--- AnyEvent-HTTP/README 2008/05/26 21:41:32 1.1 +++ AnyEvent-HTTP/README 2008/06/05 18:42:16 1.2 @@ -1,28 +1,171 @@ NAME - AnyEvent::AIO - truly asynchronous file and directrory I/O + AnyEvent::HTTP - simple but non-blocking HTTP/HTTPS client SYNOPSIS - use AnyEvent::AIO; - use IO::AIO; - - # can now use any of the aio requests your IO::AIO module supports - # as long as you use an event loop supported by AnyEvent. + use AnyEvent::HTTP; DESCRIPTION This module is an AnyEvent user, you need to make sure that you use and run a supported event loop. - Loading this module will install the necessary magic to seamlessly - integrate IO::AIO into AnyEvent, i.e. you no longer need to concern - yourself with calling "IO::AIO::poll_cb" or any of that stuff (you still - can, but this module will do it in case you don't). - - The AnyEvent watcher can be disabled by executing "undef - $AnyEvent::AIO::WATCHER". Please notify the author of when and why you - think this was necessary. + This module implements a simple, stateless and non-blocking HTTP client. + It supports GET, POST and other request methods, cookies and more, all + on a very low level. It can follow redirects supports proxies and + automatically limits the number of connections to the values specified + in the RFC. + + It should generally be a "good client" that is enough for most HTTP + tasks. Simple tasks should be simple, but complex tasks should still be + possible as the user retains control over request and response headers. + + The caller is responsible for authentication management, cookies (if the + simplistic implementation in this module doesn't suffice), referer and + other high-level protocol details for which this module offers only + limited support. + + METHODS + http_get $url, key => value..., $cb->($data, $headers) + Executes an HTTP-GET request. See the http_request function for + details on additional parameters. + + http_head $url, key => value..., $cb->($data, $headers) + Executes an HTTP-HEAD request. See the http_request function for + details on additional parameters. + + http_post $url, $body, key => value..., $cb->($data, $headers) + Executes an HTTP-POST request with a request body of $bod. See the + http_request function for details on additional parameters. + + http_request $method => $url, key => value..., $cb->($data, $headers) + Executes a HTTP request of type $method (e.g. "GET", "POST"). The + URL must be an absolute http or https URL. + + The callback will be called with the response data as first argument + (or "undef" if it wasn't available due to errors), and a hash-ref + with response headers as second argument. + + All the headers in that hash are lowercased. In addition to the + response headers, the three "pseudo-headers" "HTTPVersion", "Status" + and "Reason" contain the three parts of the HTTP Status-Line of the + same name. If the server sends a header multiple lines, then their + contents will be joined together with "\x00". + + If an internal error occurs, such as not being able to resolve a + hostname, then $data will be "undef", "$headers->{Status}" will be + 599 and the "Reason" pseudo-header will contain an error message. + + A typical callback might look like this: + + sub { + my ($body, $hdr) = @_; + + if ($hdr->{Status} =~ /^2/) { + ... everything should be ok + } else { + print "error, $hdr->{Status} $hdr->{Reason}\n"; + } + } + + Additional parameters are key-value pairs, and are fully optional. + They include: + + recurse => $count (default: $MAX_RECURSE) + Whether to recurse requests or not, e.g. on redirects, + authentication retries and so on, and how often to do so. + + headers => hashref + The request headers to use. Currently, "http_request" may + provide its own "Host:", "Content-Length:", "Connection:" and + "Cookie:" headers and will provide defaults for "User-Agent:" + and "Referer:". + + timeout => $seconds + The time-out to use for various stages - each connect attempt + will reset the timeout, as will read or write activity. Default + timeout is 5 minutes. + + proxy => [$host, $port[, $scheme]] or undef + Use the given http proxy for all requests. If not specified, + then the default proxy (as specified by $ENV{http_proxy}) is + used. + + $scheme must be either missing or "http" for HTTP, or "https" + for HTTPS. + + body => $string + The request body, usually empty. Will be-sent as-is (future + versions of this module might offer more options). + + cookie_jar => $hash_ref + Passing this parameter enables (simplified) cookie-processing, + loosely based on the original netscape specification. + + The $hash_ref must be an (initially empty) hash reference which + will get updated automatically. It is possible to save the + cookie_jar to persistent storage with something like JSON or + Storable, but this is not recommended, as expire times are + currently being ignored. + + Note that this cookie implementation is not of very high + quality, nor meant to be complete. If you want complete cookie + management you have to do that on your own. "cookie_jar" is + meant as a quick fix to get some cookie-using sites working. + Cookies are a privacy disaster, do not use them unless required + to. + + Example: make a simple HTTP GET request for http://www.nethype.de/ + + http_request GET => "http://www.nethype.de/", sub { + my ($body, $hdr) = @_; + print "$body\n"; + }; + + Example: make a HTTP HEAD request on https://www.google.com/, use a + timeout of 30 seconds. + + http_request + GET => "https://www.google.com", + timeout => 30, + sub { + my ($body, $hdr) = @_; + use Data::Dumper; + print Dumper $hdr; + } + ; + + GLOBAL FUNCTIONS AND VARIABLES + AnyEvent::HTTP::set_proxy "proxy-url" + Sets the default proxy server to use. The proxy-url must begin with + a string of the form "http://host:port" (optionally "https:..."). + + $AnyEvent::HTTP::MAX_RECURSE + The default value for the "recurse" request parameter (default: 10). + + $AnyEvent::HTTP::USERAGENT + The default value for the "User-Agent" header (the default is + "Mozilla/5.0 (compatible; AnyEvent::HTTP/$VERSION; + +http://software.schmorp.de/pkg/AnyEvent)"). + + $AnyEvent::HTTP::MAX_PERSISTENT + The maximum number of persistent connections to keep open (default: + 8). + + Not implemented currently. + + $AnyEvent::HTTP::PERSISTENT_TIMEOUT + The maximum time to cache a persistent connection, in seconds + (default: 2). + + Not implemented currently. + + $AnyEvent::HTTP::ACTIVE + The number of active connections. This is not the number of + currently running requests, but the number of currently open and + non-idle TCP connections. This number of can be useful for + load-leveling. SEE ALSO - AnyEvent, Coro::AIO (for a more natural syntax). + AnyEvent. AUTHOR Marc Lehmann