[ViewVC] Diff of: cvs/AnyEvent-HTTP/README

Comparing AnyEvent-HTTP/README (file contents):
Revision 1.12 by root, Sat Dec 5 15:37:07 2009 UTC vs.
Revision 1.23 by root, Sun Apr 22 12:58:38 2012 UTC

…		…
12	This module is an AnyEvent user, you need to make sure that you use and	12	This module is an AnyEvent user, you need to make sure that you use and
13	run a supported event loop.	13	run a supported event loop.
14		14
15	This module implements a simple, stateless and non-blocking HTTP client.	15	This module implements a simple, stateless and non-blocking HTTP client.
16	It supports GET, POST and other request methods, cookies and more, all	16	It supports GET, POST and other request methods, cookies and more, all
17	on a very low level. It can follow redirects supports proxies and	17	on a very low level. It can follow redirects, supports proxies, and
18	automatically limits the number of connections to the values specified	18	automatically limits the number of connections to the values specified
19	in the RFC.	19	in the RFC.
20		20
21	It should generally be a "good client" that is enough for most HTTP	21	It should generally be a "good client" that is enough for most HTTP
22	tasks. Simple tasks should be simple, but complex tasks should still be	22	tasks. Simple tasks should be simple, but complex tasks should still be
…		…
46	URL must be an absolute http or https URL.	46	URL must be an absolute http or https URL.
47		47
48	When called in void context, nothing is returned. In other contexts,	48	When called in void context, nothing is returned. In other contexts,
49	"http_request" returns a "cancellation guard" - you have to keep the	49	"http_request" returns a "cancellation guard" - you have to keep the
50	object at least alive until the callback get called. If the object	50	object at least alive until the callback get called. If the object
51	gets destroyed before the callbakc is called, the request will be	51	gets destroyed before the callback is called, the request will be
52	cancelled.	52	cancelled.
53		53
54	The callback will be called with the response body data as first	54	The callback will be called with the response body data as first
55	argument (or "undef" if an error occured), and a hash-ref with	55	argument (or "undef" if an error occured), and a hash-ref with
56	response headers as second argument.	56	response headers (and trailers) as second argument.
57		57
58	All the headers in that hash are lowercased. In addition to the	58	All the headers in that hash are lowercased. In addition to the
59	response headers, the "pseudo-headers" "HTTPVersion", "Status" and	59	response headers, the "pseudo-headers" (uppercase to avoid clashing
		60	with possible response headers) "HTTPVersion", "Status" and "Reason"
60	"Reason" contain the three parts of the HTTP Status-Line of the same	61	contain the three parts of the HTTP Status-Line of the same name. If
		62	an error occurs during the body phase of a request, then the
		63	original "Status" and "Reason" values from the header are available
		64	as "OrigStatus" and "OrigReason".
		65
61	name. The pseudo-header "URL" contains the original URL (which can	66	The pseudo-header "URL" contains the actual URL (which can differ
62	differ from the requested URL when following redirects).	67	from the requested URL when following redirects - for example, you
		68	might get an error that your URL scheme is not supported even though
		69	your URL is a valid http URL because it redirected to an ftp URL, in
		70	which case you can look at the URL pseudo header).
		71
		72	The pseudo-header "Redirect" only exists when the request was a
		73	result of an internal redirect. In that case it is an array
		74	reference with the "($data, $headers)" from the redirect response.
		75	Note that this response could in turn be the result of a redirect
		76	itself, and "$headers->{Redirect}[1]{Redirect}" will then contain
		77	the original response, and so on.
63		78
64	If the server sends a header multiple times, then their contents	79	If the server sends a header multiple times, then their contents
65	will be joined together with a comma (","), as per the HTTP spec.	80	will be joined together with a comma (","), as per the HTTP spec.
66		81
67	If an internal error occurs, such as not being able to resolve a	82	If an internal error occurs, such as not being able to resolve a
68	hostname, then $data will be "undef", "$headers->{Status}" will be	83	hostname, then $data will be "undef", "$headers->{Status}" will be
69	"59x" (usually 599) and the "Reason" pseudo-header will contain an	84	590-599 and the "Reason" pseudo-header will contain an error
70	error message.	85	message. Currently the following status codes are used:
		86
		87	595 - errors during connection etsbalishment, proxy handshake.
