Description

This chapter is a reference for porting code and configuration files from mod_perl 1.0 to mod_perl 2.0.

To learn about the porting process you should first read about porting Perl modules (and may be about porting XS modules).

As will be explained in details later loading Apache::compat at the server startup, should make the code running properly under 1.0 work under mod_perl 2.0. If you want to port your code to mod_perl 2.0 or writing from scratch and not concerned about backwards compatibility, this document explains what has changed compared to mod_perl 1.0.

Several configuration directives were changed, renamed or removed. Several APIs have changed, renamed, removed, or moved to new packages. Certain functions while staying exactly the same as in mod_perl 1.0, now reside in different packages. Before using them you need to find out those packages and load them.

You should be able to find the destiny of the functions that you cannot find any more or which behave differently now under the package names the functions belong in mod_perl 1.0.

Configuration Files Porting

To migrate the configuration files to the mod_perl 2.0 syntax, you may need to do certain adjustments. Several configuration directives are deprecated in 2.0, but still available for backwards compatibility with mod_perl 1.0 unless 2.0 was built with MP_COMPAT_1X=0. If you don't need the backwards compatibility consider using the directives that have replaced them.

PerlHandler

PerlHandler was replaced with PerlResponseHandler.

PerlSendHeader

PerlSendHeader was replaced with PerlOptions +/-ParseHeaders directive.

  PerlSendHeader On  => PerlOptions +ParseHeaders
  PerlSendHeader Off => PerlOptions -ParseHeaders

PerlSetupEnv

PerlSetupEnv was replaced with PerlOptions +/-SetupEnv directive.

  PerlSetupEnv On  => PerlOptions +SetupEnv
  PerlSetupEnv Off => PerlOptions -SetupEnv

PerlTaintCheck

The taint mode now can be turned on with:

  PerlSwitches -T

As with standard Perl, by default the taint mode is disabled and once enabled cannot be turned off inside the code.

PerlWarn

Warnings now can be enabled globally with:

  PerlSwitches -w

PerlFreshRestart

PerlFreshRestart is a mod_perl 1.0 legacy and doesn't exist in mod_perl 2.0. A full teardown and startup of interpreters is done on restart.

If you need to use the same httpd.conf for 1.0 and 2.0, use:

  <IfDefine !MODPERL2>
      PerlFreshRestart
  </IfDefine>

Apache Configuration Customization

mod_perl 2.0 has slightly changed the mechanism for adding custom configuration directives and now also makes it easy to access an Apache parsed configuration tree's values.

META: add to the config tree access when it'll be written.

@INC Manipulation

• Directories Added Automatically to @INC

  Only if mod_perl was built with MP_COMPAT_1X=1, two directories: $ServerRoot and $ServerRoot/lib/perl are pushed onto @INC. $ServerRoot is as defined by the ServerRoot directive in httpd.conf.

• PERL5LIB and PERLLIB Environment Variables

  mod_perl 2.0 doesn't do anything special about PERL5LIB and PERLLIB Environment Variables. If -T is in effect these variables are ignored by Perl. There are several other ways to adjust @INC.

Code Porting

mod_perl 2.0 is trying hard to be back compatible with mod_perl 1.0. However some things (mostly APIs) have been changed. In order to gain a complete compatibilty with 1.0 while running under 2.0, you should load the compatibility module as early as possible:

  use Apache::compat;

at the server startup. And unless there are forgotten things or bugs, your code should work without any changes under 2.0 series.

However, unless you want to keep the 1.0 compatibility, you should try to remove the compatibility layer and adjust your code to work under 2.0 without it. You want to do it mainly for the performance improvement.

This document explains what APIs have changed and what new APIs should be used instead.

If you have mod_perl 1.0 and 2.0 installed on the same system and the two use the same perl libraries directory (e.g. /usr/lib/perl5), to use mod_perl 2.0 make sure to load first the Apache2 module which will perform the necessary adjustments to @INC.

  use Apache2; # if you have 1.0 and 2.0 installed
  use Apache::compat;

So if before loading Apache2.pm the @INC array consisted of:

  /home/stas/perl/ithread/lib/5.8.0/i686-linux-thread-multi
  /home/stas/perl/ithread/lib/5.8.0
  /home/stas/perl/ithread/lib/site_perl/5.8.0/i686-linux-thread-multi
  /home/stas/perl/ithread/lib/site_perl/5.8.0
  /home/stas/perl/ithread/lib/site_perl
  .

