. just change POST to GET here
498 # more research is needed before we do the same
499 http_request ($method, $_[1]{location}, %arg, recurse => $recurse - 1, $cb);
500 } elsif ($_[1]{Status} == 303 && $recurse) {
501 # even http/1.1 is unclear on how to mutate the method
502 $method = "GET" unless $method eq "HEAD";
503 http_request ($method => $_[1]{location}, %arg, recurse => $recurse - 1, $cb);
504 } elsif ($_[1]{Status} == 307 && $recurse && $method =~ /^(?:GET|HEAD)$/) {
505 http_request ($method => $_[1]{location}, %arg, recurse => $recurse - 1, $cb);
506 } else {
507 $cb->($_[0], $_[1]);
508 }
509 };
510
511 if ($hdr{Status} =~ /^(?:1..|204|304)$/ or $method eq "HEAD") {
512 $finish->(undef, \%hdr);
513 } else {
514 if (exists $hdr{"content-length"}) {
515 $_[0]->unshift_read (chunk => $hdr{"content-length"}, sub {
516 # could cache persistent connection now
517 if ($hdr{connection} =~ /\bkeep-alive\b/i) {
518 # but we don't, due to misdesigns, this is annoyingly complex
519 };
520
521 $finish->($_[1], \%hdr);
522 });
523 } else {
524 # too bad, need to read until we get an error or EOF,
525 # no way to detect winged data.
526 $_[0]->on_error (sub {
527 $finish->($_[0]{rbuf}, \%hdr);
528 });
529 $_[0]->on_eof (undef);
530 $_[0]->on_read (sub { });
531 }
532 }
533 });
534 });
535 };
536
537 # now handle proxy-CONNECT method
538 if ($proxy && $uscheme eq "https") {
539 # oh dear, we have to wrap it into a connect request
540
541 # maybe re-use $uauthority with patched port?
542 $state{handle}->push_write ("CONNECT $uhost:$uport HTTP/1.0\015\012Host: $uhost\015\012\015\012");
543 $state{handle}->push_read (line => qr/\015?\012\015?\012/, sub {
544 $_[1] =~ /^HTTP\/([0-9\.]+) \s+ ([0-9]{3}) (?: \s+ ([^\015\012]*) )?/ix
545 or return (%state = (), $cb->(undef, { Status => 599, Reason => "invalid proxy connect response ($_[1])", URL => $url }));
546
547 if ($2 == 200) {
548 $rpath = $upath;
549 &$handle_actual_request;
550 } else {
551 %state = ();
552 $cb->(undef, { Status => $2, Reason => $3, URL => $url });
553 }
554 });
555 } else {
556 &$handle_actual_request;
557 }
558
559 }, sub {
560 $timeout
561 };
562 };
563
564 defined wantarray && AnyEvent::Util::guard { %state = () }
565 }
566
567 sub http_get($@) {
568 unshift @_, "GET";
569 &http_request
570 }
571
572 sub http_head($@) {
573 unshift @_, "HEAD";
574 &http_request
575 }
576
577 sub http_post($$@) {
578 my $url = shift;
579 unshift @_, "POST", $url, "body";
580 &http_request
581 }
582
583 =back
584
585 =head2 GLOBAL FUNCTIONS AND VARIABLES
586
587 =over 4
588
589 =item AnyEvent::HTTP::set_proxy "proxy-url"
590
591 Sets the default proxy server to use. The proxy-url must begin with a
592 string of the form C<http://host:port> (optionally C<https:...>).
593
594 =item $AnyEvent::HTTP::MAX_RECURSE
595
596 The default value for the C<recurse> request parameter (default: C<10>).
597
598 =item $AnyEvent::HTTP::USERAGENT
599
600 The default value for the C<User-Agent> header (the default is
601 C<Mozilla/5.0 (compatible; AnyEvent::HTTP/$VERSION; +http://software.schmorp.de/pkg/AnyEvent)>).
602
603 =item $AnyEvent::HTTP::MAX_PERSISTENT
604
605 The maximum number of persistent connections to keep open (default: 8).
606
607 Not implemented currently.
608
609 =item $AnyEvent::HTTP::PERSISTENT_TIMEOUT
610
611 The maximum time to cache a persistent connection, in seconds (default: 2).
612
613 Not implemented currently.
614
615 =item $AnyEvent::HTTP::ACTIVE
616
617 The number of active connections. This is not the number of currently
618 running requests, but the number of currently open and non-idle TCP
619 connections. This number of can be useful for load-leveling.
620
621 =back
622
623 =cut
624
625 sub set_proxy($) {
626 $PROXY = [$2, $3 || 3128, $1] if $_[0] =~ m%^(https?):// ([^:/]+) (?: : (\d*) )?%ix;
627 }
628
629 # initialise proxy from environment
630 set_proxy $ENV{http_proxy};
631
632 =head1 SEE ALSO
633
634 L<AnyEvent>.
635
636 =head1 AUTHOR
637
638 Marc Lehmann <schmorp@schmorp.de>
639 http://home.schmorp.de/
640
641 =cut
642
643 1
644