		88	596 - errors during TLS negotiation, request sending and header
		89	processing.
		90	597 - errors during body receiving or processing.
		91	598 - user aborted request via "on_header" or "on_body".
		92	599 - other, usually nonretryable, errors (garbled URL etc.).
71		93
72	A typical callback might look like this:	94	A typical callback might look like this:
73		95
74	sub {	96	sub {
75	my ($body, $hdr) = @_;	97	my ($body, $hdr) = @_;
…		…
89	authentication retries and so on, and how often to do so.	111	authentication retries and so on, and how often to do so.
90		112
91	headers => hashref	113	headers => hashref
92	The request headers to use. Currently, "http_request" may	114	The request headers to use. Currently, "http_request" may
93	provide its own "Host:", "Content-Length:", "Connection:" and	115	provide its own "Host:", "Content-Length:", "Connection:" and
94	"Cookie:" headers and will provide defaults for "User-Agent:"	116	"Cookie:" headers and will provide defaults at least for "TE:",
95	and "Referer:" (this can be suppressed by using "undef" for	117	"Referer:" and "User-Agent:" (this can be suppressed by using
96	these headers in which case they won't be sent at all).	118	"undef" for these headers in which case they won't be sent at
		119	all).
		120
		121	You really should provide your own "User-Agent:" header value
		122	that is appropriate for your program - I wouldn't be surprised
		123	if the default AnyEvent string gets blocked by webservers sooner
		124	or later.
		125
		126	Also, make sure that your headers names and values do not
		127	contain any embedded newlines.
97		128
98	timeout => $seconds	129	timeout => $seconds
99	The time-out to use for various stages - each connect attempt	130	The time-out to use for various stages - each connect attempt
100	will reset the timeout, as will read or write activity, i.e.	131	will reset the timeout, as will read or write activity, i.e.
101	this is not an overall timeout.	132	this is not an overall timeout.
102		133
103	Default timeout is 5 minutes.	134	Default timeout is 5 minutes.
104		135
105	proxy => [$host, $port[, $scheme]] or undef	136	proxy => [$host, $port[, $scheme]] or undef
106	Use the given http proxy for all requests. If not specified,	137	Use the given http proxy for all requests, or no proxy if
107	then the default proxy (as specified by $ENV{http_proxy}) is
108	used.	138	"undef" is used.
109		139
110	$scheme must be either missing, "http" for HTTP or "https" for	140	$scheme must be either missing or must be "http" for HTTP.
111	HTTPS.	141
		142	If not specified, then the default proxy is used (see
		143	"AnyEvent::HTTP::set_proxy").
112		144
113	body => $string	145	body => $string
114	The request body, usually empty. Will be-sent as-is (future	146	The request body, usually empty. Will be sent as-is (future
115	versions of this module might offer more options).	147	versions of this module might offer more options).
116		148
117	cookie_jar => $hash_ref	149	cookie_jar => $hash_ref
118	Passing this parameter enables (simplified) cookie-processing,	150	Passing this parameter enables (simplified) cookie-processing,
119	loosely based on the original netscape specification.	151	loosely based on the original netscape specification.
120		152
121	The $hash_ref must be an (initially empty) hash reference which	153	The $hash_ref must be an (initially empty) hash reference which
122	will get updated automatically. It is possible to save the	154	will get updated automatically. It is possible to save the
123	cookie_jar to persistent storage with something like JSON or	155	cookie jar to persistent storage with something like JSON or
124	Storable, but this is not recommended, as expiry times are	156	Storable - see the "AnyEvent::HTTP::cookie_jar_expire" function
125	currently being ignored.	157	if you wish to remove expired or session-only cookies, and also
		158	for documentation on the format of the cookie jar.
126		159
127	Note that this cookie implementation is not of very high	160	Note that this cookie implementation is not meant to be
128	quality, nor meant to be complete. If you want complete cookie	161	complete. If you want complete cookie management you have to do
129	management you have to do that on your own. "cookie_jar" is	162	that on your own. "cookie_jar" is meant as a quick fix to get
130	meant as a quick fix to get some cookie-using sites working.	163	most cookie-using sites working. Cookies are a privacy disaster,
131	Cookies are a privacy disaster, do not use them unless required	164	do not use them unless required to.
132	to.	165
		166	When cookie processing is enabled, the "Cookie:" and
		167	"Set-Cookie:" headers will be set and handled by this module,
		168	otherwise they will be left untouched.