It will now look as:

  /home/stas/perl/ithread/lib/site_perl/5.8.0/i686-linux-thread-multi/Apache2
  /home/stas/perl/ithread/lib/5.8.0/i686-linux-thread-multi
  /home/stas/perl/ithread/lib/5.8.0
  /home/stas/perl/ithread/lib/site_perl/5.8.0/i686-linux-thread-multi
  /home/stas/perl/ithread/lib/site_perl/5.8.0
  /home/stas/perl/ithread/lib/site_perl
  .

Notice that a new directory was prepended to the search path, so if for example the code attempts to load Apache::RequestRec and there are two versions of this module undef /home/stas/perl/ithread/lib/site_perl/:

          5.8.0/i686-linux-thread-multi/Apache/RequestRec.pm
  5.8.0/i686-linux-thread-multi/Apache2/Apache/RequestRec.pm

The mod_perl 2.0 version will be loaded first, because the directory 5.8.0/i686-linux-thread-multi/Apache2 is coming before the directory 5.8.0/i686-linux-thread-multi in @INC.

Finally, mod_perl 2.0 has all its methods spread across many modules. In order to use these methods the modules containing them have to be loaded first. The module ModPerl::MethodLookup can be used to find out which modules need to be used. This module also provides a function preload_all_modules() that will load all mod_perl 2.0 modules, implementing their API in XS, which is useful when one starts to port their mod_perl 1.0 code, though preferrably avoided in the production environment if you want to save memory.

Apache::Registry, Apache::PerlRun and Friends

Apache::Registry, Apache::PerlRun and other modules from the registry family now live in the ModPerl:: namespace. In mod_perl 2.0 we put mod_perl specific functionality into the ModPerl:: namespace, similar to APR:: and Apache:: which are used for apr and apache features, respectively.

At this moment ModPerl::Registry (and others) doesn't chdir() into the script's dir like Apache::Registry does, because chdir() affects the whole process under threads. This should be resolved by the time mod_perl 2.0 is released. Arthur Bergman works on the solution in form of: ex::threads::cwd. See: http://www.perl.com/pub/a/2002/06/11/threads.html?page=2 Someone should pick up and complete this module to make it really useful.

Meanwhile if you are using a prefork MPM and you have to rely on mod_perl performing chdir to the script's directory, you can use the following subclass of ModPerl::Registry:

  #file:ModPerl/RegistryPrefork.pm
  #-------------------------------
  package ModPerl::RegistryPrefork;
  
  use strict;
  use warnings FATAL => 'all';
  
  our $VERSION = '0.01';
  
  use base qw(ModPerl::Registry);
  
  use File::Basename ();
  
  sub handler : method {
      my $class = (@_ >= 2) ? shift : __PACKAGE__;
      my $r = shift;
      return $class->new($r)->default_handler();
  }
  
  sub chdir_file {
      my $file = @_ == 2 ? $_[1] : $_[0]->{FILENAME};
      my $dir = File::Basename::dirname($file);
      chdir $dir or die "Can't chdir to $dir: $!";
  }
  
  1;
  __END__ 

Adjust your httpd.conf to have:

  Alias /perl /path/to/perl/scripts
  <Location /perl>
     SetHandler perl-script
     PerlResponseHandler ModPerl::RegistryPrefork
     Options +ExecCGI
     PerlOptions +ParseHeaders
  </Location>

Otherwise ModPerl::Registry modules are configured and used similarly to Apache::Registry modules. Refer to one of the following manpages for more information: ModPerl::RegistryCooker, ModPerl::Registry, ModPerl::RegistryBB and ModPerl::PerlRun.

ModPerl::RegistryLoader

In mod_perl 1.0 it was only possible to preload scripts as Apache::Registry handlers. In 2.0 the loader can use any of the registry classes to preload into. The old API works as before, but new options can be passed. See the ModPerl::RegistryLoader manpage for more information.

Apache::Constants

Apache::Constants has been replaced by three classes:

• Apache::Const

  Apache constants

• APR::Const

  Apache Portable Runtime constants

• ModPerl::Const

  mod_perl specific constants

See the manpages of the respective modules to figure out which constants they provide.

