lib/perl5/5.8.8/CGI/Fast.pm

   1 package CGI::Fast;
   2
   3 # See the bottom of this file for the POD documentation.  Search for the
   4 # string '=head'.
   5
   6 # You can run this file through either pod2man or pod2html to produce pretty
   7 # documentation in manual or html file format (these utilities are part of the
   8 # Perl 5 distribution).
   9
  10 # Copyright 1995,1996, Lincoln D. Stein.  All rights reserved.
  11 # It may be used and modified freely, but I do request that this copyright
  12 # notice remain attached to the file.  You may modify this module as you
  13 # wish, but if you redistribute a modified version, please attach a note
  14 # listing the modifications you have made.
  15
  16 # The most recent version and complete docs are available at:
  17 #   http://www.genome.wi.mit.edu/ftp/pub/software/WWW/cgi_docs.html
  18 #   ftp://ftp-genome.wi.mit.edu/pub/software/WWW/
  19 $CGI::Fast::VERSION='1.05';
  20
  21 use CGI;
  22 use FCGI;
  23 @ISA = ('CGI');
  24
  25 # workaround for known bug in libfcgi
  26 while (($ignore) = each %ENV) { }
  27
  28 # override the initialization behavior so that
  29 # state is NOT maintained between invocations
  30 sub save_request {
  31     # no-op
  32 }
  33
  34 # If ENV{FCGI_SOCKET_PATH} is specified, we maintain a FCGI Request handle
  35 # in this package variable.
  36 use vars qw($Ext_Request);
  37 BEGIN {
  38    # If ENV{FCGI_SOCKET_PATH} is given, explicitly open the socket,
  39    # and keep the request handle around from which to call Accept().
  40    if ($ENV{FCGI_SOCKET_PATH}) {
  41         my $path    = $ENV{FCGI_SOCKET_PATH};
  42         my $backlog = $ENV{FCGI_LISTEN_QUEUE} || 100;
  43         my $socket  = FCGI::OpenSocket( $path, $backlog );
  44         $Ext_Request = FCGI::Request( \*STDIN, \*STDOUT, \*STDERR,
  45                                         \%ENV, $socket, 1 );
  46    }
  47 }
  48
  49 # New is slightly different in that it calls FCGI's
  50 # accept() method.
  51 sub new {
  52      my ($self, $initializer, @param) = @_;
  53      unless (defined $initializer) {
  54         if ($Ext_Request) {
  55           return undef unless $Ext_Request->Accept() >= 0;
  56         } else {
  57          return undef unless FCGI::accept() >= 0;
  58      }
  59      }
  60      return $CGI::Q = $self->SUPER::new($initializer, @param);
  61 }
  62
  63 1;
  64
  65 =head1 NAME
  66
  67 CGI::Fast - CGI Interface for Fast CGI
  68
  69 =head1 SYNOPSIS
  70
  71     use CGI::Fast qw(:standard);
  72     $COUNTER = 0;
  73     while (new CGI::Fast) {
  74         print header;
  75         print start_html("Fast CGI Rocks");
  76         print
  77             h1("Fast CGI Rocks"),
  78             "Invocation number ",b($COUNTER++),
  79             " PID ",b($$),".",
  80             hr;
  81         print end_html;
  82     }
  83
  84 =head1 DESCRIPTION
  85
  86 CGI::Fast is a subclass of the CGI object created by
  87 CGI.pm.  It is specialized to work well with the Open Market
  88 FastCGI standard, which greatly speeds up CGI scripts by
  89 turning them into persistently running server processes.  Scripts
  90 that perform time-consuming initialization processes, such as
  91 loading large modules or opening persistent database connections,
  92 will see large performance improvements.
  93
  94 =head1 OTHER PIECES OF THE PUZZLE
  95
  96 In order to use CGI::Fast you'll need a FastCGI-enabled Web
  97 server.  Open Market's server is FastCGI-savvy.  There are also
  98 freely redistributable FastCGI modules for NCSA httpd 1.5 and Apache.
  99 FastCGI-enabling modules for Microsoft Internet Information Server and
 100 Netscape Communications Server have been announced.
 101
 102 In addition, you'll need a version of the Perl interpreter that has
 103 been linked with the FastCGI I/O library.  Precompiled binaries are
 104 available for several platforms, including DEC Alpha, HP-UX and
 105 SPARC/Solaris, or you can rebuild Perl from source with patches
 106 provided in the FastCGI developer's kit.  The FastCGI Perl interpreter
 107 can be used in place of your normal Perl without ill consequences.