133		169
134	tls_ctx => $scheme \| $tls_ctx	170	tls_ctx => $scheme \| $tls_ctx
135	Specifies the AnyEvent::TLS context to be used for https	171	Specifies the AnyEvent::TLS context to be used for https
136	connections. This parameter follows the same rules as the	172	connections. This parameter follows the same rules as the
137	"tls_ctx" parameter to AnyEvent::Handle, but additionally, the	173	"tls_ctx" parameter to AnyEvent::Handle, but additionally, the
…		…
139	predefined low-security (no verification, highest compatibility)	175	predefined low-security (no verification, highest compatibility)
140	and high-security (CA and common-name verification) TLS context.	176	and high-security (CA and common-name verification) TLS context.
141		177
142	The default for this option is "low", which could be interpreted	178	The default for this option is "low", which could be interpreted
143	as "give me the page, no matter what".	179	as "give me the page, no matter what".
		180
		181	See also the "sessionid" parameter.
		182
		183	session => $string
		184	The module might reuse connections to the same host internally.
		185	Sometimes (e.g. when using TLS), you do not want to reuse
		186	connections from other sessions. This can be achieved by setting
		187	this parameter to some unique ID (such as the address of an
		188	object storing your state data, or the TLS context) - only
		189	connections using the same unique ID will be reused.
144		190
145	on_prepare => $callback->($fh)	191	on_prepare => $callback->($fh)
146	In rare cases you need to "tune" the socket before it is used to	192	In rare cases you need to "tune" the socket before it is used to
147	connect (for exmaple, to bind it on a given IP address). This	193	connect (for exmaple, to bind it on a given IP address). This
148	parameter overrides the prepare callback passed to	194	parameter overrides the prepare callback passed to
149	"AnyEvent::Socket::tcp_connect" and behaves exactly the same way	195	"AnyEvent::Socket::tcp_connect" and behaves exactly the same way
150	(e.g. it has to provide a timeout). See the description for the	196	(e.g. it has to provide a timeout). See the description for the
151	$prepare_cb argument of "AnyEvent::Socket::tcp_connect" for	197	$prepare_cb argument of "AnyEvent::Socket::tcp_connect" for
152	details.	198	details.
153		199
		200	tcp_connect => $callback->($host, $service, $connect_cb,
		201	$prepare_cb)
		202	In even rarer cases you want total control over how
		203	AnyEvent::HTTP establishes connections. Normally it uses
		204	AnyEvent::Socket::tcp_connect to do this, but you can provide
		205	your own "tcp_connect" function - obviously, it has to follow
		206	the same calling conventions, except that it may always return a
		207	connection guard object.
		208
		209	There are probably lots of weird uses for this function,
		210	starting from tracing the hosts "http_request" actually tries to
		211	connect, to (inexact but fast) host => IP address caching or
		212	even socks protocol support.
		213
154	on_header => $callback->($headers)	214	on_header => $callback->($headers)
155	When specified, this callback will be called with the header	215	When specified, this callback will be called with the header
156	hash as soon as headers have been successfully received from the	216	hash as soon as headers have been successfully received from the
157	remote server (not on locally-generated errors).	217	remote server (not on locally-generated errors).
158		218
…		…
163		223
164	This callback is useful, among other things, to quickly reject	224	This callback is useful, among other things, to quickly reject
165	unwanted content, which, if it is supposed to be rare, can be	225	unwanted content, which, if it is supposed to be rare, can be
166	faster than first doing a "HEAD" request.	226	faster than first doing a "HEAD" request.
167		227
		228	The downside is that cancelling the request makes it impossible
		229	to re-use the connection. Also, the "on_header" callback will
		230	not receive any trailer (headers sent after the response body).
		231
168	Example: cancel the request unless the content-type is	232	Example: cancel the request unless the content-type is
169	"text/html".	233	"text/html".
170		234
171	on_header => sub {	235	on_header => sub {
172	$_[0]{"content-type"} =~ /^text\/html\s*(?:;\|$)/	236	$_[0]{"content-type"} =~ /^text\/html\s*(?:;\|$)/
…		…
179		243
180	It has to return either true (in which case AnyEvent::HTTP will	244	It has to return either true (in which case AnyEvent::HTTP will
181	continue), or false, in which case AnyEvent::HTTP will cancel	245	continue), or false, in which case AnyEvent::HTTP will cancel
182	the download (and call the completion callback with an error	246	the download (and call the completion callback with an error
183	code of 598).	247	code of 598).