META: add the info how to perform the transition. XXX: may be write a script, which can tell you how to port the constants to 2.0? Currently Apache::compat doesn't provide a complete back compatibility layer.

mod_perl 1.0 and 2.0 Constants Coexistence

If the same codebase is used for both mod_perl generations, the following technique can be used for using constants:

  package MyApache::Foo;
  
  use strict;
  use warnings;
  
  use mod_perl;
  use constant MP2 => $mod_perl::VERSION >= 1.99;
  
  BEGIN {
      if (MP2) {
          require Apache::Const;
          Apache::Const->import(-compile => qw(OK DECLINED));
      }
      else {
          require Apache::Constants;
          Apache::Constants->import(qw(OK DECLINED));
      }
  }
  
  sub handler {
      # ...
      return MP2 ? Apache::OK : Apache::Constants::OK;
  }
  1;

Notice that if you don't use the idiom:

      return MP2 ? Apache::OK : Apache::Constants::OK;

but something like the following:

  sub handler1 {
      ...
      return Apache::Constants::OK();
  }
  sub handler2 {
      ...
      return Apache::OK();
  }

You need to add (). If you don't do that, let's say that you run under mod_perl 2.0, perl will complain about mod_perl 1.0 constant:

  Bareword "Apache::Constants::OK" not allowed while "strict subs" ...

Adding () prevents this warning.

Deprecated Constants

REDIRECT and similar constants have been deprecated in Apache for years, in favor of the HTTP_* names (they no longer exist Apache 2.0). mod_perl 2.0 API performs the following aliasing behind the scenes:

     NOT_FOUND     => 'HTTP_NOT_FOUND',
     FORBIDDEN     => 'HTTP_FORBIDDEN',
     AUTH_REQUIRED => 'HTTP_UNAUTHORIZED',
     SERVER_ERROR  => 'HTTP_INTERNAL_SERVER_ERROR',
     REDIRECT      => 'HTTP_MOVED_TEMPORARILY',

but we suggest moving to use the HTTP_* names. For example if running in 1.0 compatibility mode change:

  use Apache::Constants qw(REDIRECT);

to:

  use Apache::Constants qw(HTTP_MOVED_TEMPORARILY);

This will work in both mod_perl generations.

SERVER_VERSION()

Apache::Constants::SERVER_VERSION() has been replaced with:

  Apache::Server::get_server_version();

export()

Apache::Constants::export() has no replacement in 2.0 as it's not needed.

Issues with Environment Variables

There are several thread-safety issues with setting environment variables.

Environment variables set during request time won't be seen by C code. See the DBD::Oracle issue for possible workarounds.

Forked processes (including backticks) won't see CGI emulation environment variables. (META: This will hopefully be resolved in the future, it's documented in modperl_env.c:modperl_env_magic_set_all.)

Special Environment Variables

$ENV{GATEWAY_INTERFACE}

The environment variable $ENV{GATEWAY_INTERFACE} is deprecated in mod_perl 2.0 (See: MP_COMPAT_1X=0). Instead use $ENV{MOD_PERL} (available in both mod_perl generations), which is set to something like this:

  mod_perl/1.99_03-dev

However to check the version it's better to use $mod_perl::VERSION:

  use mod_perl;
  use constant MP2 => ($mod_perl::VERSION >= 1.99);

Apache:: Methods

Apache->request

Apache->request usage should be avoided under mod_perl 2.0 $r should be passed around as an argument instead (or in the worst case maintain your own global variable). Since your application may run under under threaded mpm, the Apache->request usage involves storage and retrieval from the thread local storage, which is expensive.

It's possible to use $r even in CGI scripts running under Registry modules, without breaking the mod_cgi compatibility. Registry modules convert a script like:

  print "Content-type: text/plain";
  print "Hello";

into something like:

  package Foo;
  sub handler {
    print "Content-type: text/plain\n\n";
    print "Hello";
    return Apache::OK;
  }

where the handler() function always receives $r as an argument, so if you change your script to be:

  my $r;
  $r = shift if $ENV{MOD_PERL};
  if ($r) {
      $r->content_type('text/plain');
  }
  else {
      print "Content-type: text/plain\n\n";
  }
  print "Hello"

it'll really be converted into something like:

  package Foo;
  sub handler {
      my $r;
      $r = shift if $ENV{MOD_PERL};
      if ($r) {
          $r->content_type('text/plain');
      }
      else {
          print "Content-type: text/plain\n\n";
      }
      print "Hello"
      return Apache::OK;
  }

The script works under both mod_perl and mod_cgi.

