NAME

    FCGI::EV - Implement FastCGI protocol for use in EV-based applications

VERSION

    This document describes FCGI::EV version v2.0.1

SYNOPSIS

     use FCGI::EV;
     use Some::FCGI::EV::Handler;
    
     # while in EV::loop, accept incoming connection from web server into
     # $sock, then start handling FastCGI protocol on that connection,
     # using Some::FCGI::EV::Handler for processing CGI requests:
     FCGI::EV->new($sock, 'Some::FCGI::EV::Handler');
    
    
     #
     # EXAMPLE: complete FastCGI server (without error handling code)
     #          use FCGI::EV::Std handler (download separately from CPAN)
     #
    
     use Socket;
     use Fcntl;
     use EV;
     use FCGI::EV;
     use FCGI::EV::Std;
    
     my $path = '/tmp/fastcgi.sock';
    
     socket my $srvsock, AF_UNIX, SOCK_STREAM, 0;
     unlink $path;
     my $umask = umask 0;   # ensure 0777 perms for unix socket
     bind $srvsock, sockaddr_un($path);
     umask $umask;
     listen $srvsock, SOMAXCONN;
     fcntl $srvsock, F_SETFL, O_NONBLOCK;
    
     my $w = EV::io $srvsock, EV::READ, sub {
        accept my($sock), $srvsock;
        fcntl $sock, F_SETFL, O_NONBLOCK;
        FCGI::EV->new($sock, 'FCGI::EV::Std');
     };
    
     EV::loop;

DESCRIPTION

    This module implement FastCGI protocol for use in EV-based
    applications. (That mean you have to run EV::loop in your application
    or this module will not work.)

    It receive and parse data from web server, pack and send data to web
    server, but it doesn't process CGI requests received from web server -
    instead it delegate this work to another module called 'handler'. For
    one example of such handler, see FCGI::EV::Std.

    FCGI::EV work using non-blocking sockets and initially was designed to
    use in event-based CGI applications (which able to handle multiple
    parallel CGI requests in single process without threads/fork). This
    require from CGI to avoid any operations which may block, like using
    SQL database - instead CGI should delegate all such tasks to remote
    services and talk to these services in non-blocking mode.

    It also possible to use it to run usual CGI.pm-based applications. If
    you will do this using FCGI::EV::Std handler, then only one CGI request
    will be executed at a time (which is probably not what you expect from
    FastCGI!), because FCGI::EV::Std doesn't implement any process-manager.
    But it's possible to develop another handlers for FCGI::EV, which will
    support process-management and so will handle multiple CGI request in
    parallel.

    This module doesn't require from user to use CGI.pm - any module for
    parsing CGI params can be used in general (details depends on used
    FCGI::EV handler module).

INTERFACE

 new

        FCGI::EV->new( $sock, $class );

    Start talking FastCGI protocol on $sock (which should be socket open to
    just-connected web server), and use $class to handle received CGI
    requests.

    Module $class should implement "FCGI::EV handler" interface. You can
    use either FCGI::EV::Std from CPAN or develop your own.

    Return nothing. (Created FCGI::EV object will work in background and
    will be automatically destroyed after finishing I/O with web server.)

HANDLER CLASS INTERFACE

    Handler class (which name provided in $class parameter to
    FCGI::EV->new()) must implement this interface:

    new( $server, \%env )

      When FCGI::EV object receive initial part of CGI request (environment
      variables) it will call $handler_class->new() to create handler
      object which should process that CGI request.

      Parameter $server is FCGI::EV object itself. It's required to send
      CGI reply. WARNING! Handler may keep only weaken() reference to
      $server!

      After calling new() FCGI::EV object ($server) will continue receiving
      STDIN content from web server and will call $handler->stdin() each
      time it get next part of STDIN.

    stdin( $data, $is_eof )

      The $data is next chunk of STDIN received from web server. Flag
      $is_eof will be true if $data was last part of STDIN.

      Usually handler shouldn't begin processing CGI request until all
      content of STDIN will be received.

    DESTROY

      This method is optional. It will be called when connection to web
      server is closed and FCGI::EV object going to die (but it's still
      exists when DESTROY is called - except if DESTROY was called while
      global destruction stage).

      Handler object may use DESTROY to interrupt current CGI request if
      web server close connection before CGI send it reply.

 SENDING CGI REPLY

    After handler got %env (in new()) and complete STDIN (in one or more
    calls of stdin()) it may start handling this CGI request and prepare
    reply to send to web server. To send this data it should use method
    $server->stdout(), where $server is object given to new() while
    creating handler object (it should keep weak reference to $server
    inside to be able to reply).

    stdout( $data, $is_eof )

      CGI may send reply in one or more parts. Last part should have
      $is_eof set to true. DESTROY method of handler object will be called
      shortly after handler object will do $server->stdout( $data, 1 ).

 HANDLER EXAMPLE

    This handler will process CGI requests one-by-one (i.e. in blocking
    mode). On request function main::main() will be executed. That function
    may use standard CGI.pm module to get request parameters and send it
    reply using usual print to STDOUT.

    There no error-handling code in this example, see FCGI::EV::Std for
    more details.

     package FCGI::EV::ExampleHandler;
    
     use Scalar::Util qw( weaken );
     use CGI::Stateless; # needed to re-init CGI.pm state between requests
    
     sub new {
        my ($class, $server, $env) = @_;
        my $self = bless {
            server  => $server,
            env     => $env,
            stdin   => q{},
        }, $class;
        weaken($self->{server});
        return $self;
     }
    
     sub stdin {
        my ($self, $stdin, $is_eof) = @_;
        $self->{stdin} .= $stdin;
        if ($is_eof) {
            local *STDIN;
            open STDIN, '<', \$self->{stdin};
            local %ENV = %{ $self->{env} };
            local $CGI::Q = CGI::Stateless->new();
            local *STDOUT;
            my $reply = q{};
            open STDOUT, '>', \$reply;
            main::main();
            $self->{server}->stdout($reply, 1);
        }
        return;
     }

DIAGNOSTICS

    There no errors returned in any way by this module, but there few
    warning messages may be printed:

    FCGI::EV: IO: %s

      While doing I/O with web server error %s happened and connection was
      closed.

    FCGI::EV: %s

      While parsing data from web server error %s happened and connection
      was closed. (That error probably mean bug either in web server or
      this module.)

SUPPORT

 Bugs / Feature Requests

    Please report any bugs or feature requests through the issue tracker at
    https://github.com/powerman/perl-FCGI-EV/issues. You will be notified
    automatically of any progress on your issue.

 Source Code

    This is open source software. The code repository is available for
    public review and contribution under the terms of the license. Feel
    free to fork the repository and submit pull requests.

    https://github.com/powerman/perl-FCGI-EV

        git clone https://github.com/powerman/perl-FCGI-EV.git

 Resources

      * MetaCPAN Search

      https://metacpan.org/search?q=FCGI-EV

      * CPAN Ratings

      http://cpanratings.perl.org/dist/FCGI-EV

      * AnnoCPAN: Annotated CPAN documentation

      http://annocpan.org/dist/FCGI-EV

      * CPAN Testers Matrix

      http://matrix.cpantesters.org/?dist=FCGI-EV

      * CPANTS: A CPAN Testing Service (Kwalitee)

      http://cpants.cpanauthors.org/dist/FCGI-EV

AUTHOR

    Alex Efros <powerman@cpan.org>

COPYRIGHT AND LICENSE

    This software is Copyright (c) 2009- by Alex Efros <powerman@cpan.org>.

    This is free software, licensed under:

      The MIT (X11) License