 108
 109 You can find FastCGI modules for Apache and NCSA httpd, precompiled
 110 Perl interpreters, and the FastCGI developer's kit all at URL:
 111
 112   http://www.fastcgi.com/
 113
 114 =head1 WRITING FASTCGI PERL SCRIPTS
 115
 116 FastCGI scripts are persistent: one or more copies of the script
 117 are started up when the server initializes, and stay around until
 118 the server exits or they die a natural death.  After performing
 119 whatever one-time initialization it needs, the script enters a
 120 loop waiting for incoming connections, processing the request, and
 121 waiting some more.
 122
 123 A typical FastCGI script will look like this:
 124
 125     #!/usr/local/bin/perl    # must be a FastCGI version of perl!
 126     use CGI::Fast;
 127     &do_some_initialization();
 128     while ($q = new CGI::Fast) {
 129         &process_request($q);
 130     }
 131
 132 Each time there's a new request, CGI::Fast returns a
 133 CGI object to your loop.  The rest of the time your script
 134 waits in the call to new().  When the server requests that
 135 your script be terminated, new() will return undef.  You can
 136 of course exit earlier if you choose.  A new version of the
 137 script will be respawned to take its place (this may be
 138 necessary in order to avoid Perl memory leaks in long-running
 139 scripts).
 140
 141 CGI.pm's default CGI object mode also works.  Just modify the loop
 142 this way:
 143
 144     while (new CGI::Fast) {
 145         &process_request;
 146     }
 147
 148 Calls to header(), start_form(), etc. will all operate on the
 149 current request.
 150
 151 =head1 INSTALLING FASTCGI SCRIPTS
 152
 153 See the FastCGI developer's kit documentation for full details.  On
 154 the Apache server, the following line must be added to srm.conf:
 155
 156     AddType application/x-httpd-fcgi .fcgi
 157
 158 FastCGI scripts must end in the extension .fcgi.  For each script you
 159 install, you must add something like the following to srm.conf:
 160
 161     FastCgiServer /usr/etc/httpd/fcgi-bin/file_upload.fcgi -processes 2
 162
 163 This instructs Apache to launch two copies of file_upload.fcgi at
 164 startup time.
 165
 166 =head1 USING FASTCGI SCRIPTS AS CGI SCRIPTS
 167
 168 Any script that works correctly as a FastCGI script will also work
 169 correctly when installed as a vanilla CGI script.  However it will
 170 not see any performance benefit.
 171
 172 =head1 EXTERNAL FASTCGI SERVER INVOCATION
 173
 174 FastCGI supports a TCP/IP transport mechanism which allows FastCGI scripts to run
 175 external to the webserver, perhaps on a remote machine.  To configure the
 176 webserver to connect to an external FastCGI server, you would add the following
 177 to your srm.conf:
 178
 179     FastCgiExternalServer /usr/etc/httpd/fcgi-bin/file_upload.fcgi -host sputnik:8888
 180
 181 Two environment variables affect how the C<CGI::Fast> object is created,
 182 allowing C<CGI::Fast> to be used as an external FastCGI server.  (See C<FCGI>
 183 documentation for C<FCGI::OpenSocket> for more information.)
 184
 185 =over
 186
 187 =item FCGI_SOCKET_PATH
 188
 189 The address (TCP/IP) or path (UNIX Domain) of the socket the external FastCGI
 190 script to which bind an listen for incoming connections from the web server.
 191
 192 =item FCGI_LISTEN_QUEUE
 193
 194 Maximum length of the queue of pending connections.
 195
 196 =back
 197
 198 For example:
 199
 200     #!/usr/local/bin/perl    # must be a FastCGI version of perl!
 201     use CGI::Fast;
 202     &do_some_initialization();
 203     $ENV{FCGI_SOCKET_PATH} = "sputnik:8888";
 204     $ENV{FCGI_LISTEN_QUEUE} = 100;
 205     while ($q = new CGI::Fast) {
 206         &process_request($q);
 207     }
 208
 209 =head1 CAVEATS
 210
 211 I haven't tested this very much.
 212
 213 =head1 AUTHOR INFORMATION
 214
 215 Copyright 1996-1998, Lincoln D. Stein.  All rights reserved.
 216
 217 This library is free software; you can redistribute it and/or modify
 218 it under the same terms as Perl itself.
 219
 220 Address bug reports and comments to: lstein@cshl.org
 221
 222 =head1 BUGS
 223
 224 This section intentionally left blank.
 225
 226 =head1 SEE ALSO
 227
 228 L<CGI::Carp>, L<CGI>
 229
 230 =cut