For example CGI.pm 2.93 or higher accepts $r as an argument to its new() function. So does CGI::Cookie::fetch from the same distribution.

Moreover, user's configuration may preclude from Apache->request being available at run time. For any location that uses Apache->request and uses SetHandler modperl, the configuration should either explicitly enable this feature:

  <Location ...>
      SetHandler modperl
      PerlOptions +GlobalRequest
      ...
  </Location>

It's already enabled for SetHandler perl-script:

  <Location ...>
      SetHandler perl-script
      ...
  </Location>

This configuration makes Apache->request available only during the response phase (PerlResponseHandler). Other phases can make Apache->request available, by explicitly setting it in the handler that has an access to $r. For example the following skeleton for an authen phase handler makes the Apache->request available in the calls made from it:

  package MyApache::Auth;
  
  # PerlAuthenHandler MyApache::Auth
  
  use Apache::RequestUtil ();
  #...
  sub handler {
      my $r = shift;
      Apache->request($r);
      # do some calls that rely on Apache->request being available
      #...
  }

Apache->define

Apache->define has been replaced with Apache::Server::exists_config_define() residing inside Apache::ServerUtil.

See the Apache::ServerUtil manpage.

Apache->can_stack_handlers

Apache->can_stack_handlers is no longer needed, as mod_perl 2.0 can always stack handlers.

Apache->untaint

Apache->untaint has moved to Apache::ServerUtil and now is a function, rather a class method. It'll will untaint all its arguments. You shouldn't be using this function unless you know what you are doing. Refer to the perlsec manpage for more information.

Apache::compat provides the backward compatible with mod_perl 1.0 implementation.

Apache->get_handlers

To get handlers for the server level, mod_perl 2.0 code should use:

  $s->get_handlers(...);

or:

  Apache->server->get_handlers(...);

Apache->get_handlers is avalable via Apache::compat.

Apache->push_handlers

To push handlers at the server level, mod_perl 2.0 code should use:

  $s->push_handlers(...);

or:

  Apache->server->push_handlers(...);

Apache->push_handlers is avalable via Apache::compat.

Apache->set_handlers

To set handlers at the server level, mod_perl 2.0 code should use:

  $s->set_handlers(...);

or:

  Apache->server->set_handlers(...);

Apache->set_handlers is avalable via Apache::compat.

Apache->httpd_conf

Apache->httpd_conf is now $s->add_config or $r->add_config. e.g.:

  require Apache::ServerUtil;
  Apache->server->add_config(['require valid-user']);

See the Apache::ServerUtil manpage.

Apache->httpd_conf is avalable via Apache::compat.

Apache::exit()

Apache::exit() has been replaced with ModPerl::Util::exit(), which is a function (not a method) and accepts a single optional argument: status, whose default is 0 (== do nothing).

See the ModPerl::Util manpage.

Apache::gensym()

Since Perl 5.6.1 filehandlers are autovivified and there is no need for Apache::gensym() function, since now it can be done with:

  open my $fh, "foo" or die $!;

Though the C function modperl_perl_gensym() is available for XS/C extensions writers.

Apache::module()

Apache::module() has been replaced with the function Apache::Module::loaded(), which now accepts a single argument: the module name.

Apache::log_error()

Apache::log_error() is not available in mod_perl 2.0 API. You can use:

  Apache->server->log_error

instead. See the Apache::Log manpage.

Apache:: Variables

$Apache::__T

$Apache::__T is deprecated in mod_perl 2.0. Use ${^TAINT} instead.

Apache::Server:: Methods and Variables

$Apache::Server::CWD

$Apache::Server::CWD is deprecated and exists only in Apache::compat.

$Apache::Server::AddPerlVersion

$Apache::Server::AddPerlVersion is deprecated and exists only in Apache::compat.

Server Object Methods

$s->register_cleanup

$s->register_cleanup has been replaced with APR::Pool::cleanup_register() which accepts the pool object as the first argument instead of the server object. e.g.:

  sub cleanup_callback { my $data = shift; ... }
  $s->pool->cleanup_register(\&cleanup_callback, $data);

where the last argument $data is optional, and if supplied will be passed as the first argument to the callback function.