		248
		249	The downside to cancelling the request is that it makes it
		250	impossible to re-use the connection.
184		251
185	This callback is useful when the data is too large to be held in	252	This callback is useful when the data is too large to be held in
186	memory (so the callback writes it to a file) or when only some	253	memory (so the callback writes it to a file) or when only some
187	information should be extracted, or when the body should be	254	information should be extracted, or when the body should be
188	processed incrementally.	255	processed incrementally.
…		…
202	AnyEvent::Handle object associated with the connection. In error	269	AnyEvent::Handle object associated with the connection. In error
203	cases, "undef" will be passed. When there is no body (e.g.	270	cases, "undef" will be passed. When there is no body (e.g.
204	status 304), the empty string will be passed.	271	status 304), the empty string will be passed.
205		272
206	The handle object might or might not be in TLS mode, might be	273	The handle object might or might not be in TLS mode, might be
207	connected to a proxy, be a persistent connection etc., and	274	connected to a proxy, be a persistent connection, use chunked
208	configured in unspecified ways. The user is responsible for this	275	transfer encoding etc., and configured in unspecified ways. The
209	handle (it will not be used by this module anymore).	276	user is responsible for this handle (it will not be used by this
		277	module anymore).
210		278
211	This is useful with some push-type services, where, after the	279	This is useful with some push-type services, where, after the
212	initial headers, an interactive protocol is used (typical	280	initial headers, an interactive protocol is used (typical
213	example would be the push-style twitter API which starts a	281	example would be the push-style twitter API which starts a
214	JSON/XML stream).	282	JSON/XML stream).
215		283
216	If you think you need this, first have a look at "on_body", to	284	If you think you need this, first have a look at "on_body", to
217	see if that doesn't solve your problem in a better way.	285	see if that doesn't solve your problem in a better way.
218		286
		287	persistent => $boolean
		288	Try to create/reuse a persistent connection. When this flag is
		289	set (default: true for idempotent requests, false for all
		290	others), then "http_request" tries to re-use an existing
		291	(previously-created) persistent connection to the host and,
		292	failing that, tries to create a new one.
		293
		294	Requests failing in certain ways will be automatically retried
		295	once, which is dangerous for non-idempotent requests, which is
		296	why it defaults to off for them. The reason for this is because
		297	the bozos who designed HTTP/1.1 made it impossible to
		298	distinguish between a fatal error and a normal connection
		299	timeout, so you never know whether there was a problem with your
		300	request or not.
		301
		302	When reusing an existent connection, many parameters (such as
		303	TLS context) will be ignored. See the "session" parameter for a
		304	workaround.
		305
		306	keepalive => $boolean
		307	Only used when "persistent" is also true. This parameter decides
		308	whether "http_request" tries to handshake a HTTP/1.0-style
		309	keep-alive connection (as opposed to only a HTTP/1.1 persistent
		310	connection).
		311
		312	The default is true, except when using a proxy, in which case it
		313	defaults to false, as HTTP/1.0 proxies cannot support this in a
		314	meaningful way.
		315
		316	handle_params => { key => value ... }
		317	The key-value pairs in this hash will be passed to any
		318	AnyEvent::Handle constructor that is called - not all requests
		319	will create a handle, and sometimes more than one is created, so
		320	this parameter is only good for setting hints.
		321
		322	Example: set the maximum read size to 4096, to potentially
		323	conserve memory at the cost of speed.
		324
		325	handle_params => {
		326	max_read_size => 4096,
		327	},
		328
219	Example: make a simple HTTP GET request for http://www.nethype.de/	329	Example: do a simple HTTP GET request for http://www.nethype.de/ and
		330	print the response body.
220		331
221	http_request GET => "http://www.nethype.de/", sub {	332	http_request GET => "http://www.nethype.de/", sub {
222	my ($body, $hdr) = @_;	333	my ($body, $hdr) = @_;
223	print "$body\n";	334	print "$body\n";
224	};	335	};
225		336
226	Example: make a HTTP HEAD request on https://www.google.com/, use a	337	Example: do a HTTP HEAD request on https://www.google.com/, use a
227	timeout of 30 seconds.	338	timeout of 30 seconds.
