=head1 NAME

Protocol::HTTP - very fast HTTP protocol incremental parser and serializer


=head1 SYNOPSIS

    use Protocol::HTTP;
    
    # client api - make request
    my $request = Protocol::HTTP::Request->new({
        uri     => "http://crazypanda.ru/hello/world",
        headers => {MyHeader => "my value"},
        cookies => {coo1 => "val1", coo2 => "val2"},
        body    => "my body",
    });
    
    my $req_str = $request->to_string; # => like qr|GET /hello/world HTTP/1.1|

    # server api - parse request
    my ($state, $position, $error);
    my $req_parser = Protocol::HTTP::RequestParser->new;
    ($request, $state, $position, $error) = $req_parser->parse($req_str);
    
    if ($state == Protocol::HTTP::Message::STATE_DONE) {
        say $request->uri;
        say $request->method;
        say $request->body;
    }

    # server api - make response
    my $response = Protocol::HTTP::Response->new({
        code    => 200,
        headers => {Lang => 'Perl'},
        body    => "Lorem ipsum dolor",
    });
    
    my $res_str = $response->to_string($request);

    # client api - parse response
    my $res_parser = Protocol::HTTP::ResponseParser->new;
    $res_parser->set_context_request($request);
    ($response, $state, $position, $error) = $res_parser->parse($res_str);
    say $response->code;
    say $response->status;
    say $response->body;
    
    
    # compression with chunks

    use Protocol::HTTP::Request 'METHOD_POST';
    
    $request = Protocol::HTTP::Request->new({
        method   => METHOD_POST,
        uri      => "https://images.example.com/upload",
        chunked  => 1,
        compress => Protocol::HTTP::Compression::gzip,
    });
    say $request->to_string;                    # only http headers
    say $request->make_chunk('hello-world');    # outputs first chunk
    say $request->final_chunk();                # outputs final chunk

    # cookies jar (for user-agents aka HTTP-clients)
    my $jar = Protocol::HTTP::CookieJar->new;
    $jar->populate($request);   # before request sent
    $jar->collect($response);   # after response is received


=head1 DESCRIPTION

The C<Protocol::HTTP> is a port of C<panda::protocol::http> library, an RFC-compiant very fast HTTP protocol implementation, written in C++
with XS-adapters in perl. The module has dual Perl/C++ interface (see L<XS::Manifesto>) so futher XS-bindings can be written on the top of
C<Protocol::HTTP>.

The following features are supported in the C<Protocol::HTTP>: cookies, transparent (un)compression with C<Gzip> or C<Brotli>,
transparent chunked transfer encoding for body streaming, respecting request's preferences when making response.

The module is a protocol implementation, by itself it does not perform any I/O activity.

Currenly supported HTTP versions are 1.0 and 1.1



=head1 REFERENCE

L<Protocol::HTTP::Request>

L<Protocol::HTTP::Response>

L<Protocol::HTTP::Message>

L<Protocol::HTTP::RequestParser>

L<Protocol::HTTP::ResponseParser>

L<Protocol::HTTP::Compression>

L<Protocol::HTTP::Error>

L<Protocol::HTTP::CookieJar>


=head1 CONSTANTS

=head2 error_category

The error category that all of L<Protocol::HTTP::Error> errors have.



=head1 PERFORMANCE

Tests were performed on Xeon v3 2.9Ghz, Debian 10.

We can't make a fair benchmark because C<Protocol::HTTP> is a complete HTTP protocol solution,
while L<HTTP::Parser::XS> only parses http header.

Nevertheless, <Protocol::HTTP> still runs significantly faster.

Benchmark script can be found in C<misc/bench.pl>

    ==================== request with few headers
                          Rate     HTTP::Parser HTTP::Parser::XS   Protocol::HTTP
    HTTP::Parser       19548/s               --             -97%             -99%
    HTTP::Parser::XS  601510/s            2977%               --             -57%
    Protocol::HTTP   1390157/s            7011%             131%               --
    
    ==================== request with many headers
                         Rate     HTTP::Parser HTTP::Parser::XS   Protocol::HTTP
    HTTP::Parser       7657/s               --             -97%             -98%
    HTTP::Parser::XS 240040/s            3035%               --             -53%
    Protocol::HTTP   508970/s            6547%             112%               --
    
    ==================== response with many headers
                         Rate     HTTP::Parser HTTP::Parser::XS   Protocol::HTTP
    HTTP::Parser       8295/s               --             -97%             -98%
    HTTP::Parser::XS 289616/s            3391%               --             -45%
    Protocol::HTTP   529329/s            6281%              83%               --
    
    ==================== response with many headers and 10KB body (only for Protocol::HTTP)
    timethis for 1:  1 wallclock secs ( 1.08 usr +  0.00 sys =  1.08 CPU) @ 424769.44/s (n=458751)



=head1 SEE ALSO

L<Protocol::HTTP::Compression::Brotli>

L<URI::XS>

L<Protocol::WebSocket::Fast>

L<rfc2616 (http 1.1) |https://tools.ietf.org/html/rfc2616>

L<rfc6265 (HTTP State Management Mechanism)| https://tools.ietf.org/html/rfc6265>

L<rfc7932 (brotli compression) |https://tools.ietf.org/html/rfc7932>

L<rfc1952 (gzip compression) |https://tools.ietf.org/html/rfc1952>

L<Same-Site Cookies draft |https://tools.ietf.org/html/draft-ietf-httpbis-cookie-same-site-00>

=head1 AUTHOR

Pronin Oleg <syber@cpan.org> 

Ivan Baidakou <dmol@cpan.org>

Grigory Smorkalov <g.smorkalov@crazypanda.ru>

Andrew Selivanov <andrew.selivanov@gmail.com>

Crazy Panda LTD



=head1 LICENSE

You may distribute this code under the same terms as Perl itself.

=cut