See the APR::Pool manpage.

$s->uid

See the next entry.

$s->gid

apache-1.3 had server_rec records for server_uid and server_gid. httpd-2.0 doesn't have them, because in httpd-2.0 the directives User and Group are platform specific. And only UNIX supports it: http://httpd.apache.org/docs-2.0/mod/mpm_common.html#user

It's possible to emulate mod_perl 1.0 API doing:

  sub Apache::Server::uid { $< }
  sub Apache::Server::gid { $( }

but the problem is that if the server is started as root, but its child processes are run under a different username, e.g. nobody, at the startup the above function will report the uid and gid values of root and not nobody, i.e. at startup it won't be possible to know what the User and Group settings are in httpd.conf.

META: though we can probably access the parsed config tree and try to fish these values from there. The real problem is that these values won't be available on all platforms and therefore we should probably not support them and let developers figure out how to code around it (e.g. by using $< and $().

Request Object Methods

$r->cgi_env

See the next item

$r->cgi_var

$r->cgi_env and $r->cgi_var should be replaced with $r->subprocess_env, which works identically in both mod_perl generations.

$r->current_callback

$r->current_callback is now simply a Apache::current_callback and can be called for any of the phases, including those where $r simply doesn't exist.

Apache::compat implements $r->current_callback for backwards compatibility.

$r->get_remote_host

get_remote_host() is now invoked on the connection object:

  use Apache::Connection;
  $r->connection->get_remote_host();

$r->get_remote_host is available through Apache::compat.

$r->cleanup_for_exec

$r->cleanup_for_exec doesn't exist in the Apache 2.0 API, it is now being internally called by the Apache process spawning functions. For more information see Apache::SubProcess manpage.

There is $pool->cleanup_for_exec, but it's not the same as $r->cleanup_for_exec in the mod_perl 1.0 API.

$r->content

See the next item.

$r->args in an Array Context

$r->args in 2.0 returns the query string without parsing and splitting it into an array. You can also set the query string by passing a string to this method.

$r->content and $r->args in an array context were mistakes that never should have been part of the mod_perl 1.0 API. There are multiple reason for that, among others:

• does not handle multi-value keys

• does not handle multi-part content types

• does not handle chunked encoding

• slurps $r->headers_in->{'content-length'} into a single buffer (bad for performance, memory bloat, possible dos attack, etc.)

• in general duplicates functionality (and does so poorly) that is done better in Apache::Request.

• if one wishes to simply read POST data, there is the more modern {setup,should,get}_client_block API, and even more modern filter API, along with continued support for read(STDIN, ...) and $r->read($buf, $r->headers_in->{'content-length'})

For now you can use CGI.pm or the code in Apache::compat (it's slower).

META: when Apache::Request will be ported to mod_perl 2.0, you will have the fast C implementation of these functions.

$r->chdir_file

chdir() cannot be used in the threaded environment, therefore $r->chdir_file is not in the mod_perl 2.0 API.

For more information refer to: Threads Coding Issues Under mod_perl.

$r->is_main

$r->is_main is not part of the mod_perl 2.0 API. Use !$r->main instead.

Refer to the Apache::RequestRec manpage.

$r->finfo

As Apache 2.0 doesn't provide an access to the stat structure, but hides it in the opaque object $r->finfo now returns an APR::Finfo object. You can then invoke the APR::Finfo accessor methods on it.

It's also possible to adjust the mod_perl 1.0 code using Apache::compat's overriding. For example:

  use Apache::compat;
  Apache::compat::override_mp2_api('Apache::RequestRec::finfo');
  my $is_writable = -w $r->finfo;
  Apache::compat::restore_mp2_api('Apache::RequestRec::finfo');

which internally does just the following:

 stat $r->filename and return \*_;

So may be it's easier to just change the code to use this directly, so the above example can be adjusted to be:

  my $is_writable = -w $r->filename;

with the performance penalty of an extra stat() system call. If you don't want this extra call, you'd have to write:

  use APR::Finfo;
  use Apache::RequestRec;
  use APR::Const -compile => qw(WWRITE);
  my $is_writable = $r->finfo->protection & APR::WWRITE,

See the APR::Finfo manpage for more information.