228		339
229	http_request	340	http_request
230	GET => "https://www.google.com",	341	HEAD => "https://www.google.com",
		342	headers => { "user-agent" => "MySearchClient 1.0" },
231	timeout => 30,	343	timeout => 30,
232	sub {	344	sub {
233	my ($body, $hdr) = @_;	345	my ($body, $hdr) = @_;
234	use Data::Dumper;	346	use Data::Dumper;
235	print Dumper $hdr;	347	print Dumper $hdr;
236	}	348	}
237	;	349	;
238		350
239	Example: make another simple HTTP GET request, but immediately try	351	Example: do another simple HTTP GET request, but immediately try to
240	to cancel it.	352	cancel it.
241		353
242	my $request = http_request GET => "http://www.nethype.de/", sub {	354	my $request = http_request GET => "http://www.nethype.de/", sub {
243	my ($body, $hdr) = @_;	355	my ($body, $hdr) = @_;
244	print "$body\n";	356	print "$body\n";
245	};	357	};
246		358
247	undef $request;	359	undef $request;
248		360
		361	DNS CACHING
		362	AnyEvent::HTTP uses the AnyEvent::Socket::tcp_connect function for the
		363	actual connection, which in turn uses AnyEvent::DNS to resolve
		364	hostnames. The latter is a simple stub resolver and does no caching on
		365	its own. If you want DNS caching, you currently have to provide your own
		366	default resolver (by storing a suitable resolver object in
		367	$AnyEvent::DNS::RESOLVER) or your own "tcp_connect" callback.
		368
249	GLOBAL FUNCTIONS AND VARIABLES	369	GLOBAL FUNCTIONS AND VARIABLES
250	AnyEvent::HTTP::set_proxy "proxy-url"	370	AnyEvent::HTTP::set_proxy "proxy-url"
251	Sets the default proxy server to use. The proxy-url must begin with	371	Sets the default proxy server to use. The proxy-url must begin with
252	a string of the form "http://host:port" (optionally "https:..."),	372	a string of the form "http://host:port", croaks otherwise.
253	croaks otherwise.
254		373
255	To clear an already-set proxy, use "undef".	374	To clear an already-set proxy, use "undef".
		375
		376	When AnyEvent::HTTP is laoded for the first time it will query the
		377	default proxy from the operating system, currently by looking at
		378	"$ENV{http_proxy"}.
		379
		380	AnyEvent::HTTP::cookie_jar_expire $jar[, $session_end]
		381	Remove all cookies from the cookie jar that have been expired. If
		382	$session_end is given and true, then additionally remove all session
		383	cookies.
		384
		385	You should call this function (with a true $session_end) before you
		386	save cookies to disk, and you should call this function after
		387	loading them again. If you have a long-running program you can
		388	additonally call this function from time to time.
		389
		390	A cookie jar is initially an empty hash-reference that is managed by
		391	this module. It's format is subject to change, but currently it is
		392	like this:
		393
		394	The key "version" has to contain 1, otherwise the hash gets emptied.
		395	All other keys are hostnames or IP addresses pointing to
		396	hash-references. The key for these inner hash references is the
		397	server path for which this cookie is meant, and the values are again
		398	hash-references. The keys of those hash-references is the cookie
		399	name, and the value, you guessed it, is another hash-reference, this
		400	time with the key-value pairs from the cookie, except for "expires"
		401	and "max-age", which have been replaced by a "_expires" key that
		402	contains the cookie expiry timestamp.
		403
		404	Here is an example of a cookie jar with a single cookie, so you have
		405	a chance of understanding the above paragraph:
		406
		407	{
		408	version => 1,
		409	"10.0.0.1" => {
		410	"/" => {
		411	"mythweb_id" => {
		412	_expires => 1293917923,
		413	value => "ooRung9dThee3ooyXooM1Ohm",
		414	},
		415	},
		416	},
		417	}
		418
		419	$date = AnyEvent::HTTP::format_date $timestamp
		420	Takes a POSIX timestamp (seconds since the epoch) and formats it as
		421	a HTTP Date (RFC 2616).
		422
		423	$timestamp = AnyEvent::HTTP::parse_date $date
		424	Takes a HTTP Date (RFC 2616) or a Cookie date (netscape cookie spec)
		425	or a bunch of minor variations of those, and returns the
		426	corresponding POSIX timestamp, or "undef" if the date cannot be
		427	parsed.