$r->notes

Similar to headers_in(), headers_out() and err_headers_out() in mod_perl 2.0, $r->notes() returns an APR::Table object, which can be used as a tied hash or calling its get()/set()/add()/unset() methods.

It's also possible to adjust the mod_perl 1.0 code using Apache::compat's overriding:

   use Apache::compat;
   Apache::compat::override_mp2_api('Apache::RequestRec::notes');
   $r->notes($key => $val);
   $val = $r->notes($key);
   Apache::compat::restore_mp2_api('Apache::RequestRec::notes');

See the Apache::RequestRec manpage.

$r->header_in

See the next item.

$r->header_out

See the next item.

$r->err_header_out

header_in(), header_out() and err_header_out() are not available in 2.0. Use headers_in(), headers_out() and err_headers_out() instead (which should be used in 1.0 as well). For example you need to replace:

  $r->err_header_out("Pragma" => "no-cache");

with:

  $r->err_headers_out->{'Pragma'} = "no-cache";

See the Apache::RequestRec manpage.

$r->log_reason

$r->log_reason is not available in mod_perl 2.0 API. Use the other standard logging functions provided by the Apache::Log module. For example:

  $r->log_error("it works!");

See the Apache::Log manpage.

$r->register_cleanup

$r->register_cleanup has been replaced with APR::Pool::cleanup_register() which accepts the pool object as the first argument instead of the request object. e.g.:

  sub cleanup_callback { my $data = shift; ... }
  $r->pool->cleanup_register(\&cleanup_callback, $data);

where the last argument $data is optional, and if supplied will be passed as the first argument to the callback function.

See the APR::Pool manpage.

$r->post_connection

$r->post_connection has been replaced with:

  $r->connection->pool->cleanup_register();

See the APR::Pool manpage.

$r->request

Use Apache->request.

$r->send_fd

Apache 2.0 provides a new method sendfile() instead of send_fd, so if your code used to do:

  open my $fh, "<$file" or die "$!";
  $r->send_fd($fh);
  close $fh;

now all you need is:

  $r->sendfile($fh);

There is also a compatibility implementation in pure perl in Apache::compat.

$r->send_fd_length

currently available only in the 1.0 compatibility layer. The problem is that Apache has changed the API and its functionality. See the implementation in Apache::compat.

XXX: needs a better resolution

$r->send_http_header

This method is not needed in 2.0, though available in Apache::compat. 2.0 handlers only need to set the Content-type via $r->content_type($type).

$r->server_root_relative

Apache::Server::server_root_relative is a function in 2.0 and its first argument is the pool object. For example:

  # during request
  my $conf_dir = Apache::Server::server_root_relative($r->pool, 'conf');
  # during startup
  my $conf_dir = Apache::Server::server_root_relative($s->pool, 'conf');

Alternatively:

  # during request
  my $conf_dir = $r->server_root_relative('conf');
  # during startup
  my $conf_dir = $c->server_root_relative('conf');

Note that the old form

  my $conf_dir = Apache->server_root_relative('conf');

is no longer valid - Apache::Server::server_root_relative must be called from either one of $r, $s, or $c, or be explicitly passed a pool.

See the Apache::ServerUtil manpage.

$r->hard_timeout

See the next item.

$r->reset_timeout

See the next item.

$r->soft_timeout

See the next item.

$r->kill_timeout

The functions $r->hard_timeout, $r->reset_timeout, $r->soft_timeout and $r->kill_timeout aren't needed in mod_perl 2.0.

$r->set_byterange

See the next item.

$r->each_byterange

The functions $r->set_byterange and $r->each_byterange aren't in the Apache 2.0 API, and therefore don't exist in mod_perl 2.0. The byterange serving functionality is now implemented in the ap_byterange_filter, which is a part of the core http module, meaning that it's automatically taking care of serving the requested ranges off the normal complete response. There is no need to configure it. It's executed only if the appropriate request headers are set. These headers aren't listed here, since there are several combinations of them, including the older ones which are still supported. For a complete info on these see modules/http/http_protocol.c.

Apache::Connection

$connection->auth_type

The record auth_type doesn't exist in the Apache 2.0's connection struct. It exists only in the request record struct. The new accessor in 2.0 API is $r->ap_auth_type.

Apache::compat provides a back compatibility method, though it relies on the availability of the global Apache->request, which requires the configuration to have:

  PerlOptions +GlobalRequest

to set it up for earlier stages than response handler.

$connection->user

This method is deprecated in mod_perl 1.0 and $r->user should be used instead for both versions of mod_perl. $r->user() method is available since mod_perl version 1.24_01.

$connection->local_addr

See the next item.

$connection->remote_addr

$connection->local_addr and $connection->remote_addr return an APR::SocketAddr object and you can use this object's methods to retrieve the wanted bits of information, so if you had a code like:

  use Socket 'sockaddr_in';
  my ($serverport, $serverip) = sockaddr_in($r->connection->local_addr);
  my ($remoteport, $remoteip) = sockaddr_in($r->connection->remote_addr);

now it'll be written as:

  require APR::SockAddr;
  my $serverport = $c->local_addr->port;
  my $serverip   = $c->local_addr->ip_get;
  my $remoteport = $c->remote_addr->port;
  my $remoteip   = $c->remote_addr->ip_get;

It's also possible to adjust the code using Apache::compat's overriding:

  use Socket 'sockaddr_in';
  use Apache::compat;
  
  Apache::compat::override_mp2_api('Apache::Connection::local_addr');
  my ($serverport, $serverip) = sockaddr_in($r->connection->local_addr);
  Apache::compat::restore_mp2_api('Apache::Connection::local_addr');
  
  Apache::compat::override_mp2_api('Apache::Connection::remote_addr');
  my ($remoteport, $remoteip) = sockaddr_in($r->connection->remote_addr);
  Apache::compat::restore_mp2_api('Apache::Connection::remote_addr');

Apache::File

The methods from mod_perl 1.0's module Apache::File have been either moved to other packages or removed.

open() and close()

The methods open() and close() were removed. See the back compatibility implementation in the module Apache::compat.

tmpfile()

The method tmpfile() was removed since Apache 2.0 doesn't have the API for this method anymore.

See File::Temp, or the back compatibility implementation in the module Apache::compat.

With Perl v5.8.0 you can create anonymous temporary files:

   open $fh, "+>", undef or die $!;

That is a literal undef, not an undefined value.

Apache::Util

A few Apache::Util functions have changed their interface.

Apache::Util::size_string()

Apache::Util::size_string() has been replaced with APR::String::format_size(), which returns formatted strings of only 4 characters long. See the APR::String manpage.

Apache::Util::escape_uri()

Apache::Util::escape_uri() has been replaced with Apache::Util::escape_path() and requires a pool object as a second argument. For example:

  $escaped_path = Apache::Util::escape_path($path, $r->pool);

Apache::Util::unescape_uri()

Apache::Util::unescape_uri() has been replaced with Apache::URI::unescape_url().

Apache::Util::escape_html()

Apache::Util::escape_html currently is available only via Apache::compat until ap_escape_html is reworked to not require a pool.

Apache::Util::parsedate()

Apache::Util::parsedate() has been replaced with APR::Date::parse_http().

Apache::Util::ht_time()

Apache::Util::ht_time() has been replaced (temporary?) with Apache::Util::format_time(), which requires a pool object as a forth argument. All four arguments are now required.

For example:

   use Apache::Util ();
   $fmt = '%a, %d %b %Y %H:%M:%S %Z';
   $gmt = 1;
   $fmt_time = Apache::Util::format_time(time(), $fmt, $gmt, $r->pool);

See the Apache::Util manpage.

Apache::Util::validate_password()

Apache::Util::validate_password() has been replaced with APR::password_validate(). For example:

   my $ok = Apache::Util::password_validate("stas", "ZeO.RAc3iYvpA");

Apache::URI

Apache::URI->parse($r, [$uri])

parse() and its associate methods have moved into the APR::URI package. For example:

  my $curl = $r->construct_url;
  APR::URI->parse($r->pool, $curl);

See the APR::URI manpage.

unparse()

Other than moving to the APR::URI package, unparse is now protocol-agnostic. Apache won't use http as the default protocol if hostname was set, but scheme wasn't not. So the following code:

  # request http://localhost.localdomain:8529/TestAPI::uri
  my $parsed = $r->parsed_uri;
  $parsed->hostname($r->get_server_name);
  $parsed->port($r->get_server_port);
  print $parsed->unparse;

prints:

  //localhost.localdomain:8529/TestAPI::uri

forcing you to make sure that the scheme is explicitly set. This will do the right thing:

  # request http://localhost.localdomain:8529/TestAPI::uri
  my $parsed = $r->parsed_uri;
  $parsed->hostname($r->get_server_name);
  $parsed->port($r->get_server_port);
  $parsed->scheme('http');
  print $parsed->unparse;

prints:

  http://localhost.localdomain:8529/TestAPI::uri

See the APR::URI manpage for more information.