256		428
257	$AnyEvent::HTTP::MAX_RECURSE	429	$AnyEvent::HTTP::MAX_RECURSE
258	The default value for the "recurse" request parameter (default: 10).	430	The default value for the "recurse" request parameter (default: 10).
		431
		432	$AnyEvent::HTTP::TIMEOUT
		433	The default timeout for connection operations (default: 300).
259		434
260	$AnyEvent::HTTP::USERAGENT	435	$AnyEvent::HTTP::USERAGENT
261	The default value for the "User-Agent" header (the default is	436	The default value for the "User-Agent" header (the default is
262	"Mozilla/5.0 (compatible; U; AnyEvent-HTTP/$VERSION;	437	"Mozilla/5.0 (compatible; U; AnyEvent-HTTP/$VERSION;
263	+http://software.schmorp.de/pkg/AnyEvent)").	438	+http://software.schmorp.de/pkg/AnyEvent)").
264		439
265	$AnyEvent::HTTP::MAX_PER_HOST	440	$AnyEvent::HTTP::MAX_PER_HOST
266	The maximum number of concurrent connections to the same host	441	The maximum number of concurrent connections to the same host
267	(identified by the hostname). If the limit is exceeded, then the	442	(identified by the hostname). If the limit is exceeded, then the
268	additional requests are queued until previous connections are	443	additional requests are queued until previous connections are
269	closed.	444	closed. Both persistent and non-persistent connections are counted
		445	in this limit.
270		446
271	The default value for this is 4, and it is highly advisable to not	447	The default value for this is 4, and it is highly advisable to not
272	increase it.	448	increase it much.
		449
		450	For comparison: the RFC's recommend 4 non-persistent or 2 persistent
		451	connections, older browsers used 2, newers (such as firefox 3)
		452	typically use 6, and Opera uses 8 because like, they have the
		453	fastest browser and give a shit for everybody else on the planet.
		454
		455	$AnyEvent::HTTP::PERSISTENT_TIMEOUT
		456	The time after which idle persistent conenctions get closed by
		457	AnyEvent::HTTP (default: 3).
273		458
274	$AnyEvent::HTTP::ACTIVE	459	$AnyEvent::HTTP::ACTIVE
275	The number of active connections. This is not the number of	460	The number of active connections. This is not the number of
276	currently running requests, but the number of currently open and	461	currently running requests, but the number of currently open and
277	non-idle TCP connections. This number of can be useful for	462	non-idle TCP connections. This number can be useful for
278	load-leveling.	463	load-leveling.
		464
		465	SHOWCASE
		466	This section contaisn some more elaborate "real-world" examples or code
		467	snippets.
		468
		469	HTTP/1.1 FILE DOWNLOAD
		470	Downloading files with HTTP can be quite tricky, especially when
		471	something goes wrong and you want to resume.
		472
		473	Here is a function that initiates and resumes a download. It uses the
		474	last modified time to check for file content changes, and works with
		475	many HTTP/1.0 servers as well, and usually falls back to a complete
		476	re-download on older servers.
		477
		478	It calls the completion callback with either "undef", which means a
		479	nonretryable error occured, 0 when the download was partial and should
		480	be retried, and 1 if it was successful.