It's also possible to adjust the behavior to be mod_perl 1.0 compatible using Apache::compat's overriding, in which case unparse() will transparently set scheme to http.

  # request http://localhost.localdomain:8529/TestAPI::uri
  Apache::compat::override_mp2_api('APR::URI::unparse');
  my $parsed = $r->parsed_uri;
  # set hostname, but not the scheme
  $parsed->hostname($r->get_server_name);
  $parsed->port($r->get_server_port);
  print $parsed->unparse;
  Apache::compat::restore_mp2_api('APR::URI::unparse');

prints:

  http://localhost.localdomain:8529/TestAPI::uri

Miscellaneous

Method Handlers

In mod_perl 1.0 the method handlers could be specified by using the ($$) prototype:

  package Bird;
  @ISA = qw(Eagle);
  
  sub handler ($$) {
      my($class, $r) = @_;
      ...;
  }

mod_perl 2.0 doesn't handle callbacks with ($$) prototypes differently than other callbacks (as it did in mod_perl 1.0), mainly because several callbacks in 2.0 have more arguments than just $r, so the ($$) prototype doesn't make sense anymore. Therefore if you want your code to work with both mod_perl generations and you can allow the luxury of:

  require 5.6.0;

or if you need the code to run only on mod_perl 2.0, use the method subroutine attribute. (The subroutine attributes are supported in Perl since version 5.6.0.)

Here is the same example rewritten using the method subroutine attribute:

  package Bird;
  @ISA = qw(Eagle);
  
  sub handler : method {
      my($class, $r) = @_;
      ...;
  }

See the attributes manpage.

If Class->method syntax is used for a Perl*Handler, the :method attribute is not required.

The porting tutorial provides examples on how to use the same code base under both mod_perl generations when the handler has to be a method.

Stacked Handlers

Both mod_perl 1.0 and 2.0 support the ability to register more than one handler in each runtime phase, a feature known as stacked handlers. For example,

  PerlAuthenHandler My::First My::Second

The behavior of stacked Perl handlers differs between mod_perl 1.0 and 2.0. In 2.0, mod_perl respects the run-type of the underlying hook - it does not run all configured Perl handlers for each phase but instead behaves in the same way as Apache does when multiple handlers are configured, respecting (or ignoring) the return value of each handler as it is called.

See Stacked Handlers for a complete description of each hook and its run-type.

Apache::src

For those who write 3rd party modules using XS, this module was used to supply mod_perl specific include paths, defines and other things, needed for building the extensions. mod_perl 2.0 makes things transparent with ModPerl::MM.

Here is how to write a simple Makefile.PL for modules wanting to build XS code against mod_perl 2.0:

  use Apache2;
  use mod_perl 1.99;
  use ModPerl::MM ();
  
  ModPerl::MM::WriteMakefile(
      NAME => "Foo",
  );

and everything will be done for you.

META: we probably will have a compat layer at some point.

META: move this section to the devel/porting and link there instead

Apache::Table

Apache::Table has been renamed to APR::Table.

Apache::SIG

Apache::SIG currently exists only Apache::compat and it does nothing.

Apache::StatINC

Apache::StatINC has been replaced by Apache::Reload, which works for both mod_perl generations. To migrate to Apache::Reload simply replace:

  PerlInitHandler Apache::StatINC

with:

  PerlInitHandler Apache::Reload

However Apache::Reload provides an extra functionality, covered in the module's manpage.

Maintainers

Maintainer is the person(s) you should contact with updates, corrections and patches.

• Stas Bekman <stas (at) stason.org>

Authors

• Stas Bekman <stas (at) stason.org>

Only the major authors are listed above. For contributors see the Changes file.