		481
		482	use AnyEvent::HTTP;
		483
		484	sub download($$$) {
		485	my ($url, $file, $cb) = @_;
		486
		487	open my $fh, "+<", $file
		488	or die "$file: $!";
		489
		490	my %hdr;
		491	my $ofs = 0;
		492
		493	warn stat $fh;
		494	warn -s _;
		495	if (stat $fh and -s _) {
		496	$ofs = -s _;
		497	warn "-s is ", $ofs;
		498	$hdr{"if-unmodified-since"} = AnyEvent::HTTP::format_date +(stat _)[9];
		499	$hdr{"range"} = "bytes=$ofs-";
		500	}
		501
		502	http_get $url,
		503	headers => \%hdr,
		504	on_header => sub {
		505	my ($hdr) = @_;
		506
		507	if ($hdr->{Status} == 200 && $ofs) {
		508	# resume failed
		509	truncate $fh, $ofs = 0;
		510	}
		511
		512	sysseek $fh, $ofs, 0;
		513
		514	1
		515	},
		516	on_body => sub {
		517	my ($data, $hdr) = @_;
		518
		519	if ($hdr->{Status} =~ /^2/) {
		520	length $data == syswrite $fh, $data
		521	or return; # abort on write errors
		522	}
		523
		524	1
		525	},
		526	sub {
		527	my (undef, $hdr) = @_;
		528
		529	my $status = $hdr->{Status};
		530
		531	if (my $time = AnyEvent::HTTP::parse_date $hdr->{"last-modified"}) {
		532	utime $fh, $time, $time;
		533	}
		534
		535	if ($status == 200 \|\| $status == 206 \|\| $status == 416) {
		536	# download ok \|\| resume ok \|\| file already fully downloaded
		537	$cb->(1, $hdr);
		538
		539	} elsif ($status == 412) {
		540	# file has changed while resuming, delete and retry
		541	unlink $file;
		542	$cb->(0, $hdr);
		543
		544	} elsif ($status == 500 or $status == 503 or $status =~ /^59/) {
		545	# retry later
		546	$cb->(0, $hdr);
		547
		548	} else {
		549	$cb->(undef, $hdr);
		550	}
		551	}
		552	;
		553	}
		554
		555	download "http://server/somelargefile", "/tmp/somelargefile", sub {
		556	if ($_[0]) {
		557	print "OK!\n";
		558	} elsif (defined $_[0]) {
		559	print "please retry later\n";
		560	} else {
		561	print "ERROR\n";
		562	}
		563	};
		564
		565	SOCKS PROXIES
		566	Socks proxies are not directly supported by AnyEvent::HTTP. You can
		567	compile your perl to support socks, or use an external program such as
		568	socksify (dante) or tsocks to make your program use a socks proxy
		569	transparently.
		570
		571	Alternatively, for AnyEvent::HTTP only, you can use your own
		572	"tcp_connect" function that does the proxy handshake - here is an
		573	example that works with socks4a proxies:
		574
		575	use Errno;
		576	use AnyEvent::Util;
		577	use AnyEvent::Socket;
		578	use AnyEvent::Handle;
		579
		580	# host, port and username of/for your socks4a proxy
		581	my $socks_host = "10.0.0.23";
		582	my $socks_port = 9050;
		583	my $socks_user = "";
		584
		585	sub socks4a_connect {
		586	my ($host, $port, $connect_cb, $prepare_cb) = @_;
		587
		588	my $hdl = new AnyEvent::Handle
		589	connect => [$socks_host, $socks_port],
		590	on_prepare => sub { $prepare_cb->($_[0]{fh}) },
		591	on_error => sub { $connect_cb->() },
		592	;
		593
		594	$hdl->push_write (pack "CCnNZZ", 4, 1, $port, 1, $socks_user, $host);
		595
		596	$hdl->push_read (chunk => 8, sub {
		597	my ($hdl, $chunk) = @_;
		598	my ($status, $port, $ipn) = unpack "xCna4", $chunk;
		599
		600	if ($status == 0x5a) {
		601	$connect_cb->($hdl->{fh}, (format_address $ipn) . ":$port");
		602	} else {
		603	$! = Errno::ENXIO; $connect_cb->();
		604	}
		605	});
		606
		607	$hdl
		608	}
		609
		610	Use "socks4a_connect" instead of "tcp_connect" when doing
		611	"http_request"s, possibly after switching off other proxy types:
		612
		613	AnyEvent::HTTP::set_proxy undef; # usually you do not want other proxies
		614
		615	http_get 'http://www.google.com', tcp_connect => \&socks4a_connect, sub {
		616	my ($data, $headers) = @_;
		617	...
		618	};
279		619
280	SEE ALSO	620	SEE ALSO
281	AnyEvent.	621	AnyEvent.
282		622
283	AUTHOR	623	AUTHOR

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Comparing AnyEvent-HTTP/README (file contents): Revision 1.12 by root, Sat Dec 5 15:37:07 2009 UTC vs. Revision 1.23 by root, Sun Apr 22 12:58:38 2012 UTC

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Comparing AnyEvent-HTTP/README (file contents):
Revision 1.12 by root, Sat Dec 5 15:37:07 2009 UTC vs.
Revision 1.23 by root, Sun Apr 22 12:58:38 2012 UTC